OXIDIZED LOW-DENSITY-LIPOPROTEIN INDUCES ACTIVATION OF THE TRANSCRIPTION FACTOR NF-KAPPA-B IN FIBROBLASTS, ENDOTHELIAL AND SMOOTH-MUSCLE CELLS

The effect of cupric ions or endothelial cell-oxidized LDL on the tran scription factor NF kappa B activation was investigated by electrophor etic mobility shift assay. Oxidized LDL induced NFkB activation in fib roblasts, endothelial and smooth muscle cells. The extent of NF kappa B activation was proportional to the degree of LDL oxidation, as asses sed by the lipid peroxidation product and the conjugated diene level. A similar activation was observed with the lipid extract of copper-oxi dized LDL, which indicates that lipid peroxidation products are involv ed in the activation mechanism. Furthermore, alpha-tocopherol, a lipop hilic free radical scavenger, partially inhibited the stimulatory effe ct of Cu2+-oxidized LDL. Since NF kappa B is considered as an oxidativ e stress-responsive transcription factor, our study supports the evide nce that the stress induced by oxidized LDL causes NF kappa B activati on in different cell types, and that this effect can be ascribed to th e lipid peroxidation products.