12-Hydroxyeicosatetraenoic acid upregulates P-selectin-induced tissue factor activity on monocytes

12-Hydroxyeicosatetraenoic acid (12-HETE), a product of the platelet lipoxy genase pathway, amplifies tissue factor expression by P-selectin-stimulated monocytes in a time- and dose-dependent fashion. The same effect is observ ed when monocytes are incubated with Chinese hamster ovary transfected with the P-selectin cDNA. Both 5-HETE and leukotriene C-4 are inactive in this system, Furthermore, the effect is not dependent on non-specific monocyte a dhesion, since monocytes incubated with CHO cells expressing E-selectin do not express tissue factor, either in the presence or in the absence of 12-H ETE. These results show that 12-HETE is a cofactor for the expression of ti ssue factor by monocytes. (C) 1998 Federation of European Biochemical Socie ties.