小鼠牙胚发育过程中釉原蛋白和釉蛋白的表达特征  

Expression patterns of amelogenin and enamelin in developing mouse tooth germs

作　　者：田华[1] 吕平[1] 周春燕[2] 高学军[1] 

机构地区：[1]北京大学口腔医学院·口腔医院牙体牙髓科,100081 [2]北京大学基础医学院生物化学与分子生物学系

出　　处：《中华口腔医学杂志》2012年第3期173-176,共4页Chinese Journal of Stomatology

基　　金：国家自然科学基金（81070800）

摘　　要：目的 观察釉原蛋白和釉蛋白在小鼠牙胚发育中的表达特征,进一步揭示釉原蛋白和釉蛋白的生物学特性.方法 分别制备出生后第1、3、7和14天小鼠下颌第一磨牙牙胚切片,采用免疫组织化学和反转录聚合酶链反应法检测釉原蛋白和釉蛋白的组织学定位和基因转录表达水平.结果 釉原蛋白表达于分泌期成釉细胞的胞质和釉质基质全层,在新生小鼠牙胚成牙本质细胞中有一过性表达；釉蛋白表达于分泌期釉质基质中,在成釉质细胞突边缘和釉质基质深层呈强阳性表达,釉原蛋白和釉蛋白在矿化成熟的釉质中均未见表达.釉原蛋白和釉蛋白在出生后第7天mRNA表达量的相对值分别为0.813±0.085和0.799±0.064,显著高于其他时间的表达水平（P＜0.05）.结论 釉原蛋白和釉蛋白主要由分泌期成釉细胞合成并分泌到釉质基质中,其表达具有高度的时空特异性,提示它们在釉质形成和生物矿化中有重要的作用.Objective To invesitgate the expression patterns of amelogenin and enamelin in the developing tooth germs.Methods Mandible sections of postnatal day 1,3,7 and 14 mouse were prepared,immunohistochemical analysis and reverse transcriptase polymerase chain reaction（RT-PCR） were performed to detect the expression patterns of amelogenin and enamelin in mandibular first molars. Results Amelogenin was observed in the cytoplasm of secretory ameloblasts and the whole enamel matrix layer.It was also transiently expressed in the odontoblasts of postnatal day 1 molars.Enamelin proteins were observed in the enamel layer deposited by secretory ameloblasts,especially intense beneath the ameloblast process and dentino-enamel junction.The mRNA levels of both amelogenin and enamelin were highest on postnatal day 7（the ratio to glyceraldehyde phosphate dehydrogenase of amelogenin and enamelin：0.813 ± 0.085 and 0.799 ± 0.064,respectively,P 〈 0.05 ）.Conclusions Amelogenin and enamelin were enamel matrix proteins predominately expressed by secretory ameloblasts. The temporal-spatial expression patterns of amelogenin and enamelin indicate the important roles they played in amelogenesis and biomineralization.

关 键 词：釉原蛋白质 釉质发生 釉蛋白 生物矿化 

分 类 号：R78[医药卫生—口腔医学]