Effects of Acute Aerobic Exercise Intensity on Plasma sRAGE in Lean Healthy Individuals

Skeletal muscle inflammation is implicated in the pathogenesis of many health disparities including diabetes. The Receptor for Advanced Glycation End Products (RAGE) is a major contributor to inflammation, but is negatively regulated by its soluble isoform sRAGE which is able scavenge RAGE ligands. Our preliminary data demonstrate that skeletal muscle RAGE expression is associated with inflammation and that aerobic exercise training increases plasma sRAGE concentration. However, the effects of acute exercise and exercise intensity are not known. In addition, the effect of exercise on sRAGE production in lean healthy individuals is not known leaving a gap in our knowledge of the normal biology. Finally, no study to date has examined the effects of exercise on mechanisms of sRAGE production. ADAM10 protein expression and the ratio of Tra2 and hnRNPA1 proteins are two mechanisms that are responsible for sRAGE production. The purpose of this study was to determine the effect of acute aerobic exercise intensity on plasma sRAGE and the mechanisms by which skeletal muscle may be modulating their production in lean healthy individuals. Fifteen (8M, 7F) participants (BMI: 22.4 26 kg/m2; AGE: 25.7 4 y ; VO2 47.7 7.4 mL/kg/min) were recruited for this study. Subjects performed 4 visits on separate occasions. Visits consisted of exercise at 40% of VO2Max for 60 minutes, 65% VO2Max for 30 minutes, and 80% VO2Max until calories matched the 40% bout. Plasma samples were collected before and after each exercise bout. On the final visit (80% VO2Max) muscle biopsies and blood draws were taken before, after and 3 hours after exercise. Plasma was analyzed for sRAGE concentration via a commercially available ELISA. There was no significant effect of exercise or exercise intensity on plasma sRAGE (p > 0.05). Western blot analysis of muscle homogenates revealed no significant changes in muscle ADAM10, Tra2, or hnRNPA1 following exercise at 80% of VO2Max (p > 0.05). In conclusion, there was no effect of acute aerobic exercise or exercise intensity on plasma sRAGE levels in lean healthy individuals. Furthermore, expression of proteins responsible for sRAGE production did not change following acute aerobic exercise.