Purpose: Lipid oxidation has been proposed to be a factor in the pathophysiology of glaucoma. We investigated whether elevated levels of isolevuglandin (isoLGE2) protein adducts are associated with astrocytes derived from the glaucomatous optic nerve head. In addition, we examined whether the isoLGE2 protein adducts are altered following exposure of astrocytes to elevated pressure. Methods: Astrocytes were isolated from rat brain cortex and human optic nerve and were subjected to pressure treatments, western blot analyses, liquid chromatography tandem mass spectrometry, and immunocytochemistry. Results: Elevated levels of isolevuglandin (isoLGE2) protein adducts were associated with astrocytes derived from the glaucomatous (n=10) optic nerve head when compared to those from controls (n=6). Astrocytes subjected to in vitro pressure treatment resulted in increased levels of isoLGE2 protein adducts. Pressure exposure and the recovery period affect isoLGE2 protein modification, and pyridoxamine was effective in decreasing the appearance of isoLGE2 protein adduct immunoreactivity when applied immediately after pressure treatment. Conclusions: These results suggest that the elevated isoLGE2 protein adduct immunoreactivity observed in glaucomatous astrocytes may be due to chronic and/or prolonged exposure to pressure, and pyridoxamine may have prophylactic utility against such oxidative protein modification.
|Original language||English (US)|
|Number of pages||13|
|State||Published - Jun 1 2009|
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