Osteoblast maturation suppressed osteoclastogenesis in coculture with bonemarrow cells

The analysis of co-culture system using osteoblast and bone marrow indicate d that the mineralized osteoblast decreased osteoclast formation. This find ing was an incentive to better investigate the relation of osteoblast devel opment and osteoclastogenesis. The expression of osteoclast differentiation factor (ODF/ RANKL) mRNA and protein dramatically decreased. Alternatively , macropharge colony stimulation factor (M-CSF/CSF-1) transcription and pro tein secreted in media slightly decreased as the development of osteoblast. On the other hands, mRNA expression and the secretion to the culture mediu m of osteoclastogenesis inhibitory factor (OPG/OCIF) didn't significantly c hange depending on osteoblast differentiation. We conclude that osteoblast development might suppress osteoclastogenesis especially with the decrease of ODF/RANKL. (C) 2000 Academic Press.