Fig. 6

let-7b is upregulated in LPS-pre EVs, and knockdown of let-7b inhibits LPS-pre EVs-mediated effects on protein expression in vitro. a SMSCs were transfected with siRNA-Ago2, and transfection efficiency was evaluated using real-time PCR (n = 6, Student’s t test). b Protein expression of Ago-2 analyzed by western blot (n = 3, one-way ANOVA). c Protein expression of aggrecan, COL2A1, and ADAMTS5 in chondrocytes treated with NC^KD-LPS-pre EVs or Ago2^KD-LPS-pre EVs. d Heat map of miRNA levels between EVs and LPS-pre EVs groups (n = 3, Student’s t test). e Comparisons of the five most significantly upregulated miRNAs between EVs and LPS-pre EVs. f Venn diagram showing the five most significant targets for ADAMTS5 identified by three independent miRNA target prediction programs, and the target sequence of let-7b estimated within 3′-UTR of ADAMTS5. g Inhibitor-let-7b was transfected into chondrocytes, and RT-PCR was performed to evaluate transfection efficiency (n = 6, Student’s t test). h–i Aggrecan, COL2A1, and ADAMTS5 protein expression levels within chondrocytes after let-7b knockdown (n = 3, Student’s t test). j Luciferase reporter assay showing that ADAMTS5 is the target gene for let-7b (n = 3, Student’s t test). a, g, i, j Values are presented as mean ± SD. NS, no significance; *P < 0.05, **P < 0.01, ***P < 0.001, Student’s t test and one-way ANOVA