RT Journal Article
SR Electronic
T1 Adenovirus-Mediated Overexpression of Catalase in the Cytosolic or Mitochondrial Compartment Protects against Toxicity Caused by Glutathione Depletion in HepG2 Cells Expressing CYP2E1
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 111
OP 118
DO 10.1124/jpet.301.1.111
VO 301
IS 1
A1 Marı́, Montserrat
A1 Bai, Jingxiang
A1 Cederbaum, Arthur I.
YR 2002
UL http://jpet.aspetjournals.org/content/301/1/111.abstract
AB Induction of cytochrome P450 CYP2E1 by ethanol appears to be one of the mechanisms by which ethanol creates a state of oxidative stress. Glutathione (GSH) is a key cellular antioxidant that detoxifies reactive oxygen species. Depletion of GSH, especially mitochondrial GSH, is believed to play a role in the ethanol-induced liver injury. Previous results reported that depletion of GSH by buthionine-(S,R)-sulfoximine (BSO) treatment caused apoptosis and necrosis in HepG2 cells, which overexpress CYP2E1. In the current work, adenoviral infection with vectors that resulted in expression of catalase either in the cytosol or mitochondrial compartments was able to abolish the loss of mitochondrial membrane potential or damage to mitochondria observed in HepG2 cells overexpressing CYP2E1 that were treated with BSO. Loss of cell viability, either necrotic or apoptotic, was also prevented by the catalase overexpression after infection with the adenoviral vectors. The protective effects of catalase were associated with the suppression of the increase in the production of reactive oxygen species and of mitochondrial lipid peroxidation observed after GSH depletion. These results reveal a prominent role for H2O2 as a mediator in the cytotoxicity observed after depletion of GSH in HepG2 cells overexpressing CYP2E1. Damage to mitochondria may be a critical step for cellular toxicity by CYP2E1-derived reactive oxygen species. The American Society for Pharmacology and Experimental Therapeutics