Fig. 4

mTOR was the target of miR-99b-5p transferred by MSC-EVs. (A) Bioinformatics analysis was performed via the TargetScan, mirDIP and miRDB databases to predict potential interactions between mTOR and miR-99b-5p. (B) Scheme of the putative binding sites between the 3’ UTR of mTOR mRNA and miR-99b-5p. (C, D) The relative expression of miR-99b-5p and mTOR in mMCs incubated with MSC-EVs for 24 h was detected by RT‒qPCR. n = 3. ^*P < 0.05 versus PBS. (E) The relative expression of miR-99b-5p in the miR-99b-5p inhibitor-stimulated MSC-EVs was assessed via RT‒qPCR. n = 3. ^*P < 0.05 versus EVs-NC. (F, G) Western blot analysis and quantification of mTOR and p-mTOR expression in mMCs treated with EV-NC or EV-KD for 24 h. β-actin was used as a loading control. The full-length blots are presented in Supplementary Fig. 8; n = 3. ^*P < 0.05 versus PBS; ^#p < 0.05 versus EV-KD. The data are expressed as the means ± SEMs. For (C, D and E), statistical analysis was performed via a two-tailed unpaired Student’s t test. For (F), statistical analysis was performed via one-way ANOVA with Tukey’s multiple comparison test