Figure 2.

Impaired ischemic AMPK activation in aged and icSIRT1 KO hearts. (A) Immunoblotting measured the phosphorylation level of AMPK of ischemic region in response to different time points of myocardial ischaemia in young SIRT1^flox/floxand young icSIRT1 KO hearts. Values are means ± SEM, n = 4, *P < 0.05 vs. sham, respectively; ^†P < 0.05 vs. SIRT1^flox/flox ischaemia using 2-way ANOVA with Tukey’s post-test. (B) Immunoblotting of phosphorylation level of AMPK and AMPK downstream acetyl CoA carboxylase (ACC) in SIRT1^flox/floxand icSIRT1 KO hearts under sham or 10 min of ischaemia. Values are means ± SEM, n = 3–4, *P < 0.05 vs. sham, respectively; ^†P < 0.05 vs. SIRT1^flox/flox ischaemia using 2-way ANOVA with Tukey’s post-test. (C) Immunoblotting of phosphorylation level of AMPK and AMPK downstream ACC in the ischemic region of young and aged hearts under sham or 10 min of ischaemia. Values are means ± SEM, n = 4–6, *P < 0.05 vs. sham, respectively; ^†P < 0.05 vs. young ischaemia using 2-way ANOVA with Tukey’s post-test. (D) Immunoblotting showed the phosphorylation levels of AMPK upstream kinase LKB1 in the ischemic region of young, aged, and icSIRT1 KO hearts under sham or ischaemia conditions, the immunoprecipitation of LKB1 were used for assessing acetylation and ubiquitination levels of LKB1 occurred in young, aged, and icSIRT1 KO hearts as shown by the immunoblotting with antibodies recognized acetyl-lysine and ubiquitin, respectively.