Succinate independently stimulates full platelet activation via cAMP and phosphoinositide 3-kinase-β signaling
Succinate independently stimulates full platelet activation via cAMP and phosphoinositide 3-kinase-β signaling
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DOI：
10.1111/j.1538-7836.2010.04158.x
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发表时间：
2011-02-01
影响因子：
10.4
通讯作者：
Olde, B.
中科院分区：
文献类型：
--
作者：
Hogberg, C.;Gidlof, O.;Olde, B.
背景：柠檬酸循环中间体琥珀酸最近被鉴定为G蛋白偶联受体（GPCR）SUCNR 1的配体。我们以前已经发现，这种受体是人类血小板中最高表达的GPCR之一。目的：本研究旨在探讨SUCNR 1在血小板聚集中的作用及其信号通路。方法和结果：使用实时PCR，我们证明了SUCNR 1在人血小板中的表达水平与P2 Y（1）受体的水平相对应。光透射聚集实验显示琥珀酸诱导的剂量依赖性聚集，在0.5 mm处达到最大响应。琥珀酸对血小板聚集的影响用流式细胞术证实，显示活化的糖蛋白IIb-IIIa和P-选择素的表面表达增加。发现细胞内SUCNR 1信号传导导致cAMP水平降低、由磷酸肌醇3-激酶-β激活介导的Akt磷酸化和受体脱敏。此外，琥珀酸诱导的血小板聚集被证明依赖于Src、血栓素A的产生（2）和ATP的释放。血小板SUCNR 1通过同源和异源机制进行脱敏。此外，P2 Y（12）受体抑制剂替格瑞洛完全阻止了琥珀酸诱导的血小板聚集。结论：我们的实验表明琥珀酸通过SUCNR 1诱导人血小板的完全聚集。琥珀酸诱导的血小板聚集依赖于血栓素A（2）的生成、ATP的释放和P2 Y（12）的激活。
Background: The citric cycle intermediate succinate has recently been identified as a ligand for the G-protein-coupled receptor (GPCR) SUCNR1. We have previously found that this receptor is one of the most highly expressed GPCRs in human platelets. Objective: The aim of this study was to investigate the role of SUCNR1 in platelet aggregation and to explore the signaling pathways of this receptor in platelets. Methods and Results: Using real-time-PCR, we demonstrated that SUCNR1 is expressed in human platelets at a level corresponding to that of the P2Y(1) receptor. Light transmission aggregation experiments showed dose-dependent aggregation induced by succinate, reaching a maximum response at 0.5 mm. The effect of succinate on platelet aggregation was confirmed with flow cytometry, showing increased surface expression of activated glycoprotein IIb-IIIa and P-selectin. Intracellular SUCNR1 signaling was found to result in decreased cAMP levels, Akt phosphorylation mediated by phosphoinositide 3-kinase-beta activation, and receptor desensitization. Furthermore, succinate-induced platelet aggregation was demonstrated to depend on Src, generation of thromboxane A(2), and ATP release. Platelet SUCNR1 is subject to desensitization through both homologous and heterologous mechanisms. In addition, the P2Y(12) receptor inhibitor ticagrelor completely prevented platelet aggregation induced by succinate. Conclusions: Our experiments show that succinate induces full aggregation of human platelets via SUCNR1. Succinate-induced platelet aggregation depends on thromboxane A(2) generation, ATP release, and P2Y(12) activation.