Suzuki Yuko, Mathews Nitty S, Sano Hideto, Morooka Nanami, Honkura Naoki, Urano Tetsumei
Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Department of Transfusion Medicine & Immunohematology, Christian Medical College Vellore, India.
Thromb Haemost. 2025 Aug;125(8):766-778. doi: 10.1055/a-2497-4213. Epub 2025 Jan 9.
Fibrinolysis is spatiotemporally well-regulated and greatly influenced by activated platelets and coagulation activity. Our previous real-time imaging analyses revealed that clotting commences on activated platelet surfaces, resulting in uneven-density fibrin structures, and that fibrinolysis initiates in dense fibrin regions and extends to the periphery. Despite the widespread clinical use of direct oral anticoagulants (DOACs), their impact on thrombin-dependent activation of thrombin-activatable fibrinolysis inhibitor (TAFI) and fibrinolysis remains unclear. Here, we investigated the effects of different DOACs on the TAFI-mediated inhibition of fibrinolysis.Using human platelet-containing plasma, we performed turbidimetric assays, thrombin generation assays, and confocal laser scanning microscopy to assess the effects of anticoagulants on fibrinolysis.Activated platelets-prolonged plasma clot lysis time, shortened by activated TAFI inhibitor (TAFIaI), positively correlated with the amount of thrombin generated. Rivaroxaban (an activated factor X inhibitor) and dabigatran (a direct thrombin inhibitor) dose-dependently shortened lysis time comparably. The highest concentration of DOACs showed no further shortening of lysis time with TAFIaI. The fibrin network structures initiated by activated platelets and the localization of fluorescently labeled plasminogen were unique for these two drugs. Rivaroxaban maintained an uneven fibrin network but promoted faster plasminogen accumulation and fibrinolysis from outside dense fibrin regions. Conversely, dabigatran resulted in a more even fibrin network, with fibrinolysis starting from the activated platelets and propagating to the periphery. Visualizing and analyzing the patterns of fibrin network formation, plasminogen accumulation, and fibrinolysis provide new insights into the specific impact of anticoagulants on coagulation and fibrinolysis.
纤维蛋白溶解在时空上受到良好调控，并受到活化血小板和凝血活性的极大影响。我们之前的实时成像分析表明，凝血在活化血小板表面开始，导致纤维蛋白结构密度不均，并且纤维蛋白溶解在致密纤维蛋白区域启动并延伸至周边。尽管直接口服抗凝剂（DOACs）在临床上广泛使用，但其对凝血酶依赖性激活凝血酶可激活纤维蛋白溶解抑制剂（TAFI）和纤维蛋白溶解的影响仍不清楚。在此，我们研究了不同DOACs对TAFI介导的纤维蛋白溶解抑制作用的影响。我们使用含人血小板的血浆进行比浊法测定、凝血酶生成测定和共聚焦激光扫描显微镜检查，以评估抗凝剂对纤维蛋白溶解的影响。活化血小板延长血浆凝块溶解时间，而活化TAFI抑制剂（TAFIaI）可缩短该时间，且与产生的凝血酶量呈正相关。利伐沙班（一种活化因子X抑制剂）和达比加群（一种直接凝血酶抑制剂）剂量依赖性地同等程度缩短溶解时间。DOACs的最高浓度与TAFIaI联合使用时未进一步缩短溶解时间。这两种药物由活化血小板引发的纤维蛋白网络结构以及荧光标记纤溶酶原的定位是独特的。利伐沙班维持不均匀的纤维蛋白网络，但促进纤溶酶原从致密纤维蛋白区域外部更快积累和纤维蛋白溶解。相反，达比加群导致更均匀的纤维蛋白网络，纤维蛋白溶解从活化血小板开始并向周边扩散。可视化和分析纤维蛋白网络形成、纤溶酶原积累和纤维蛋白溶解的模式，为抗凝剂对凝血和纤维蛋白溶解的具体影响提供了新的见解。
