Fig. 1.

Exosomes attenuated IL-1β-induced inhibitions on the proliferation and migration of chondrocytes. a Immunofluorescence staining of chondrocytes and BMSC-derived exosomes (PKH26) showed that exosomes gathered inside the chondrocytes. b The proliferation of chondrocytes was evaluated by CCK-8 assay. c Chondrocyte migration was determined by the transwell migration assay. Chondrocytes (1 × 10⁶ cells, in 100 μl serum-free medium) were added to the upper chamber in a 24-well plate, in which the lower chamber contained 600 μl of complete medium. Five fields were randomly selected from each sample for quantification. All experiments were repeated independently at least three biological replicates. In the in vitro model of chondrocyte degeneration, PCR (d) and western blot (e) assays were performed to determine the mRNA and protein levels of growth factor (TGFβ1), proliferation marker (PCNA), and apoptosis marker (Casp3). Scale bar = 50 μm. *< 0.05, **< 0.01, ***< 0.001, compared with the control group. ^#< 0.05, ^##< 0.01, ^###< 0.001, compared with the IL-1β group