Journal
FREE RADICAL BIOLOGY AND MEDICINE
Volume 40, Issue 1, Pages 63-74Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.freeradbiomed.2005.08.012
Keywords
CYP2E1; HepG2 cells; serum deprivation; apoptosis; ROS; free radicals
Funding
- NIAAA NIH HHS [AA-03312, AA-06610] Funding Source: Medline
- NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM [R37AA006610, R56AA003312, R01AA003312, R01AA006610] Funding Source: NIH RePORTER
Ask authors/readers for more resources
Induction of oxidative stress plays a key role in serum deprivation-induced apoptosis. CYP2E1 plays an important role in toxicity of many chemicals and ethanol and produces oxidant stress. We investigated whether CYP2E1 expression can sensitize HepG2 cells to toxicity as a consequence of serum deprivation. The models used were HepG2 E47 cells that express human CYP2E1, and C34 HepG2 cells which do not express CYP2E1. E47 cells showed greater growth inhibition and enhanced cell death after serum deprivation, as compared to the C34 cells. DNA ladder and flow cytometry assays indicated that apoptosis occurred at earlier times after serum deprivation in E47 than C34 cells. Serum withdrawal-induced E47 cell death could be rescued by antioxidants, the mitochondrial permeability transition inhibitor cyclosporine A, z-DEVD-fmk, and a CYP2E1 inhibitor 4-methylpyrazole. Increased production of reactive oxygen species (ROS) and lipid peroxidation occurred in E47 cells after serum deprivation, and there was a corresponding decline in the E47 cell mitochondrial membrane potential and reduced glutathione (GSH) levels. We propose that the mechanism of this serum withdrawal plus CYP2E1 toxicity involves increased production of intracellular ROS, lipid peroxidation, and decline of GSH levels, which results in mitochondrial membrane damage and loss of membrane potential, followed by apoptosis. Potentiation of serum deprivation-induced cell death by CYP2E1 may contribute to the sensitivity of the liver to alcohol-induced ischemia and growth factor deprivation. (c) 2005 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available