Effects of anti-rheumatic gold salts on NF-kappa B mobilization and tumournecrosis factor-alpha (TNF-alpha)-induced neutrophil-dependent cytotoxicity for human endothelial cells

We have previously shown that the gold-containing disease-modifying anti-rh eumatic drugs, auranofin (AF) and gold sodium aurothiomalate (GSTM) reduce human umbilical vein endothelial cell (HUVEC) adhesion molecule expression and neutrophil (PMN) adherence. AF diminishes E-selectin and intercellular adhesion molecule-1 (ICAM-1) on cytokine-activated HUVEC, while GSTM decrea ses only E-selectin. Since tight adhesion is critical for PMN to damage EC, we tested whether these drugs modulated human PMN-mediated injury to TNF-a lpha-activated HUVEC in vitro (as measured by Cr-51 release). Here we show that TNF-alpha caused a prominent PMN-mediated cytotoxicity that was dose-d ependently reduced when AF and GSTM were added to the assay system. We also found that a potent inhibitor of NF-kappa B, pyrrolidine dithiocarbamate ( PDTC) in a dose-dependent manner impaired TNF-alpha-induced cytotoxicity, i ndicating a role of NF-kappa B activation in cytokine-induced endothelial i njury. To examine the effects of AF and GSTM on TNF-alpha-induced NF-kappa B activation this was measured in HUVEC nuclear extracts by an electrophore tic mobility shift assay. AF, but not GSTM, decreased TNF-alpha-induced NF- kappa B activation in HUVEC. Thus, in this in vitro model of vasculitis, AF and GSTM dose dependently reduced TNF-alpha-mediated neutrophil-dependent cytotoxicity for HUVEC, and AF, but not GSTM, inhibited NF-kappa B mobiliza tion, thereby providing possible mechanisms for effects of AF and GSTM.