Formation of gamma-ketoaldehyde-protein adducts during ethanol-induced liver injury in mice

Free Radic Biol Med. 2009 Dec 1;47(11):1526-38. doi: 10.1016/j.freeradbiomed.2009.07.015. Epub 2009 Jul 17.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alanine Transaminase / blood
  • Aldehydes / metabolism*
  • Animals
  • Biomarkers / metabolism
  • Chemical and Drug Induced Liver Injury / blood
  • Chemical and Drug Induced Liver Injury / drug therapy*
  • Chemical and Drug Induced Liver Injury / physiopathology
  • Cytochrome P-450 CYP2E1 / genetics
  • Cytochrome P-450 CYP2E1 / metabolism
  • Ethanol / toxicity
  • Female
  • Liver / drug effects
  • Liver / metabolism*
  • Liver Diseases, Alcoholic / blood
  • Liver Diseases, Alcoholic / drug therapy*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Prostaglandins E / metabolism
  • Protein Binding
  • Protein Multimerization / drug effects
  • Receptors, Tumor Necrosis Factor, Type I / genetics
  • Triglycerides / metabolism

Substances

  • Aldehydes
  • Biomarkers
  • Prostaglandins E
  • Receptors, Tumor Necrosis Factor, Type I
  • Triglycerides
  • Ethanol
  • levuglandin E2
  • Cytochrome P-450 CYP2E1
  • Alanine Transaminase