Fig. 3

The effect of different neurodegeneration-related aggregates on the survival of P. acuticornis. The Kaplan-Meier curves demonstrate the survival of rotifers (n = 24 one-housed individuals per sample type; aggregation time: 3 h = 3 h and 3d = 3 days). a Dose dependency: the effect of 3 h–aggregated Aβ1–42 and BSA were tested in three different concentrations. This neurotoxic peptide as well as the non-toxic protein served as nutriments to rotifers. The survival was dose-dependent (0.1, 10, and 100 μg/mL) and was significantly higher in both type of treatments compared to the untreated control group (UC; p < 0.001; log-rank test). b Natural Aβ isoforms: we tested four natural variants of the Aβ peptide (1–42 [Gln22], 1–40, 11–42 and 1–28) on rotifers in two different aggregated forms (3 h and 3d). All types of natural Aβs had a positive effect on the survival of the treated rotifers compared to the UC (a). c Artificial Aβ isoforms: the rotifers were able to use both scrambled forms of Aβ1–42 (S1 and S2) as nutrients. As a unique exception in the series, Aβ25–35 was toxic to the rotifers, decreasing their survival as compared to the UC (a). All three types of artificial Aβs were measured in 3 h- and 3d–aggregated forms. d Non-Aβ proteins: the animals treated with alpha-synuclein (α-Syn, type E46K; in 3 h- and 3d–aggregated forms) and the cellular (PrPC) or ‘scrapie’ (PrPSc) forms of prion protein (1d = aggregated for 1 day) also showed a significantly longer lifespan compared to the UC (a). Each protein was used in 100 μg/mL concentration. The significance of log-rank (Mantel-Cox) test was p < 0.0001 in the statistical analyses in panels b-d. Median survival (ms) values in days are presented in the graphs. The statistical analysis of survival was performed by GraphPad Prism 7.0b