title: The P2Y(2) nucleotide receptor mediates tissue factor expression in human coronary artery endothelial cells.
abstract: The discovery of the role of P2Y(12) receptor in platelet aggregation leads to a new anti-thrombotic drug Plavix; however, little is known about non-platelet P2Y receptors in thrombosis. This study tested the hypothesis that endothelial P2Y receptor(s) mediates up-regulation of tissue factor (TF), the initiator of coagulation cascade. Stimulation of human coronary artery endothelial cells (HCAEC) by UTP/ATP increased the mRNA level of TF but not of its counterpart-tissue factor pathway inhibitor, which was accompanied by up-regulation of TF protein and cell surface activity. RT-PCR revealed a selective expression of P2Y(2) and P2Y(11) receptors in HCAEC. Consistent with this, TF up-regulation was inhibited by suramin or by siRNA silencing of P2Y(2) receptor, but not by NF-157, a P2Y(11)-selective antagonist, suggesting a role for the P2Y(2) receptor. In addition, P2Y(2) receptor activated ERK1/2, JNK, and p38 MAPK pathways without affecting the positive NF-κB and negative AKT regulatory pathways of TF expression. Furthermore, TF up-regulation was abolished or partially suppressed by inhibition of p38 or JNK but not ERK1/2. Interestingly, blockade of the PLC/Ca(2+) pathway did not affect P2Y(2) receptor activation of p38, JNK, and TF induction. However, blockade of Src kinase reduced phosphorylation of p38 but not JNK, eliminating TF induction. In contrast, inhibition of Rho kinase reduced phosphorylation of JNK but not p38, decreasing TF expression. These findings demonstrate that P2Y(2) receptor mediates TF expression in HCAEC through new mechanisms involving Src/p38 and Rho/JNK pathways, possibly contributing to a pro-thrombotic status after vascular injury.
authors.affiliation: Division of Pharmacology, Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, Alabama 36849, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Ding
authors.forename: Wanshu
authors.initials: W
authors.lastname: Ma
authors.forename: Timothy
authors.initials: T
authors.lastname: Littmann
authors.forename: Riley
authors.initials: R
authors.lastname: Camp
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shen
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000969:Antinematodal Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D003331:Coronary Vessels / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D020935:MAP Kinase Signaling System; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058473:Receptors, Purinergic P2Y2 / Q000235:genetics / Q000378:metabolism*; D013498:Suramin / Q000494:pharmacology; D013925:Thromboplastin / Q000096:biosynthesis* / Q000235:genetics; D014544:Uridine Triphosphate / Q000494:pharmacology
chemical_list: D000969:Antinematodal Agents; D016328:NF-kappa B; C109734:P2RY11 protein, human; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; D013498:Suramin; D000255:Adenosine Triphosphate; D013925:Thromboplastin; D020929:Mitogen-Activated Protein Kinase Kinases; D014544:Uridine Triphosphate