Effects of hyperthermia treatment on myotube morphology during myogenic differentiation of C2C12 myoblasts.

<p>Schematics of (A) hyperthermia performed on myogenic differentiation after myoblast proliferation, and (B) myoblasts undergoing three steps, i.e. myogenic determination, early fusion, and late fusion, during myogenic differentiation. (C) Characteristic microscopy images of myoblasts in bright field (0 h) and myosin heavy chain-positive myotubes (green). The myotube images were taken at four different time periods, i.e. 24 h, 48 h, 72 h, and 120 h, and three different temperatures, i.e. 37°C, 39°C, and 41°C. Scale: 500 μm. (D-H) Myotube morphologies, including myotube width (D), myotube length (E), myotube density (F), nucleus density per myotube (G), and overall nucleus density (H), were quantitatively analyzed. The error bars in (D-H) represent the standard deviation of the mean. Myotubes differentiated over 24 h were tested as a control in (D1, E1, F1, G1 and H1), and the myotubes cultured at 37°C were used as a control in (D2, E2, F2, G2 and H2). All statistical differences against the controls are indicated. *<i>p</i> < 0.05, **<i>p</i> < 0.01, ***<i>p</i> < 0.001.