CC BY-NC-ND 4.0 · Thromb Haemost 2023; 123(01): 016-026
DOI: 10.1055/s-0042-1757407
Coagulation and Fibrinolysis

Visualization of Domain- and Concentration-Dependent Impact of Thrombomodulin on Differential Regulation of Coagulation and Fibrinolysis

Liina Mochizuki
1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
2   Department of Dentistry and Oral and Maxillofacial Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
,
Hideto Sano
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
,
Kazuma Masumoto
2   Department of Dentistry and Oral and Maxillofacial Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
,
Tetsumei Urano
1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
3   Shizuoka Graduate University of Public Health, Shizuoka, Japan
,
1   Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
› Author Affiliations


Abstract

Background Thrombomodulin (TM) functions as a dual modulator—anticoagulant and antifibrinolytic potential—by the thrombin-dependent activation of protein C and thrombin-activatable fibrinolysis inhibitor (TAFI). Activated TAFI cleaves the C-terminal lysine of partially degraded fibrin and inhibits both plasminogen binding and its activation on the fibrin surface. We have reported previously that activated platelets initiate fibrin network formation and trigger fibrinolysis after the accumulation of tissue-type plasminogen activator and plasminogen.

Objective To analyze the effects of domain-deletion variants of TM on coagulation and fibrinolysis at different concentrations.

Methods Domain-deletion variants of TM, such as D123 (all extracellular regions), E3456 (minimum domains for thrombin-dependent activation of protein C and TAFI), and E456 (minimum domains for that of protein C but not TAFI), were used at 0.25 to 125 nM for turbidimetric assay to determine the clotting time and clot lysis time and to visualize fibrin network formation and lysis in platelet-containing plasma.

Results and Conclusions A low concentration of either D123 or E3456, but not of E456, prolonged clot lysis time, and delayed the accumulation of fluorescence-labeled plasminogen at the activated platelets/dense fibrin area due to effective TAFI activation. Conversely, only the highest concentrations of all three TM variants delayed the clotting time, though fibrin network formation in the vicinity of activated platelets was almost intact. TAFI activation might be affected by attenuation in thrombin activity after the clot formation phase. These findings suggest that the spatiotemporal balance between the anticoagulant and antifibrinolytic potential of TM is controlled in domain- and concentration-dependent manners.

Author Contributions

L.M. performed the experiments, analyzed the data, and wrote the manuscript; Y.S. designed the study, analyzed and interpreted the data, and wrote the manuscript; H.S., N.H., and K.M. discussed the results; T.U. conceptualized the study and wrote the manuscript. All authors read and approved the manuscript.


Supplementary Material



Publication History

Received: 18 April 2022

Accepted: 10 August 2022

Article published online:
28 October 2022

© 2022. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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