Oxidative stress causes ERK phosphorylation and cell death in cultured retinal pigment epithelium: prevention of cell death by AG126 and 15-deoxy-delta 12, 14-PGJ2.
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.


CONCLUSIONS
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.
Garg
Tarun K
TK
Departments of Anatomy & Neurobiology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA. gargtarunk@uams.edu
Chang
Jason Y
JY
D000199:Actins / Q000378:metabolism; D000447:Aldehydes / Q000378:metabolism; D015153:Blotting, Western; D016923:Cell Death; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D007124:Immunoenzyme Techniques; D007155:Immunologic Factors / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015230:Prostaglandin D2 / Q000031:analogs & derivatives / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists / Q000378:metabolism; D014157:Transcription Factors / Q000819:agonists / Q000378:metabolism; D020032:Tyrphostins / Q000494:pharmacology*
C097240:15-deoxy-delta(12,14)-prostaglandin J2; D000199:Actins; D000447:Aldehydes; D004791:Enzyme Inhibitors; D007155:Immunologic Factors; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D020032:Tyrphostins; C069028:AG 127; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; D020928:Mitogen-Activated Protein Kinases; C027576:4-hydroxy-2-nonenal; D015230:Prostaglandin D2