small extracellular vehicles 

Despite its widespread effects, the (patho-)physiological mechanisms linking stress exposure to the onset of various disorders and overall health remain poorly understood. One of the most exciting and promising areas of research involves small extracellular vesicles (sEVs), including exosomes, microvesicles, and apoptotic vesicles. These sEVs, particularly exosomes, are crucial mediators of intercellular communication, playing key roles in cell-specific signaling that can reach even distant cells.

Recent studies have shown that physical exercise triggers the release of distinct sEV populations, referred to as ExerVs (Brahmer et al., 2019). We hypothesize that psychosocial stress can similarly induce the release of specific sEVs, which we term PsychEVs. Additionally, sEVs released in response to both psychosocial and physical stress would be classified as StressEVs. However, our recent findings suggest that psychosocial stress leads to a decoupled stress response, contrasting with the more consistent and regulated release observed with physical activity.

Our data reveal that psychosocial stress induces a highly heterogeneous response, with sEV levels—particularly CD81-positive vesicles—displaying inconsistent changes across individuals. No significant or clear return to baseline levels was observed, further supporting the notion that psychosocial stress may trigger a unique physiological response compared to physical stress. These findings suggest that sEVs could serve as valuable biomarkers for stress-related disorders, with the observed differential responses offering insights into the distinct physiological mechanisms underlying psychosocial versus physical stress