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Background: With the use of cultured human retinal pigment epithelial cells, we have previously described a number of cellular responses to oxidative stress caused by H2O2. We also demonstrated that the cytotoxicity caused by H2O2 could be prevented by the prostaglandin derivative, 15-deoxy-delta 12, 14-Prostaglandin J2 (15d-PGJ2)., Results: Further characterization of the experimental system indicated that the half-life of H2O2 in cultures was ~1 hour. At a fixed H2O2 concentration, the cytotoxicity was dependent on the volume of H2O2 solution used in the culture, such that higher volume caused more cytotoxicity. Most cells were committed to die if the culture was treated for 2 hours with a cytotoxic concentration of H2O2. The prostaglandin derivative, 15d-PGJ2, could prevent oxidative damage caused by t-butyl hydroperoxide, in addition to H2O2. Further studies indicated that both H2O2 and tBH caused an increase in reactive oxygen species and depolarization of mitochondrial membrane potential. Pretreatment of cells with 1 microM 15d-PGJ2 led to a modest decrease in reactive oxygen species generation, and a significant restoration of mitochondrial membrane potential., Conclusion: This agent may be used in the future as a pharmacological tool for preventing cellular damage caused by oxidative stress.

Background: The retina, which is exposed to both sunlight and very high levels of oxygen, is exceptionally rich in polyunsaturated fatty acids, which makes it a favorable environment for the generation of reactive oxygen species. The cytotoxic effects of hydrogen peroxide (H2O2) induced oxidative stress on retinal pigment epithelium were characterized in this study., Methods: The MTT cell viability assay, Texas-Red phalloidin staining, immunohistochemistry and Western blot analysis were used to assess the effects of oxidative stress on primary human retinal pigment epithelial cell cultures and the ARPE-19 cell line., Results: The treatment of retinal pigment epithelial cells with H2O2 caused a dose-dependent decrease of cellular viability, which was preceded by a significant cytoskeletal rearrangement, activation of the Extracellular signal-Regulated Kinase, lipid peroxidation and nuclear condensation. This cell death was prevented partially by the prostaglandin derivative, 15d-PGJ2 and by the protein kinase inhibitor, AG126., Conclusion: 15d-PGJ2 and AG126 may be useful pharmacological tools in the future capable of preventing oxidative stress induced RPE cell death in human ocular diseases.