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Downregulation of let-7 by Electrical Acupuncture Increases Protein Synthesis in Mice
- Source :
- Frontiers in Physiology, Vol 12 (2021)
- Publication Year :
- 2021
- Publisher :
- Frontiers Media S.A., 2021.
-
Abstract
- BackgroundOur previous study found that acupuncture with low frequency electrical stimulation (Acu/LFES) prevents muscle atrophy by attenuation of protein degradation in mice. The current study examines the impact of Acu/LFES on protein synthesis.MethodC57/BL6 mice received Acu/LFES treatment on hindlimb for 30 min once. Acu/LFES points were selected by WHO Standard Acupuncture Nomenclature and electric stimulation applied using an SDZ-II Electronic acupuncture instrument. Muscle protein synthesis was measured by the surface-sensing of translation (SUnSET) assay. Exosomes were isolated using serial centrifugation and concentration and size of the collected exosomes were measured using a NanoSight instrument. The mature microRNA library in serum exosomes was validated using a High Sensitivity DNA chip.ResultsProtein synthesis was enhanced in the both hindlimb and forelimb muscles. Blocking exosome secretion with GW4869 decreased the Acu/LFES-induced increases in protein synthesis. MicroRNA-deep sequencing demonstrated that four members of the Let-7 miRNA family were significantly decreased in serum exosomes. Real time qPCR further verified Acu/LFES-mediated decreases of let-7c-5p in serum exosomes and skeletal muscles. In cultured C2C12 myotubes, inhibition of let-7c not only increased protein synthesis, but also enhanced protein abundance of Igf1 and Igf1 receptors. Using a luciferase reporter assay, we demonstrated that let-7 directly inhibits Igf1.ConclusionAcu/LFES on hindlimb decreases let-7-5p leading to upregulation of the Igf1 signaling and increasing protein synthesis in both hindlimb and forelimb skeletal muscles. This provides a new understanding of how the electrical acupuncture treatment can positively influence muscle health.
- Subjects :
- Acu/LFES
exosome
IGF-1 signaling
microRNA
mTOR
skeletal muscle
Physiology
QP1-981
Subjects
Details
- Language :
- English
- ISSN :
- 1664042X
- Volume :
- 12
- Database :
- Directory of Open Access Journals
- Journal :
- Frontiers in Physiology
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.631979de4a059571a9ef153434cd
- Document Type :
- article
- Full Text :
- https://doi.org/10.3389/fphys.2021.697139