Fig. 4.

SRT1720-induced mitochondrial biogenesis requires AMPK.

(A) Real-time PCR measurements of the mRNA levels of PGC-1α, MCAD and ERRα in WT, AMPKα1/α2 KO and Sirt1 KO mefs after treatment with SRT1720 for the indicated times. The mRNA levels at time 0 were arbitrarily set to one in all cases. All values are given as mean ± s.e.m. *p < 0.05; **p < 0.01; ***p < 0.001. (B) Citrate synthase activity was measured in WT, AMPKα1/α2 KO and Sirt1 KO mefs after treatment with SRT1720 for the indicated times. All values are given as mean ± s.e.m. **p < 0.01. (C) Skeletal muscle was isolated from WT and AMPKα2 KO mice treated with either vehicle or SRT1720 for 17 weeks. The mRNA levels (in arbitrary units) of genes important for mitochondrial biogenesis were measured by using real-time PCR (n = 5–6). All values are given as mean ± s.e.m. **p < 0.01; ***p < 0.001. (D) Relative mtDNA levels in skeletal muscle of WT and AMPKα2 knockout mice treated with either vehicle or SRT1720 (n = 5–7 per genotype). #p = 0.067. All values are given as mean ± s.e.m. (E) Citrate synthase activity was measured in skeletal muscle of WT and AMPKα2 knockout mice treated with either vehicle or SRT1720 (n = 5–7 per genotype). All values are given as mean ± s.e.m. *p < 0.05.