Fig. 2

 N-CDH+FLS induces chondrocyte degeneration by paracrine

(A) Assessment of EMT markers in the FLSs derived from different patients with N-CDH⁻ and N-CDH⁺ OA by Western blot (n = 3). (B) Illustration of co-culture of OA-FLS and chondrocytes. (C-D) Expression of OA chondrocyte inflammation and degradation mechanism genes (MMP1, MMP3, MMP13, and COMP) after co-culture with N-CDH⁻ or N-CDH⁺ FLSs for 0, 1, 3, and 5 days or not. (n = 3, bar = 100 μm). (E-F) After co-culture for 7 days, assessment of cell hypertrophy (E, bar = 100 μm) and collagen synthesis ability (F) of the chondrocytes. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001