The Effect of Interleukin-4 on Tumour Necrosis Factor-Alpha Induced Expression of Tissue Factor and Plasminogen Activator Inhibitor-1 in Human Umbilical Vein Endothelial Cells

Abstract

SummaryThe pro-inflammatory cytokine tumour necrosis factor-a (TNF-α) is able to alter the haemostatic balance of human umbilical vein endothelial cells (HUVECs) towards that of a procoagulant and anti-fibrinolytic state. Treatment of HUVECs in culture with human recombinant TNF-α (0.5-50 U/ml; 6 h) significantly increased total cell expression of tissue factor (TF) 10-fold from 40 mU/well to 400-500 mU/well. Levels of plasminogen activator inhibitor-1 (PAI-1) antigen secreted from HUVECs also increased up to 2-fold in concentration-dependent fashion following addition of TNF-α (10-100 U/ml; 24 h). TNF-α induced total and cell surface expression of TF on HUVECs was significantly inhibited when the cells were pre-incubated with interleukin-4 (IL-4; p <0.001). This effect was time and concentration dependent. Pretreatment of HUVECs with IL-4 for 4 h had no significant effect, but increasing inhibition of total TF expression occurred after 8 and 16 h pre-incubations. Treatment with IL-4 at 20 and 200 U/ml significantly inhibited cell surface TF responses induced by TNF-α, whereas a low concentration (0.2 U/ml) was without effect. In contrast, the production of PAI-1 from HUVECs stimulated by TNF-α (50 U/ml) was unaffected by the presence and/or prior incubation with 200 U/ml IL-4. Thus, IL-4 may regulate the pro-coagulant but not the antifibrinolytic effects of TNF-α at sites of vascular inflammation.

Interleukin-4 Down-regulates Both Forms of Tumor Necrosis Factor Receptor and Receptor-mediated Apoptosis, NF-κB, AP-1, and c-Jun N-Terminal Kinase

“…Several previous reports indicate that IL-4 antagonizes the effects of TNF in vitro (13)(14)(15)(16)(17)(18)(19) and in vivo (15,20). Among in vitro effects, IL-4 inhibits TNF-induced activation of endothelial cells (13), blocks TNF-induced expression of tissue factor and plasminogen activator inhibitor-1 from endothelial cells (17), inhibits TNF-induced E-selectin expression (19), and blocks TNF-induced proliferation of B cells (16).…”

“…Among in vitro effects, IL-4 inhibits TNF-induced activation of endothelial cells (13), blocks TNF-induced expression of tissue factor and plasminogen activator inhibitor-1 from endothelial cells (17), inhibits TNF-induced E-selectin expression (19), and blocks TNF-induced proliferation of B cells (16). In vivo, IL-4 blocks TNF-induced hepatic lipogenesis (15) and cachexia and death (20).…”

“…down-regulate a wide variety of TNF-induced effects (13)(14)(15)(16)(17)(18)(19)(20). There are also reports demonstrating that IL-4 and TNF are synergistic in their action (21,22).…”

Coordinated induction of plasminogen activator inhibitor-1 (PAI-1) and inhibition of plasminogen activator gene expression by hypoxia promotes pulmonary vascular fibrin deposition.

“…Treatment of rats with endotoxin results in decreased tPA activity and increased PAI-1 expression in several tissues, including aorta, with tPA activity decreasing due to a shift in the balance between tPA and PAI-1 (41,42). TNF not only decreases endothelial anticoagulant properties by reducing thrombomodulin expression (3,43), but increases PAI-1 expression in human umbilical vein endothelial cells in vitro (44). In addition, hypoxic endothelial cells secrete IL-1␣, which can stimulate the proinflammatory response and cause increased PAI-1 expression in human umbilical vein endothelial cells in vitro (45)(46)(47), although IL-1 and TNF appear not to be necessary for PAI-1 induction (48).…”

PPARγ Activation in Human Endothelial Cells Increases Plasminogen Activator Inhibitor Type-1 Expression

“…1 PAI-1, a member of the serine protease inhibitor (serpin) family, is the major physiological inhibitor of tissue plasminogen activator and urokinase and thus, limits fibrinolysis. 2 Considerable evidence links PAI-1 to myocardial infarction and deep venous thrombosis [3][4][5] ; endothelial production of PAI-1 likely influences these events.…”