Endogenously generated plasmin at the vascular wall injury site amplifies lysine binding site-dependent plasminogen accumulation in microthrombi.
Endogenously generated plasmin at the vascular wall injury site amplifies lysine binding site-dependent plasminogen accumulation in microthrombi.
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DOI：
10.1371/journal.pone.0122196
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Urano T
中科院分区：
文献类型：
--
作者：
Brzoska T;Tanaka-Murakami A;Suzuki Y;Sano H;Kanayama N;Urano T
纤维蛋白溶解系统在止血调节中起着关键作用;然而，目前尚不清楚如何以及何时触发该系统以诱导血栓溶解。使用活体共聚焦荧光显微镜，我们研究了纤溶酶原结合的过程中，激光诱导的富含血小板的微血栓中产生的转基因小鼠表达绿色荧光蛋白（GFP）的肠系膜静脉。通过测量相应荧光强度的增加来评估表达GFP的血小板以及外源性输注的Alexa Fluor 568标记的Glu-纤溶酶原（Glu-plg）在受损血管壁上的积累。Glu-plg以时间依赖性的方式在微血栓的中心积累，其中磷脂酰丝氨酸暴露在血小板表面上并且发生纤维蛋白形成。在存在ε-氨基己酸和羧肽酶B的情况下，Glu-plg的结合率，以及缺乏Kringle结构域1-4和赖氨酸结合位点的迷你纤溶酶原的结合率，均显着低于单独的Glu-plg，表明结合依赖于赖氨酸结合位点。此外，抑肽酶显著抑制Glu-plg的积累，表明内源性产生的纤溶酶活性是积累的先决条件。尽管纤溶酶的内源性产生和Glu-plg在微血栓中心的积累，但在2小时的观察期内，微血栓的大小没有变化。静脉注射人组织型纤溶酶原激活剂后，Glu-plg进一步蓄积，微血栓溶解。Glu-plg在微血栓形成的早期在微血栓中心聚集，并且纤溶酶活性和赖氨酸结合位点是这种聚集所必需的。
The fibrinolytic system plays a pivotal role in the regulation of hemostasis; however, it remains unclear how and when the system is triggered to induce thrombolysis. Using intra-vital confocal fluorescence microscopy, we investigated the process of plasminogen binding to laser-induced platelet-rich microthrombi generated in the mesenteric vein of transgenic mice expressing green fluorescent protein (GFP). The accumulation of GFP-expressing platelets as well as exogenously infused Alexa Fluor 568-labeled Glu-plasminogen (Glu-plg) on the injured vessel wall was assessed by measuring the increase in the corresponding fluorescence intensities. Glu-plg accumulated in a time-dependent manner in the center of the microthrombus, where phosphatidylserine is exposed on platelet surfaces and fibrin formation takes place. The rates of binding of Glu-plg in the presence of ε-aminocaproic acid and carboxypeptidase B, as well as the rates of binding of mini-plasminogen lacking kringle domains 1-4 and lysine binding sites, were significantly lower than that of Glu-plg alone, suggesting that the binding was dependent on lysine binding sites. Furthermore, aprotinin significantly suppressed the accumulation of Glu-plg, suggesting that endogenously generated plasmin activity is a prerequisite for the accumulation. In spite of the endogenous generation of plasmin and accumulation of Glu-plg in the center of microthrombi, the microthrombi did not change in size during the 2-hour observation period. When human tissue plasminogen activator was administered intravenously, Glu-plg further accumulated and the microthrombi were lysed. Glu-plg appeared to accumulate in the center of microthrombi in the early phase of microthrombus formation, and plasmin activity and lysine binding sites were required for this accumulation.
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影响因子：
20.3
作者：
Suzuki, Yuko;Yasui, Hideki;Urano, Tetsumei
通讯作者：
Urano, Tetsumei
影响因子：
10.4
作者：
Collen, D;Lijnen, HR
通讯作者：
Lijnen, HR
影响因子：
3.7
作者：
Brzoska T;Suzuki Y;Mogami H;Sano H;Urano T
通讯作者：
Urano T
DOI：
10.1111/j.1538-7836.2011.04300.x
发表时间：
2011-07
期刊：
Journal of thrombosis and haemostasis : JTH
影响因子：
--
作者：
Morrissey JH;Tajkhorshid E;Rienstra CM
通讯作者：
Rienstra CM
影响因子：
4.5
作者：
Hayashi, Tadataka;Mogami, Hideo;Urano, Tetsumei
通讯作者：
Urano, Tetsumei