Open Access
Thromb Haemost 2017; 117(05): 899-910
DOI: 10.1160/TH16-09-0704
Coagulation and Fibrinolysis
Schattauer GmbH

Impact of fibrinogen carbamylation on fibrin clot formation and stability

Veronika Binder*
1   Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
,
Brith Bergum*
1   Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
,
Stéphane Jaisson
2   University of Reims Champagne-Ardenne, Laboratory of Biochemistry and Molecular Biology, CNRS/URCA UMR N° 7369 MEDyC, Reims, France
,
Philippe Gillery
2   University of Reims Champagne-Ardenne, Laboratory of Biochemistry and Molecular Biology, CNRS/URCA UMR N° 7369 MEDyC, Reims, France
,
Carsten Scavenius
3   Interdisciplinary Nanoscience Center at the Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
,
Endy Spriet
4   Department of Biomedicine, University of Bergen, Bergen, Norway
,
Anne Karin Nyhaug
4   Department of Biomedicine, University of Bergen, Bergen, Norway
,
Helen M. Roberts
5   Periodontal Research Group MRC Centre for Immune Regulation, University of Birmingham, Birmingham, UK
,
Iain L. C. Chapple
5   Periodontal Research Group MRC Centre for Immune Regulation, University of Birmingham, Birmingham, UK
,
Annelie Hellvard
6   Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
,
Nicolas Delaleu
1   Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
7   Swiss Institute of Bioinformatics, Lausanne, Switzerland
,
Piotr Mydel
1   Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
8   Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
› Author Affiliations

Financial support: This work was funded by grants from the EC Marie Curie ITN (RAPID no. 290246) and (FP7-HEALTH-F3–2012–306029 ‘TRIGGER’). PM was supported by a grant from the National Science Center (2014/14/E/NZ6/00162, Poland), PM and ND were supported by the Broegelmann Foundation. VB was supported by the Austrian Science Fund (FWF, J 3770-B31).
Further Information

Publication History

Received: 14 September 2016

Accepted after major revision: 07 February 2016

Publication Date:
28 November 2017 (online)

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Summary

Carbamylation is a non-enzymatic post-translational modification induced upon exposure of free amino groups to urea-derived cyanate leading to irreversible changes of protein charge, structure and function. Levels of carbamylated proteins increase significantly in chronic kidney disease and carbamylated albumin is considered as an important biomarker indicating mortality risk. High plasma concentrations and long half-life make fibrinogen a prime target for carbamylation. As aggregation and cross-linking of fibrin monomers rely on lysine residues, it is likely that carbamylation impacts fibrinogen processing. In this study we investigated carbamylation levels of fibrinogen from kidney disease patients as well as the impact of carbamylation on fibrinogen cleavage by thrombin, fibrin polymerisation and cross-linking in vitro. In conjunction, all these factors determine clot structure and stability and thus control biochemical and mechanical properties. LC-MS/MS analyses revealed significantly higher homocitrulline levels in patient fibrinogen than in fibrinogen isolated from control plasma. In our in vitro studies we found that although carbamylation does not affect thrombin cleavage per se, it alters fibrin polymerisation kinetics and impairs cross-linking and clot degradation. In addition, carbamylated fibrin clots had reduced fiber size and porosity associated with decreased mechanical stability. Using mass spectroscopy, we discovered that N-terminally carbamylated fibrinopeptide A was generated in this process and acted as a strong neutrophil chemoattractant potentially mediating recruitment of inflammatory cells to sites of fibrin(ogen) turnover. Taken together, carbamylation of fibrinogen seems to play a role in aberrant fibrin clot formation and might be involved in haemostatic disorders associated with chronic inflammatory diseases.

* Equally contributing authors.