Figure 2

Effects of FGF21 on signaling molecules and transactivating function of PPARα. (A) mRNA levels for FGF21, PPARα and β-klotho were compared between the vehicle (ctrl) and FGF21 (10 ng/mL)-treated cardiac myocytes. Data are mean ± SD (n = 6). **p < 0.01 vs control analyzed by unpaired Student’s t-test. (B) Cultured neonatal rat ventricular cardiac myocytes were transfected with the reporter constructs contained three copies of PPRE in front of TK promoter. Following transfection, cells were treated with vehicle, 0.5 mM of βOHB, or 10 ng/mL of FGF21 for 24 h before harvest for luciferase activity assay. Luciferase activity was plotted as fold-activation relative to untreated control cells. Data are mean ± SD (n = 3–4). **p < 0.01 vs control analyzed by one-way ANOVA followed by Dunnett correction for multiple comparisons. (C) Cultured neonatal rat ventricular cardiac myocytes were transfected with the reporter constructs containing four copies of the UAS_G cloned upstream of the TK-Luc reporter (UAS_Gx4-TK-Luc) together with CMX-Gal-PPARα, CMX-Gal-PPARδ-, or CMX-Gal-PPARγ-LBD. Following transfection, cells were treated with vehicle, 0.5 mM of βOHB, or 10 ng/mL of FGF21 for 24 h before harvest for luciferase activity assay. Luciferase activity was plotted as fold-activation relative to untreated control cells. Data are mean ± SD (n = 4). **p < 0.01 vs control analyzed by one-way ANOVA followed by Dunnett correction for multiple comparisons. (D) Neonatal rat ventricular cardiac myocytes transfected with UAS_Gx4-TK-Luc and CMX-Gal-PPARα were stimulated by βOHB and/or Pemafibrate. Data are mean ± SD (n = 3–4). **p < 0.01 vs control analyzed by unpaired Student’s t-test (left panel) and one-way ANOVA followed by Dunnett correction for multiple comparisons (right panel).