title: ADP ribose is an endogenous ligand for the purinergic P2Y1 receptor.
abstract: The mechanism by which extracellular ADP ribose (ADPr) increases intracellular free Ca(2+) concentration ([Ca(2+)](i)) remains unknown. We measured [Ca(2+)](i) changes in fura-2 loaded rat insulinoma INS-1E cells, and in primary β-cells from rat and human. A phosphonate analogue of ADPr (PADPr) and 8-Bromo-ADPr (8Br-ADPr) were synthesized. ADPr increased [Ca(2+)](i) in the form of a peak followed by a plateau dependent on extracellular Ca(2+). NAD(+), cADPr, PADPr, 8Br-ADPr or breakdown products of ADPr did not increase [Ca(2+)](i). The ADPr-induced [Ca(2+)](i) increase was not affected by inhibitors of TRPM2, but was abolished by thapsigargin and inhibited when phospholipase C and IP(3) receptors were inhibited. MRS 2179 and MRS 2279, specific inhibitors of the purinergic receptor P2Y1, completely blocked the ADPr-induced [Ca(2+)](i) increase. ADPr increased [Ca(2+)](i) in transfected human astrocytoma cells (1321N1) that express human P2Y1 receptors, but not in untransfected astrocytoma cells. We conclude that ADPr is a specific agonist of P2Y1 receptors.
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, Research Centre, Stockholm South Hospital, Stockholm, Sweden. amajab@ki.se
authors.forename: Amanda Jabin
authors.initials: AJ
authors.lastname: Gustafsson
authors.forename: Lucia
authors.initials: L
authors.lastname: Muraro
authors.forename: Carin
authors.initials: C
authors.lastname: Dahlberg
authors.forename: Marie
authors.initials: M
authors.lastname: Migaud
authors.forename: Olivier
authors.initials: O
authors.lastname: Chevallier
authors.forename: Hoa Nguyen
authors.initials: HN
authors.lastname: Khanh
authors.forename: Kalaiselvan
authors.initials: K
authors.lastname: Krishnan
authors.forename: Nailin
authors.initials: N
authors.lastname: Li
authors.forename: Md Shahidul
authors.initials: MS
authors.lastname: Islam
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D054879:Halogenation; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000037:antagonists & inhibitors; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008024:Ligands; D058912:Purinergic P2Y Receptor Agonists / Q000378:metabolism*; D058921:Purinergic P2Y Receptor Antagonists / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D058472:Receptors, Purinergic P2Y1 / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: C465253:2-chloro-N6-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphate; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008024:Ligands; C111914:N(6)-methyl-2'-deoxyadenosine 3',5'-diphosphate; D058912:Purinergic P2Y Receptor Agonists; D058921:Purinergic P2Y Receptor Antagonists; D058472:Receptors, Purinergic P2Y1; D000246:Adenosine Diphosphate Ribose; D000244:Adenosine Diphosphate; D019284:Thapsigargin; D010738:Type C Phospholipases; D002118:Calcium