Fig. 3: Expression and role of USP32 in inflammatory chondrocytes in vitro.

A Western blot analysis of USP32 expression in MCCs treated with 10 ng/ml IL-1β or a negative control of PBS and quantitative analysis (N = 3) is shown in (B). C Quantification of RNA expression of USP32, MMP13, ADAMTs, COL2A1, and BAX (N = 3) in siNC and siUSP32-transfected groups under inflammatory and non-inflammatory conditions. D Protein expression of USP32, Col2a1, Mmp13, Bax, and Cleaved caspase 3 following transfection of siNC and siUSP32 in each group and quantitative analysis shown in (E) (N = 3). F TUNEL staining of each group, with TUNEL (green) and DAPI (blue) staining, and quantitative analysis shown in (G) (N = 6). Scale bar 40 μm. H Flow cytometric assessment of apoptosis using Annexin V/PI staining in respective groups. I Changes in ROS levels in each group and their quantitative analysis in (J), along with flow cytometry results (N = 6) (K). Scale bar 40 μm. L JC-1 mitochondrial membrane potential staining in respective groups. Scale bar 20 μm. M Quantitative analysis of the JC-1 monomer-to-aggregate fluorescence intensity ratio in each group (N = 6). N flow cytometry analysis of JC-1 staining. O Quantification of ATP synthesis in different groups. P Quantitative lactate assay in each treatment group. Statistical significance is indicated by *P < 0.05, **P < 0.01, ***P < 0.001.