1992 Fiscal Year Final Research Report Summary
Biological and clinical study on regulation of gene expression in osteoblast and its osteogenesis
| Project/Area Number |
03454468
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
外科・放射線系歯学
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| Research Institution | The University of Tokushima |
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Principal Investigator |
NAGAYAMA Masaru Tokushima University School of Dentistry Professor, 歯学部, 教授 (30022867)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANISHI Hiroaki Tokushima University School of Dontistry Research Associate, 歯学部・附属病院, 助手 (00243717)
TAMAI Kenichiro Tokushima University School of Dentistry Research Associate, 歯学部, 助手 (90243716)
SATOMURA Kazuhito Tokushima University School of Dentistry Research Associate, 歯学部, 助手 (80243715)
GOTOH Yuji Tokushima University School of Dentistry Research Associate, 歯学部, 助手 (60225670)
RIKIMARU Koichi Tokushima University School of Dentistry Associate Professor, 歯学部, 助教授 (40220800)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Human Osteoblast / Bone Formation / Mineralization / PDGF / Osteopetrosis / Bone Marrow Stromal Cell / chondrocyte |
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| Research Abstract |
We investigated the effect of PDGF on growth stimulation in human osteoblastic cells. PDGF stimulated the proliferation of these cells and this mechanism was mediated by tyrosin kinase activity of the PDGFrecepter followed by phosphorylation of cellular proteins. We are also studying the induction of gene expression by PDGF in these cells.
Biological bone formation system is necessary for studying on a role of osteoblast during bone remodeling. Osteoblasts derived from human bone were injected in diffusion chamber and implanted intraperitoneally into nude mouse. After 6-8 weeks, calcified body was formed in the cell layer touched membrane filter. Ultrastructually, we showed this calcified body had the similar process to bone formation in vivo.
Bone marrow tissue is known to contain the cells which can differentiate to the osteogenic direction. On this culture system, mineralized nodules which embedded osteoblasts and osteocytes were formed. By electron-microscopic study, this mineralization was considered to be initiated in association with the matrix vesicles and to progress along the collagen fibrils.
Osteopetrosis, characterized by a systemic osteosclerosis, has been given attention to the osteoclast differentiation and bone remodering. We studied the structures of the mandible of a man who had osteopetrosis. The bone marrow cavity was almost occupied by sclerotic bone with very irregular lamination. There was no sign of normal bone remodeling in cortical bone.
Not only osteoblast but also chondrocyte concerns the skeletal growth. Using terminal differentiated chondrocyte, we intestigated how retionic acid stimulates their proliferation and induces dedifferentiation. From our experiments, we suggested that protein kinase C activity mediates the effect of retinoic acid in this chondrocyte.
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