Fig. 3
RT-QuIC analysis of OM samples collected from patients with PD and neurodegenerative parkinsonisms. a Kinetics of rec-αS aggregation after the addition of OM samples. Two μL of OM collected from PD (n = 18), MSA (n = 11), CBD (n = 6) and PSP (n = 12) was added to rec-αS substrate and analyzed by means of RT-QuIC. 10/18 samples of PD, 9/11 samples of MSA, 1/6 sample of CBD and 2/12 samples of PSP induced the aggregation of the substrate. Average ThT fluorescence intensity was plotted against time. b Biochemical analyses of RT-QuIC products of OM samples collected from PD and MSA patients that induced rec-αS aggregation (representative image). Ten μL of final RT-QuIC products were digested with PK and analyzed by means of Western blot. Green arrows indicate peculiar bands of RT-QuIC products seeded with PD samples. One band migrating at around 6–8 kDa is found in these samples. Orange arrows indicate peculiar band of RT-QuIC products seeded with MSA samples. Two bands are detected at around 6–8 kDa and a third band is detected at around 22 kDa. Blots were immunostained with the AS08 358 antibody. One asterisk (*) indicates the presence of aggregated species of α-synuclein, while two asterisks (**) indicate partially digested protein. Numbers in the right indicate the position of molecular weights. Dashed lines indicate cropped images from separate gels. c Biochemical analyses of RT-QuIC products of OM samples collected from PD, MSA, CBD and PSP patients that did not induce rec-αS aggregation. Ten μL of final RT-QuIC products were digested with PK and analyzed by means of Western blot and revealed the lack of PK-resistant bands. Blots were immunostained with the AS08 358 antibody. Numbers in the right indicate the position of molecular weights. d Densitometric analysis of RT-QuIC products seeded with PD (n = 4) or MSA (n = 4) samples. Three replicates per sample were subjected to PK treatment (100 μg/mL, 37 °C, 60 min) and immunostained with the AS08 358 antibody before quantification. This analysis confirmed that differences in PK resistance between PD and MSA samples were statistically significant (p = 0.0061)