Oxidative stress and
free radical production have been implicated in
Alzheimer's disease, where low levels of the
antioxidant vitamin C (ascorbate) have been shown to be associated with the disease. In this study,
neuroblastoma SH-SY5Y cells were treated with
hydrogen peroxide in the presence of ascorbate in order to elucidate the mechanism(s) of protection against oxidative stress afforded by ascorbate.
Protein oxidation,
glutathione levels, cell viability and the effects on the
proteome and its oxidized counterpart were monitored. SH-SY5Y cells treated with ascorbate prior to co-incubation with
peroxide showed increased viability in comparison to cells treated with
peroxide alone. This dual treatment also caused an increase in
protein carbonyl content and a decrease in
glutathione levels within the cells.
Proteins, extracted from SH-SY5Y cells that were treated with either ascorbate or
peroxide alone or with ascorbate prior to
peroxide, were separated by two-dimensional gel electrophoresis and analyzed for oxidation. Co-incubation for 24 hours decreased the number of oxidised
proteins (e.g.
acyl CoA oxidase 3) and induced
brain derived neurotrophic factor (
BDNF) expression. Enhanced expression of
BDNF may contribute to the protective effects of ascorbate against oxidative stress in neuronal cells.