TNF-alpha suppresses IL-6 upregulation of protein S in HepG-2 hepatoma cells.

The pathogenesis of disseminated intravascular coagulation (DIC) has, in part, been attributed to the impairment of the natural anticoagulant protein C/protein S pathway. DIC, which frequently occurs during sepsis, has been linked to cytokines that can induce or modulate procoagulant activity. Three of these cytokines, IL-1 alpha, IL-6, and TNF-alpha have been reported to be increased in the early stages of sepsis. In the present study, we have stimulated HepG-2 hepatoma cell cultures with recombinant human IL-1 alpha, IL-6, TNF-alpha, and oncostatin M (OSM). The results demonstrated that TNF-alpha, and to a lesser degree, IL-1 alpha, could significantly suppress IL-6 upregulation of protein S, whereas the effects of OSM was only suppressed by the combination of IL-1 alpha and TNF-alpha. The combination of IL-1 alpha and TNF-alpha also suppressed protein S production below that of control or basal levels. These results indicate that IL-1 alpha and TNF-alpha may play important regulatory roles in coagulation.