Identification of 5′ AMP-activated Kinase as a Target of Reactive Aldehydes during Chronic Ingestion of High Concentrations of Ethanol*
| Autor: | David J. Orlicky, Rebecca L. Smathers-McCullough, Colin T. Shearn, Dennis R. Petersen, Donald S. Backos |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Male
Protein Carbonylation Biotin hydrazide AMP-Activated Protein Kinases Cysteine Proteinase Inhibitors medicine.disease_cause Biochemistry Mice AMP-activated protein kinase medicine Animals Humans Phosphorylation Protein kinase A Molecular Biology Liver Diseases Alcoholic Aldehydes biology Ethanol Chemistry Acetyl-CoA carboxylase AMPK Central Nervous System Depressants Cell Biology Hep G2 Cells Lipids digestive system diseases Fatty Liver Mice Inbred C57BL Disease Models Animal Oxidative Stress Models Chemical biology.protein Lipid Peroxidation Oxidative stress Signal Transduction |
| Popis: | The production of reactive aldehydes including 4-hydroxy-2-nonenal (4-HNE) is a key component of the pathogenesis in a spectrum of chronic inflammatory hepatic diseases including alcoholic liver disease (ALD). One consequence of ALD is increased oxidative stress and altered β-oxidation in hepatocytes. A major regulator of β-oxidation is 5' AMP protein kinase (AMPK). In an in vitro cellular model, we identified AMPK as a direct target of 4-HNE adduction resulting in inhibition of both H2O2 and 5-aminoimidazole-4-carboxyamide ribonucleoside (AICAR)-induced downstream signaling. By employing biotin hydrazide capture, it was confirmed that 4-HNE treatment of cells resulted in carbonylation of AMPKα/β, which was not observed in untreated cells. Using a murine model of alcoholic liver disease, treatment with high concentrations of ethanol resulted in an increase in phosphorylated as well as carbonylated AMPKα. Despite increased AMPK phosphorylation, there was no significant change in phosphorylation of acetyl CoA carboxylase. Mass spectrometry identified Michael addition adducts of 4-HNE on Cys(130), Cys(174), Cys(227), and Cys(304) on recombinant AMPKα and Cys(225) on recombinant AMPKβ. Molecular modeling analysis of identified 4-HNE adducts on AMPKα suggest that inhibition of AMPK occurs by steric hindrance of the active site pocket and by inhibition of hydrogen peroxide induced oxidation. The observed inhibition of AMPK by 4-HNE provides a novel mechanism for altered β-oxidation in ALD, and these data demonstrate for the first time that AMPK is subject to regulation by reactive aldehydes in vivo. |
| Databáze: | OpenAIRE |
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