Fig. 2: Quantification of Lef-NP and nanoparticle - induced vacuolisation in primary microglial cells.

a Time-course of cellular vacuolisation in Lef-NP-treated cells. Box-Whisker Plots represent the frequency of cells revealing a vacuolated phenotype (i.e. foam, gitter and balloon cells) as described in Fig. 1. Individual experimental data are highlighted by coloured circles. ++ p < 0.005 for the differences between the time points as indicated (Friedman test); ** p < 0.005 compared to 0 h (Bonferroni post-hoc test). N ≥ 3 independent experiments. Insert: comparison between initial treatment for 5 h and 45 h (i.e. the „plateau-phase”); bars represent the mean±2 SEM. * p < 0.05 compared to 5 h (two-tailed independent samples t-test). b Effect of solvent control (Control), ceramide (Cer), Percoll-nanoparticles (NP) and ceramide-coated Percoll (Cer-NP) on vacuolisation. Bars represent the mean±2 SEM of the percentage of vacuolated cells seen after 45 hours (plateau phase) of incubation. p < 0.005 for the observed differences (ANOVA). ** p < 0.005 compared to the control or as indicated (Tukey post-hoc test). The number of independent experiments is given in parentheses. Addition of MBCD had no effect on the vacuolization. c Comparison between the different vacuolated phenotypes in cells treated with NP or Cer-NP. Bars represent the mean±2 SEM of the percentage of vacuolated cells seen after 45 hours (plateau phase) of incubation. * p < 0.05; ** p < 0.005 compared to the corresponding NP group (two-tailed independent samples t-test); + p < 0.05; ++ p < 0.005 compared as indicated (paired samples t-test). The number of independent experiments is given in parentheses.