Fig. 7: Different effect of BafA1 and GW4869 on secretion of CD63, CD9, and the novel EV markers.

a Western blot showing CD9, CD63, and CD81, and the new markers LAMP1, BSG, and SLC3A2 in cell lysates (CL) and the pellets obtained from HeLa conditioned media after differential ultracentrifugation (2 K, 10 K, and 200 K). The loaded material comes from 20 × 10⁶ cells for the centrifugation pellets, and from 0.2 × 10⁶ cells for the cell lysate. One representative image. For each marker, mean ± SD of the quantification of the signal in 200 K pellets divided by the signal in the total lysate, run on the same blot, is shown for 3 independent experiments. Ordinary one-way ANOVA, Tukey’s multiple comparisons test. b Viability of HeLa cells at the end of the 16 h medium conditioning period in the presence of DMSO (control) or BafA1 (100 nM) or GW4869 (10 μM) drugs, measured by trypan blue in 6 independent experiments, mean ± SD is represented. No significant difference observed with an ordinary one-way ANOVA, Tukey’s multiple comparisons test. c Nanoparticle tracking analysis (NTA) of EVs obtained by differential ultracentrifugation from equal numbers of HeLa cells treated with DMSO (control), BafA1 or GW4869 during 16 h. The particles concentration according to their size and the fold change of the total particle concentration between treated and control conditions are represented as mean ± SD of 5 (200 K) or 3 (10 K) independent experiments. Two-tailed one sample t test to compare each condition with a theoretical mean of 0. d TEM analysis (1 representative image) and size measurement (in 3 independent experiments) of EVs in 200 K pellets of cells exposed to DMSO, BafA1 or GW4869. Mean ± SD of the frequency distribution of CD63 and CD9 in EVs of different diameters is represented. e Representative Western blot of cell lysates from 0.2 × 10⁶ HeLa cells and EVs from 20 × 10⁶ HeLa cells treated with DMSO, BafA1, or GW4869, corresponding to the samples of b–d. The mean fold change ± SD between DMSO and BafA1 or GW4869 treatment of the bands intensity in the 200 K and 10 K pellets divided by the cell lysate is represented for 6 independent experiments. Two-tailed one sample t test to compare each condition with a theoretical mean of 0.