Interplay between P2Y1, P2Y12, and P2X1 receptors in the activation of megakaryocyte cation influx currents by ADP:: evidence that the primary megakaryocyte represents a fully functional model of platelet P2 receptor signaling
Interplay between P2Y1, P2Y12, and P2X1 receptors in the activation of megakaryocyte cation influx currents by ADP:: evidence that the primary megakaryocyte represents a fully functional model of platelet P2 receptor signaling
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DOI：
10.1182/blood-2005-02-0725
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发表时间：
2005-09-01
期刊：
影响因子：
20.3
通讯作者：
Mahaut-Smith, MP
中科院分区：
文献类型：
--
作者：
Tolhurst, G;Vial, C;Mahaut-Smith, MP
从血小板进行电生理记录的困难限制了对离子通道在血栓形成和止血中作用的研究。我们现在证明，在血小板α（IIb）β（3）整联蛋白的腺苷二磷酸（ADP）依赖性激活过程中，P2Y（1）和P2Y（12）受体之间已确立的协同作用也存在于鼠骨髓巨核细胞中，进一步支持祖细胞作为血小板P2受体信号传导的真正模型。在膜片钳记录中，ADP (30 μM) 在-70 mV 处刺激瞬时内向电流，该电流由 Na+ 和 Ca2+ 携带，并被氧化苯胂放大，氧化苯胂是通过磷脂酰肌醇 4,5-二磷酸消耗而增强某些瞬时受体电位 (TRP) 离子通道的增强剂。该初始电流衰减到持续阶段，其上叠加了主要具有类似 P2X(1) 动力学的重复瞬态内向阳离子电流。消除 P2X(1),-受体活性可阻止大部分重复电流，这与分泌的三磷酸腺苷 (ATP) 对其的激活一致。 P2Y(1)受体缺陷型巨核细胞中的记录表明，该受体对于激活所有 ADP 诱发的内向电流是必需的。然而，P2Y(12)受体通过Pl3激酶的激活，在P2Y(1)和P2X(1)受体依赖性电流中发挥协同作用。因此，直接刺激 P2Y(1) 和 P2Y(12) 受体以及自分泌 P2X(1) 激活，是血小板激动剂 ADP 激活非选择性阳离子电流的原因。
The difficulty of conducting electrophysiologic recordings from the platelet has restricted investigations into the role of ion channels in thrombosis and hemostasis. We now demonstrate that the well-established synergy between P2Y(1) and P2Y(12) receptors during adenosine diphosphate (ADP)-dependent activation of the platelet alpha(llb)beta(3) integrin also exists in murine marrow megakaryocytes, further supporting the progenitor cell as a bona fide model of platelet P2 receptor signaling. In patch clamp recordings, ADP (30 mu M) stimulated a transient inward current at -70 mV, which was carried by Na+ and Ca2+ and was amplified by phenylarsine oxide, a potentiator of certain transient receptor potential (TRP) ion channels by phosphatidlylinositol 4,5-bisphosphate depletion. This initial current decayed to a sustained phase, upon which repetitive transient inward cation currents with predominantly P2X(1)-like kinetics were superimposed. Abolishing P2X(1),-receptor activity prevented most of the repetitive currents, consistent with their activation by secreted adenosine triphosphate (ATP). Recordings in P2Y(1),-receptor- deficient megakaryocytes demonstrated an essential requirement of this receptor for activation of all ADP-evoked inward currents. However, P2Y(12) receptors, through the activation of Pl3-kinase, played a synergistic role in both P2Y(1), and P2X(1),- receptor-dependent currents. Thus, direct stimulation of P2Y(1), and P2Y(12) receptors, together with autocrine P2X(1) activation, is responsible for the activation of nonselective cation currents by the platelet agonist ADP.