Non-Invasive Ultrasound Treatment Enhances the Release of Skeletal Muscle-Derived Extracellular Vesicles in Mice

Skeletal muscle, the largest secretory organ, regulates distant organs through the secretion of various factors. Among these are extracellular vesicles (EVs), which play a significant role in mediating communication between muscle and other tissues and hold therapeutic potential due to their target specificity and anti-inflammatory properties. Enhancing the release of EVs from skeletal muscle into the circulation is crucial for eliciting their diverse effects, including anti-inflammatory actions; however, effective strategies to increase the levels of muscle-derived EVs in the bloodstream have not yet been developed. While exercise is the most studied method to increase blood EV levels, its efficacy in enhancing skeletal muscle-derived EVs remains unclear. This study reveals that a brief, 5-min ultrasound (US) treatment of skeletal muscle robustly elevates circulating levels of muscle-derived EVs, introducing a novel, non-invasive stategy to modulate EV release. US-induced EVs showed altered miRNA profiles enriched with anti-inflammatory miRNAs that target pathways involved in inflammatory responses. Additionally, transient upregulation of reactive oxygen species and activation of the endoplasmic reticulum stress pathway were observed in US-treated muscle, suggesting a mechanism for enhanced EV release. Our findings establish US as the first non-invasive and rapid method to selectively enhance skeletal muscle-derived EV release into the circulation, highlighting its potential for therapeutic applications through its anti-inflammatory effect.