title: Effects of WY-14,643 on the phosphorylation and activation of AMP-dependent protein kinase.
abstract: BACKGROUND
  AMP-dependent protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR) alpha facilitate fatty acid oxidation. We have shown that treatment of hepatoma cells with ethanol or feeding ethanol-containing diets to mice inhibited both PPARalpha and AMPK activity. Importantly, WY-14,643 reversed the development of fatty liver in alcohol-fed mice. Whether WY-14,643, a PPARalpha agonist, has any effects on AMPK is not known. The aim of this study was to investigate the effect of WY-14,643 on AMPK activity.
  
  
  METHODS
  The effect of WY-14,643 on AMPK phosphorylation and activity were examined in rat hepatoma cells (H4IIEC3). The effect of WY-14,643 on upstream kinases of AMPK, PKC-zeta/LKB1, intracellular AMP:ATP ratio, oxidative stress, and AMPK gene expression were studied.
  
  
  RESULTS
  Treatment of the H4IIEC3 cells with WY-14,643 for 24h led to 60% increase in the phosphorylation of AMPK. The effect of WY-14,643 on AMPK phosphorylation is PKC-zeta/LKB1 independent. WY-14,643 did not alter the levels of intracellular AMP:ATP ratio and it did not increase the levels of reactive oxygen species at 24-h of treatment. WY-14,643-induced AMPK alpha subunit expression by 2- to 2.5-fold, but there was no change in AMPKalpha subunit protein at 24h. The effect of WY-14,643 on AMPK phosphorylation did not altered by the presence of an NADPH oxidase inhibitor.
  
  
  CONCLUSIONS
  WY-14,643 induced AMPKalpha subunit phosphorylation and the activity of the enzyme. This was associated with induction of AMPKalpha1 and alpha2 mRNA, but the mechanism for this activation is uncertain.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine and Roudebush Veterans Administration Medical Center, 545 N. Barnhill Drive, Indianapolis, IN 46202, USA.
authors.forename: Suthat
authors.initials: S
authors.lastname: Liangpunsakul
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Wou
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Wineinger
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.forename: Izabela
authors.initials: I
authors.lastname: Cyganek
authors.forename: Hiremagalur N
authors.initials: HN
authors.lastname: Jayaram
authors.forename: David W
authors.initials: DW
authors.lastname: Crabb
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002460:Cell Line; D004734:Energy Metabolism / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D047493:PPAR alpha / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000099221:Protein Kinase C zeta
chemical_list: D055372:AMP-Activated Protein Kinases; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D047493:PPAR alpha; D011493:Protein Kinase C; D011743:Pyrimidines; D017382:Reactive Oxygen Species; D000099221:Protein Kinase C zeta; C006253:pirinixic acid