Leucine Modulates Mitochondrial Biogenesis and SIRT1-AMPK Signaling in C2C12 Myotubes

Figure 2

Leucine improves mitochondrial biogenesis in C2C12 myotubes in a SIRT1-dependent manner. (a) Mitochondrial content was measured using NAO (10 μM) dye after 48-hour leucine (dark bars), leucine plus SIRT1 inhibitor (EX527 25 μM; grey bars) for 48 hours in C2C12 myotubes. (b, c) SIRT1 activity and mitochondrial biogenesis- related genes (PGC-1α, Sirt3, and COX5b) mRNA levels were measured after the same treatments. The relative SIRT1 activity was normalized to cellular protein level, and mRNA level was normalized to housekeeper gene 18S. (b) Dark bars are DMSO control, grey bars are EX527. (c) Dark bars are PGC-1α, grey bars are Sirt3; striped bars are COX5b. (d) Palmitate oxidation level was detected after the same treatment, and the results were normalized to cellular protein for each sample. Data are mean ± SE (). Different letters indicate significant differences within a given variable. Dark bars are DMSO control and grey bars are EX527. Significantly different from controls, and significantly different from control and EX527 groups with .

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