S100A12 stimulates human osteoclast differentiation in a dose-dependent manner.

Human blood CD14⁺ monocytes were cultured with M-CSF (50 ng/ml), alone or in combination with RANKL (100 ng/ml) and the indicated concentration of S100A12. Cells were fixed and stained for TRAP after 6 days of culture. (A) TRAP-positive multinucleated cells (MNCs) were counted. Values are the mean and SD of the results from 6 independent experiments. * = p < 0.05 (B) Representative images of TRAP staining (original magnification × 40).