Figure 5. Fra-1 in myeloid cells exacerbates the development of K/BxN SIA inflammation in joints.

BM from Fra-1^ΔMx or control mice was transferred to previously irradiated Fra-1^ΔMx or WT mice (WT→WT, WT→Fra-1^ΔMx, Fra-1^ΔMx→WT, and Fra-1^ΔMx→Fra-1^ΔMx). Six weeks after BM reconstitution, K/BxN arthritis was induced in recipient mice. (A) Fra-1 expression in arthritic paws. (B) Arthritis score as well as quantification of the AUC. (C) Quantification and representative images of paw volume ascertained by MRI analysis of healthy control paws and arthritic paws from WT→WT and Fra-1^ΔMx→WT mice. (D) Quantification of the inflammatory area, erosion area, and number of osteoclast and representative images ascertained from H&E (top) and TRAP (bottom) staining of arthritic paws. The arrows indicate cell infiltrated areas in H&E staining and osteoclasts in TRAP staining, respectively. Scale bars: 500 μm. (E) Representative μCT imaging analysis of arthritic ankles from WT→WT and Fra-1^ΔMx→WT. The arrows indicate osteophyte formation. Graph points indicate individual mice. Data are also shown as mean values, and error bars represent SEM. *P < 0.05; ***P < 0.001, Student’s t test (A, C, D) or ANOVA (B).