Co-localization of tissue factor protein and its mRNA in human blood monocytes

Fast detection of tissue factor and tissue factor pathway inhibitor messenger RNA in endothelial cells and monocytes by sensitive reverse transcription-polymerase chain reaction

We developed fast and sensitive reverse transcription-polymerase chain reaction (RT-PCR) procedures to study the expression of tissue factor (TF) and tissue factor pathway inhibitor (TFPI-1) mRNA in human endothelial cells and monocytes. The sensitivity of the technique was checked by performing RT-PCR with limited numbers of cells. Cells were stimulated either with tumor necrosis factor (TNF-alpha) or endotoxin to induce TF mRNA expression or with phorbol ester to increase TFPI-1 mRNA expression. Thus, RT-PCR specific for TF mRNA provided detection from as few as 10(3) TNF-alpha stimulated endothelial cells and 5 x 10(2) monocytes stimulated by endotoxin. TF mRNA expression was increased by TNF-alpha in endothelial cells and in monocytes stimulated by endotoxin. Elevated expression of TF mRNA in monocytes without stimulation by endotoxin was mainly related to cell adhesion. TFPI-1 mRNA was constitutively expressed in endothelial cells and was detected in only 5 x 10(2) unstimulated cells and 10(2) phorbol ester-stimulated cells. Expression was increased upon stimulation with phorbol ester. With this technique, TFPI-1 mRNA in monocytes was rather low even when cells were stimulated with phorbol ester or after adhesion.

Suppression of human monocyte tissue factor synthesis by antisense oligodeoxynucleotide

Tissue factor (TF) is a cellular receptor and cofactor for factor V11/V11a which initiates the blood coagulation cascade. An understanding of TF cell biology is therefore of critical importance to the pathophysiology of many disorders. We have utilized an antisense oligodeoxynucleotide (aODN), directed against human blood monocyte TF mRNA, to investigate the feasibility of inhibiting the synthesis of TF. CD14 receptor-mediated endocytosis was used as a means of delivering TF aODN to monocytes. This DNA carrier system consists of the fab portion of anti-CD14 antibody covalently linked to poly (L-lysine). Co-treatment of monocytes with TF aODN and endotoxin resulted in 80.4 +/- 2.2% suppression of TF activity when compared with control endotoxin stimulated cells. Control experiments with TF sense ODN, mismatched aODN, and an irrelevant aODN were performed to exclude nonspecific inhibitory effects. The cytotoxicity of the DNA carrier complex was also evaluated. These results demonstrate that this TF mRNA antisense ODN specifically suppressed the synthesis of biologically active monocyte TF and that antisense ODNs might therefore represent a useful tool in the investigation of monocyte/macrophage TF function.