2003 Fiscal Year Final Research Report Summary
Molecular mechanisms of bone formation and absorption in the ankle joint of adjuvant arthritic rats
| Project/Area Number |
14571737
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Morphological basic dentistry
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| Research Institution | Kyushu University |
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Principal Investigator |
IIJIMA Tadahiko Kyushu University, Faculty of Dental Science, Professor, 大学院・歯学研究院, 教授 (50090874)
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| Co-Investigator(Kenkyū-buntansha) |
NAGATA Kengo Kyushu University, Faculty of Dental Science, Associate Professor, 大学院・歯学研究院, 助手 (90189134)
KUKITA Toshio Kyushu University, Faculty of Dental Science, Associate Professor, 大学院・歯学研究院, 助教授 (70150464)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Adiuvant arthritis / Th1 / Th2 balance / MIP-1α / cytokine / osteophyte formation / osteoclasts / sensory nerve / bone absorption |
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| Research Abstract |
Adjuvant arthritis (AA), an experimental model of rheumatoid arthritis, Is characterized by the infiltration of mononuclear cells in synovial tissues, pannus formation, articular cartilage erosion, bone absorption, and periosteal bone formation of ankle joints. The molecular mechanism of bone absorption and formation in the Inflamed tissues of AA rats was of particular interest in this investigation. The following findings were published or will soon be published.
1) The sensory nerves may be related to a remission of the synovial inflammation and that the sensory nerves and the macrophages can be involves in osteophyte formation. It seems highly probable that a sensory innervation will influence the inflammatory processes and these, in turn, will affect the formation of osteophytes, though a possible direct effect of sensory nerves on the osteoblasts can not be excluded In the ankle joints of AA rats (Wu et al., 2002).
2) CGRP being released from newly sprouted sensory nerve fibers after adjuvant injection may be involved in a remission of the synovial inflammation via regulation of Th1/Th2 balance. This appears to be supported by recent studies which have demonstrated the characteristic increase of Th1 cytokine expression in the early stage and that of Th2 in later stages of AA. Our observation strongly suggested the presence of the anti-inflammatory action of sensory nerves In rats with AA (Wu et al., 2004).
3) MIP-1α may be involved in the migration of osteoclast progenitors to the distal tibia as well as in osteoclastogenesis in AA rats. Migrated osteoclast progenitors are thought to be efficiently differentiate into osteoclasts in response to RANKL expressed by the aggregates of oseoclast-like cells under the influence of the MIP-1α. Such positive-feedback regulation of osteoclastogenesis could result in the highest recruitment of active osteoclasts In the area of marked bone destruction (Toh et al., In press).
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Research Products
(8 results)
