Alteration in endothelial permeability occurs in response to the activation of PAR2 by factor Xa but not directly by the TF-factor VIIa complex.

Autor: Benelhaj NE; Division of Cancer-Hull York Medical School, University of Hull, Cottingham Road, Hull HU6 7RX, UK., Maraveyas A; Division of Cancer-Hull York Medical School, University of Hull, Cottingham Road, Hull HU6 7RX, UK., Featherby S; Biomedical Section, School of Life Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK., Collier MEW; Department of Cardiovascular Sciences, University of Leicester, Glenfield General Hospital, Leicester LE3 9QP, UK., Johnson MJ; Division of Cancer-Hull York Medical School, University of Hull, Cottingham Road, Hull HU6 7RX, UK., Ettelaie C; Biomedical Section, School of Life Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK. Electronic address: C.Ettelaie@hull.ac.uk.
Jazyk: angličtina
Zdroj: Thrombosis research [Thromb Res] 2019 Mar; Vol. 175, pp. 13-20. Date of Electronic Publication: 2019 Jan 16.
DOI: 10.1016/j.thromres.2019.01.009
Abstrakt: Alterations in the endothelial permeability occur in response to the activation of coagulation mechanisms in order to control clot formation. The activation of the protease activated receptors (PAR) can induce signals that regulate such cellular responses. PAR2 is a target for the coagulation factor Xa (fXa) and tissue factor-factor VIIa (TF-fVIIa) complex. By measuring the permeability of dextran blue across endothelial monolayer, we examined the mechanisms linking coagulation and endothelial permeability. Activation of PAR2 using the agonist peptide (PAR2-AP) resulted in increased permeability across the monolayer and was comparable to that obtained with VEGF at 60 min. Incubation of cells with activated factor Xa (fXa) resulted in an initial decrease in permeability by 30 min, but then significantly increased at 60 min. These responses required fXa activity, and were abrogated by incubation of the cells with a PAR2-blocking antibody (SAM11). Activation of PAR2 alone, or inhibition of PAR1, abrogated the initial reduction in permeability. Additionally, inclusion of Rivaroxaban (0.6 μg/ml) significantly inhibited the response to fXa. Finally, incubation of the endothelial monolayers up to 2 h with TF-containing microvesicles derived from MDA-MB-231 cells, in the presence or absence of fVIIa, did not influence the permeability across the monolayers. In conclusion, fXa but not TF-fVIIa is a noteworthy mediator of endothelial permeability. The rapid initial decrease in permeability requires PAR2 and PAR1 which may act to constrain bleeding. The longer-term response is mediated by PAR2 with increased permeability, presumably to enhance clot formation at the site of damage.
(Copyright © 2019 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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