Hepatic overexpression of SIRT1 is sufficient to enhance phosphorylation
of AMPK and ACC over the basal levels in HepG2 cells and in mouse liver in
vivo. A, immunoblots with SIRT1 antibody confirm
overexpression of recombinant SIRT1 protein (∼120 kDa) in HepG2 cells
infected with adenovirus-mediated vector encoding wild type SIRT1 (Ad-SIRT1).
B and C, overexpression of SIRT1 is sufficient to increase
the baseline phosphorylation of AMPK and ACC in HepG2 cells. D, in
vivo expression of adenovirus-mediated vector encoding FLAG-tagged wild
type SIRT1 (Ad-FLAG-SIRT1) is visualized by Western blots with anti-FLAG
antibody in the livers from different C57BL/6 mice that were sacrificed 7 days
postinjection as indicated. Ad-GFP-infected mice were used as a control.
E and F, phosphorylation of AMPK and ACC is increased in the
livers of mice injected with Ad-FLAG-SIRT1 in vivo. Representative
immunoblots of phosphorylation of AMPK and ACC in the livers from two mice
each group as indicated and densitometric analysis are shown. *, p
< 0.05 versus Ad-GFP-infected HepG2 cells or Ad-GFP-injected mice
(mean ± S.E., n = 3).