Download PDF
Open Access
CC BY 4.0 · Thromb Haemost 2025; 125(08): 766-778
DOI: 10.1055/a-2497-4213
Coagulation and Fibrinolysis

Real-Time Imaging of Platelet-Initiated Plasma Clot Formation and Lysis Unveils Distinct Impacts of Anticoagulants

Authors

  • Yuko Suzuki 

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan

  • Nitty S. Mathews

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
    2   Department of Transfusion Medicine & Immunohematology, Christian Medical College Vellore, India

  • Hideto Sano

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
    3   Department of Physiology, Tokai University School of Medicine, Kanagawa, Japan

  • Nanami Morooka

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan

  • Naoki Honkura

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan

  • Tetsumei Urano

    1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
    4   Shizuoka Graduate University of Public Health, Shizuoka, Japan

Funding This work was supported by JSPS KAKENHI Grant Number JP22K08153 to Y.S. and Grant Number JP22H03172 to T.U., a grant from the Smoking Research Foundation to Y.S., and HUSM Grant-in-Aid to Y.S.
Further Information
  Permissions and Reprints


Graphical Abstract

Abstract

Background

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.

Methods

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.

Results and Conclusion

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.

Keywords

anticoagulants - confocal microscopy - fibrinolysis - platelets - thrombin-activatable fibrinolysis inhibitor

Authors' Contribution

Y.S. designed the study, conducted the experiments, analyzed and interpreted the data, and wrote the manuscript. N.S.M. discussed the results and revised the manuscript. H.S., N.M., and N.H. discussed the results. T.U. conceptualized the study and revised the paper. All the authors have read and approved this manuscript.


Supplementary Material



Publication History

Received: 17 September 2024

Accepted: 08 November 2024

Article published online:
09 January 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany