Article
Iron-ions trigger lipid-peroxidation-mediated toxicity to corneal endothelial cells and lead to apoptosis
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Published: | September 22, 2004 |
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Outline
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Objective
To determine the effects of lipid-peroxidation-mediated toxicity of iron-ions on corneal endothelial cells leading to apoptosis.
Methods
Murine corneal endothelial cells were maintained in tissue culture medium substituted with increasing concentrations of free iron-ions, known to lead to increased lipid-peroxidation. The concentration of antioxidative vitamins (ascorbic acid, tocopherole and retinoic acid) in the cell supernatant was determined using HPLC. Apoptosis was assessed by quantification of caspase-3-like-activity. The lipid-peroxidation was measured using the Malondialdehyde-method. Supplementation of antioxidative vitamins was tested in the setting of apoptosis.
Results
Increasing levels of free iron lead to a rapid loss of antioxidative vitamins in the supernatant and the corneal endothelial cells. This was correlated with rising levels of Malondialdehyde and increased apoptosis. Substitution of ascorbic acid or α-Tocopherol alone could not prevent lipid peroxidation in the cells, whereas a combination of vitamin C and E could do so. In contrast the supplementation of vitamin A alone significantly reduced oxidative stress and apoptosis in this study.
Conclusions
In this study the authors present a novel in vitro model to test the direct influence of pro-oxidative species to corneal endothelial cells. The authors also prove that supplementation of antioxidative vitamins to corneal endothelial cells sufficiently prevents generation of free-radical injury and apoptosis.