CYP2E1 Sensitizes the Liver to LPS- and TNF α-Induced Toxicity via Elevated Oxidative and Nitrosative Stress and Activation of ASK-1 and JNK Mitogen-Activated Kinases
Figure 6
Effect of thioredoxin (TRX) knockdown on E47 (express CYP2E1) and C34 (do not express CYP2E1) HepG2 cell viability. E47 and C34 cells were treated with control siRNA or cytosolic TRX-1 siRNA or mitochondrial TRX-2 siRNA or both TRX-1 and TRX-2 siRNAs for 72 hours. (a) Cell viability was determined by a MTT assay. (b) ROS production was determined by a fluorescence assay. Arbitrary units of fluorescence by the E47 and C34 cells. (c) Cellular levels of glutathione (GSH). The GSH level in each group was expressed as the value relative to that of the control siRNA treatment group in E47 cells. (d) Supplementation with GSH restores E47 cell viability after TRX knockdown. At 24 hours, 5 mM glutathione ethyl ester (GSSE) was added to the cell culture medium, and the cells were incubated with the indicated siRNA for 48 hours followed by MTT assay. Note: both cytosolic and mitochondrial TRX are important in protection of HepG2 cells from CYP2E1-generated oxidant stress.
