Steady-state redox status in circulating extracellular vesicles: A proof-of-principle study on the role of fitness level and short-term aerobic training in healthy young males

Considering the role of redox homeostasis in exercise-induced signaling and adaptation, this study focuses on the exercise training-related intercellular communication of redox status mediated by circulating extracellular ves-icles (EVs).19 healthy young males were divided into trained (TG, 7) and untrained (UG, 12) subjects based on their VO2MAX. The UG subjects were further randomly distributed in experimental (UGEX, N = 7) and control (UGCTRL, N = 5) groups. The steady state of plasma EVs in TG and UGEX have been characterized for total number and size, as well as cargo redox status (antioxidants, transcription factors, HSPs) before, 3 and 24 h after a single bout of aerobic exercise (30', 70% HRM). Plasma EVs from UGEX and UGCTRL have been further characterized after 24 h from the last session of a 5-day consecutive aerobic training or no training, respectively.No differences were detected in the EVs' size and distribution at baseline in TG and UGEX (p>0.05), while the EVs cargo of UGEX showed a significantly higher concentration of protein carbonyl, Catalase, SOD2, and HSF1 compared to TG (p<0.05). 5 days of consecutive aerobic training in UGEX did not determine major changes in the steady-state number and size of EVs. The post-training levels of protein carbonyl, HSF1, Catalase, and SOD2 in EVs cargo of UGEX resulted significantly lower compared with UGEX before training and UGCTRL, resembling the steady-state levels in circulating EVs of TG subjects.Altogether, these preliminary data indicate that individual aerobic capacity influences the redox status of circulating EVs, and that short-term aerobic training impacts the steady-state redox status of EVs. Taking this pilot study as a paradigm for physio-pathological stimuli impacting redox homeostasis, our results offer new insights into the utilization of circulating EVs as biomarkers of exercise efficacy and of early impairment of oxidative-stress related diseases.

Automated summary

This study investigates the role of redox homeostasis in exercise-induced signaling and adaptation, with a focus on the intercellular communication of redox status mediated by circulating extracellular vesicles (EVs). The findings suggest that aerobic capacity and short-term aerobic training can impact the redox status of circulating EVs, highlighting the potential use of EVs as biomarkers for assessing exercise efficacy and oxidative-stress related diseases.