Figure 5.

Inhibition of HIF-1α in 1% O₂ ambient hypoxia increased FNDC5 expression, and myotube formation in C2C12 myotubes HIF-1α was increased significantly in hypoxia for 12h (A), which was rescued by YC-1 (B); meanwhile, YC-1 reversed the decrease in FNDC5 (C, n = 3). The expression of PGC-1α was not affected by both hypoxia and YC-1 (D). Hypoxia significantly reduced the area and diameter of C2C12 myotubes, and which were rescued by YC-1 treatment (E–G), while myotube fusion index was not influenced (H, n = 13). Values represented means ± SD. * p < 0.05, *** p < 0.001. Green, MyHC; blue, Hoechst. Scale bar, 50 µm.