Effects of WY-14,643 on the phosphorylation and activation of AMP-dependent protein kinase

Background pendent protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR) α facilitate fatty acid oxidation. We have shown that treatment of hepatoma cells with ethanol or feeding ethanol-containing diets to mice inhibited both PPARα and AMPK activity. Importantly, WY-14,643 reversed the development of fatty liver in alcohol-fed mice. Whether WY-14,643, a PPARα 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. s fect 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-ζ/LKB1, intracellular AMP:ATP ratio, oxidative stress, and AMPK gene expression were studied. s ent of the H4IIEC3 cells with WY-14,643 for 24 h led to 60% increase in the phosphorylation of AMPK. The effect of WY-14,643 on AMPK phosphorylation is PKC-ζ/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 α subunit expression by 2- to 2.5-fold, but there was no change in AMPKα subunit protein at 24 h. The effect of WY-14,643 on AMPK phosphorylation did not altered by the presence of an NADPH oxidase inhibitor. sions 643 induced AMPKα subunit phosphorylation and the activity of the enzyme. This was associated with induction of AMPKα1 and α2 mRNA, but the mechanism for this activation is uncertain.