Oxidative stress induces differential gene expression in a human lens epithelial cell line

PURPOSE. To identify differentially expressed genes in a human lens epithel ial cell line exposed to oxidative stress. METHODS. Reverse transcriptase-polymerase chain reaction (RT-PCR) different ial display was used to evaluate differential gene expression in a human le ns epithelial cell line (SRA 01-04) when cells were exposed for 3 hours to a single bolus of 200 mu M hydrogen peroxide. differentially expressed gene s were identified through DNA sequencing and a nucleotide database search. Differential expression was confirmed by northern blot and RT-PCR analyses. RESULTS. Using 18 primer sets, 28 RT-PCR products were differentially expre ssed between control and hydrogen peroxide-treated cells. In stressed cells , mitochondrial transcripts nicotinamide adenine dinucleotide (NADH) dehydr ogenase subunit 4 and cytochrome b were downregulated 4-fold. Of the cytopl asmic mRNAs, glutamine cyclotransferase decreased 10-fold, whereas cytokine -inducible nuclear protein, alternative splicing factor 2, and beta-hydroxy isobutryl-coenzyme A hydrolase increased 2-, 4-, and 10-fold, respectively. Analysis of mitochondrial transcripts in a 24-hour time course showed that NADH dehydrogenase subunit 4 mRNA decreased by 2-fold as early as 1 hour a fter oxidative stress, whereas the rate of decrease was slower for cytochro me b, cytochrome oxidase III, and 16S rRNA. CONCLUSIONS. Oxidative stress induced specific expressed gene changes in hy drogen peroxide-treated lens cells, including genes involved in cellular re spiration and mRNA and peptide processing. These early changes may reflect pathways involved in the defense, pathology or both of the Lens epithelium, which is exposed to oxidative stress throughout life.