Fig. 3

Comparing Tau seed uptake and degradation across distinct hiPSC-neuron subtypes. a Sonicated paired helical filaments (sPHFs, 2 N4R P301L) labeled with Tau uptake probe (A594, not depicted in schematic) or Tau degradation probe (QA594, example shown in schematic) produce a fluorescent signal following hiPSC-neuron uptake (A594 rPHFs) or intracellular degradation (QA594 rPHFs). Adapted from “Cellular Uptake of MIL-89 Nanoparticles into Endocytic Vesicles”, by BioRender.com (2024). b Quantification of Tau uptake normalized to nuclei count over a 12-h timecourse (left) and at the final timepoint (right) in DIV16 hiPSC-neurons treated with 50 nM A594 sPHFs (Tau uptake probe). Data represents the mean + SD (3 technical replicate wells, 12 fields per well). * = p-value < 0.05, ** = p-value < 0.01, **** = p-value < 0.0001 according to one-way ANOVA with Tukey’s test. c Representative live cell images of Tau uptake in DIV16 hiPSC-neurons 12 h post-treatment with 50 nM A594 sPHFs (tau uptake probe). 594 fluorescence represents sPHF uptake, nuclei stained with Hoechst dye. Scale bar = 50 µm. d Ratio of Tau degradation to Tau uptake in DIV16 hiPSC-neurons 12 h post-treatment with 50 nM QA594 sPHFs (Tau degradation probe). Data represents the mean + SD (3 technical replicate wells, 12 fields per well). ** = p-value < 0.01, *** = p-value < 0.001 according to one-way ANOVA with Tukey’s test. e Quantification of Tau degradation normalized to Tau degradation in BafA1 pretreated DIV16 hiPSC-neurons 12 h post-treatment with 50 nM QA594 sPHFs (tau degradation probe). Data represents the mean + SD (3 technical replicate wells, 12 fields per well). * = p-value < 0.05, ** = p-value < 0.01, *** = p-value < 0.001 according to one-way ANOVA with Tukey’s test. f Quantification of MC1-positive spot area normalized to HT7 area in DIV44 hiPSC-neurons seeded with 0.5 nM SI-AD alone or in combination with StemFect. Data represents the mean + SD (3 technical replicate wells, 20 fields per well). g Ratio of transfected Tau aggregation to untransfected Tau aggregation in DIV44 hiPSC-neurons seeded with 0.5 nM SI-AD alone (untransfected) or in combination with StemFect (transfected). Data represents the mean + SD (3 technical replicate wells, 20 fields per well). Dotted line indicates a 1:1 ratio. * = p-value < 0.05 according to one-way ANOVA with Tukey’s test