Glutathione is implied in the control of 7-ketocholesterol-induced apoptosis, which is associated with radical oxygen species production.
FASEB J
; 12(15): 1651-63, 1998 Dec.
Article
em En
| MEDLINE
| ID: mdl-9837855
ABSTRACT
In a number of experimental systems, inhibition of apoptosis by antioxidants has led to the production of radical oxygen species (ROS) in certain apoptotic forms of cell death. Since antioxidant therapies can reduce vascular dysfunctions in hypercholesterolemic patients who frequently have increased plasma levels of oxysterols constituting potent inducers of apoptosis, we speculate that oxysterol-induced apoptosis could involve oxidative stress. Here, we tested the protective effects of the aminothiols glutathione (GSH) and N-acetylcysteine (NAC), which are two potent antioxidants, on apoptosis induced by 7-ketocholesterol in U937 cells, and we present evidence indicating that oxidative processes are involved in 7-ketocholesterol-induced cell death. Thus, GSH and NAC prevented phenomenona linked to apoptosis such as reduction of cell growth, increase cellular permeability to propidium iodide, and occurrence of nuclear condensation and/or fragmentation, and they delayed internucleosomal DNA fragmentation. In addition, cell treatment with GSH impaired cytochrome c release into the cytosol and degradation of caspase-8 occurring during cell death. During 7-ketocholesterol-induced apoptosis, we also observed a rapid decrease in cellular GSH content, oxidation of polyunsaturated fatty acids, and a production of ROS by flow cytometry with the use of the dye 2', 7'-dichlorofluorescin-diacetate; both phenomena were inhibited by GSH. Prevention of cell death by GSH and NAC does not seem to be a general rule since these antioxidants impaired etoposide (but not cycloheximide) -induced apoptosis. Taken together, our data demonstrate that GSH is implied in the control of 7-ketocholesterol-induced apoptosis associated with the production of ROS.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espécies Reativas de Oxigênio
/
Apoptose
/
Glutationa
/
Cetocolesteróis
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
França