2005 Fiscal Year Final Research Report Summary
THE SIGNIFICANCE OF GENE EXPRESSION IN EXTRINSIC FIBROBLASTS IN THE REMODELING OF THE TENDON MATRIX
| Project/Area Number |
16591468
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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 |
Orthopaedic surgery
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TOHYAMA Harukazu Hokkaido Univ., School of Medicine, Associate Prof., 大学院・医学研究科, 助教授 (60301884)
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| Co-Investigator(Kenkyū-buntansha) |
YASUDA Kazunori Hokkaido Univ., School of Medicine, Prof., 大学院・医学研究科, 教授 (20166507)
SHIMIZU Hiroshi Hokkaido Univ., School of Medicine, Prof., 大学院・医学研究科, 教授 (00146672)
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| Project Period (FY) |
2004 – 2005
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| Keywords | tendon / ligament / matrix / remodeling / fibroblast / collagen |
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| Research Abstract |
1.PURPOSE
To clarify the role of collagen production and cytokine expression in extrinsic fibroblasts in the remodeling of the tendon matrix after fibroblast necrosis.
2.METHODS
Using the rat model, we examined type-III collagen expression in the patellar tendon after the in situ freeze-thaw treatment by RT-PCR and immunohistology. We also examined local expression of IL-1beta,PDGF-BB, and TGF-betal in fibroblasts infiltrating the rat frozen-thawed patellar tendon using immunohistological observation and compared the responses to IL-1beta,PDGF-BB, and TGF-beta1 between the extrinsic fibroblasts infiltrating the rat frozen-thawed patellar tendon which simulates an idealized patellar tendon graft and the normal tendon fibroblasts concerning gene expression of matrix metalloproteinase (MMP)-13 and types I and III collagen using Northern blot analysis.
3.RESULTS
Analysis by RT-PCR showed that the expression level of type III procollagen mRNA in the frozen-thawed tendon was significantly higher than that in the sham-operated tendon at 6 and 12 weeks. Immunohistological findings showed positive type III collagen staining around cells that had infiltrated the necrotized tendon at 3,6, and 12 weeks. The immunohistological findings revealed that IL-1beta was over-expressed in extrinsic fibroblasts that infiltrate the patellar tendon 2 and 6 weeks after the in situ freeze-thaw procedure, although PDGF-BB or TGF-beta1 was not over-expressed in these extrinsic fibroblasts. Northern blot analysis of the present study showed that fibroblasts derived from the patellar tendon 6 weeks after the in situ freeze-thaw procedure exhibited a less response to IL-1beta than normal tendon fibroblasts in respect to MMP-13 mRNA regulation.
4.CONCLUSIONS
The present study indicated that type-III collagen and IL-1beta have a function with a close relationship to matrix remodeling of the tendon after necrosis, besides the commencement of inflammation during the tissue healing process.
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Research Products
(27 results)
