Thrombin and Tumor Necrosis Factor α Synergistically Stimulate Tissue Factor Expression in Human Endothelial Cells

Abstract

Tissue factor is critically important for initiating the activation of coagulation zymogens leading to the generation of thrombin. Quiescent endothelial cells do not express tissue factor on their surface, but many stimuli including cytokines and coagulation proteases can elicit tissue factor synthesis. We challenged human endothelial cells simultaneously with tumor necrosis factor ␣ (TNF␣) and thrombin because many pathophysiological conditions, such as sepsis, diabetes, and coronary artery disease, result in the concurrent presence of circulating inflammatory mediators and activated thrombin. We observed a remarkable synergy in the expression of tissue factor by thrombin plus TNF␣. This was due to altered regulation of the transcription factors c-Jun and c-Fos. The activation of c-Jun was greater and more sustained than that obtained with either thrombin or TNF␣ alone. Thrombin-stimulated expression of c-Fos was both enhanced and prolonged by the concurrent presence of TNF␣. These changes support the increased availability of c-Jun/c-Fos AP-1 complexes for mediating transcription at the tissue factor promoter. Transcription factors downstream of the extracellular signal-regulated kinases as well as changes in NFB regulation were not involved in the synergistic increase in tissue factor expression by thrombin and TNF␣. Thus, concurrent exposure of vascular endothelial cells to cytokines and procoagulant proteases such as thrombin can result in greatly enhanced tissue factor expression on the endothelium, thereby perpetuating the prothrombotic phenotype of the endothelium.Many diseases with a pronounced inflammatory component, such as sepsis, type II diabetes, coronary artery disease, heparin-induced thrombocytopenia, and anti-phospholipid syndrome, also exhibit enhanced activation of coagulation enzymes (1-5). These serine proteases, most notably thrombin, stimulate protease-activated receptors (PARs) 1 on the surface of endothelial cells. Signaling through the PARs shifts the endothelium toward a prothrombotic phenotype, exacerbating the initiating pathophysiological condition. Our interest in thrombin signaling by endothelial cells (6, 7) led us to question how inflammatory mediators such as TNF␣ might alter thrombininitiated signaling events and thereby bolster the prothrombotic phenotype of the endothelium. Normally, the apical surface of endothelial cells is designed to minimize interactions with circulating coagulation zymogens and blood cells. Inflammatory stimuli (cytokines, lipopolysaccharide, vascular endothelial cell growth factor, sphingosine 1-phosphate, thrombin (8 -12)) can alter the anticoagulatory phenotype of the endothelium by promoting the expression of adhesive molecules, receptors, and chemoattractants. Expression of tissue factor (TF), the coagulation Factor VII receptor, on the surface of endothelial cells serves as an excellent marker for an activated endothelium with an inflamed and procoagulant phenotype (13,14). Binding of Factor VII to tissue factor can then initiate the consecutive...

Histamine Induces Tissue Factor Expression

“…19 Interestingly, in both LPS-stimulated monocytes and thrombin-stimulated en- dothelial cells, TF expression occurs through activation of all 3 MAP kinase pathways. 27,39 We show here that specific inhibition of any of the 3 MAP kinases leads to a marked reduction in histamine-induced TF expression in HAECs even at low concentrations of the respective inhibitor. Thus, similar to LPS-stimulated monocytes, 27 activation of p38, ERK, and JNK cooperatively regulates histamine-induced TF expression in HAECs.…”

Carbon monoxide (CO)-releasing molecule-derived CO regulates tissue factor and plasminogen activator inhibitor type 1 in human endothelial cells

“…The ERK1/2 inhibitor suppressed TNF-α-induced PAI-1 protein up-regulation, but did not inhibit TF protein up-regulation. A previous study indicated that pretreatment of HUVECs with an ERK inhibitor (U0126, 10 µM) did not significantly inhibit TF induction by TNF-α [30]. In contrast, another study showed that ERK activation by TNF-α increased TF expression in endothelial cells [31].…”

Histamine differentially interacts with tumor necrosis factor‐α and thrombin in endothelial tissue factor induction: the role of c‐Jun NH2‐terminal kinase

“…Both p38 and JNK are involved in TF induction by histamine [13], TNF-a [14,18], and thrombin [18,26]. As the two MAPKs mediated TF induction by TNF-a and thrombin in both the presence and the absence of histamine, we sought to determine whether p38 or JNK could be involved in the differential augmenting effect of histamine on TNF-a-vs. thrombin-induced TF expression.…”