Differential Gene Expression in Explanted Human Retinal Pigment Epithelial Cells 12-Hours Post-Exposure to 532 nm, 120 ps Pulsed Laser Light

摘要

The use of laser light for military and commercial applications has sharply increased the likelihood of personnel exposure to laser light during operations. The increased potential for human exposure highlights the fact that there is paucity of basic science at the cell and molecular level concerning the effects of laser exposure of human cells. We assessed the sublethal insult to human retinal pigment epithelial cells using a cadaver organ donor explant system for genes differentially expressed 12 hours post-exposure using gene expression microarray technology (gene chip). The 64 pulses of 532 nm light, 107 mJ per square centimeter appeared to induce the cells into cessation of cell cycling. Notably several key genes involved in protein degradation, the inflammatory response, translation initiation, DNA metabolism (repair/ replication) and a remarkable percentage of genes involved in ribosomal/ translational machinery reconstruction were significantly up-regulationed (37% of the first 100 genes) and also indicate that the ribosome may be the primary chromophore for damage in this exposure regime. Genes up-regulated an order of magnitude are involved in prevention of oxidative damage (thioredoxin, 15 fold; glutathione metabolism, 8 fold) Up-regulated genes involved in the elimination of denatured proteins provided strong evidence for oxygen-related damage (hypoxia and/or ROS.).