Fig. 6.

SKP-SC-EVs promoted neuronal viability and attenuated neuronal apoptosis via miR-21-5p negatively regulating PTEN-PI3K pathway. a Expression of miR-19b, miR-21-5p, miR-29b-3p, miR-223, and miR-340-5p, showing increased miR-21-5p in sensory neurons treated with SKP-SC-EVs after OGD. b, c Histograms showing the cell viability and the percentage of TUNEL positive neurons in different groups (see also Additional file 4: Figure S2). d Representative image of Western blot analysis for PTEN and GAP43 expression in different groups. e, f Histograms showing increasing expression level of PTEN and decreased expression level of GAP43 after treatment of OGD, while miR-21-5p overexpression reversed their expression, whereas GAP43 expression was abolished by LY294002. g Representative image of Western blot analysis for Bax and Bcl-2 in different groups. h, i Histograms showing decreased Bax expression level and increased Bcl-2 expression level after overexpression miR-21-5p in OGD-injured sensory neurons, while the expression level of Bax and Bcl-2 was reversed by adding LY294002. j Representative image of Western blot analysis for p-Akt, p-mTOR, and p-p70S6K expression in different groups. k Histograms showing increased expression level of p-Akt, p-mTOR, and p-p70S6K in the OGD + miR-21-5p mimics group, and decreased expression level when LY294002 was added. n = 3; *p < 0.05, **p < 0.01, ***p < 0.001 compared with the control group; ^#p < 0.05, ^###p < 0.001 compared with the OGD group; ^§p < 0.05, ^§§p < 0.01, ^§§§p < 0.001 compared with the OGD + miR-21-5p mimics group