Elucidation of the mechanism for differentiation of odontoblasts and mineralization of dentin

阐明成牙本质细胞分化和牙本质矿化的机制

• 批准号: 11671913
• 负责人: KAWATA Akir
• 金额: $ 1.92万
• 依托单位: KANAGAWA DENTAL COLLEGE
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11671913/
• 关键词: odontoblasts; matorigel; phosphophoryn; type IV collagen; gelatinase; metalloproteinase; enzymogram; knock out mouse; (1)象牙芽細胞; (2)マトリゲル; (3)フォスフォフォリン; (4)タイプIVコラーゲン; (5)ゼラチナーゼA; (6)マトリックスメタロプロテアーゼ; (7)エンザイモグラム; (8)ノックアウトマウス

In the serum-free culture medium of bovine odontoblasts, we detected active gelatinolytic metalloproteinases, MMP-2 and MMP-9 (gelatinase A and B). The activity of MMP-2, in particular, appeared suddenly around day 21 in the culture, coinciding with the development of odontoblastic cell processes and the loss of alkaline phosphatase. RT-PCR analysis of these odontoblasts demonstrated that messages of MMP-2 but not MMP-9 increased significantly between day 15 and day 21. This in vitro observation indicates that medium conditioned by these odontoblasts and containing significant amounts of MMP-2 mRNA, degrades not only the collagenous substrates but also purified dentin phosphophoryn as well.We have also observed that dephosphorylated dentin phosphoprotein beccmes a better substrate for casein kinase II after limited proteolysis with MMP-2. These results support our working hypothesis that MMP-2 mediated proteolytic processing is an important step in accelerating the process of dentin matrix maturation, which includes phosphorylation and subsequent mineralization. The authors and others have suggested the significance of extracellular phosphorylation of matrix proteins in biomineralization both in bone and in dentin (Zhu et al., Biochem. J., 323 : 637-643, 1997 ; Mikuni-Takagaki et al., J.Bone Miner. Res., 10 : 231-241, 1995). Our present histochemical analysis in MMP-2 knockout mice confirms this idea, with the the delayed formation of mineralized tissues, dentin and bone.

在牛成牙本质细胞的无血清培养基中，我们检测到活性明胶分解金属蛋白酶MMP-2和MMP-9（明胶酶A和B）。MMP-2的活性，特别是，突然出现在培养的第21天左右，与成牙本质细胞过程的发展和碱性磷酸酶的损失相一致。这些成牙本质细胞的RT-PCR分析表明，MMP-2，但不是MMP-9的消息显着增加之间的第15天和第21天。体外实验结果表明，含有大量MMP-2 mRNA的成牙本质细胞条件培养液不仅降解胶原基质，而且降解纯化的牙本质磷蛋白，我们还观察到，脱磷酸化的牙本质磷蛋白在MMP-2有限的蛋白水解后，成为酪蛋白激酶II的更好底物。这些结果支持了我们的工作假设，MMP-2介导的蛋白水解加工是加速牙本质基质成熟过程的重要步骤，该过程包括磷酸化和随后的矿化。作者和其他人已经提出了基质蛋白的细胞外磷酸化在骨和牙本质中的生物矿化中的重要性（Zhu等人，生物化学杂志，323：637-643，1997 ; Mikuni-Takagaki等人，J.Bone Miner。结果：10：231-241，1995）。我们目前对MMP-2基因敲除小鼠的组织化学分析证实了这一观点，矿化组织、牙本质和骨的形成延迟。

项目成果

M.Satoyoshi, et al.: "Matrix Metalloproteinase-2 in Dentinogenesis in Chemistry and Biology of Mineralized Tissues"American Academy of Orthopaedic Surgeons. 458. (2000)

M.Satoyoshi 等人：“矿化组织化学和生物学中牙本质发生中的基质金属蛋白酶-2”美国骨科医师学会。

M.Satoyoshi, et al.: "Matrix metalloproteinase-2 in dentin matrix mineralization."Journal of Endodontics. (In press). (2001)

M.Satoyoshi 等人：“牙本质基质矿化中的基质金属蛋白酶-2”。牙髓病学杂志。

Satoyoshi M. et al.: "Matrix Metalloproteinase-2 in Dentinogenesis in Chemistry and Biology of Mineralized Tissues"American Academy of Orthopaedic Surgeons. 458 (2000)

Satoyoshi M.等人：“矿化组织化学和生物学中牙本质发生中的基质金属蛋白酶-2”美国骨科医师学会。

M.Satoyoshi, et al.: "Matrix metalloproteinase-2 in detin matrix mineralization."Journal of Endodontics. (In press). (2001)

M.Satoyoshi 等人：“决定蛋白基质矿化中的基质金属蛋白酶-2”。牙髓病杂志。

Satoyoshi,M. et al.: "Matrix metalloproteinase-2 in dentin matrix mineralization."J.Endodontics. (In press). (2001)

里吉，M.