FIG. 5.

In C2C12 myotubes, atrogin-1 knockdown prevents berberine (BBR)-induced atrophy. A: At 36 h after atrogin-1 siRNA transfection, C2C12 myotubes were treated for 16 h with DMSO, berberine (3 μm), or dexamethasone (DEX) (1 μm DEX, a positive control) before atrogin-1 mRNA was measured by Northern blotting. B: At 36 h after atrogin-1 siRNA transfection, C2C12 myotubes were treated overnight with 3 μmol/l berberine or without (CTL). The diameters of 300 myotubes were measured and averaged (n = 3 independent experiments). C: C2C12 myotubes were treated as in B and then used to measure protein synthesis (see research design and methods). Measurements were made in duplicate in n = 3 independent experiments. D: C2C12 myotubes were treated as in B and then used to measure protein degradation (see research design and methods and the legend to Fig. 4E). Measurements were made in duplicate in n = 3 independent experiments.