We performed hematologic analysis using automated hematology analyzer and investigated platelets morphology by transmission electron microscope. We explored the role of AGK in platelet activation and arterial thrombosis utilizing transgenic mice, platelet functional experiments in vitro, and thrombosis models in vivo. We revealed the regulation effect of AGK on Talin-1 by coimmunoprecipitation, mass spectrometry, immunofluorescence, and Western blot. We tested the role of AGK on lipid synthesis of phosphatidic acid/lysophosphatidic acid and thrombin generation by specific Elisa kits.
In this study, we found that AGK depletion or AGK mutation had no effect on the platelet average volumes, the platelet microstructures, or the expression levels of the major platelet membrane receptors. However, AGK deficiency or AGK mutation conspicuously decreased multiple aspects of platelet activation, including agonists-induced platelet aggregation, granules secretion, JON/A binding, spreading on Fg (fibrinogen), and clot retraction. AGK deficiency or AGK mutation also obviously delayed arterial thrombus formation but had no effect on tail bleeding time and platelet procoagulant function. Mechanistic investigation revealed that AGK may promote Talin-1Ser425 phosphorylation and affect the αIIbβ3-mediated bidirectional signaling pathway. However, AGK does not affect lipid synthesis of phosphatidic acid/lysophosphatidic acid in platelets.
AGK, through its kinase activity, potentiates platelet activation and arterial thrombosis by promoting Talin-1 Ser425 phosphorylation and affecting the αIIbβ3-mediated bidirectional signaling pathway.
方法:我们使用自动血液学分析仪进行血液学分析,并通过透射电子显微镜研究血小板形态。我们利用转基因小鼠探索AGK在血小板活化和动脉血栓形成中的作用,体外血小板功能实验,和体内血栓形成模型。我们通过共免疫沉淀揭示了AGK对Talin-1的调节作用,质谱,免疫荧光,和Westernblot。我们通过特定的Elisa试剂盒测试了AGK在磷脂酸/溶血磷脂酸的脂质合成和凝血酶生成中的作用。
结果:在这项研究中,我们发现AGK耗竭或AGK突变对血小板平均体积没有影响,血小板微结构,或主要血小板膜受体的表达水平。然而,AGK缺乏或AGK突变显著降低血小板活化的多个方面,包括激动剂诱导的血小板聚集,颗粒分泌,JON/A绑定,在Fg(纤维蛋白原)上扩散,和凝块收缩。AGK缺乏或AGK突变也明显延迟动脉血栓形成,但对尾部出血时间和血小板促凝功能无影响。机制研究表明,AGK可能促进Talin-1Ser425磷酸化并影响αIIbβ3介导的双向信号通路。然而,AGK不影响血小板中磷脂酸/溶血磷脂酸的脂质合成。
结论:AGK,通过其激酶活性,通过促进Talin-1Ser425磷酸化和影响αIIbβ3介导的双向信号通路来增强血小板活化和动脉血栓形成。