title: The role of P2Y(14) and other P2Y receptors in degranulation of human LAD2 mast cells.
abstract: Mast cell degranulation affects many conditions, e.g., asthma and urticaria. We explored the potential role of the P2Y(14) receptor (P2Y(14)R) and other P2Y subtypes in degranulation of human LAD2 mast cells. All eight P2YRs were expressed at variable levels in LAD2 cells (quantitative real-time RT-PCR). Gene expression levels of ADP receptors, P2Y(1)R, P2Y(12)R, and P2Y(13)R, were similar, and P2Y(11)R and P2Y(4)R were highly expressed at 5.8- and 3.8-fold of P2Y(1)R, respectively. Least expressed P2Y(2)R was 40-fold lower than P2Y(1)R, and P2Y(6)R and P2Y(14)R were ≤50 % of P2Y(1)R. None of the native P2YR agonists alone induced β-hexosaminidase (β-Hex) release, but some nucleotides significantly enhanced β-Hex release induced by C3a or antigen, with a rank efficacy order of ATP > UDPG ≥ ADP >> UDP, UTP. Although P2Y(11)R and P2Y(4)R are highly expressed, they did not seem to play a major role in degranulation as neither P2Y(4)R agonist UTP nor P2Y(11)R agonists ATPγS and NF546 had a substantial effect. P2Y(1)R-selective agonist MRS2365 enhanced degranulation, but ~1,000-fold weaker compared to its P2Y(1)R potency, and the effect of P2Y(6)R agonist 3-phenacyl-UDP was negligible. The enhancement by ADP and ATP appears mediated via multiple receptors. Both UDPG and a synthetic agonist of the P2Y(14)R, MRS2690, enhanced C3a-induced β-Hex release, which was inhibited by a P2Y(14)R antagonist, specific P2Y(14)R siRNA and pertussis toxin, suggesting a role of P2Y(14)R activation in promoting human mast cell degranulation.
authors: Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA. zg21o@nih.gov
authors: Zhan-Guo
authors: ZG
authors: Gao
authors: Qiang
authors: Q
authors: Wei
authors: M P Suresh
authors: MP
authors: Jayasekara
authors: Kenneth A
authors: KA
authors: Jacobson
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D015550:Cell Degranulation / Q000187:drug effects* / Q000235:genetics*; D002478:Cells, Cultured; D015926:Complement C3a / Q000378:metabolism; D003432:Cross-Linking Reagents; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008407:Mast Cells / Q000187:drug effects* / Q000502:physiology; D009711:Nucleotides / Q000494:pharmacology; D058912:Purinergic P2Y Receptor Agonists / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018048:Receptors, Purinergic P2 / Q000187:drug effects* / Q000235:genetics; D058470:Receptors, Purinergic P2Y / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D009711:Nucleotides; C518528:P2Y14 receptor, human; D058912:Purinergic P2Y Receptor Agonists; D034741:RNA, Small Interfering; D018048:Receptors, Purinergic P2; D058470:Receptors, Purinergic P2Y; D007073:Immunoglobulin E; D000244:Adenosine Diphosphate; D015926:Complement C3a; D000255:Adenosine Triphosphate; D001619:beta-N-Acetylhexosaminidases