Non-collagenous proteins in the apical portion of the forming root in porcine permanent incisor tooth germs

Research Project

Project/Area Number	11671859
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Functional basic dentistry
Research Institution	TSURUMI UNIVERSITY
Principal Investigator	FUKAE Makoto Tsurumi University, Biochemistry, Professor, 歯学部, 教授 (40064373)
Co-Investigator(Kenkyū-buntansha)	TANABE Takako Tsurumi University, Biochemistry, Lecturer, 歯学部, 講師 (00089393) YAMADA Marie Tokyo Dental College, Anatomy, Associated Professor, 歯学部, 助教授 (70115088) OIDA Shinichiro Tsurumi University, Biochemistry, Associated Professor, 歯学部, 助教授 (10114745) YAMAKOSHI Yasuo Tsurumi University, Biochemistry, Assistant, 歯学部, 助手 (20182470)
Project Period (FY)	1999 – 2000
Project Status	Completed (Fiscal Year 2000)
Budget Amount *help	¥3,100,000 (Direct Cost: ¥3,100,000) Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000) Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
Keywords	forming root / cement formation / amelogenin / enamelin / sheathlin / EMSP1 / enamelysin / RT-PCR / ブタ永久歯歯胚 / 非コラーゲン性タンパク質 / ウェスタンブロット
Research Abstract	Detection and expression of enamel proteins were explored on the tissue sample prepared from the apical portion of forming root (APFR) in porcine permanent incisor tooth germs. It was confirmed according to a histochemical method that the sample contained predentin, dentin and thin cement as extracellular matrices, and also contained a lot of cells as odontoblasts, dental papilla cells, cementoblasts, follicular cells, and fragmentized HERS cells. When a guanidine solution was employed for the extraction, it contained a lot of histons, which were croos-reacted with anti-enamel proteins sera. The employment of acetic acid solution was reasonable for the immunoblot studies, since the extractant contained small amount of histons. Amelogenin, enamelin and sheathlin were detected by immunoblot analyses, but in a small amounts. The expressions of enamel proteins were also proved in the APFR sample with PCR amplification products of their cDNAs, and may be related to the cells of fragmentized Hertwig's epithelial root sheath. The amelogenin was not expressed superior to the enamelin and sheathlin. It was different from the expression pattern of the secretary ameloblasts involved to the enamel matrix formation. These results suggest that the amelogenins found in the APFR do not form the three-dimensional structure constructed by amelogenin micelles, which is proposed on the secretary enamel matrix structure. The immunochemical detections of enamel proteins' derivatives showed the occurrences of their degradation. It is at present unclear about the proteinases related to these degradations, since the activities of enamel matrix serine proteinase 1 and enamelysin were not detected on gelatin and casein zymograms. therefore, the enamel proteins spread easily out with degradation into the matrix of future cementum. Some of their derivatives may play a role in cementum formation.