Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Aichi, Japan.
Physiol Res. 2019 Apr 30;68(2):265-273. doi: 10.33549/physiolres.933992. Epub 2019 Jan 10.
Microcurrent electrical neuromuscular stimulation (MENS) is known as an extracellular stimulus for the regeneration of injured skeletal muscle in sports medicine. However, the effects of MENS-associated increase in muscle protein content are not fully clarified. The purpose of this study was to investigate the effects of MENS on the muscular protein content, intracellular signals, and the expression level of caveolin-3 (Cav-3), tripartite motif-containing 72 (TRIM72) and MM isoenzyme of creatine kinase (CK-MM) in skeletal muscle using cell culture system. C2C12 myotubes on the 7th day of differentiation phase were treated with MENS (intensity: 10-20 microA, frequency: 0.3 Hz, pulse width: 250 ms, stimulation time: 15-120 min). MENS-associated increase in the protein content of myotubes was observed, compared to the untreated control level. MENS upregulated the expression of Cav-3, TRIM72, and CK-MM in myotubes. A transient increase in phosphorylation level of Akt was also observed. However, MENS had no effect on the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 and 5'AMP-activated protein kinase. MENS may increase muscle protein content accompanied with a transient activation of Akt and the upregulation of Cav-3 and TRIM72.
微电流电神经肌肉刺激（MENS）在运动医学中被称为一种用于损伤骨骼肌再生的细胞外刺激。然而，MENS 相关的肌肉蛋白含量增加的影响尚未完全阐明。本研究旨在使用细胞培养系统研究 MENS 对骨骼肌中肌肉蛋白含量、细胞内信号以及 caveolin-3（Cav-3）、三结构域蛋白 72（TRIM72）和肌酸激酶 MM 同工酶（CK-MM）表达水平的影响。在分化第 7 天的 C2C12 肌管上进行 MENS（强度：10-20μA，频率：0.3 Hz，脉冲宽度：250 ms，刺激时间：15-120 min）处理。与未处理的对照组相比，观察到 MENS 相关的肌管蛋白含量增加。MENS 上调了肌管中 Cav-3、TRIM72 和 CK-MM 的表达。还观察到 Akt 的磷酸化水平短暂增加。然而，MENS 对 p42/44 细胞外信号调节激酶 1/2 和 5'AMP 激活的蛋白激酶的磷酸化水平没有影响。MENS 可能会增加肌肉蛋白含量，同时短暂激活 Akt 并上调 Cav-3 和 TRIM72。
