Fig. 4
C16-exo uptake and functional assays. a MNI cells were labeled with C16 and incubated for 24 h with ctr or pH 6.0 medium. C16-exo (ctr) and (pH 6.0) were recovered and incubated at increasing doses for 2 h at 37 °C with MNI cells at pH 7.4. Cell fluorescence was analyzed by FACS. The number of incorporated exosomes per cell was calculated and represented in the graph. Points: mean ± S.D. (n = 4). b and c Confocal microscopy analysis of MNI cells after 2 h incubation with C16-exo (2 × 103 per cell) (ctr) (b) or (pH 6.0) (c). DAPI stains show the nucleus (blue). Green: C16-exo. Scale bars, 10 μm. d Migration and invasion assays of MNI cells (3.5 × 104) after incubation with (10 × 106) C16-exo, deriving from (ctr) or (pH 6.0) treated MNI cells. Migration and invasion were evaluated after 72 h of incubation by a colorimetric assay at 620 nm. * p < 0.05. e and f Cell viability was assayed by trypan blue exclusion of dead cells. MNI cells (2 × 103) were incubated with C16-exo (ctr), (pH 6.7), (pH 6.0) (5 × 106) and counted at the indicated days, or with 1 × 106, 5 × 106, 10 × 106 C16-exo (ctr), (pH 6.7), (pH 6.0) and counted after two days. Histograms: means ± S.D. (n = 3). Results indicate that in e and f the differences among ctr and pH 6.0 are not statistically significant