Preliminary Report: Osteoarthritis and Rheumatoid Arthritis Synovial Fluid Increased Osteoclastogenesis In Vitro by Monocyte Differentiation Pathway Regulating Cytokines

Figure 4

Osteoclast numbers in cultures with RA and OA synovial fluid. Panel (a) shows the mean osteoclast count in cultures with synovial fluid from RA () and OA () patients with healthy control serums as control. Both RA and OA synovial fluids increased the number of osteoclasts when compared to healthy serum. Surprisingly, OA synovial fluid increased the number of osteoclasts significantly more than RA synovial fluid. A difference in osteoclast phenotype was seen between cultures with RA (b) and OA (c) synovial fluids. 10x magnification confocal microscope images. The cells cultured with OA synovial fluid, which contained less inflammatory cytokines, were larger and contained more nuclei () than the osteoclasts cultures with RA synovial fluid that contained higher concentrations of inflammatory cytokines. The osteoclasts cultured with healthy control serum (d) were even smaller and with fewer nuclei than in either culture with synovial fluid. Red color indicates TRAcP and blue Hoechst stain marks the nuclei. Changes in cell morphology are described in detail in Table 3.

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