SIRT1 and obesity due to melanocortin 4 receptor deficiency: Obesity downregulated the abundance of SIRT1 and PGC-1α proteins and upregulated the abundance of SIRT1-p53 acetylation and ACC proteins but had no effect on p-AMPK (Figure 4), whereas exercise training increased the abundance of SIRT1, PGC-1α, and also p-AMPK and decreased the abundance of SIRT1-p53 acetylation and ACC proteins.