The Change in the Concentration Levels of Extracellular Vesicles and of Cytokines in the circulatory blood system in Response to different exercise protocols

Introduction. There is little is known about the effects of different types of exercise and the release of extracellular vesicles (EVs) during exercise into the circulatory blood system. Also, there is a paucity of published data on the relationship between different modalities and types of exercise and the secretions of inflammatory cytokines into the circulatory blood system. Moreover, although it is becoming increasingly evident that a physically active lifestyle is associated with lower concentration levels of inflammatory markers, many studies have researched only leisure-time physical activity and have not investigated whether different modalities and eccentric exercise as compared to moderate intensity concentric cycling exercise may be associated with changes in inflammatory marker concentrations. Therefore, this study aims to measure the content of extracellular vesicles levels in resting healthy male individuals and then to use this information to investigate the systemic concentration levels of EVs and inflammatory cytokines in response to eccentric exercise in healthy individuals. Methods. Eleven healthy male individuals were eligible and participated in this study. In order to measure perceptual responses to exercise level and to provide a valuable and reliable indicator of exercise tolerance, Rate of Perceived Exertion (RPE) scale was used as the subjective measure in this study. The variation in the concentration levels of extracellular vesicles and also of inflammatory cytokines (IL-6, TNF-α, IL-10) were assessed during resting and in response to a single bout of eccentric and a single bout of moderate intensity cycling exercise. The study also isolated and examined the variability and content of plasma EVs concentration levels within and between subjects. EVs were prepared and isolated, and Nanoparticle Tracking Analysis (NTA) was then used to assess EV concentration levels and vesicle sizes. A mouse muscle cell line (C2C12) model was used to explore the effect of exercise on EVs concentration levels. As a measure of changes in differentiation of muscle cells the expression level of Myogenin in EV-treated C2C12 cells by plasma samples was determined by qPCR. The experimental conditions and cell model for the differentiation of C2C12 was standardised and the expression of muscle differentiation gene markers was analysed by quantitative real time Reverse Transcription-Polymerase Chain Reaction. The effect of plasma EVs on C2C12 myoblast differentiation was also explored. Results. This study suggests that exercise triggers a release into the circulatory blood system of vesicles with the characteristic size of EVs. It was found that there is a significant difference between the average EV concentration levels during the first three hours of rest and after eccentric exercise p<0.05, and that there was a reduction in the average EV concentration levels after two hours following eccentric exercise p<0.05. There was a trend for a reduction in myogenin in all treated plasma samples at the time point t=27 h, but the difference was not significant p> 0.05. Contrary to our hypothesis our results suggest plasma EVs had no statistically significant effect on C2C12 myogenesis. Conclusion. It is hypothesised that that the reduced EV after exercise may be because EVs are taken in by muscles and become involved in the recovery process from the damage caused by eccentric exercise. However, the mechanism of the secretion and uptake remains to be clarified. The consistent reduction in myogenin in all the samples may point to potential clinical significance. In order to more fully understand the role of EVs in muscle cell differentiation, further studies need to be conducted.

Grantor dc:publisher

Oxford Brookes University

Year dc:date

2021

Author dc:creator

• Abu-Seer, Ayman A

Statement dc:rights

• All rights reserved

Language dc:language

en

DOI dc:identifier

https://doi.org/10.24384/2188-wz36

OAI identifier oai:identifier

tle:e36d7c3c-6e43-41da-8984-4069cdcf35c4:d6bd9758-527a-46cd-bfe2-c433766e8fca:1