7ND protein exerts inhibitory effects on both osteoclast differentiation in vitro and lipopolysaccharide‑induced bone erosion in vivo.

Excessive numbers of osteoclasts are responsible for inflammation‑induced osteolysis. Identification of osteoclast‑targeting agents may facilitate the development of a novel therapeutic approach for the treatment of pathological bone loss. Seven‑amino acid truncated (7ND) protein, a mutant form of monocyte chemoattractant protein‑1 (MCP‑1), functions as a competitive inhibitor of MCP‑1. However, the effects of 7ND protein on osteoclast differentiation remain unknown. Therefore, in the present study, the effects of 7ND protein on osteoclast differentiation induced by tumour necrosis factor superfamily member 11 were investigated. In the present study, 7ND protein inhibited the osteoclast differentiation of peripheral blood mononuclear cells without influencing cell proliferation. Furthermore, to evaluate the effects of 7ND protein in vivo, a lipopolysaccharide (LPS)‑induced calvarial bone erosion animal model was established. The 7ND protein remarkably attenuated LPS‑induced bone resorption, as assessed by micro‑computed tomography and histological analysis. Taken together, the present results suggested the feasibility of local delivery of 7ND protein to mitigate osteoclast differentiation and LPS‑induced osteolysis, which may represent a potential approach to treat inflammatory bone destruction.