2026 Volume 68 Issue 3 Pages 147-154
In this study, we analyzed the effects of the periodontal ligament-specific molecule PLAP-1 on osteoclast formation in vitro, using recombinant PLAP-1. First, using mouse bone marrow cells, we examined the effect of recombinant PLAP-1 on the differentiation of the cells into osteoclast precursors in the presence of M-CSF. No significant changes were observed in the differentiation into F4/80- and CD11b-positive cells or in the RANK (Tnfrsf11a) expression. On the other hand, during the osteoclast differentiation process induced by the addition of RANKL, PLAP-1 significantly suppressed the expression of osteoclast marker genes (Ctsk, Acp5, Calcr, Oscar) in a concentration-dependent manner and significantly reduced the number of TRAP-positive multinucleated cells. Similar results were obtained for RANKL-stimulated osteoclast marker gene expression in the mouse macrophage cell line RAW264.7. Thus, while recombinant PLAP-1 had no effect on M-CSF-induced differentiation into osteoclast precursor cells, it suppressed RANKL-induced osteoclast differentiation in a concentration-dependent manner, suggesting its involvement in controlling bone resorption in periodontal tissues.
