Fig. 1

α-Synuclein fibrils induce Lrrk2/LRRK2 in monocyte-derived macrophages. A α-Synuclein purification and short-rod fibril construction. Preparations were verified to have low or no detectable endotoxins (see Methods). Additional quality control data are presented in Supplemental Fig. 1. B Electron-microscopy photomicrographs of representative human α-synuclein monomers and sonicated α-synuclein fibrils. Scale bar is 100 nm. C Representative dynamic light-scattering characterization of matched monomer and fibril preparations. D Representative immunoblots of mouse (male nTg C57Bl/6 J) bone-marrow derived macrophages, expanded with MCSF, exposed to mouse fibrils (~ 0.7 nM, 1 μg・mL^− 1, see Methods), or mouse monomer (~ 70 nM, 1 μg・mL^− 1), with or without the LRRK2 inhibitor MLi2 (100 nM). Results from the quantification of three independent experiments for E Lrrk2 protein and F pT73-Rab10 levels (ratio of pT73-Rab10 to total Rab10 protein). G Representative immunoblots of human (two healthy males and one healthy female, age range 24 to 34 years old) monocyte-derived macrophages (MCSF expanded) with quantification from three independent experiments for H LRRK2 protein and I pT73-Rab10 levels. J Representative confocal images of pT73-Rab10, LAMP1, and pHRodo-labeled human α-synuclein fibrils (1 μg・ mL^− 1) in human macrophages, K with or without MLi2 (100 nM). Scale bars are 50 μm. L Quantification of the average number of pT73-Rab10 vesicles per cell. Each dot represents the mean vesicles per cell of images procured from three independent experiments, with ~ 75% of cells in control wells not showing any pT73-Rab10 vesicles, consistent with past observations in macrophages [9]. All data are group means ± SEM from n = 3 biologically independent experiments. Significance is determined by one-way ANOVA with Tukey’s post hoc test and ***p < 0.001