Glutathione-S-transferases (GSTs) are a superfamily of enzymes that function to catalyze the nucleophilic attack of glutathione on electrophilic groups of a second substrate. GSTs are present in many organs and have been implicated in the detoxification of endogenous α, β unsaturated aldehydes, including 4-hydroxynonenal (HNE). Exogenous GST protects hippocampal neurons against HNE in culture. To test the hypothesis that overexpression of GST in cells would increase resistance to exogenous or endogenous HNE induced by oxidative stress, stable transfectants of SY5Y neuroblastoma cells with GST were established. Stable GST transfectants demonstrated enzyme activities 13.7 times (Clone 1) and 30 times (Clone 2) higher than cells transfected with vector alone. GST transfectants (both Clones 1 and 2) demonstrated significantly (p < .05) increased resistance to ferrous sulfate/hydrogen peroxide (20.9% for Clone 1; 46.5% for Clone 2), amyloid β-peptide (12.2% for Clone 1; 27.5.% for Clone 2), and peroxynitrite (24.3% for Clone 1; 43.9% for Clone 2), but not to exogenous application of HNE in culture medium. GST transfectants treated with 1,1,4-tris (acetyloxy)nonane, a nontoxic derivative of HNE that is degraded to HNE intracellularly, demonstrated a statistically significant (p < .05) increase in viability in a dose-dependent manner compared with SY5Y cells transfected with vector alone. These results suggest that overexpression of GST increases resistance to endogenous HNE induced by oxidative stress or released in the degradation of 1,1,4-tris (acetyloxy)nonane, but not to exogenous application of HNE.
|Number of pages||9|
|Journal||Free Radical Biology and Medicine|
|State||Published - Jul 1 2001|
Bibliographical noteFunding Information:
This research was supported by National Institutes of Health grants 1 P01-AG05119 and 5P50-AG0 5144, and a grant from the Abercrombie Foundation. The authors are grateful for the technical assistance of Jane Meara and the editorial assistance of Paula Thomason.
- Free radicals
- Neuroblastoma cells
- Oxidative stress
ASJC Scopus subject areas
- Physiology (medical)