Platelet associated u-PA up-regulates u-PA synthesis by endothelial cells.
Thromb Haemost
; 88(3): 517-23, 2002 Sep.
Article
em En
| MEDLINE
| ID: mdl-12353084
ABSTRACT
Adhesion of platelets to endothelium has been shown to induce important changes in endothelial properties. In this study, we examined the effect of platelet-endothelial cell interactions on the expression of urokinase-type plasminogen activator (u-PA) by human microvascular endothelial cells. After incubation of endothelial cells with platelets, a dose-dependent increase in the expression of u-PA Ag was observed and reached a plateau for a ratio of 300 platelets per endothelial cells. The u-PA Ag upregulation resulted from an increase in u-PA mRNA that originated from a synthesis by endothelial cells since no u-PA mRNA was detected in platelets. The platelet-induced u-PA synthesis was inhibited when the endothelial cells were pre-treated with phospholipase C to remove the u-PA receptor, or when the platelets were incubated with an antibody that blocks the binding of u-PA to u-PAR. Taken together, these data indicate that u-PA present on the platelet surface interacts with u-PAR on the endothelial cells and induces the u-PA synthesis. This mechanism may represent a physiological control of platelet-mediated intravascular fibrin deposition.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plaquetas
/
Endotélio Vascular
/
Ativador de Plasminogênio Tipo Uroquinase
/
Comunicação Celular
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article