Figure 6 : EPPS disaggregates Aβ aggregates by selective binding.

From: EPPS rescues hippocampus-dependent cognitive deficits in APP/PS1 mice by disaggregation of amyloid-β oligomers and plaques

Figure 6

(ac) Preformed Aβ42 aggregates (25 μM, Day 0) were incubated with EPPS. (a) EPPS concentration-dependent (200, 20, 2, 0.2, 0.02, 0.002, 0.0002 or 0 mM of EPPS, 3-day treatment) and incubation time-dependent (20 mM EPPS for 1, 2, 3 and 7 days) ThT assays. Fluorescence intensity was normalized to preformed Aβ aggregates (100%, Day 0). Statistical comparisons were made with day 0 (n=4, Student’s t-test; from the left: P=0.034, 0.004, 0.005, 0.000, 0.000). (b) Transmission electron microscopic images of EPPS-induced Aβ fibril disassembly. Scale bars, 200 nm. The inset shows the chemical structure of EPPS. (c) Silver staining for the SDS–PAGE analysis of PICUP cross-linked Aβ aggregates and the densitometry analysis in the ratio of monomer to fibril (HMW, high molecular weight; LMW, low molecular weight). Full-length version (see Supplementary Fig. 9). (d) SEC analysis. Size markers: BSA (yellow) and thioredoxin (Trx, pink). Control: Aβ42 monomer (green). a.u., arbitrary unit. (e) Surface plasmon resonance analyses. Dose-dependent kinetics of EPPS targeting Aβ40 oligomers and the corresponding fitting curve from the saturated region of the sensorgram. (f) MTT assays. Aβ42: 2.5 μM Aβ42 aggregates, Aβ42(7d): 2.5 μM Aβ42 aggregates were incubated for 7 days with/without EPPS (2 mM). HT-22 cells were treated with the prepared samples for 24 hours. Cell viability was normalized to that of the non-treated cells (100%). All P-values were <0.0001 (n=5). The error bars represent the s.e.m. of independent triplicate measurements. One-way analysis of variance followed by Bonferroni’s post-hoc comparison tests were performed in the statistical analyses (*P<0.05, **P<0.01, ***P<0.001; other comparisons were not significant).