Fig. 3.

FGF23 treatment has no effect on C₂C₁₂ proliferation. A and B: cellular proliferation of undifferentiated C₂C₁₂ myoblasts (A) and differentiated C₂C₁₂ myotubes (B) treated with FGF23 (100 ng/ml), soluble Klotho (1 µg/ml), FGF23 + Klotho, or FGF2 (100 ng/ml, positive control) for 24 and 48 h, as assessed by absorbance at 490 nm using CellTiter 96 AQueous One kit (n = 3; 3 separate experiments). C: MTT assay of undifferentiated C₂C₁₂ myoblast proliferation after treatment with FGF23 (2–50 ng/ml) or FGF2 (50 ng/ml) for 24, 48, and 72 h (n = 4; repeated twice). D: hemocytometer-based cell count of undifferentiated C₂C₁₂ myoblasts after treatment with FGF23 (2–50 ng/ml) or FGF2 (50 ng/ml) for 24, 48, and 72 h (n = 3; repeated twice). *P < 0.05, **P < 0.01, and ***P < 0.001, 1-way ANOVA with Bonferroni post hoc analysis.