Purchase this article with an account.
Kasey C. Nelson, Joanne L. Carlson, Melanie L. Newman, Paul Sternberg, Dean P. Jones, Terrance J. Kavanagh, Dolores Diaz, Jiyang Cai, Mei Wu; Effect of Dietary Inducer Dimethylfumarate on Glutathione in Cultured Human Retinal Pigment Epithelial Cells. Invest. Ophthalmol. Vis. Sci. 1999;40(9):1927-1935.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. To determine the effect of dimethylfumarate (DMF), an inducer of
glutathione (GSH)-dependent detoxification, on intracellular GSH levels
in cultured human retinal pigment epithelium (hRPE) cells, its
mechanism of action, and its effect on hRPE cells subjected to
methods. Established hRPE cell lines were treated with DMF and assayed by
high-pressure liquid chromatography for intracellular and extracellular
GSH levels. Quantification of γ-glutamylcysteine synthetase (GLCL)
was determined through northern and western blot analyses, and activity
was measured. Effects of pretreatment with DMF on GSH redox status of
hRPE cells was determined. Sensitivity of hRPE cells to oxidative
stress was determined using tert-butylhydroperoxide as the
results. Dimethylfumarate caused a transient decrease followed by a significant
increase in intracellular GSH. Glutathione increased maximally at 24
hours with 100 to 200 μM DMF. The initial decrease could be accounted
for by the formation of a DMF-GSH conjugate. Dimethylfumarate treatment
increased the steady state mRNA expression of the regulatory subunit of
GLCL, but no increase was seen for the catalytic subunit. However,
protein levels were increased for both, and the catalytic activity of
GLCL was also increased. Whereas the initial decrease in GSH made hRPE
cells more susceptible to oxidative damage, pretreatment with DMF under
conditions that increased intracellular GSH protected hRPE cells
against oxidative damage.
conclusions. These results suggest a means by which the antioxidant capability of
hRPE may be augmented without direct antioxidant supplementation.
Specifically, a dietary compound that conjugates with GSH can induce
GSH synthesis, increase GSH concentration, and improve protection by
GSH-dependent detoxification pathways in hRPE. However, the early
depletion of GSH before stimulated synthesis necessitates caution in
prevention strategies using dietary inducers.
This PDF is available to Subscribers Only