Post-transcriptional control of increased hepatic catalase gene expression in response to oxidative stress

Catalase is an important member of the antioxidant network that protects the cell against reactive oxygen species (ROS). We studied catalase gene expression in the liver of rats exposed to oxidative stress induced by the ROS-generating drug nitrofurantoin (NF). Catalase enzymatic activity and content are enhanced by NF treatment. The corresponding increase in the steady state level of the messenger ribonucleic acid (mRNA) occurs without significant changes in transcription and seems therefore controlled post-transcriptionally. Indeed, RNA band-shift assays demonstrated a reduced binding of redox-sensitive cytoplasmic protein(s) to the 3' region of catalase mRNA in NF-treated rats, thus suggesting that the redox state of protein that binds to an antioxidant enzyme mRNA may play a role in the hepatic response to oxidative stress.