SDF-1α/CXCR4 Signaling in Lipid Rafts Induces Platelet Aggregation via PI3 Kinase-Dependent Akt Phosphorylation.
SDF-1α/CXCR4 Signaling in Lipid Rafts Induces Platelet Aggregation via PI3 Kinase-Dependent Akt Phosphorylation.
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DOI：
10.1371/journal.pone.0169609
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Kasahara K
中科院分区：
文献类型：
--
作者：
Ohtsuka H;Iguchi T;Hayashi M;Kaneda M;Iida K;Shimonaka M;Hara T;Arai M;Koike Y;Yamamoto N;Kasahara K
基质细胞衍生因子-1 α（SDF-1α）诱导的血小板聚集通过其G蛋白偶联受体CXCR 4和磷脂酰肌醇3激酶（PI 3 K）介导。在这里，我们证明了SDF-1α诱导人血小板中Akt在Thr 308和Ser 473处磷酸化。SDF-1α诱导的血小板聚集和Akt磷酸化可通过CXCR 4拮抗剂AMD 3100或PI 3 K抑制剂LY 294002预处理抑制。SDF-1α还诱导PDK 1在Ser 241（Akt的上游激活剂）、GSK 3 β在Ser 9（Akt的下游底物）和肌球蛋白轻链在Ser 19（Akt信号通路的下游元件）的磷酸化。用Akt抑制剂MK-2206预处理可剂量依赖性地抑制SDF-1α诱导的血小板聚集。此外，SDF-1α诱导的血小板聚集和Akt磷酸化被筏破坏剂甲基-β-环糊精预处理抑制。蔗糖密度梯度分析显示，35%的CXCR 4、93%的异源三聚体G蛋白Gαi-1、91%的Gαi-2、50%的Gβ和4.0%的PI 3 K β以及4.5%的Akt 2定位于耐洗涤剂膜筏部分。这些结果表明，脂筏中的SDF-1α/CXCR 4信号通过PI 3 K依赖性Akt磷酸化诱导血小板聚集。
Stromal cell-derived factor-1α (SDF-1α)-induced platelet aggregation is mediated through its G protein-coupled receptor CXCR4 and phosphatidylinositol 3 kinase (PI3K). Here, we demonstrate that SDF-1α induces phosphorylation of Akt at Thr308 and Ser473 in human platelets. SDF-1α-induced platelet aggregation and Akt phosphorylation are inhibited by pretreatment with the CXCR4 antagonist AMD3100 or the PI3K inhibitor LY294002. SDF-1α also induces the phosphorylation of PDK1 at Ser241 (an upstream activator of Akt), GSK3β at Ser9 (a downstream substrate of Akt), and myosin light chain at Ser19 (a downstream element of the Akt signaling pathway). SDF-1α-induced platelet aggregation is inhibited by pretreatment with the Akt inhibitor MK-2206 in a dose-dependent manner. Furthermore, SDF-1α-induced platelet aggregation and Akt phosphorylation are inhibited by pretreatment with the raft-disrupting agent methyl-β-cyclodextrin. Sucrose density gradient analysis shows that 35% of CXCR4, 93% of the heterotrimeric G proteins Gαi-1, 91% of Gαi-2, 50% of Gβ and 4.0% of PI3Kβ, and 4.5% of Akt2 are localized in the detergent-resistant membrane raft fraction. These findings suggest that SDF-1α/CXCR4 signaling in lipid rafts induces platelet aggregation via PI3K-dependent Akt phosphorylation.