2006 Fiscal Year Final Research Report Summary
Elucidation of dental root resorption and its restoration, induced by orthodontic force ; Application of mechanical stress to epithelial cells derived of dental lamina
| Project/Area Number |
16592057
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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 |
Orthodontic/Pediatric dentistry
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| Research Institution | Kanagawa Dental College |
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Principal Investigator |
YAMAUCHI Masato Kanagawa Dental College, Dentistry, Orthodontics, Assistant professor (30230311)
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| Co-Investigator(Kenkyū-buntansha) |
TSUNODA Akira Kanagawa Dental College, Dentistry, Endodontics, Lecturer (70236933)
KOBAYASHI Masaru Kanagawa Dental College, Dentistry, Oral Surgeon, Lecturer (00162024)
HATA Ryu-ichiro Kanagawa Dental College, Dentistry, Oral Biochemistry, Professor (10014276)
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| Project Period (FY) |
2004 – 2006
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| Keywords | cementum / dental root resorption / mechanical stress / amelogenin / bone sialoprotein / promoter / transcription |
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| Research Abstract |
Cementblast precursor cell could induce osteoclast and could produce its matrix to restore on the dental root resorption lacunae, which regulated by amelogenin or its variants. Bone sialoprotein (BSP) is sialic acid-rich glycophosphoprotein that is abundant in surface of dental root, likewise trabecular bone. It was conceivable that BSP participate with the defense mechanism against dental root resorption and restoration. Orthodontic forces might be a determination factor on the dental root resorption, which was involved in the cellular events. To elucidate the functional roles of BSP in cementblast precursor cell on the dental root resorption, we examined the effects of purified amelogenin as well as cyclic stretch on its gene expression.
RT-PCR analyses revealed that 1.0 μg amelogenin purified from immature enamel of bovine tooth could induced a 1.6 fold increase of BSP mRNA expression in mouse immortalized dental follicle progenitor cells, MDFE6Δ127. Application of Cyclic stretch (6%
… More
, 1Hz) caused approximately 2.0 fold enhancement of BSP mRNA expression in MDFE6Δ127. No synergistically effects between addition of amelogenin and application of cyclic stretch were observed in MDFE6Δ127. Transcription analyses revealed amelogenin increased a 4 fold of promoter activity in pLUC9.0kb, 1.5 fold of in pLUC5.2kb, whereas any enhancement was not observed in pLUC0.8kb. It was presumed that amelogenin response ' cis-element was existed in the upstream promoter between nts -5394 and-9254 lesion within BSP gene. In contrast, 3.2 fold increase of transcription was observed in pLUC5.2kb induced by application of cyclic stretch. Moreover, relative enhancement of promoter activities has been shown in both pLUC9.0kb and pLUC0.8kb with cyclic stretch. We assumed that broad distribution of cyclic stretch response cis-elements of which activity was peaked around nts-5394 legion were existed in the transcription regulatory gene of BSP.
Taken together, these results suggest that amelogenin could cause enhancement of BSP transcription and its gene expression in MDFE6Δ127, which had distinct reaction pathways compared with the induction of cyclic stretch. Less
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