Phosphofructokinase 2 (PFK‐2) is rapidly degraded in the absence of insulin signaling. A, Primary adult mouse cardiomyocytes from control C57B6/J mice were cultured overnight with standard conditions (C), lacking insulin, high glucose (HG; 450 mg/dL), or a high‐fat (HF) diet (100 μmol/L oleate/100 μmol/L palmitate conjugated to 0.02% BSA, HG). Cells were then analyzed by Western blot analysis for PFK‐2 (A) or phosphorylated protein kinase B (pAKT)/AKT (B). C, Primary adult mouse cardiomyocytes from control C57B6/J mice were cultured overnight with 10 mg/L insulin or 200 μg/L insulin‐like growth factor 1 (IGF‐1), as indicated. D, Primary adult mouse cardiomyocytes from control C57B6/J mice were cultured with insulin and treated with either 50 μg/mL cycloheximide (black) or cycloheximide with 500 nmol/L wortmannin (red). The dotted line represents a theoretical degradation curve for the listed half‐life. Densitometry from Western blots of cardiac homogenates was standardized to actin (A and C), Akt (B), or cardiac PFK‐2 (D). Data are presented as mean±SEM. *P<0.05, **P<0.01, and ****
P≤0.0001 by ANOVA with the Dunnett post hoc test (A [n=5], B [n=5], and C [n=3]) or an unpaired Student t test (D [n=4]).