Formation of gamma-ketoaldehyde-protein adducts during ethanol-induced liver injury in mice.
Ethanol metabolism promotes the formation of a variety of reactive aldehydes in the liver. These aldehydes can rapidly form covalent protein adducts. Accumulating evidence indicates that these protein adducts may contribute to ethanol-mediated liver injury. Overproduction of gamma-ketoaldehydes, levuglandins (LGs) and isolevuglandins, is implicated in the pathogenesis of several chronic inflammatory diseases. gamma-Ketoaldehydes can form protein adducts orders of magnitude more quickly than 4-hydroxynonenal (4-HNE) or malondialdehyde. We hypothesized that ethanol-induced oxidative stress in vivo results in overproduction of LGE(2)- and iso[4]LGE(2)-protein adducts in mouse liver. Female C57BL/6 mice were allowed free access to an ethanol-containing diet for up to 39 days or pair-fed control diets. Pathological markers of ethanol-induced hepatic injury including serum alanine aminotransferase, hepatic triglyceride, and CYP2E1 were elevated in response to ethanol feeding. Ethanol-induced formation of iso[4]LGE(2)-, LGE(2)-, and 4-HNE-protein adducts in mouse liver was dependent on both dose and duration of ethanol feeding. Deficiency of cyclooxygenase 1 or 2 did not prevent ethanol-induced iso[4]LGE(2) or LGE(2) adducts in the liver, but adduct formation was reduced in both TNFR1- and CYP2E1-deficient mice. In summary, ethanol feeding enhanced gamma-ketoaldehyde-protein adduct production via a TNFR1/CYP2E1-dependent, but cyclooxygenase-independent, mechanism in mouse liver.
Roychowdhury
Sanjoy
S
Department of Pathobiology, Cleveland Clinic, Cleveland, OH 44195, USA. roychos@ccf.org
McMullen
Megan R
MR
Pritchard
Michele T
MT
Li
Wei
W
Salomon
Robert G
RG
Nagy
Laura E
LE
D000410:Alanine Transaminase / Q000097:blood; D000447:Aldehydes / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000633:toxicity; D005260:Female; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008108:Liver Diseases, Alcoholic / Q000097:blood / Q000188:drug therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011458:Prostaglandins E / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization / Q000187:drug effects; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics; D014280:Triglycerides / Q000378:metabolism
D000447:Aldehydes; D015415:Biomarkers; D011458:Prostaglandins E; D047888:Receptors, Tumor Necrosis Factor, Type I; D014280:Triglycerides; D000431:Ethanol; C047684:levuglandin E2; D019392:Cytochrome P-450 CYP2E1; D000410:Alanine Transaminase