Vitamin E reduces platelet adhesion to human endothelial cells in vitro

Intact endothelial cells are known to form a non-thrombogenic surface and to actively restrict the extent of thrombus formation on denuded vessel walls via such mechanisms as the binding of thrombin and activation of protein C, or the synthesis and release of prostacyclin. In an in vitro system, we have investigated how platelet inhibitors modulate the antithrombotic effects of human endothelial cells. Human endothelial cells isolated from umbilical veins were plated on one half of a subendothelial matrix (SEM) harvested from bovine cornea endothelial cells. The endothelial cells were preincubated with a drug and then exposed to anticoagulated whole blood from human donors in the presence or absence of the same drug and agitated for 15 min. The number and size of platelets interacting with the SEM were quantified by morphometric analysis.In our in vitro system, platelet aggregates on SEM that was partially covered with human endothelial cells were significantly smaller than on uncovered SEM. No difference in platelet adhesion was observed. In the absence of endothelial cells, the cyclooxigenase inhibitors acetylsalicylic acid (ASA) and flurbiprofen strongly reduced the size of aggregates formed on the SEM. Pretreatment of only the endothelial cells with ASA increased the size of the aggregates, while ASA treatment of endothelial cells as well as the whole blood did not reduce the mean aggregate size below that of controls. in contrast, the platelet phosphodiesterase inhibitors AHP 719 and UDCG 212 strongly decreased platelet aggregation without reducing platelet adhesion not only in the absence but also in the presence of endothelial cells pretreated with the inhibitors.Our results demonstrate that this in vitro model of a partially injured vessel wall is well suited to study the effects of endothelial cells on platelet function. Moreover, inhibitors of phosphodiesterase in contrast to ASA have profound antithrombotic effects in this model.

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Perturbation of Platelet Adhesion to Endothelial Cells by Plasminogen Activation In Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657655 ◽

1997 ◽

Vol 78 (02) ◽

pp. 934-938 ◽

Cited By ~ 5

Author(s):

Hsiun-ing Chen ◽

Yueh-I Wu ◽

Yu-Lun Hsieh ◽

Guey-Yueh Shi ◽

Meei-Jyh Jiang ◽

...

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Platelet Adhesion ◽

Treatment Time ◽

Shape Change ◽

Umbilical Vein ◽

Tissue Type ◽

Apical Surface ◽

Plasminogen Activation

SummaryTo investigate whether the endothelium-platelet interactions may be altered by plasminogen activation, cultured human umbilical vein endothelial cells (ECs) were treated with tissue-type plasminogen activator (t-PA) in the presence of plasminogen, and platelet adhesion to ECs was subsequently measured by using a tapered flow chamber. Our results demonstrated that platelets adhered more readily to t-PA treated EC monolayer than to the control monolayer at all shear stress levels tested. This phenomenon was treatment time-dependent and dose-dependent, and it could be blocked by adding plasmin inhibitors, such as e-amino caproic acid and aprotinin. Adherent platelets on t-PA treated EC monolayer underwent more severe shape change than those on the control monolayer. While the extracellular matrix directly treated with t-PA attracted less platelets than the control matrix did, platelet adhesion to the matrix that was produced by t-PA-treated ECs was unaltered. These data suggest that t-PA treatment on ECs compromised antiplatelet-adhesion capability on their apical surface without altering the reactivity of their extracellular matrix towards platelets.

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Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656088 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0975-0980 ◽

Cited By ~ 23

Author(s):

Angel Gálvez ◽

Goretti Gómez-Ortiz ◽

Maribel Díaz-Ricart ◽

Ginés Escolar ◽

Rogelio González-Sarmiento ◽

...

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Tissue Factor ◽

Platelet Adhesion ◽

Umbilical Vein ◽

Procoagulant Activity ◽

Experimental Conditions ◽

Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

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Acute damage to human endothelial cells by brief exposure to contrast media in vitro.

Radiology ◽

10.1148/radiology.147.3.6844604 ◽

1983 ◽

Vol 147 (3) ◽

pp. 681-684 ◽

Cited By ~ 50

Author(s):

F Laerum

Keyword(s):

Endothelial Cells ◽

Contrast Media ◽

Human Endothelial Cells

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Vascular repair utilising immobilised heparin conjugate for protection against early activation of inflammation and coagulation

Thrombosis and Haemostasis ◽

10.1160/th14-09-0724 ◽

2015 ◽

Vol 113 (06) ◽

pp. 1312-1322 ◽

Cited By ~ 18

Author(s):

Sofia Nordling ◽

Jaan Hong ◽

Karin Fromell ◽

Fredrik Edin ◽

Johan Brännström ◽

...

Keyword(s):

Endothelial Cells ◽

Thrombus Formation ◽

Innate Immune ◽

Human Endothelial Cells ◽

Coagulation Activation ◽

Ischaemia Reperfusion Injury ◽

Novel Approach ◽

One Step ◽

Chamber Model

SummaryIschaemia-reperfusion injury (IRI) poses a major challenge in many thrombotic conditions and in whole organ transplantation. Activation of the endothelial cells and shedding of the protective vascular glycocalyx during IRI increase the risk of innate immune activation, cell infiltration and severe thrombus formation, promoting damage to the tissue. Here, we present a novel one-step strategy to protect the vasculature by immobilisation of a unique multi-arm heparin conjugate to the endothelium. Applying a new in vitro blood endothelial cell chamber model, the heparin conjugate was found to bind not only to primary human endothelial cells but also directly to the collagen to which the cells adhered. Incubation of hypoxic endothelial cells with freshly drawn human blood in the blood chambers elicited coagulation activation reflected by thrombin anti-thrombin formation and binding of platelets and neutrophils. Immobilisation of the heparin conjugate to the hypoxic endothelial cells created a protective coating, leading to a significant reduction of the recruitment of blood cells and coagulation activation compared to untreated hypoxic endothelial cells. This novel approach of immobilising multi-arm heparin conjugates on the endothelial cells and collagen of the basement membrane ensures to protect the endothelium against IRI in thrombotic disorders and in transplantation.

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