a The mRNA expression of TRAP, CTSK, DC-STAMP and OPG in joint tissue. Each plot shows data for an individual mouse (n = 3). b Soluble receptor activator of nuclear factor-κB ligand (sRANKL) production in joint tissue. Each plot shows data for an individual mouse (n = 6). c The mRNA expression of RANKL in joint tissue. Each plot shows data for an individual mouse (n = 3). d Levels of sRANKL in the serum. Each plot shows data for an individual mouse (n = 6). e Joint tissues were subjected to immunofluorescence staining for CD19 and RANKL, and the nuclei were stained with DAPI. The data are shown as the means ± SEMs; **P < 0.01 and ***P < 0.001, significantly different from the vehicle-treated group. f Representative histograms showing the MFI of RANKL on the surface of CD19+CD27+ memory B cells from RA patients following stimulation, incubation with medium alone or incubation with compounds. The dot plots show the MFI of RANKL induction under different conditions (n = 4). The data are shown as the means ± SEMs; *P < 0.05 and **P < 0.01, significantly different from cells stimulated with anti-IgM/anti-CD40 antibodies only.