Dovlatova Natalia, Wijeyeratne Yanushi D, Fox Susan C, Manolopoulos Panagiotis, Johnson Andrew J, White Ann E, Latif M Liaque, Ralevic Vera, Heptinstall Stanley
Cardiovascular Medicine, Queen's Medical Centre, Nottingham, UK.
Thromb Haemost. 2008 Aug;100(2):261-70.
mRNA encoding the recently discovered P2Y(14) receptor has been reported in platelets, but the presence of P2Y(14) receptor protein and its functionality have not been studied. If P2Y(14) is expressed along with P2Y(1) and P2Y(12) receptors it may have a role in haemostasis. It was the objective of this study to investigate the presence of the P2Y(14) receptor in platelets and its role in platelet function. The effects of the agonist UDP-glucose were compared with those of sulprostone, a selective EP(3) receptor agonist. Expression of P2Y(14) receptor was investigated by immunoblotting and confocal microscopy. Platelet aggregation in platelet-rich plasma (PRP) and whole blood was measured using light absorbance and platelet counting. VASP phosphorylation was investigated using flow cytometry. Immunoblotting provided evidence for P2Y(14) receptor protein and microscopy confirmed its presence on platelets. Despite this, UDP-glucose (up to 100 muM) did not induce platelet aggregation in either PRP or whole blood, and did not potentiate aggregation induced by other agonists. P2Y(14) did not substitute for P2Y(12) in experiments using the P2Y(12) antagonist AR-C69931. No effect of UDP-glucose was seen on adenylate cyclase activity as measured by VASP phosphorylation. In contrast, sulprostone acting via the EP(3) receptor promoted platelet aggregation with effects on adenylate cyclase activity. EP(3) also partially substituted for P2Y(12) receptor. We have demonstrated the presence of P2Y(14) receptor protein in platelets, but no contribution of this receptor to several measures of platelet function has been observed. Further studies are necessary to determine whether the P2Y(14) receptor in platelets has any functionality.
据报道，血小板中存在编码最近发现的P2Y(14)受体的信使核糖核酸（mRNA），但尚未对P2Y(14)受体蛋白的存在及其功能进行研究。如果P2Y(14)与P2Y(1)和P2Y(12)受体共同表达，它可能在止血过程中发挥作用。本研究的目的是调查血小板中P2Y(14)受体的存在情况及其在血小板功能中的作用。将激动剂UDP-葡萄糖的作用与选择性EP(3)受体激动剂舒前列素的作用进行了比较。通过免疫印迹和共聚焦显微镜研究了P2Y(14)受体的表达。使用光吸收和血小板计数法测量富血小板血浆（PRP）和全血中的血小板聚集情况。使用流式细胞术研究了血管舒张刺激蛋白（VASP）磷酸化情况。免疫印迹为P2Y(14)受体蛋白提供了证据，显微镜检查证实其存在于血小板上。尽管如此，UDP-葡萄糖（高达100微摩尔）在PRP或全血中均未诱导血小板聚集，也未增强其他激动剂诱导的聚集。在使用P2Y(12)拮抗剂AR-C69931的实验中，P2Y(14)不能替代P2Y(12)。通过VASP磷酸化测量，未观察到UDP-葡萄糖对腺苷酸环化酶活性有影响。相比之下，通过EP(3)受体起作用的舒前列素促进了血小板聚集，并对腺苷酸环化酶活性有影响。EP(3)也部分替代了P2Y(12)受体。我们已经证明血小板中存在P2Y(14)受体蛋白，但未观察到该受体对多种血小板功能指标有任何作用。需要进一步研究以确定血小板中的P2Y(14)受体是否具有任何功能。
