Metformin-induced up-regulation of ECH1 is mediated by PPARα.

<p>A) Representative western blot of nuclear and cytosolic extracts from hepatocytes exposed to metformin (10 µM) and the PPARα inhibitor, GW6471 (5 µM). As shown, GW6471 reduces metformin-induced ECH1 up-regulation in the cytoplasmic fraction but do not affet either PPARα nuclear expression or AMPK phosphorylation. B) ECH1 mRNA levels in hepatocytes exposed to metformin (10 µM) and the PPARα inhibitor, GW6471 (5 µM) C) Inhibition of PPARα activity with the antagonist GW6471 reduces metformin-induced fat oxidation. D) Inhibition of PPARα activity with the antagonist GW6471 reduces metformin-induced trigyceride accumulation. *p<0.05, **p<0.01.</p>