Avtor/Urednik		Pirkmajer, Sergej; Kulkarni, Sameer S.; Tom, Robby Z.; Fyffe, Fiona A.; Hawley, Simon A.; Hardie, D. Grahame; Zierath, Juleen R.; Chibalin, Alexander V.
Naslov		Methotrexate promotes glucose uptake and lipid oxidation in skeletal muscle via AMPK activation
Tip		članek
Leto izdaje		2014
ISSN		0012-1797 - Diabetes
Jezik		eng
Abstrakt		Methotrexate (MTX) is a widely used anticancer and antirheumatic drug that has been postulated to protect against metabolic risk factors associated with type 2 diabetes, although the mechanism remains unknown. MTX inhibits 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC) and thereby slows the metabolism of 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranosyl-5'-monophosphate (ZMP) and its precursor AICAR, which is a pharmacological AMPK activator. We explored whether MTX promotes AMPK activation in cultured myotubes and isolated skeletal muscle. We found MTX markedly reduced the threshold for AICAR-induced AMPK activation and potentiated glucose uptake and lipid oxidation. Gene silencing of the MTX target ATIC activated AMPK and stimulated lipid oxidation in cultured myotubes. Furthermore, MTX activated AMPK in wild-type HEK-293 cells. These effects were abolished in skeletal muscle lacking the muscle-specific, ZMP-sensitive AMPK-gamma3 subunit and in HEK-293 cells expressing a ZMP-insensitive mutant AMPK-gamma2 subunit. Collectively, our findings underscore a role for AMPK as a direct molecular link between MTX and energy metabolism in skeletal muscle. Cotherapy with AICAR and MTX could represent a novel strategy to treat metabolic disorders and overcome current limitations of AICAR monotherapy.
Proste vsebinske oznake		methotrexate glucose lipids metotreksat glukoza lipidi