Fig. 4

LM11A-31 treatment reduces tau seeding activity. a–d Confocal FRET images of cultured HEK 293T RD-P301S-CFP/-YFP biosensor cells transfected with hippocampal homogenate from 9-month old vehicle- (a, c) or LM11A-31- treated (b, d) Ntg and Tg mice. e, f FRET images of biosensor cells transfected with brain lysates from 9-month old vehicle-treated Ntg (e) and Tg (f) mice in the presence (e, f) of LM11A-31 in the bioassay test medium. In Tg brain lysate transfected conditions, abundant FRET-positive aggregates are present with a notable reduction associated with lysate from LM11A-31 treated mice. Scale bar: 50 µm (inserts, 3X). g–k Quantitative analysis of FRET-positive aggregates. g Percentage of FRET-positive cells. h Number of aggregates per number of nuclei. i Volume of aggregates per volume of nuclei. j Cumulative frequency plot of aggregate volumes. k Average aggregate volume. Statistical significance was determined using Mann–Whitney (g, h), student t (i, k) and two-sample Kolmogorov–Smirnov testing (j). For each above outcome measure, n = 8 wells assessed from 3 independent studies with 2 wells per mouse and 4 mice per group. l Acute addition of LM11A-31 (100 nM) during transfection with vehicle-treated Tg lysate had no detectable effect in reducing FRET signal (student t test, n = 6 z-stacks)