Effect of heat stress on contractility of tissue-engineered artificial skeletal muscle
The effects of heat stress on tissue like skeletal muscle have been widely studied. However, the mechanism responsible for the effect of heat stress is still unclear. A useful experimental tissue model is necessary because muscle function in cell culture may differ from native muscle and measuring its contractility is difficult. We previously reported three-dimensional tissue-engineered artificial skeletal muscle (TEM) that can be easily set in a measurement apparatus for quantitative evaluation of contractility. We have now applied TEM to the investigation of heat stress. We analyzed contractility immediately after thermal exposure at 39 °C for 24 or 48 h to evaluate the acute effects and after thermal exposure followed by normal culture to evaluate the aftereffects. Peak twitch contractile force and time-to-peak twitch were used as contractile parameters. Heat stress increased the TCF in the early stage (1 week) after normal culture; the TCF decreased temporarily in the middle to late stages (2–3 weeks). These results suggest that heat stress may affect both myoblast fusion and myotube differentiation in the early stage of TEM culture, but not myotube maturation in the late stage. The TCF increase rate with thermal exposure was significantly higher than that without thermal exposure. Although detailed analysis at the molecular level is necessary for further investigation, our artificial skeletal muscle may be a promising tool for heat stress investigation.
KeywordsTissue-engineered muscle Contractility Heat stress
This work was supported by JSPS KAKENHI Grant Numbers JP24500521 and JP16K01383.
- 5.Lehmann JF, de Lateur BJ. Diathermy and superficial heat, laser and cold therapy. In: Kottke FJ, Lehmann JF, editors. Krusen’s handbook of physical medicine and rehabilitation. Philadelphia: Saunders; 1990. pp. 283–435.Google Scholar
- 6.Smith W. The application of cold and heat in the treatment of athletic injuries. In: Michlovitz SL, editor. Thermal agents in rehabilitation. Philadelphia: Davis; 1990. pp. 245–56.Google Scholar