Extended Data Fig. 3: ME-injected PD-extracts trigger macrophage uptake and propagation of αS.

a, ELISA αS analysis in human brain soluble (cytosolic) and insoluble protein (used for injections) sequential extracts from frontal cortical samples of NHC vs PD patient samples. Samples were normalized for total protein amount before measurement (BCA). n = 12 per disease status and sample, data analysed using multiple Mann-Whitney tests with Benjamini-Krieger-Yekutiel to control for FDR. b, SAA analysis of insoluble protein extracts from NHC-αS vs PD-αS extracts. Samples with lag times <control (equal-concentration recombinant monomer) were classified as positive; those with ≥ lag times were considered negative. c, TEM images of PD brain insoluble preparations show the presence of amyloid fibrils. d, Proteinase K digest of insoluble human brain fractions shows high PK resistance of pathology associated αS in contrast to monomeric recombinant protein. Representative of 3 experiments. For gel source data, see Supplementary Fig. 1. e, Endotoxin concentration (EU/mL) in NHC vs. PD isolated αS fibrils samples used in gut injection models. For comparison recombinant monomer and PFF preparations at equal doses typically used in previous studies are shown. Kruskal-Wallis test, Dunn’s multiple comparisons test. f, Unbiased stereological quantification of TH⁺ Nissl⁺ neurons, n = 5 mice for NHC-αS (SNpc and VTA) and n = 8 mice for PD-αS (SNpc and VTA). 3 experiments, linear mixed-effect model. g-i, Reconstructed images of lysosomal s129p engulfment in ME-Macs at 1 mo post-NHC-αS vs PD-αS injection (g), quantification of engulfment (h) and duodenal ME-Mac area (i), n = 5–6 per condition. 2 experiments, unpaired t test (h) with Welch’s correction (h). j, Densitometry analysis of cytokine panel from duodenal ME lysates at 1 mo post-αS-NHC vs αS-PD injection, n = 4 per condition. 2 experiments, multiple Mann-Whitney tests with Benjamini-Krieger-Yekutiel to control for FDR. Data are mean ± s.e.m.

Source data