Thromb Haemost 2014; 112(06): 1244-1251
DOI: 10.1160/th14-01-0079
Wound Healing and Inflammation/Infection
Schattauer GmbH

Polymerisation of fibrin αC-domains promotes endothelial cell migration and proliferation

Sergiy Yakovlev
1   Center for Vascular and Inflammatory Diseases and the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
,
Irina Mikhailenko
2   Center for Vascular and Inflammatory Diseases and the Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
,
Galina Tsurupa
1   Center for Vascular and Inflammatory Diseases and the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
,
Alexey M. Belkin
1   Center for Vascular and Inflammatory Diseases and the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
,
Leonid Medved
1   Center for Vascular and Inflammatory Diseases and the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
› Author Affiliations

Financial support: This work was supported by National Institutes of Health Grant HL056051 to L. M. and American Heart Association Grant-in-Aid 11GRNT7200007 to A. M. B.
Further Information

Publication History

Received: 24 January 2014

Accepted after major revision: 03 July 2014

Publication Date:
29 November 2017 (online)

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Summary

Upon conversion of fibrinogen into fibrin, fibrinogen αC-domains containing the RGD recognition motif form ordered αC polymers. Our previous study revealed that polymerisation of these domains promotes integrin-dependent adhesion and spreading of endothelial cells, as well as integrin-mediated activation of the FAK and ERK1/2 signalling pathways. The major goal of this study was to test the impact of αC-domain polymerisation on endothelial cell migration and proliferation during wound healing, and to clarify the mechanism underlying superior activity of αC polymers toward endothelial cells. In an in vitro wound healing assay, confluent endothelial cell monolayers on tissue culture plates coated with the αC monomer or αC polymers were wounded by scratching and wound closure was monitored by timelapse videomicroscopy. Although the plates were coated with equal amounts of αC species, as confirmed by ELISA, wound closure by the cells occurred much faster on αC polymers, indicating that αC-domain polymerisation promotes cell migration and proliferation. In agreement, endothelial cell proliferation was also more efficient on αC polymers, as revealed by cell proliferation assay. Wound closure on both types of substrates was equally inhibited by the integrin-blocking GRGDSP peptide and a specific antagonist of the ERK1/2 signalling pathway. In contrast, blocking the FAK signaling pathway by a specific antagonist decreased wound closure only on αC polymers. These results indicate that polymerisation of the αC-domains enhances integrin-dependent endothelial cell migration and proliferation mainly through the FAK signalling pathway. Furthermore, clustering of integrin-binding RGD motifs in αC polymers is the major mechanism triggering these events.