ABSTRACT
AIM:To investigate the effect of liraglutide ( LG) on the expression of fibronectin type Ⅲdomain-containing protein 5 (FNDC5) in the C2C12 myotubes.METHODS:The C2C12 mouse myoblast cell line was induced to differentiation.Differentiated cells were stimulated with gradient concentrations (1 ~1000 nmol/L) of LG for different time (0 ~24 h).The effects of LG on the expression of FNDC5 and the activation of adenosine 5'-monophosphate ( AMP)-activated protein kinase ( AMPK) signaling pathway were determined .After pretreated with glucagon-like peptide-1 ( GLP-1 ) receptor antagonist exendin 9-39 , the inhibitor of Ca 2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2), STO609, or the inhibitor of AMPK, Compound C, the LG-induced FNDC5 expression in C2C12 myotubes was examined.The expression of FNDC5 and the activation of AMPK were determined by Western blot .RESULTS: In C2C12 myotubes, LG promoted the expression of FNDC5 in a dose-and time-dependent manner .LG also activated AMPK signaling pathway .These effects of LG were partly abolished by exendin 9-39 , STO609 and Compound C .CONCLUSION:LG promotes the expression of FNDC5 via GLP-1 receptor in the C2C12 myotubes possibly through activation of the CAMKK2/AMPK signaling pathways .