Evidence map›Paper›PMID 41821314›Full record

ArticleBiophysical journal2026

Mechanisms of thrombin inhibition by protein S and the TFPIα-fVshort-protein S complex.

Alexander G Ginsberg, Josefin Ahnström, James T B Crawley, Karin Leiderman, Dougald M Monroe, Keith B Neeves, Suzanne F Sindi, Aaron L Fogelson

Abstract read
In one paragraph

Article in Biophysical journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

8 authors.

Alexander G GinsbergDepartment of Mathematics, University of Utah, Salt Lake City, Utah.
Josefin AhnströmCentre for Haematology, Imperial College London, London, UK.
James T B CrawleyCentre for Haematology, Imperial College London, London, UK.
Karin LeidermanUNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Dougald M MonroeUNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Keith B NeevesDepartment of Bioengineering, University of Colorado Denver, Anschutz Campus, Aurora, Colorado.
Suzanne F SindiDepartment of Applied Mathematics, University of California, Merced, Merced, California.
Aaron L FogelsonDepartment of Mathematics, University of Utah, Salt Lake City, Utah; Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah. Electronic address: fogelson@math.utah.edu.

Funding

An integrated computational and experimental approach to understanding the hemostatic response during treatment of bleedingR01HL151984 · NHLBI · UNIV OF NORTH CAROLINA CHAPEL HILL · PI FOGELSON, AARON L, LEIDERMAN, KARIN · 2020 to 2023
$2.8M
NHLBI NIH HHS R01 HL151984
6 · The paper itself

Abstract

Protein S (PS) is an important anticoagulant implicated in both bleeding and thrombotic disorders, making it a promising drug target. The anticoagulant function of PS arises in part because PS enhances the anticoagulant function of tissue factor pathway inhibitor α (TFPIα). PS has been proposed to circulate in the bloodstream together with TFPIα and a truncated form of factor V (fV-short) in the trimolecular complex, TFPIα-PS-fV-short, which we call protein S complex (PSC). PSC has been proposed to strongly inhibit thrombin production by enhancing the ability of TFPIα to inhibit clotting factor Xa up to 100-fold and by localizing to platelet membranes, limiting fXa activity shortly after coagulation starts. Yet, exactly how PS functions with TFPIα as an anticoagulant remains poorly understood. To investigate, we extend an experimentally validated mathematical model of blood coagulation to include PSC and free PS (not a part of PSC) in the plasma, as well as free PS and TFPIα in platelets. We find that shortly after coagulation initiation, PSC strongly inhibits thrombin production. We find that the (unknown) magnitude of the enhanced affinity of PSC binding to inhibit fXa critically regulates PSC's impact on thrombin production. We find that, under flow, PSC can accumulate on platelets to concentrations ∼50 times higher than in the plasma, previously unreported to our knowledge. We also find that PSC limits thrombin production by occupying fV-specific binding sites on platelets. Our results show that changes in PSC can dramatically impact severity of pathological bleeding disorders. For the east Texas bleeding disorder, elevated PSC concentrations eliminate thrombin bursts, leading to bleeding. With fV deficiency, reducing PSC rescues thrombin production in severe fV deficiency and returns thrombin production due to mild fV deficiency to normal. Finally, thrombin production in severe hemophilia A can be substantially improved by blocking PSC's anticoagulant function.

Indexed as

Factor VLipoproteinsProtein SThrombinBlood CoagulationBlood PlateletsHumansModels, BiologicalProtein BindingFactor Vlipoprotein-associated coagulation inhibitorLipoproteinsProtein SThrombin

Identifiers

PMID41821314
PMCPMC13351996

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.