법랑모세포 분화와 성숙과정에서 OD314의 발현 = EXPRESSION OF OD314 DURING AMELOBLAST DIFFERENTIATION AND MATURATION

국문 초록 (Abstract)

법랑모세포는 법랑질을 형성하고 유지하는 세포로, 법랑질의 유기기질을 분비하고 법랑질 석회화 과정에도 관여한다. 치아 발생과정에서 법랑모세포의 분화는 순차적인 상피-간엽 상호작용에 의하여 조절되나, 분화나 성숙과정의 정확한 기전은 아직까지 잘 알려져 있지 않다. 최근에 상아모세포에서 처음 발견된 OD314가 치아 발생과정에서 상아질을 형성하는 상아모세포 뿐 아니라 법랑모세포에도 발현된다고 하였다.
이에 본 연구에서는 생쥐 하악 전치의 다양한 시기의 법랑모세포를 이용하여, 형태학적 분석과 in-situ hybridization에 의한 OD314 mRNA의 발현 그리고 OD314 항체를 이용한 면역조직화학적 분석을 통하여 OD314 유전자의 법랑 모세포 분화와 성숙과정에서의 역할을 연구하여 다음과 같은 결과를 얻었다.
1. 형태학적으로 법랑모세포는 분화 단계에 따라 분비 전단계 법랑모세포, 분비기 법랑모세포, 성숙기의 평탄끝 법랑모세포와 성숙기의 주름끝 법랑모세포로 구분되었다.
2. OD314 mRNA는 분비기의 법랑모세포에서부터 발현되기 시작하여 법랑모세포가 성숙해갈 수록 그 발현이 증가하였다.
3. OD314 단백질은 분비 전단계의 법랑모세포에서는 발현되지 않고, 분비기의 법랑모세포에서는 세포질에 전체적으로 발현되었다. 성숙기의 평탄끝 법랑모세포와 주름끝 법랑모세포에서는 세포의 근심과 원심끝단에 OD314 단백질이 강하게 발현되었다.
이상의 결과를 종합하여 OD314는 법랑모세포의 분화와 성숙과정에서 세포질 내부에서 특징적인 역할을 하는 것으로 사료된다.

다국어 초록 (Multilingual Abstract)

Ameloblasts are responsible for the formation and maintenance of enamel which is an epithelially derived protective covering for teeth. Ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions. However, little is known about the differentiation and maturation mechanisms. OD314 was firstly identifled from odontoblasts by subtraction between odontoblast/pulp cells and osteoblast/dental papilla cells, even though OD314 protein was also expressed in ameloblast during tooth formation.
In this study, to better understand the biologcal function of OD314 during amelogenesis, we examined expression of the OD314 mRNA and protein in various stages of ameloblast differentiation using in-situ hybridization and immunohistochemistry.
The results were as follows :
1. The ameloblast showed 4 main morphological and functional stages referred to as the presecretory, secretory, smooth-ended, and ruffle-ended.
2. ○D314 mRNA was expressed in secretory ameloblast and increased according to the maturation of the cells.
3. OD314 protein was not expressed in presecretory ameloblast but expressed in secretory ameloblast and maturative ameloblast. OD314 protein was distributed in entire cytoplasm of secretory ameloblast. However, OD314 was localized at the proxiamal and distal portion of the cytoplasm of smooth- ended and ruffle-ended ameloblast.
These results suggest that ○D314 may play important roles in the ameloblast differentiation and maturation.

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