Fig. 2: Internalization of astrocyte-derived EV-miRNA-382-5p promotes apoptosis in primary neurons.

a, b Relative expression levels of miRNA-382-5p and premiR-382 in neurons, microglia and astrocytes at 24 h after scratch injury (n = 6 per group; Student’s t test). c Relative miRNA-382-5p expression levels among NDEVs, MDEVs, and ADEVs at 24 h after scratch injury (n = 6 per group; Student’s t test). d Representative images of immunofluorescence staining of mouse brain sections obtained 2 weeks after the stereotactic injection of AAV-SMPD3-shRNA containing a GFAP-specific promoter. Scale bars, 50 µm. e qRT‒PCR analysis of the level of EV-derived miRNA-382-5p in the perilesional cortex and hippocampus of TBI mice with or without astrocyte-specific knockdown of SMPD3 (n = 6 per group; one-way ANOVA). f qRT‒PCR analysis of the level of miRNA-382-5p in neurons isolated from TBI mice with or without astrocyte-specific knockdown of SMPD3 (n = 6 per group; one-way ANOVA). g Translocation of the extracellular vesicle Cy3-miR-382-5p from astrocytes to primary neurons. Confocal imaging of primary neurons. h–k ADEVs promoted apoptosis (h, i), decreased cell viability (j), and increased lactate dehydrogenase (LDH) (k) release from scratched primary neurons (n = 6 per group; one-way ANOVA). l Triton X-100/RNase treatment prevented the transfer of miRNA-382-5p from astrocytes into primary neurons (n = 6 per group; one-way ANOVA). The data are presented as the means ± SDs; *p < 0.05, **p < 0.01, ***p < 0.001, and NS not significant.