Figure 4

Hypertrophic cardiomyocytes show a reduced insulin response. A) Western blot of p-Akt (Ser⁴⁷³) and Akt (Upper) and densitometric analysis (lower) of control and hypertrophic NE-treated cardiomyocytes (NE 10 μM, 24 h) either stimulated with insulin 100 nM for 15 min or left unstimulated. Data were relativized against insulin (white bar) and expressed as mean ± SEM, N = 6, ***P < 0.001 vs. insulin. B) Glucose uptake of control and hypertrophic NE-treated cardiomyocytes (NE 10 μM for 24 h) either stimulated with insulin 100 nM for 15 min or left unstimulated. Cytochalasin B (Cyto B) was used as a negative control. Data are expressed as mean ± SEM, N = 7, **P < 0.01, ns: non significant. C) Oxygen consumption rates of control and hypertrophic cardiomyocytes (NE 10 μM for 24 h) either stimulated with insulin 100 nM for 3 h or left unstimulated. Data are expressed as mean ± SEM, N = 3, **P < 0.01 vs. control, ns: non significant. D) Mitochondrial membrane potential quantification in control cardiomyocytes or treated with NE 10 μM for 24 h and stimulated with insulin. CCCP (50 μM, 30 min) was used as a negative control. Data are expressed as mean ± SEM, N = 3, *P < 0.05 vs. control, ns: non significant. E) qPCR for Hk2, Pfkfb2, Slc2a1, Slc2a4 and Pdk4 mRNA levels of control (Ctrl) and hypertrophic cardiomyocytes (NE 10 μM for 24 h) either stimulated with insulin 100 nM for 3 h or left unstimulated. Data are expressed as mean ± SEM, N = 4, *P < 0.05, **P < 0.01 and ***P < 0.001 vs. Ctrl; ^###P < 0.001 vs. Insulin and ^&&&P < 0.001 vs. NE.