Extracellular vesicles as predictors of individual response to exercise training in youth living with obesity

Abstract

Exercise is associated with various health benefits, including the prevention and management of obesity and cardiometabolic risk factors. However, a strong heterogeneity in the adaptive response to exercise training exists. The objective of this study was to evaluate if changes in extracellular vesicles (EVs) after acute aerobic exercise (AE) were associated with the responder phenotype following 6-weeks of resistance exercise training. This is a secondary analysis of plasma samples from the EXIT trial (clinical trial #02204670). Eleven sedentary youth with obesity (15.7±0.5 years, BMI ≥ 95th percentile) underwent an acute bout of AE (60% heart rate reserve, 45 min). Blood was collected before exercise [at time (AT) 0 min], during [AT15, 30, 45 min], and 75 min after exercise [AT120]. Afterward, youth participated in 6-week resistance training program, and were categorized into responders (RE) or non-responders (NRE) based on changes in insulin sensitivity as measured by the Matsuda Index. EVs were isolated using size exclusion chromatography (Izon®). The primary outcome variable was EV biophysical profile, which includes size, zeta potential, protein yield and expression of markers associated with EV subtypes. The variables were analyzed in a single-blind fashion. Overall, there was a general increase in EV production in both groups. Average EV size was larger in RE (~147 nm) vs. NRE (~124 nm; p<0.05). Average EV size at AT0 was associated with absolute change in Matsuda index following 6-weeks of resistance training (r=0.44, p=0.08). EV size distribution revealed RE preferentially expressed EVs between 150 – 250 nm in size, whereas NRE expressed EVs between 50 – 100 nm (p<0.05). At baseline, RE-EVs contained ~25% lower Tsg101 protein, ~85% higher MMP2 content, while CD63 levels remained unchanged between the groups. Total protein yield in RE-EVs was higher than NRE at AT15 (p<0.05). Our data suggest that youth with obesity that respond to exercise training produce larger EVs, with lower exosome- and higher microvesicle-specific protein expression. RE-EVs also had higher EV protein yield during AE. The relationship between larger EV subtypes and/or cargo, and the individual response to exercise has yet to be fully elucidated.

Skeletal muscle-derived extracellular vesicles are altered with chronic contractile activity

“…Previous work on the effect of acute/chronic exercise on skeletal muscle-derived EVs mostly focused on EV preparations made from whole blood (plasma or serum) [23]–[28], [30], [35], [41]–[43]. Whole blood comprise a heterogenous mixture of vesicles derived from platelets, erythrocytes, endothelial cells, leukocytes, and with a comparatively little proportion from skeletal muscle [21], [24], [25].…”

“…Previous work on the effect of acute/chronic exercise on skeletal muscle-derived EVs mostly focused on EV preparations made from whole blood (plasma or serum) [23]- [28], [30], [35], [41]- [43].…”

“…Our results showed no difference in EV protein yield between CS-EVs vs. CON-EVs, and to the best of our knowledge, no other study has measured the effect of chronic contractile activity on total EV protein yield. The studies that have reported an increase in EV protein concentration in humans [35] and rats [27] after exercise utilized acute exercise models. To ascertain the subtype of EVs isolated, we measured the expression of proteins including exosomal markers (CD81, CD63, Tsg101, HSP70, Alix and Flotillin-1), m/l EV markers (Cyt C and β-actin), and a non-EV marker (Apo-A1) according to MISEV guidelines [4].…”

“…EV protein extraction, concentration and yield EV preparations were lysed using 1:1 Pierce RIPA solution with protease inhibitor tablet (Roche) and EV concentration was determined using Pierce™ MicroBCA protein assay kit (ThermoFisher Scientific) following the manufacturer's instructions. Briefly, the working reagent was prepared by mixing 25 parts of Reagent A, 24 parts of Reagent B and 1 part of Reagent C as detailed before [35]. Standards were prepared by serial dilution of 2 mg/ml bovine serum albumin (BSA) ampule into clean vials using ultrapure water.…”

Chronic contractile activity induced skeletal muscle-derived extracellular vesicles increase mitochondrial biogenesis in recipient myocytes via transmembrane or peripheral membrane proteins

“…EV preparations were lysed using 1:1 Pierce RIPA solution with protease inhibitor tablet (Roche) and EV concentration was determined using Pierce™ MicroBCA protein assay kit (Thermo Fisher Scientific) following the manufacturer's instructions. Briefly, the working reagent was prepared by mixing 25 parts of Reagent A, 24 parts of Reagent B and 1 part of Reagent C as detailed before [33]. Standards were prepared by serial dilution of 2 mg/mL bovine serum albumin (BSA) ampule into clean vials using ultrapure water.…”