| Project/Area Number |
05671605
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | Meikai University |
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Principal Investigator |
SHIMOJIMA Takahiro Meikai Univ., Dept., Periodontology, Lecturer, 歯学部, 講師 (60146230)
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| Co-Investigator(Kenkyū-buntansha) |
TATSUMI Junichi Meikai Univ., Dept., Periodontology, Lecturer, 歯学部, 講師 (60227105)
KURIHARA Noriyoshi Meikai Univ., Dept., Periodontology, Lecturer, 歯学部, 講師 (10186512)
IKEDA Katsumi Meikai Univ., Dept., Periodontology, Proffesor, 歯学部, 教授 (50049350)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | lipopolysaccharide / osteoblast / osteoclast formation / GM-CSF / IL-6 / リポ多糖体 / 破骨細胞 |
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| Research Abstract |
We recentily found that LPS stimulates osteoclast formation by IL-1 production on its precursor cell in long-term human cord blood cultures. This suggests that the mechanisms of osteoclast formation on LPS might removed by disaggregation from the influence of some cell typy, present in intact bone, that mediates cytokine resposiveness. We therefore tested the ability of cloned osteoblastic cell derived from human osteosalcoma (MG63) and osteoblastic cells derived from human alveolar bone restore hormone and cytokine responsiveness to unresponsive populations of osteoclast precursors. We found that conditioned medium (CM) from LPS (100ng/ml) -treated MG63 cell cultures induced a two-fold stimulation of osteoclast formation from human hemopoietic stem cells. Stimulation was observed at dilution of 33% (v/v) concentration of CM in the medium. The effects of LPS onthe regulation of IL-6, macrophage-colony stimulating factor (M-CSF), and granulocyte macrophage-colony stimulating factor (GM-CSF) gene expression were also studied in MG63 cells. GM-CSF,IL-6, and M-CSF transcripts were detectable in LPS-treated MG63 cells. However, GM-CSF gene expression did not occur in PTH or non stimulated osteoblast cultures. When CD34-positive hemopoietic cells were incubated with CM from LPS-treated osteoblasts, CFU-GM colonies which contain osteoclast early precursors were formed. This finding is proof that GM-CSF was present in the cell-free CM that stimulated osteoclast formation. Furthermore demonstrate in situ hybridization studies could be performed to have GM-CSF mRNA in LPS-treated osteoblasts from normal human bone. These experiments suggest that LPS stimulates osteoclast formation through a primary action on osteoblastic cells, which cells are induced by the LPS to produce IL-6, M-CSF,and GM-CSF which in turn stimulate osteoclast formation, resulting in osteoclastic bone resorption.
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