Men and Women Display Distinct Extracellular Vesicle Biomarker Signatures in Response to Military Operational Stress
Conkright, William R., Meaghan E. Beckner, Amrita Sahu, Qi Mi, Zachary J. Clemens, Mita Lovalekar, Shawn D. Flanagan, et al. 2022. “Men and Women Display Distinct Extracellular Vesicle Biomarker Signatures in Response to Military Operational Stress.” Journal of Applied Physiology, March. https://doi.org/10.1152/japplphysiol.00664.2021.
BACKGROUND: Extracellular vesicles (EVs) are mediators of physiological changes that occur during physical exertion. This study examined the effects physical exertion with and without sleep and caloric restriction on EV size, concentration, and surface proteins in men and women. METHODS: Twenty participants (10 men) completed a 5-d simulated military operational stress protocol with daily physical exertion. Blood was drawn before and immediately after exertion at baseline (D1) and following 48-hr of sleep and caloric restriction (D3). EV size and concentration were assessed using nanoparticle tracking analysis. EVs were identified with markers associated with exosomes (CD63), microvesicles (VAMP3), apoptotic bodies (THSD1), and skeletal muscle-derived EVs (SGCA) and quantified using imaging flow cytometry. Interactive and main effects of sex, day, and time on EVs were assessed using three-way ANOVAs. RESULTS: EV concentration declined pre- to post-exertion in women on D1 and D3 but was stable in men. EV size increased from pre- to post-exertion and from D1 to D3 in men and women. Physical exertion following sleep and caloric restriction increased CD63+ EV concentration, proportion of total EVs, and CD63 surface protein expression regardless of sex. The proportion of SGCA+ EVs increased in men and women following exertion and from D1 to D3 but were higher in women than men. No differences were observed in VAMP3+ and THSD1+ EVs. CONCLUSION: This study identified sexually dimorphic EV profiles in response to various stressors. Further investigations are necessary to determine if dimorphic EV responses affect health and performance outcomes during stress.View full article