Figure 1.

Therapeutic treatment with sCD83 prevents excessive bone destruction in vivo as well as in vitro. (A) Schematic overview of the applied antigen-induced arthritis (AIA) model (A; left-hand side). Percent increase of knee swelling (normalized to baseline) after the local intra-articular injection of mBSA and sCD83 treatment (n = 9) or a vehicle control (n = 10) (A; right-hand side). (B) Histologic arthritis score (mean value of inflammation, synovitis, cartilage destruction, and bone resorption) was assessed from Safranin O-stained 5-µm joint slides derived from sCD83- or PBS- treated AIA mice on day 17 with n = 4 each, wherein 5 represents the highest score and 0 represents healthy animals. (C) Representative μ-computed tomography images of knee joints (left-hand side) and quantification of bone mass of femoral epiphysis [right-hand side with sCD83 (n = 8) and phosphate-buffered saline, PBS (n = 10)]. (D) RT-PCR analyses of synovial RNA expression levels of arthritis-related gene transcripts. Rpl4 was used as a housekeeping gene (n = 3). € Upper part: representative images used for the quantification of large multinucleated TRAP⁺ cells with more than 15 nuclei. Lower part: quantification of PBS- and sCD83-treated samples with n = 9. (F) RT-PCR analyses regarding the expression of osteoclast-related gene transcripts from a representative experiment [sCD83 (n = 5) and PBS (n = 4)]. (A) Two-way ANOVA, (D) Student’s t-test, and (B, C, E, F) Mann–Whitney test.