Salicylates inhibit lipopolysaccharide-induced transcriptional activation of the tissue factor gene in human monocytic cells

Abstract

Binding of plasma Factor VII/VIIa to the tissue factor (TF) receptor initiates the coagulation protease cascades. TF expression by circulating monocytes is associated with thrombotic and inflammatory complications in a variety of diseases. Transcriptional activation of the human TF gene in monocytic cells exposed to bacterial lipopolysaccharide (LPS) is mediated by binding of c-Rel/p65 heterodimers to a κB site in the TF promoter. Here, we report that a family of anti-inflammatory agents, known as the salicylates, inhibited LPS induction of TF activity and TF gene transcription in human monocytes and monocytic THP-1 cells at clinically relevant doses. Furthermore, sodium salicylate blocked the LPS-induced proteolytic degradation of IκBα, which prevented the nuclear translocation of c- Rel/p65 heterodimers. In contrast, two other nonsteroidal anti-inflammatory drugs, ibuprofen and indomethacin, did not inhibit LPS induction of the TF gene. These results indicated that salicylates inhibited LPS induction of TF gene transcription in monocytic cells by preventing nuclear translocation of c-Rel/p65 heterodimers. The clinical benefits of salicylates in the treatment of several diseases, including atherosclerosis and rheumatoid arthritis, may be related to their ability to reduce monocyte gene expression.