Blood extracellular vesicles contribute to the exercise-mediated suppression of brain Aβ pathology in the AppNL-G-F knockin mouse model of Alzheimer's disease.

Epidemiological, clinical, and experimental evidence suggest that physical exercise suppresses the deposition of amyloid β (Aβ) plaques in the brain and reduces the risk of Alzheimer's disease (AD). However, how exercise provides such beneficial effects on AD remains largely unclear. In this study, we show that the exercise-mediated suppression of Aβ deposition requires blood extracellular vesicles (EVs) that are upregulated by exercise. We demonstrated that treadmill exercise induces a transient increase in the secretion of blood EVs in both wild-type mice and the AppNL-G-F knockin mouse model of AD. Comprehensive analysis of protein contents of the exercise-induced blood EVs demonstrated that molecular chaperones, such as heat shock proteins and cochaperones, are substantially increased, together with substantial changes in proteomic profiles after exercise. Importantly, long-term exercise led to the suppression of Aβ plaque deposition in AppNL-G-F knockin mice, but this suppressive effect was almost completely diminished by the pharmacological inhibition of EV secretion. These results indicate that the secretion of blood EVs is increased by exercise, which contributes to the suppression of Aβ pathology in the brain. Our study identifies blood EVs as a key mediator of the benefits of exercise throughout the body including the brain, highlighting the therapeutic potential of exercise-induced EVs for the treatment of AD pathology.