Dental follicle cell-conditioned medium enhances the formation of osteoclast-like multinucleated cells

An influx of mononuclear cells and the subsequent increase of osteoclasts a round tooth germs suggests that the dental follicle (DF) regulates or influ ences bone resorption required for tooth eruption. In order to study the ef fects of DF cell products on osteoclast formation during tooth eruption, a conditioned medium (CM) was created in which DF cells were added to mouse b one marrow cultures, Tartrate-resistant acid phosphatase (TRAP)-positive os teoclast-like multinucleated cells were formed in the presence of 10 nM 1,2 5-dihydroxyvitamin D-3 [1,25(OH)(2)D-3]. The CM, dose-dependently, stimulat ed the formation of TRAP-positive cells in the presence of 1,25(OH)(2)D-3 f or 14 days culture. The number of these cells decreased due to degradation in the control culture. A semi-solid methylcellulose assay in the presence of CM showed little expression of colony-stimulating activity. These result s suggest that the DF cells of a developing tooth produce factor(s) that en hance osteoclast formation and bone resorption necessary for tooth eruption .