A, scheme of cell culture, siRNA treatment, AICAR treatment, and CM transfer experiments. B, relative cell survival (%) of differentiated C2C12 myotubes treated with 30 nm of AMPKα1 and AMPKα2 siRNA with or without AICAR, n = 4−5. C, AMPK protein levels in differentiated C2C12 myotubes treated with 30 nm of AMPKα1 and AMPKα2 siRNA. Protein expressions were quantified, n = 3 for all groups. D, AMPK phosphorylation and expression levels with and without AICAR treatment in differentiated C2C12 myotubes treated with 30 nm of AMPKα1 and AMPKα2 siRNA. Protein expressions were quantified, n = 3−4 for all groups. E, relative cell survival (%) of differentiated brown adipocytes incubated with CM of AMPK knock‐down with AICAR‐treated, differentiated C2C12 cells determined, n = 8 for all groups. F, UCP1 protein levels in differentiated brown adipocytes incubated with CM of the AICAR‐treated AMPK knock‐down C2C12 myotubes. Protein expression levels were quantified, n = 6 for all groups. Data are represented as means ± SD. Differences between the groups were analysed using one‐way ANOVA and post hoc Tukey's multiple comparisons test. P < 0.05 was considered statistically significant. [Colour figure can be viewed at wileyonlinelibrary.com]