Extracellular vesicle transcriptomic analysis to investigate muscle adaptation in microgravity

Extracellular vesicles (EVs) serve as critical regulators of intercellular communication by carrying diverse molecular cargos which reflect cellular states associated with environmental stressors. We investigated transcriptomic profiles of EVs derived from human skeletal muscle tissue chips flown abroad the SpaceX CRS-25 mission to characterize age- and microgravity-induced adaptation. EVs were isolated using a novel magnetic capture-release method (ExCy) from conditioned media of muscle chips cultured in microgravity or ground control conditions. Next-generation sequencing and differential gene expression analysis were performed on EV RNA. In this exploratory study, we identified age- and spaceflight-specific transcriptomic signatures. Young donor-derived EVs in microgravity appear to exhibit upregulation of oxidative stress and signaling pathways, while older donor-derived EVs showed markers of mitochondrial quality control, ER stress, and proteostasis failure. Muscle-derived EVs capture environment- and age-dependent molecular signatures in space, supporting their use as non-invasive biomarkers for physiological stress and tissue adaptation under microgravity.