Intracellular redox regulation by a cystine derivative suppresses UV-induced NF-kappa B activation

Nuclear factor (NF)-kappa B pathways are influenced by the intracellular reduction-oxidation (redox) balance. While NF-kappa B is activated through inhibitor (I)-kappa B degradation by oxidative stress, its DNA binding is accelerated in the reduced state. We found that N,N'-diacetyl-L-cystine dimethylester (DACDM) suppressed the UVB-induced NF-kappa B binding activity at a much lower concentration (50-100 microM) than N-acetyl-L-cysteine (NAC, 10-30 mM). While NAC suppressed the I-kappa B degradation but not the DNA binding, DACDM prevented the activated NF-kappa B from binding DNA, without influencing the I-kappa B degradation. These properties of DACDM make it possible to effectively regulate the intracellular redox balance.