An anti-c-Fms antibody inhibits osteoclastogenesis in a mouse periodontitis model.

OBJECTIVE: Bacterial lipopolysaccharide (LPS) can induce inflammatory bone loss such as periodontal disease. The formation of osteoclasts depends on macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kb ligand (RANKL). It has recently been reported that administration of an antibody of the M-CSF receptor c-Fms completely blocked osteoclastogenesis and bone erosion induced by LPS in mouse calvaria. In this study, the effect of antibody against c-Fms in the mouse periodontitis model by injection of LPS was investigated.
MATERIALS AND METHODS: C57BL6/J mice were injected with LPS and anti-c-Fms antibody into the mesial gingiva of the first molar in the left mandible. Histological sections of periodontal tissue were stained for tartrate-resistant acid phosphatase, and osteoclast numbers and ratio of alveolar bone resorption determined.
RESULTS: The number of osteoclasts and ratio of alveolar bone resorption in mice administered both LPS and anti-c-Fms antibody was lower than those in mice administered LPS alone. The expression of RANKL receptor, RANK, was inhibited by the anti-c-Fms antibody in periodontal tissue.
CONCLUSION: M-CSF and/or its receptor are potential therapeutic targets for the treatment of bone resorption, caused by LPS, in periodontitis. Injection of an anti-c-Fms antibody might be useful for inhibition of pathological bone resorption in periodontitis.