2003 Fiscal Year Final Research Report Summary
Studies on the differentiation and fate of medial edge epithelium during mouse palatogenesis : Elucidation of temporo-spatial cellular events and related molecules
Project/Area Number |
14370588
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Morphological basic dentistry
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Research Institution | The Nippon Dental University |
Principal Investigator |
TAYA Yuji The Nippon Dental University, School of Dentistry at Tokyo, Department of Pathology, Lecturer, 歯学部, 講師 (30197587)
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Co-Investigator(Kenkyū-buntansha) |
SHIMAZU Yoshihito The Nippon Dental University, School of Dentistry at Tokyo, Department of Pathology, Assistant Professor, 歯学部, 助手 (10297947)
SATO Kaori The Nippon Dental University, School of Dentistry at Tokyo, Department of Pathology, Lecturer, 歯学部, 講師 (90287772)
YAGISHITA Hisao The Nippon Dental University, School of Dentistry at Tokyo, Department of Pathology, Lecturer, 歯学部, 講師 (50256989)
AOBA Takaaki The Nippon Dental University, School of Dentistry at Tokyo, Department of Pathology, Professor, 歯学部, 教授 (30028807)
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Project Period (FY) |
2002 – 2003
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Keywords | Palatogenesis / Mouse / Medial edge epithelium / Apoptosis / Cell adhesion / Cell motility / Rho family / Proteoglycan |
Research Abstract |
In mammalian palatogenesis, medial edge epithelia (MEE) of opposing secondary palatal shelves form a midline epithelial seam, which appears to be disintegrated to achieve mesenchymal integration. The present study aimed to investigate the fusion and disintegration of MEE seam in vivoandin culture. Palatal shelves were obtained from mouse embryos (embryonic day 13.5〜14.6), and organ-cultured up to 48h individually or in pair. We also conducted a series of cultures of palatal shelves in combination with skin and mucosal tissues, as well as artificial substrates (i.e., type I collagen and agarose beads). The fusion processes in culture were reproducible and quite comparable to that in vivo. A multi-layered epithelial seam was formed at 4〜8 hours in culture, and then started to appear partial disintegration. Similar to culture of paired shelves, removal of MEE was mostly achieved within 24 h in most cases combining with heterogenous tissues or various substrates. In culture of single palat
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al shelf, the MEE layer became thinner, but did not appear significant elimination until 24 h, suggesting further incubation was required to accomplish MEE removal. Analysis of apoptosis within the MEE seam, using TUNEL and anti-ssDNA antibody, verified that apoptosis occurred shortly after palatal fusion and that the incidence of apoptosis was constant during the formation through disintegration of the midline seam. RT-PCR examination of the MEE cells, separated from the mesenchymal cells by microdissection, validated mRNA expression of Rho family, e.g., cdc42・N-WASP・MRCK・ERM and ROCK-I. These results indicated that:(1) the fate of MEE cells might be determined before contact of palatal shelves, (2) MEE cells were sensitive to mechanical stimulation, resulting in acceleration of MEE removal, (3) serum was opposed to MEE disintegration, possibly maintaining MEE phenotype. Thus we conclude that the fate of MEE cells is mostly pre-determined, and secondarily affected by environmental factors. Less
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Research Products
(4 results)