Fig. 6: CREBRF represses glycolysis and promotes oxidative metabolism in mammalian myotubes.

a–c Crebrf mRNA levels in: mouse quadriceps muscle upon ad libitum feeding, 24 h fast or 4 h re-feeding (Ctrl vs Fasted p < 0.0001****, Fasted vs Re-fed p < 0.0001****) (a), C2C12 myotubes incubated in HBSS for 4 h (p = 0.0002***) (b) or C2C12 myotubes treated with insulin (100 nM) (p = 0.006**) (c). N = 3–6 biologically independent samples. d ATP production rate contributed by glycolysis and mitochondrial respiration in C2C12 myotubes upon adenoviral expression of Crebrf. (Glycolysis p < 0.0001****, Mitochondria p < 0.0001****). Values for glycolysis and mitochondrial respiration were calculated from N = 10 biologically independent bioanalyzer wells for each condition. e Secreted lactate measurement in media conditioned by C2C12 myotubes expressing Crebrf (p = 0.0092**). f Glucose uptake in myotubes expressing Crebrf (p = 0.027*). g Glycogen content in myotubes expressing Crebrf (p = 0.0125*). N = 3–4 biologically independent samples (e–g). Results were reproduced in two independent experiments (b–g). Data shows mean with ±SD (d) or boxplots (median and quartiles) with whiskers (minimum to maximum) (a–c, e–g). All values were normalized to the average of control samples (a–c, e–g). Statistical analysis was done using one-way ANOVA with Sidak correction test for multiple comparisons (a), or two-tailed t-test with Welch’s correction (b–g). Source data are provided as a Source Data file.