Fig. 4

Pharmacological inhibition of Notch1 signaling impeded the EVs-mediated effects on NP cells. A NP cells were treated with 50 μg/ml common EVs, EVs-si-VASN (isolated from si-VASN transfected MSCs) or EVs-si-scr (isolated from si-scr transfected MSCs) for 24 h. The expression levels of Notch1, Hey1 and Hey2 were measured and quantified. B Representative images of Notch1 fluorescence in NP cells and the quantification of mean fluorescence intensity. C NP cells were treated with EVs (50 μg/ml), IMR-1 (10 μm), valproic acid (VPA, 100 μm), or EVs combined with IMR-1. The expression levels of Notch1, Hey1, Hey2, ACAN, COL2A1, MMP3 and MMP13 were measured and quantified. D Representative images of Notch1 fluorescence in NP cells and the quantification of mean fluorescence intensity. E Representative images of Wound healing assay and the percentages of filled wounded area were quantified. F The NP cell viability in different group was evaluated by CCK-8 assay. Data were presented as mean ± SD of three independent replicates. P > 0.05 (ns, not significant), *P < 0.05, **P < 0.01, and ***P < 0.001