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Abstract #20632 Published in IGR 10-1
Sustained stress response after oxidative stress in trabecular meshwork cells
Li G; Luna C; Liton PB; Navarro I; Epstein DL; Gonzalez PMolecular Vision 2007; 13: 2282-2288
See also comment(s) by Ted Acott •
PURPOSE: To investigate the mechanisms by which chronic oxidative stress may lead to a sustained stress response similar to that previously observed in the trabecular meshwork (TM) of glaucoma donors. METHODS: Porcine TM cells were treated with 200 μM H2O2 twice a day for-four days and were allowed to recover for three additional days. After the treatment, TM cells were analyzed for generation of intracellular reactive oxygen species (iROS), mitochondrial potential, activation of NF-κB, and the expression of inflammatory markers IL-1α, IL-6, IL-8, and ELAM-1. Potential sources of iROS were evaluated using inhibitors for nitric oxide, nitric oxide synthetase, cyclooxygenase, xanthine oxidase, NADPH oxidase, rnitochondrial ROS, and PKC. The role of NF-κB activation in the-induction of inflammatory markers was evaluated using the inhibitors Lactacystin and BAY11-7082. RESULTS: Chronic oxidative stress simulated by H2O2 exposure of porcine TM cells resulted in the sustained production of iROS by the mitochondria. Inhibition of mitochondrial iROS had a significant inhibitory effect on the activation of NF-κB and the induction of IIL-1α, IL-6, IL-8, and ELAM-1 triggered by chronic oxidative stress. Inhibition of NF-κB partially prevented the induction of IL-1α, IL-8, and ELAM-1, but not IL-6. CONCLUSIONS: Chronic oxidative stress in TM cells induced iROS production in mitochondria. This increase in iROS may contribute to the pathogenesis of the TM in glaucoma by inducing the expression of inflammatory mediators previously observed in glaucoma donors as well as the levels of oxidative damage in the tissue.
Dr. P. Gonzalez, Department of Ophthalmology, Duke University Medical Center, Erwin Rd., Durham, NC 27710, USA. gonz012@mc.duke.edu
Classification:
2.5.1 Trabecular meshwork (Part of: 2 Anatomical structures in glaucoma > 2.5 Meshwork)
3.6 Cellular biology (Part of: 3 Laboratory methods)
