Activation of the AMPK/Sirt1 pathway by a leucine-metformin combination increases insulin sensitivity in skeletal muscle, and stimulates glucose and lipid metabolism and increases life span in Caenorhabditis elegans

摘要

Background. We have previously shown leucine (Leu) to activate Sirt1 by lowering its KM for NAD(+), thereby amplifying the effects of other sirtuin activators and improving insulin sensitivity. Metformin (Met) converges on this pathway both indirectly (via AMPK) and by direct activation of Sirt1, and we recently found Leu to synergize with Met to improve insulin sensitivity and glycemic control while achieving similar to 80% dose-reduction in diet-induced obese mice. Accordingly, we sought here to define the mechanism of this interaction.