|Budget Amount *help
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
The analysis of osteoclasts differentiation in calvariae of op/op mouse. Recently, precursor cells of osteoclasts, which are induced from bone marrow stem cells by macrophage-colony stimulating factor (M-CSF), have been shown to differentiate into multinuclear osteoclasts at the bone tissue by the action of osteoprotegerin ligand (OPGL). However, precise biochemical reactions included in the differentiation process have to be elucidated. In the osteopetrotic, op/op mouse, the mutation of M-CSF gene prevents formation of macrophage and osteoclasts and, consequently, bone resorption. We have found that there are two sub-groups in the brain macrophages, microglia ; M-CSF dependent and M-CSF independent. The former is Mac-1, while the latter is ER-MP12 positive and can be detected in the op/op mouse. Since immature bone marrow cells share ER-MP antigen, it was conceivable that ER-MP12 positive precursor cells differentiate into osteoclasts at calvariae. TRAP-positive cells could not be found in the mixed glial culture prepared from op/op mouse. However, TRAP-negative calvariae of new born op/op mouse became TRAP-positive after culture for 13 days, suggesting the existence of the alternative pathway of osteoclast differentiation.