Oral Presentation Australasia Extracellular Vesicles Conference 2017

Quantitative proteomic analysis of the exercise-induced extracellular vesicle proteome reveals a marked upregulation of circulating exosomes (#18)

Martin Whitham 1 , Benjamin L Parker 2 , Bente Kiens 3 , Lena N.N Cron 1 , Navind Jayasooriah 4 , Erik A Richter 3 , David E James 2 , Jørgen F.P Wojtaszewski 3 , Mark A Febbraio 5
  1. Myokine Biology Group, Garvan Institute of Medical Research, Sydney, NSW, Australia
  2. Metabolic Systems Biology Group, University of Sydney, Sydney, New South Wales, Australia
  3. Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
  4. Epigenetics Laboratory, Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
  5. Diabetes & Metabolism, Garvan Institute of Medical Research, Sydney, NSW, Australia

Exercise capacity is a powerful predictor of mortality and physical activity is known to prevent and treat a wide range of diseases. That these benefits might be mediated by secreted proteins is an attractive hypothesis, since it raises the possibility that such products might be manipulated for therapeutic gain. However, screening for proteins in the circulation of exercising participants is frequently hampered by the immense complexity and dynamic range of the plasma proteome. Inspired by the growing appreciation that tissue-tissue cross talk might be partially mediated by proteins packaged in extracellular vesicles, we have carried out a quantitative proteomic analysis of plasma from exercising participants, focussing entirely on the extracellular vesicle fraction. Using a series of centrifugation and PBS wash steps, we isolated extracellular vesicles from the arterial plasma of 11 human participants carrying out a 1hr bout of cycling. Nanoparticle tracking analysis revealed this isolation methodology gave rise to predominantly 50-300nm sized vesicles. All samples were analysed by nano-ultra high-pressure liquid chromatography coupled to tandem MS facilitating a quantitative comparison of 1159 proteins. Analysis revealed 325 proteins to be differentially regulated by exercise with a notable upregulation of several classes of proteins that compose the canonical ~40-150nm exosome. Proteins associated with the formation of multivesicular bodies (ALIX, Clathrin), membrane trafficking (RAB GTPases, Annexins, Rho GDIs, Flotillin) and target adhesion (Integrins, tetraspanins) of exosomes were all upregulated by exercise. Pathway analysis revealed significant enrichments in several biological processes and signalling pathways. In particular, proteins involved in the rate limiting steps of glycolysis, which do not contain a signal peptide sequence were upregulated by exercise. These data provide a potential mechanism by which newly released exosomes can influence metabolism during the high energy demands of exercise and reveal an intriguing pathway by which exercise can exert multiple biological effects.