Fig 1: PTX3 promotes OA by interaction with macrophage CD32.A, B Immunofluorescent staining and quantification of CD32 for RAW264.7 and chondrocytes, n = 5 per group. Scale bar: 50 µm. C, D Immunofluorescent staining and quantification of CD32 of synovial tissues (upper) and knee cartilage (lower) from controls and 8 week-DMM-OA mice, n = 5 per group. Scale bar: 50 µm. E Relative mRNA expression levels of IL-1ß, IL-6 and TNF-a in Si-CD32- or rmPTX3-treated RAW264.7 cells, n = 9 per group. F Relative mRNA expression levels of iNOS and ARG in Si-CD32- or rmPTX3-treated RAW264.7 cells, n = 9 per group. G Immunoblotting of P-p65 and p65 of RAW264.7 cells treated with Si-CD32 or rmPTX3. H, I IF staining and quantification of F4/80 and P-p65 in RAW264.7 treated with Si-CD32 or rmPTX3, n = 6 per group. Scale bar: 25 µm. *P < 0.05, **P < 0.01, ***P < 0.001, ns not significant. Data are shown as means ± SD. Statistical analyses were conducted by unpaired t-test (B) or two-way analysis of variance followed by Sidak’s multiple comparison test (D, E, F, and I). Boxed area is enlarged in the top right corner.