| ironjustice@aol.com 2005-04-20, 11:51 am |
| Cell Tissue Res. 2005 Apr 19; [Epub ahead of print] Links
Anti-oxidative vitamins prevent lipid-peroxidation and apoptosis in
corneal endothelial cells.
Serbecic N, Beutelspacher SC.
Department of Ophthalmology, SMZ-Ost, Donauspital, Vienna, Austria,
nermin.serbecic@web.de.
To determine the effects of vitamin supplementation on the
lipid-peroxidation-mediated toxicity of iron-ions on corneal
endothelial cells (CECs) leading to apoptosis, murine CECs were
maintained in tissue culture medium supplemented with increasing
concentrations of free iron-ions, a treatment known to lead to
increased lipid-peroxidation. The concentration of anti-oxidative
vitamins (ascorbic acid, tocopherol and retinoic acid) in the cell
supernatant and in the cells was determined by high-pressure liquid
chromatography. Apoptosis was assessed by quantification of
caspase-3-like activity and by using annexin-V/propidium iodide stains
for flow cytometry. Lipid-peroxidation was measured by the
malondialdehyde method. Supplementation with anti-oxidative vitamins
was tested for the ability to counteract the induction of apoptosis.
The production of nitric oxide was assessed spectrophotometrically and
the expression levels of inducible and endothelial nitric oxide
synthase were determined by Western blot. Increasing levels of free
iron led to a rapid loss of anti-oxidative vitamins in the supernatant
and in the CECs. This was correlated with rising levels of
malondialdehyde and increased apoptosis. Supplementation with ascorbic
acid or alpha-tocopherol alone did not prevent lipid-peroxidation in
the cells. A combination of vitamins C and E (ascorbic acid,
tocopherol) or solitary supplementation with vitamin A (retinoic acid)
prevented lipid-peroxidation. We thus present a novel in vitro model
for testing the direct influence of pro-oxidative species on CECs. We
also show that supplementation with anti-oxidative vitamins to CECs
significantly prevents the generation of free-radical-induced oxidative
injury and apoptosis. These findings may have important implications
for the storage of human corneae prior to transplantation and for the
prolongation of corneal graft survival.
PMID: 15838641 [PubMed - as supplied by publisher]
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