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: Suthat Liangpunsakul, Sung-Eun Wou, Kevin D Wineinger, Yan Zeng, Izabela Cyganek, Hiremagalur N Jayaram, David W Crabb
• Journal: Archives of biochemistry and biophysics (Arch Biochem Biophys) Vol. 485 Issue 1 Pg. 10-5 (May 01 2009) ISSN: 1096-0384 [Electronic] United States
• PMID: 19236843 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• PPAR alpha
• Pyrimidines
• Reactive Oxygen Species
• Adenosine Monophosphate
• pirinixic acid
• Adenosine Triphosphate
• protein kinase C zeta
• Protein Kinase C
• AMP-Activated Protein Kinases

Topics

• AMP-Activated Protein Kinases (genetics, metabolism)
• Adenosine Monophosphate (metabolism)
• Adenosine Triphosphate (metabolism)
• Cell Line
• Energy Metabolism (drug effects)
• Enzyme Activation (drug effects)
• Gene Expression Regulation, Enzymologic (drug effects)
• PPAR alpha (metabolism)
• Phosphorylation (drug effects)
• Protein Kinase C (metabolism)
• Pyrimidines (pharmacology)
• Reactive Oxygen Species (metabolism)