Figure 5

AMPK activation regulates EC migration through transactivation of MMP-2. (A) ChIP analysis illustrating the level of ATF2 binding to the MMP-2 promoter in HUVECs transfected with control, AMPK, or AKT2 siRNA, then treated with AICAR (1 mM). Results are expressed as fold change. (B) HUVECs were transfected with control, AMPK, AKT2, or ATF2 siRNA and treated with AICAR prior to quantifying MMP-2 mRNA abundance with qRT-PCR. Immunoblot analysis and densitometry of MMP-2 and ATF2 (phosphorylated and total) in (C) HUVECs transfected with control, AMPK, or AKT2, siRNA or (D) AMPK^+/+ and AMPK^−/− MEFs treated with AICAR or left untreated. (E) HUVECs were transfected with control, AMPK, AKT2, or ATF2 siRNA and then treated with AICAR or left untreated for 8 h prior to analyzing the level of MMP-2 activity. (F) Scratch assay with confluent ECs transfected with control, AMPK, AKT2, or ATF2 siRNA followed by scratch induction then treated with AICAR or left untreated for 8 hr prior to imaging and quantifying EC migration (G). Data analyzed using Wilcoxon signed-rank test or Mann–Whitney U test. *p < 0.05, all experiments were repeated at least 3 times.