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 transcription factor NF kappa B activation was investigated by electrophoretic mobility shift assay. Oxidized LDL induced NF kappa B activation in fibroblasts, endothelial and smooth muscle cells. The extent of NF kappa B activation was proportional to the degree of LDL oxidation, as assessed by the lipid peroxidation product and the conjugated diene level. A similar activation was observed with the lipid extract of copper-oxidized LDL, which indicates that lipid peroxidation products are involved in the activation mechanism. Furthermore, alpha-tocopherol, a lipophilic free radical scavenger, partially inhibited the stimulatory effect of Cu(2+)-oxidized LDL. Since NF kappa B is considered as an oxidative stress-responsive transcription factor, our study supports the evidence that the stress induced by oxidized LDL causes NF kappa B activation in different cell types, and that this effect can be ascribed to the lipid peroxidation products.