Figure 3.

EVs derived from OECs can enhance axonal elongation of DRG neurons and explants. Notes: Representative images of DRG neurons stained for β-tubulin III (red) and NeuN (green), the DRG explants were stained for β-tubulin III (green) with nuclear DAPI counterstaining. Axonal elongation of DRGs after 3 days PBS (A,E), OECs-EVs (10⁷ particles/ml; B,F), OECs-EVs (10⁸ particles/ml; C,G) and OECs-EVs (10⁹ particles/ml; D,H) daily treatment. Treatment of OECs-EVs with different concentrations increased the average length of the longest neurite and the ratio of total area of neurites/total area of explant body (I,J). Effect of pre-treated OECs-EVs on axonal elongation with 3 days daily treatment (K,L). OECs-EVs were incubated with trypsin, lysed by water or treated with trypsin followed by water lysis, control represents PBS treatment; n = 4 per group; scale bars: (A–D) 100 μm; (E,F) 300 μm; (G,H) 1,000 μm. The results are expressed as the mean ± SEM. One-way analysis of variance (ANOVA) test with Tukey’s post hoc test was used to examine the significance of results. **p < 0.01 for comparison with control group, ^$p < 0.05 and ^$$p < 0.01 for comparison with OECs-EVs (10⁷ particles/ml) group, ^##p < 0.01 for comparison with intact EVs group. Abbreviations: EVs, extracellular vesicles; OECs, olfactory ensheathing cells; DRG, dorsal root ganglion; DAPI, 4′,6-diamidino-2-phenylindole.