Related Experiment Video
Updated: Aug 12, 2025

Enzymatic Isolation of Skeletal Muscle Interstitial Extracellular Vesicles
Published on: February 7, 2025
Skeletal muscle releases extracellular vesicles with distinct protein and microRNA signatures that function in the
Sho Watanabe1, Yuri Sudo1, Takumi Makino1
1Laboratory of Food Biochemistry, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
Abstract:
Extracellular vesicles (EVs) contain various regulatory molecules and mediate intercellular communications. Although EVs are secreted from various cell types, including skeletal muscle cells, and are present in the blood, their identity is poorly characterized in vivo, limiting the identification of their origin in the blood. Since skeletal muscle is the largest organ in the body, it could substantially contribute to circulating EVs as their source. However, due to the lack of defined markers that distinguish skeletal muscle-derived EVs (SkM-EVs) from others, whether skeletal muscle releases EVs in vivo and how much SkM-EVs account for plasma EVs remain poorly understood. In this work, we perform quantitative proteomic analyses on EVs released from C2C12 cells and human iPS cell-derived myocytes and identify potential marker proteins that mark SkM-EVs. These markers we identified apply to in vivo tracking of SkM-EVs. The results show that skeletal muscle makes only a subtle contribution to plasma EVs as their source in both control and exercise conditions in mice. On the other hand, we demonstrate that SkM-EVs are concentrated in the skeletal muscle interstitium. Furthermore, we show that interstitium EVs are highly enriched with the muscle-specific miRNAs and repress the expression of the paired box transcription factor Pax7, a master regulator for myogenesis. Taken together, our findings confirm previous studies showing that skeletal muscle cells release exosome-like EVs with specific protein and miRNA profiles in vivo and suggest that SkM-EVs mainly play a role within the muscle microenvironment where they accumulate.
Related Concept Videos
Microscopic Anatomy of Skeletal Muscles
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
Overview of Skeletal Muscle
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Overview of Exosomes
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
Satellite Stem Cells and Muscular Dystrophy
Formation of Muscle Fibers from Myoblasts
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription...

