Fig. 1
Assessment of periodontal tissue and evaluation of joint swelling in Pg-administered SKG mice. To determine the effect of Pg infection in periodontal tissue, Pg W83 (108 CFU/50 mL/mouse in 2% CMC/PBS solution) was administered into the oral cavity of SKG mice (6–8 weeks old, female) twice a week for 42 days. SKG mice also received LA i.p. injection. All mice were sacrificed, and serum, gingival tissue, and leg joint tissues were collected. Increased IL-6 in gingival tissue of each group was found (a). Data represent mean ± SD of 6 mice per group. Ctrl, PBS inoculation; LA, PBS inoculation + LA i.p. injection (10 μg/mouse); Pg, Pg inoculation; Pg/LA, Pg inoculation + LA i.p. injection. H&E staining of joint tissue sections (b Ctrl, c LA, d Pg, e Pg+LA). Histological scores of inflammation, and cartilage damage from each group of mice (n = 6 per group) (f, g). Data represent the mean ± SEM. Original magnification; scale bar 500 μm. The titer of serum ACPA in mice was measured by ELISA (h). The amount of IL-6 in each group was determined by ELISA (i serum, j joint tissue). Data represent mean ± SD (b–d and i–k) of 6 mice per group. Statistical analyses were performed using the Tukey-Kramer test and Bonferroni corrected Mann-Whitney U test for multiple comparisons (*P < 0.05, ** P < 0.01)