Department of Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Department of Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
In Vivo. 2020 Jul-Aug;34(4):1779-1788. doi: 10.21873/invivo.11972.
BACKGROUND/AIM: Mechanical loading of differentiated myoblasts in vitro may mimic loading patterns of skeletal muscle in vivo. However, it is still uncharacterized the loading conditions that can produce the most effective muscle cells' biological responses, in vitro. This study investigated the effects of different loading protocols on the expression of myogenic regulatory factors, anabolic, atrophy and pro-apoptotic factors in skeletal myotubes.
C2C12 myoblasts were differentiated and underwent various stretching protocols by altering their elongation, frequency and duration, utilizing an in vitro cell tension system. The loading-induced expression changes of MyoD, Myogenin, MRF4, IGF-1 isoforms, Murf1, Atrogin, Myostatin, Foxo and Fuca were measured by Real Time-PCR.
Stretching by 2% elongation at 0.25 Hz for 12 h was overall the most effective in inducing beneficial responses.
A low strain, low frequency intermediate duration stretching can most effectively up-regulate myogenic/anabolic factors and down-regulate pro-apoptotic and atrophy genes in myotubes.
背景/目的：体外分化的成肌细胞的机械加载可以模拟体内骨骼肌的加载模式。然而，目前仍不清楚哪种加载条件可以在体外产生最有效的肌细胞生物学反应。本研究旨在探讨不同加载方案对成肌管中肌生成调节因子、合成代谢、萎缩和促凋亡因子表达的影响。
C2C12 成肌细胞分化后，利用体外细胞张力系统通过改变其伸长率、频率和持续时间，进行各种拉伸方案。通过实时 PCR 测量加载诱导的 MyoD、Myogenin、MRF4、IGF-1 同工型、Murfl、Atrogin、Myostatin、Foxo 和 Fuca 的表达变化。
2%伸长率、0.25 Hz 频率、12 小时持续时间的拉伸总体上最有效地诱导有益反应。
低应变、低频、中等持续时间的拉伸可以最有效地上调成肌/合成代谢因子，并下调成肌管中的促凋亡和萎缩基因。
