Pharmaceutical Sciences Faculty Publications
Inactivation of Oxidized and S-Nitrosylated Mitochondrial Proteins in Alcoholic Fatty Liver of Rats
Document Type
Article
Publication Date
11-1-2006
Journal Title
Hepatology
ISSN
0270-9139
Volume
44
Issue
5
First Page
1218
Last Page
1230
DOI
10.1002/hep.21372
PubMed ID
17058263
Abstract
Increased oxidative/nitrosative stress is a major contributing factor to alcohol-mediated mitochondrial dysfunction. However, which mitochondrial proteins are oxidatively modified under alcohol-induced oxidative/nitrosative stress is poorly understood. The aim of this study was to systematically investigate oxidized and/or S-nitrosylated mitochondrial proteins and to use a biotin-N-maleimide probe to evaluate their inactivation in alcoholic fatty livers of rats. Binge or chronic alcohol exposure significantly elevated nitric oxide, inducible nitric oxide synthase, and ethanol-inducible CYP2E1. The biotin-N-maleimide-labeled oxidized and/or S-nitrosylated mitochondrial proteins from pair-fed controls or alcohol-fed rat livers were subsequently purified with streptavidin-agarose. The overall patterns of oxidized and/or S-nitrosylated proteins resolved by 2-dimensional polyacrylamide gel electrophoresis were very similar in the chronic and binge alcohol treatment groups. Seventy-nine proteins that displayed differential spot intensities from those of control rats were identified by mass spectrometry. These include mitochondrial aldehyde dehydrogenase 2 (ALDH2), ATP synthase, acyl-CoA dehydrogenase, 3-ketoacyl-CoA thiolase, and many proteins involved in chaperone activity, mitochondrial electron transfer, and ion transport. The activity of 3-ketoacyl-CoA thiolase involved in mitochondrial beta-oxidation of fatty acids was significantly inhibited in alcohol-exposed rat livers, consistent with hepatic fat accumulation, as determined by biochemical and histological analyses. Measurement of activity and immunoblot results showed that ALDH2 and ATP synthase were also inhibited through oxidative modification of their cysteine or tyrosine residues in alcoholic fatty livers of rats. In conclusion, our results help to explain the underlying mechanism for mitochondrial dysfunction and increased susceptibility to alcohol-mediated liver damage.
Keywords
Central nervous system depressants, cysteine, ethanol, fatty liver, alcoholic, isoenzymes, maleimides, mitochondria, liver, mitochondrial proteins, nitric oxide synthase, nitrites, nitrosation, oxidation-reduction, oxidative stress, rats, sprague-dawley, protein
Recommended Citation
Moon, Kwan-Hoon; Hood, Brian L.; Kim, Bong-Jo; Hardwick, James P.; Conrads, Thomas P.; Veenstra, Timothy D.; and Song, Byoung J., "Inactivation of Oxidized and S-Nitrosylated Mitochondrial Proteins in Alcoholic Fatty Liver of Rats" (2006). Pharmaceutical Sciences Faculty Publications. 386.
https://digitalcommons.cedarville.edu/pharmaceutical_sciences_publications/386