Denervation-related alterations and biological activity of miRNAs contained in exosomes released by skeletal muscle fibers

Scientific Reports, 2017 · DOI: 10.1038/s41598-017-13105-9 · Published: September 20, 2017

Simple Explanation

Exosomes are vesicles released by cells that can transfer proteins, mRNA, and microRNA (miR) to other cells, regulating cellular processes. This study investigated whether skeletal muscle fibers (myofibers) release exosomes. The study found that cultured myofibers release nanovesicles containing exosomal proteins and miRNAs, which are taken up by other cells. Treatment of cells with these exosomes altered protein levels, confirming their biological effects. Denervation (nerve damage) resulted in changes in the miRNA profile of exosomes released by myofibers, suggesting that these changes could influence responses to disease states.

Study Duration

Not specified

Participants

Male C57B/6 J mice

Evidence Level

Not specified

Key Findings

1
Skeletal muscle fibers release exosomes containing proteins and miRNAs.
2
Myofiber-derived exosomes can be taken up by recipient cells and exert biological effects by downregulating target proteins.
3
Denervation induces alterations in the miRNA profile of exosomes released by myofibers, specifically increasing miR-206 and reducing miRs 1, 133a, and 133b.

Research Summary

The study demonstrates that skeletal muscle fibers release exosomes, extending previous research on exosomes from myoblasts and myotubes. These exosomes contain microRNAs and can be taken up by recipient cells, influencing biological processes such as protein expression. Denervation alters the miRNA cargo of these exosomes, suggesting a role in intercellular signaling during muscle atrophy and repair.

Practical Implications

Paracrine Regulation

Myofiber-derived exosomes may regulate nearby cells through the transfer of miRNAs, affecting processes like myogenesis and osteogenesis.

Biomarker Potential

Circulating myomiRs from myofiber-derived exosomes could serve as biomarkers for muscle health and disease.

Therapeutic Targets

Understanding the mechanisms by which denervation alters exosomal miRNA profiles could lead to new therapeutic strategies for muscle atrophy and related conditions.

Study Limitations

1
The study was performed in vitro using cultured myofibers, which may not fully replicate in vivo conditions.
2
The origin of exosomes (myofiber vs. satellite cells) could not be definitively determined.
3
The precise mechanisms by which denervation alters miRNA expression profiles remain unclear.

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