| Project/Area Number |
12557180
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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 |
矯正・小児・社会系歯学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
MITANI Hideo Tohoku University, Graduate School of Dentistry, Professor, 大学院・歯学研究科, 教授 (50014220)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Mikako Tohoku University, Dental Hospital, Research associate, 歯学部・附属病院, 助手 (60241642)
TAKAHASHI Ichiro Tohoku University, Graduate School of Dentistry, Research associate, 大学院・歯学研究科, 助手 (70241643)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥13,200,000 (Direct Cost: ¥13,200,000)
Fiscal Year 2001: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 2000: ¥8,900,000 (Direct Cost: ¥8,900,000)
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| Keywords | chondrocytes / mechanica lstress / cell adhesion / integrin / extracellular matrix / type II collagen / focal adhesion kinase / fibronectin / Focal Adehesion kinase / 細胞-基質間接着 / 細胞内情報伝達 |
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| Research Abstract |
Biomechanical forces are major epigenetic factors that determine the form and differentiation of skeletal tissues, and may be transduced by cell adhesion to the extracellular matrix (ECM). To test the hypothesis that stepwise tension forces are transduced into molecular signals during early chondrogenesis, we developed a culture system studying the proliferation and differentiation of chondrocytes. Rat embryonic day-12 limb buds were microdissected and dissociated into cells which were then micro-mass cultured on a silicone membrane and maintained for up to 6 days. Stepwise tension was applied to these cultures from day 3. The time course of the expression pattern and level of cartilage-specific markers and non-chondrogenic markers were analyzed and compared with those in non-stretched control cultures. Under tension conditions, Alcian blue staining showed an apparent decrease in the rate and extent of chondrogenesis, and confocal laser scanning microscopy demonstrated apparent stretching of the cells. Quantitatively, type II collagen and aggrecan expression were significantly inhibited by 20 to 30% and 10 to 20%, respectively, after 12 hrs of tension force loading, and this difference was maintained through 3 days of culture. In contrast, the expression of type I collagen and fibronectin remained relatively constant throughout the experimental period. This down-regulation in the expression of chondrogenic markers was completely rescued when cell-ECM attachment was inhibited by GRGDSPK (Gly-Arg-Gly-Asp-Ser-Pro-Lys) peptide. We conclude that stepwise tension inhibits chondrogenesis through integrins in embryonic limb bud mesenchyme, and propose that signal transduction from biomechanical stimuli may be mediated by cell-ECM adhesion.
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