Although electrical muscle stimulation (EMS) of skeletal muscle effectively prevents muscle atrophy, its effect on the breakdown of muscle component proteins is unknown. In this study, we investigated the biological mechanisms by which EMS-induced muscle contraction inhibits disuse muscle atrophy progression. Experimental animals were divided into a control group and three experimental groups: immobilized (Im; immobilization treatment), low-frequency (LF; immobilization treatment and low-frequency muscle contraction exercise), and high-frequency (HF; immobilization treatment and high-frequency muscle contraction exercise). Following the experimental period, bilateral soleus muscles were collected and analyzed. Atrogin-1 and Muscle RING finger 1 (MuRF-1) mRNA expression levels were significantly higher for the experimental groups than for the control group but were significantly lower for the HF group than for the Im group. Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) mRNA and protein expression levels in the HF group were significantly higher than those in the Im group, with no significant differences compared to the Con group. Both the Forkhead box O (FoxO)/phosphorylated FoxO and protein kinase B (AKT)/phosphorylated AKT ratios were significantly lower for the Im group than for the control group and significantly higher for the HF group than for the Im group. These results, the suppression of atrogin-1 and MuRF-1 expression for the HF group may be due to decreased nuclear expression of FoxO by AKT phosphorylation and suppression of FoxO transcriptional activity by PGC-1alpha. Furthermore, the number of muscle contractions might be important for effective EMS.

Institute of Biomedical Sciences Nagasaki University Nagasaki Japan

See more in PubMed

Rudrappa SS, Wilkinson DJ, Greenhaff PL, Smith K, Idris I, Atherton PJ. Human Skeletal Muscle Disuse Atrophy: Effects on Muscle Protein Synthesis, Breakdown, and Insulin Resistance-A Qualitative Review. Front Physiol. 2016;7:361. doi: 10.3389/fphys.2016.00361. PubMed DOI PMC

Graham ZA, Lavin KM, O’Bryan SM, Thalacker-Mercer AE, Buford TW, Ford KM, Broderick TJ, et al. Mechanisms of exercise as a preventative measure to muscle wasting. Am J Physiol Cell Physiol. 2021;321:C40–C57. doi: 10.1152/ajpcell.00056.2021. PubMed DOI PMC

Mukund K, Subramaniam S. Skeletal muscle: A review of molecular structure and function, in health and disease. Wiley Interdiscip Rev Syst Biol Med. 2020;12:e1462. doi: 10.1002/wsbm.1462. PubMed DOI PMC

Thomason DB, Booth FW. Atrophy of the soleus muscle by hindlimb unweighting. J Appl Physiol (1985) 1990;68:1–12. doi: 10.1152/jappl.1990.68.1.1. PubMed DOI

Phillips SM, McGlory C. CrossTalk proposal: The dominant mechanism causing disuse muscle atrophy is decreased protein synthesis. J Physiol. 2014;592:5341–5343. doi: 10.1113/jphysiol.2014.273615. PubMed DOI PMC

Atherton PJ, Greenhaff PL, Phillips SM, Bodine SC, Adams CM, Lang CH. Control of skeletal muscle atrophy in response to disuse: clinical/preclinical contentions and fallacies of evidence. Am J Physiol Endocrinol Metab. 2016;311:E594–E604. doi: 10.1152/ajpendo.00257.2016. PubMed DOI PMC

Sanchez AM, Candau RB, Bernardi H. FoxO transcription factors: their roles in the maintenance of skeletal muscle homeostasis. Cell Mol Life Sci. 2014;71:1657–1671. doi: 10.1007/s00018-013-1513-z. PubMed DOI PMC

Chen K, Gao P, Li Z, Dai A, Yang M, Chen S, Su J, et al. Forkhead Box O Signaling Pathway in Skeletal Muscle Atrophy. Am J Pathol. 2022;192:1648–1657. doi: 10.1016/j.ajpath.2022.09.003. PubMed DOI

Vainshtein A, Sandri M. Signaling Pathways That Control Muscle Mass. Int J Mol Sci. 2020;21:4759. doi: 10.3390/ijms21134759. PubMed DOI PMC

Bonaldo P, Sandri M. Cellular and molecular mechanisms of muscle atrophy. Dis Model Mech. 2013;6:25–39. doi: 10.1242/dmm.010389. PubMed DOI PMC

Yoshida T, Delafontaine P. Mechanisms of IGF-1-Mediated Regulation of Skeletal Muscle Hypertrophy and Atrophy. Cells. 2020;9:1970. doi: 10.3390/cells9091970. PubMed DOI PMC

Stitt TN, Drujan D, Clarke BA, Panaro F, Timofeyva Y, Kline WO, Gonzalez M, et al. The IGF-1/PI3K/Akt pathway prevents expression of muscle atrophy-induced ubiquitin ligases by inhibiting FOXO transcription factors. Mol Cell. 2004;14:395–403. doi: 10.1016/S1097-2765(04)00211-4. PubMed DOI

Baar K, Wende AR, Jones TE, Marison M, Nolte LA, Chen M, Kelly DP, et al. Adaptations of skeletal muscle to exercise: rapid increase in the transcriptional coactivator PGC-1. FASEB J. 2002;16:1879–1886. doi: 10.1096/fj.02-0367com. PubMed DOI

Russell AP, Feilchenfeldt J, Schreiber S, Praz M, Crettenand A, Gobelet C, Meier CA, et al. Endurance training in humans leads to fiber type-specific increases in levels of peroxisome proliferator-activated receptor-gamma coactivator-1 and peroxisome proliferator-activated receptor-alpha in skeletal muscle. Diabetes. 2003;52:2874–2881. doi: 10.2337/diabetes.52.12.2874. PubMed DOI

Brault JJ, Jespersen JG, Goldberg AL. Peroxisome proliferator-activated receptor gamma coactivator 1alpha or 1beta overexpression inhibits muscle protein degradation, induction of ubiquitin ligases, and disuse atrophy. J Biol Chem. 2010;285:19460–19471. doi: 10.1074/jbc.M110.113092. PubMed DOI PMC

Allen DL, Bandstra ER, Harrison BC, Thorng S, Stodieck LS, Kostenuik PJ, Morony S, et al. Effects of spaceflight on murine skeletal muscle gene expression. J Appl Physiol (1985) 2009;106:582–595. doi: 10.1152/japplphysiol.90780.2008. PubMed DOI PMC

Cannavino J, Brocca L, Sandri M, Bottinelli R, Pellegrino MA. PGC1-α over-expression prevents metabolic alterations and soleus muscle atrophy in hindlimb unloaded mice. J Physiol. 2014;592:4575–4589. doi: 10.1113/jphysiol.2014.275545. PubMed DOI PMC

Kang C, Ji LL. PGC-1α overexpression via local transfection attenuates mitophagy pathway in muscle disuse atrophy. Free Radic Biol Med. 2016;93:32–40. doi: 10.1016/j.freeradbiomed.2015.12.032. PubMed DOI

Sandri M, Lin J, Handschin C, Yang W, Arany ZP, Lecker SH, Goldberg AL, et al. PGC-1alpha protects skeletal muscle from atrophy by suppressing FoxO3 action and atrophy-specific gene transcription. Proc Natl Acad Sci U S A. 2006;103:16260–16265. doi: 10.1073/pnas.0607795103. PubMed DOI PMC

Qin W, Pan J, Wu Y, Bauman W, Cardozo C. Protection against dexamethasone-induced muscle atrophy is related to modulation by testosterone of FOXO1 and PGC-1a. Biochem Biophys Res Commun. 2010;403:473–478. doi: 10.1016/j.bbrc.2010.11.061. PubMed DOI

Booth FW, Gollnick PD. Effects of disuse on the structure and function of skeletal muscle. Med Sci Sports Exerc. 1983;15:415–420. doi: 10.1249/00005768-198315050-00013. PubMed DOI

Mirzoev TM. Skeletal Muscle Recovery from Disuse Atrophy: Protein Turnover Signaling and Strategies for Accelerating Muscle Regrowth. Int J Mol Sci. 2020;21:7940. doi: 10.3390/ijms21217940. PubMed DOI PMC

Jones S, Man WD, Gao W, Higginson IJ, Wilcock A, Maddocks M. Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease. Cochrane Database Syst Rev. 2016;10:CD009419. doi: 10.1002/14651858.CD009419.pub3. PubMed DOI PMC

Maffiuletti NA, Green DA, Vaz MA, Dirks ML. Neuromuscular Electrical Stimulation as a Potential Countermeasure for Skeletal Muscle Atrophy and Weakness During Human Spaceflight. Front Physiol. 2019;10:1031. doi: 10.3389/fphys.2019.01031. PubMed DOI PMC

Nader GA, Esser KA. Intracellular signaling specificity in skeletal muscle in response to different modes of exercise. J Appl Physiol (1985) 2001;90:1936–1942. doi: 10.1152/jappl.2001.90.5.1936. PubMed DOI

Dow DE, Faulkner JA, Dennis RG. Distribution of rest periods between electrically generated contractions in denervated muscles of rats. Artif Organs. 2005;29:432–435. doi: 10.1111/j.1525-1594.2005.29086.x. PubMed DOI

Doucet BM, Lam A, Griffin L. Neuromuscular electrical stimulation for skeletal muscle function. Yale J Biol Med. 2012;85:201–215. doi: 10.1016/j.jelekin.2011.12.005. PubMed DOI PMC

Sillen MJ, Franssen FM, Gosker HR, Wouters EF, Spruit MA. Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review. PLoS One. 2013;8:e69391. doi: 10.1371/journal.pone.0069391. PubMed DOI PMC

de Freitas GR, Santo CCDE, de Machado-Pereira NAMM, Bobinski F, Dos Santos ARS, Ilha J. Early Cyclical Neuromuscular Electrical Stimulation Improves Strength and Trophism by Akt Pathway Signaling in Partially Paralyzed Biceps Muscle After Spinal Cord Injury in Rats. Phys Ther. 2018;98:172–181. doi: 10.1093/ptj/pzx116. PubMed DOI

Russo TL, Peviani SM, Durigan JL, Gigo-Benato D, Delfino GB, Salvini TF. Stretching and electrical stimulation reduce the accumulation of MyoD, myostatin and atrogin-1 in denervated rat skeletal muscle. J Muscle Res Cell Motil. 2010;31:45–57. doi: 10.1007/s10974-010-9203-z. PubMed DOI

Dupont E, Cieniewski-Bernard C, Bastide B, Stevens L. Electrostimulation during hindlimb unloading modulates PI3K-AKT downstream targets without preventing soleus atrophy and restores slow phenotype through ERK. Am J Physiol Regul Integr Comp Physiol. 2011;300:R408–R417. doi: 10.1152/ajpregu.00793.2009. PubMed DOI

Dirks ML, Wall BT, Snijders T, Ottenbros CL, Verdijk LB, van Loon LJ. Neuromuscular electrical stimulation prevents muscle disuse atrophy during leg immobilization in humans. Acta Physiol (Oxf) 2014;210:628–641. doi: 10.1111/apha.12200. PubMed DOI

Oga S, Goto K, Sakamoto J, Honda Y, Sasaki R, Ishikawa K, Kataoka H, et al. Mechanisms underlying immobilization-induced muscle pain in rats. Muscle Nerve. 2020;61:662–670. doi: 10.1002/mus.26840. PubMed DOI

Honda Y, Tanaka N, Kajiwara Y, Kondo Y, Kataoka H, Sakamoto J, Akimoto R, et al. Effect of belt electrode-skeletal muscle electrical stimulation on immobilization-induced muscle fibrosis. PLoS One. 2021;16:e0244120. doi: 10.1371/journal.pone.0244120. PubMed DOI PMC

Hintz CS, Coyle EF, Kaiser KK, Chi MM, Lowry OH. Comparison of muscle fiber typing by quantitative enzyme assays and by myosin ATPase staining. J Histochem Cytochem. 1984;32:655–660. doi: 10.1177/32.6.6202737. PubMed DOI

Ohira Y, Yoshinaga T, Nomura T, Kawano F, Ishihara A, Nonaka I, Roy RR, et al. Gravitational unloading effects on muscle fiber size, phenotype and myonuclear number. Adv Space Res. 2002;30:777–781. doi: 10.1016/S0273-1177(02)00395-2. PubMed DOI

Zhong H, Roy RR, Siengthai B, Edgerton VR. Effects of inactivity on fiber size and myonuclear number in rat soleus muscle. J Appl Physiol (1985) 2005;99:1494–1499. doi: 10.1152/japplphysiol.00394.2005. PubMed DOI

Wang J, Wang F, Zhang P, Liu H, He J, Zhang C, Fan M, et al. PGC-1α over-expression suppresses the skeletal muscle atrophy and myofiber-type composition during hindlimb unloading. Biosci Biotechnol Biochem. 2017;81:500–513. doi: 10.1080/09168451.2016.1254531. PubMed DOI

Canon F, Goubel F, Guezennec CY. Effects of chronic low frequency stimulation on contractile and elastic properties of hindlimb suspended rat soleus muscle. Eur J Appl Physiol Occup Physiol. 1998;77:118–124. doi: 10.1007/s004210050309. PubMed DOI

Boonyarom O, Kozuka N, Matsuyama K, Murakami S. Effect of electrical stimulation to prevent muscle atrophy on morphologic and histologic properties of hindlimb suspended rat hindlimb muscles. Am J Phys Med Rehabil. 2009;88:719–726. doi: 10.1097/PHM.0b013e31818e02d6. PubMed DOI

Dow DE, Cederna PS, Hassett CA, Kostrominova TY, Faulkner JA, Dennis RG. Number of contractions to maintain mass and force of a denervated rat muscle. Muscle Nerve. 2004;30:77–86. doi: 10.1002/mus.20054. PubMed DOI

Valero-Breton M, Warnier G, Castro-Sepulveda M, Deldicque L, Zbinden-Foncea H. Acute and Chronic Effects of High Frequency Electric Pulse Stimulation on the Akt/mTOR Pathway in Human Primary Myotubes. Front Bioeng Biotechnol. 2020;8:565679. doi: 10.3389/fbioe.2020.565679. PubMed DOI PMC