Fig. 1

Higher levels of exosome-enriched EVs in the brains of DS patients and of Ts2 mice as compared to age-matched diploid controls. a Representative Western-blots of EVs isolated from human brain tissue and purified on a sucrose step gradient column. The sucrose gradient fractions b, c and d showed the presence of the exosomal proteins Alix and CD63, and the EVs proteins Flotillin-1 and Flotillin-2. b Quantification of total protein levels of EVs isolated from the brain extracellular space of DS patients, normalized to brain tissue protein levels, showed higher EVs levels compared to controls. c Higher EVs levels were also found in the brain extracellular space of 12- and 24-month-old Ts2 mice compared to 2N littermates. No significant differences were found in total EVs protein levels of 3- and 8-month-old Ts2 mice compared to controls. Similar results were obtained when AChE activity levels were measured in EVs isolated from the brain extracellular space of DS patients (d) and Ts2 mice (e) as compared to 2N controls when normalized to brain tissue protein content. AChE activity levels normalized to EVs protein content were not different between brains of DS patients (f) and Ts2 mice (g) compared to 2N controls. EVs levels are presented as trisomic to 2N ratio. Student t-test, n = 5 (DS and 2N human brains), n = 4 (3- and 24-month-old), n = 5 (8-month-old), and n = 7 (12-month-old) brains of Ts2 and 2N mice (*p < 0.05; **p < 0.01; ***p < 0.001)