Fenofibrate, a
fibric acid derivative, is known to possess
lipid-lowering effects. Although
fenofibrate may activate
peroxisome proliferator-activated receptor (
PPAR)α and regulate the transcription of several genes, the underlying mechanisms are poorly understood. In this study, we demonstrated that incubation of C2C12 myotubes with
fenofibrate increased adipose
triglyceride lipase (ATGL) expression and suppressed
fatty acid synthase (FAS) level, thereby decreasing intracellular
triglyceride accumulation when cells were incubated at high-
glucose condition.
Fenofibrate increased the phosphorylation of
AMP-activated protein kinase (AMPK), which subsequently increased
fatty acid β-oxidation. AMPK phosphorylation was reduced by pretreatment with
GW9662 (a PPARα inhibitor), suggesting that AMPK may be a downstream effector of PPARα. Pretreatment with compound C (an AMPK inhibitor) or
GW9662 blocked
fenofibrate-induced ATGL expression and the
lipid-lowering effect. Our results suggest that AMPK is as an upstream regulator of ATGL. With further exploration, we demonstrated that
fenofibrate stimulated FoxO1 translocation from the cytosol to nuclei by immunefluorescence assay,
chromatin immuneprecipitation assay, and reporter assay. Furthermore,
oral administration of
fenofibrate ameliorated the
body weight, visceral fat and serum biochemical indexes in db/db mice. Taken together, our results suggest that the
lipid-lowering effect of
fenofibrate was achieved by activating PPARα and AMPK signaling pathway that resulted in increasing ATGL expression, lipolysis, and
fatty acid β-oxidation.