PYRROLIDINE DITHIOCARBAMATE INHIBITS THE PRODUCTION OF INTERLEUKIN-6,INTERLEUKIN-8, AND GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR BY HUMAN ENDOTHELIAL-CELLS IN RESPONSE TO INFLAMMATORY MEDIATORS - MODULATION OF NF-KAPPA-B AND AP-1 TRANSCRIPTION FACTORS ACTIVITY

Endothelial cells (EC) play a key role in the inflammatory response, b oth by the production of proinflammatory cytokines and by their intera ction with leukocytes. Molecular genetic analysis has demonstrated tha t functional NF-kappa B sites are involved in the transcription of int erleukin-6 (IL-6), IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) genes in response to inflammatory mediators, Thus, we have explored the effect of two inhibitors of the NF-kappa B activati on, pyrrolidine dithiocarbamate (PDTC) and N-acetylcysteine (NAC), on the production of these cytokines by EC. Both PDTC and NAC inhibited, in a dose-dependent manner, the synthesis of IL-6, IL-8, and GM-CSF in duced by tumor necrosis factor (TNF)-alpha or bacterial lipopolysaccha rides (LPS) in human umbilical vein endothelial cells (HUVEC). PDTC ap peared to prevent IL-6, IL-8, and GM-CSF gene transcription, as it blo cked the induction of specific mRNA by TNF-alpha or LPS. The TNF-alpha -mediated transcriptional activation of a chloramphenicol acetyltransf erase (CAT) plasmid containing three copies of the -72 kappa B binding site from the IL-6 promoter was abrogated by PDTC. According to trans fection experiments, electrophoretic mobility shift assays (EMSA) demo nstrated that the antioxidant prevented the induction of NF-kappa B DN A-binding activity by TNF-alpha. Under the same conditions, PDTC by it self or in combination with TNF-alpha, enhanced the DNA-binding activi ty of AP-1, as well as c-fos and c-jun mRNA levels, Altogether, these results indicate that the antioxidant PDTC specifically inhibits the t ranscription of IL-6, IL-8, and GM-CSF genes through the inhibition of the NF-kappa B activation, while increasing the expression of AP-1. O ur data make evident the antiinflammatory and immunoregulatory potenti al of the pharmacological inhibition of the NF-kappa B activation. In addition, PDTC and related molecules may be a useful tool to explore t he expression of genes involved in the inflammatory response. (C) 1996 by The American Society of Hematology.