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Imaging analysis of phosphatidylserine-evoked initiation of coagulation cascade on activated platelets surface.

磷脂酰丝氨酸诱发活化血小板表面凝血级联启动的成像分析。

基本信息

批准号：
21590230
负责人：
URANO Tetsumei
金额：
$ 3.16万
依托单位：
Hamamatsu University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2009
资助国家：
日本
起止时间：
2009 至 2011
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21590230/
关键词：
血液凝固血液レオロジー線溶

项目摘要

(1) Analyses of the regulatory mechanisms on PS exposure on platelets' surface and its contribution to micro-particle bearing TF-evoked activation of coagulation cascade.Exposure of PS on platelets' surface plays essential role in thrombus formation. Based on our recent finding in in-vivo study that platelets expose PS only when they exist in the center of the thrombus, we analyzed the factors to regulate PS exposure on platelets surface. To elucidate how PS exposure is regulated within the thrombus, we analyzed PS exposure on platelets existing in fibrin network using diluted platelet-rich plasma by Confocal Laser Scanning Microscopy. Almost all platelets bound to fibrin scaffold and exposed PS after treatment with TF, thrombin or ionomycin. An attenuation of fibrin mesh formation by several pharmacological methods suppressed PS exposure. FK633, a GPIIb/IIIa antagonist, entirely inhibited fibrin(ogen) binding abrogated fibrin network formation, but also reduced PS exposure without suppressing fibrin(ogen) binding. Cytochalasin B impaired both platelets' binding to fibrin(ogen) and PS exposure. These results suggest that GPIIb/IIIa-mediated outside-in signals in platelets generated by the binding to fibrin scaffold and the associated mechanical foci, appear to be essential for PS exposure. Such regulation of platelet PS exposure may play an important role in the control of hemostasis.(submitted)U937 cells were treated by calcium ionophore, and TF bearing microparticles were obtained. Supplementation of the TF-bearing microparticle to the system mentioned above, successfully generated fibrin network. We stared to analyze the space-and time-dependent interaction between TF bared on microparticle and PS exposed on activated platelets both of which are essential to activate coagulation cascade.

(1)血小板表面PS暴露的调控机制及其对载TF微颗粒激活凝血级联反应的贡献分析血小板表面PS暴露在血栓形成中起重要作用。基于我们最近在体内研究中发现血小板仅在血栓中心暴露PS，我们分析了调节血小板表面PS暴露的因素。为了阐明PS暴露是如何在血栓内调节的，我们通过共聚焦激光扫描显微镜使用稀释的富血小板血浆分析了存在于纤维蛋白网络中的血小板上的PS暴露。在用TF、凝血酶或离子霉素处理后，几乎所有的血小板都与纤维蛋白支架和暴露的PS结合。通过几种药理学方法减弱纤维蛋白网形成抑制PS暴露。FK633是一种GPIIb/IIIa拮抗剂，可完全抑制纤维蛋白（原）结合，消除纤维蛋白网络形成，但也可减少PS暴露，而不抑制纤维蛋白（原）结合。细胞松弛素B损害血小板与纤维蛋白（原）的结合和PS暴露。这些结果表明，GPIIb/IIIa介导的由外而内的信号在血小板中产生的结合纤维蛋白支架和相关的机械灶，似乎是必不可少的PS曝光。血小板PS暴露的这种调节可能在止血控制中起重要作用。用钙离子载体处理U937细胞，获得携带TF的微粒。将携带TF的微粒补充到上述系统中，成功地产生了纤维蛋白网络。我们开始分析暴露在微粒上的TF和暴露在活化血小板上的PS之间的空间和时间依赖性相互作用，这两者对于激活凝血级联至关重要。