Fig 5. S. aureus inhibits RANKL-stimulated osteoclast formation in bone marrow macrophage cultures without affecting RANKL-stimulated osteoclast formation in periosteal/endosteal cell cultures or bone resorption in parietal bones but enhances osteoclast formation in periosteal/endosteal cell cultures in the absence of RANKL.

(A) S. aureus (10⁷ CFU/ml), LPS P. gingivalis (P.g.; 10 μg/ml) and Pam2 (100 ng/ml) inhibited formation of TRAP⁺MuOCL in RANKL (RL; 4 ng/ml) stimulated bone marrow macrophages. (B) S. aureus (10⁷ CFU/ml) did not inhibit formation of TRAP⁺MuOCL in RANKL (RL; 10 ng/ml) stimulated periosteal/endosteal cell cultures. (C) S. aureus (10⁷ CFU/ml) did not affect RANKL (RL; 10 ng/ml) stimulated release of CTX from periosteal bone organ cultures. (D, E) S. aureus (10⁷ CFU/ml), in the absence of RANKL, stimulated formation of TRAP⁺MuOCL in periosteal/endosteal cell cultures. (F-H) S. aureus (10⁷ CFU/ml) stimulated the mRNA expression of Tnfsf11, Ctsk and Acp5 mRNA in periosteal/endosteal cell cultures. Data are means of 6 observations and SEM is given as vertical bars. ***P<0.001 compared to unstimulated control.