1999 Fiscal Year Final Research Report Summary
APOPTOSIS OF OSTEOCLASTS AND INFLAMMATORY BONE
| Project/Area Number |
10557203
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Periodontal dentistry
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| Research Institution | NATIONAL INSTITUTE OF INFECTIOUS DISEASES |
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Principal Investigator |
OKAHASHI Nobuo NATIONAL INSTITUTE OF INFECTIOUS DISEASES, DEPARTMENT OF ORAL SCIENCE, SENIOR RESEARCHER, 口腔科学部, 主任研究官 (40150180)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBASAKI Kenichiro LION Co., Ltd., ORAL CARE RESEARCH INSTITUTE, SENIOR RESEARCHER, オーラルケア研究所, 主任研究員
NISHIHARA Tatsuji NATIONAL INSTITUTE OF INFECTIOUS DISEASES, DEPARTMENT OF ORAL SCIENCE, CHIEF, 口腔科学部, 室長 (80192251)
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| Project Period (FY) |
1998 – 1999
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| Keywords | OSTEOCLAST / APOPTOSIS / PERIODONTITIS / LIPOPOLYSACCHARIDE / リポ多糖 / サイトカイン |
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| Research Abstract |
Periodontitis often results in tooth loss due to inflammatory bone resorption. Bone resorption is mediated by osteoclasts. Although the differentiation pathway of osteoclasts is not well known at present, various inflammatory mediators are known to trigger the production of osteoclasts. We have found that lipopolysaccharides (LPS) of various periodontophatic bacteria mediate osteoclast formation and stimulate bone resorption in vitro. In this project, we investigate the mechanism of osteoclast differentiation mediated by LPS from a periodontophatic bacteria Actinobacillus actinomycetemcomitans.
In mouse bone marrow cultures, LPS of A. actinomycetemocomitans induced osteoclast formation. Indomethacin and anti-IL-1 antibodies significantly inhibited the osteoclast formation, suggesting that prostaglandin E2 (PGE2) and IL-1 were involved in LPS-mediated osteoclast formation. We also found that LPS from A. actinomycetemcomitans induced expression of osteoclast differentiation factor (ODF) on cells of osteoblastic lineage. These results indicated that LPS of A. actinomycetemcomitans mediated osteoclast formation through upregulation of PGE2, IL-1 and ODF in periodontal tissues. Furthermore, we found that taurine, a sulfer containing amino acid, inhibited the osteoclast formation mediated by LPS from A. actinomycetemcomitans. Taurine was also found to inhibit the experimental bone resorption in ligature-mediated periodontitis in hamsters.
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