【作者】 程敏；

【导师】 孙宏晨；

【作者基本信息】 吉林大学 ， 口腔医学， 2006， 硕士

【摘要】 牙的发育是由上皮-间充质之间相互作用复杂而有序的过程。上皮-间充质通过信号分子相互诱导,在不同的时间和空间位点进行精确地调控成牙细胞的增殖、分化和矿化。现在已知有多种信号分子参与牙的发育,Osterix(Osx)是一种新的锌指转录因子,对成骨细胞分化和骨形成具有重要作用。目前国内外相关报道仅限于骨的研究,关于Osx对牙发育调控的研究未见报道。本研究通过免疫组织化学方法,观察Osx在牙发育过程中的时空表达规律,探索其在牙发育中的功能及意义。免疫组化结果显示,Osx主要定位于细胞浆中,在蕾状期,Osx分布于牙蕾上皮细胞;帽状期,成釉器包括内釉上皮细胞、外釉上皮细胞及星网状层细胞均表达Osx,但内釉上皮处釉结Osx表达明显集中;钟状期,成釉细胞、成牙本质细胞及邻近的牙乳头细胞高表达Osx,此外在釉牙本质界、牙本质小管及新形成的釉质中也见到Osx的分布。表明Osx可能参与成釉细胞和成牙本质细胞的分化、成熟及细胞间信号传导,参与调节釉质和牙本质基质的分泌及生物矿化过程。更多还原

【Abstract】 To understanding the regulation mechanism in toothdevelopment is the hot spot and difficult problems in dental pulpbiology , there are extraordinary theory and clinic significance notonly in damage repair of dental tissue , dental pulp and toothregeneration, but also in good model of multi-germinal layerorgan development.More recently, osterix (Osx), a zinc finger-transcriptionfactor related with bone differentiation and morphogenesis wasfound by Nakashimi in 2002. Osterix (Osx) is osteoblast-specifictranscription factors and essential for the development of a matureosteoblast phenotype and bone forming. Osx functions geneticallydownstream of Runx2, which controls both growth anddifferentiation in osteoblast. Gene expression Osx-deficient micelack osteoblasts and do not form endochondralorintramembranous bones. It is likely that Osx control differentstages of osteoblast differentiation. Osx protein only appeardin development bone. Nakashima found that in mice embryo andnew bone tissue Osx gene was detected early in differentialcartilage cell of 13.5d embryo, and then widely in cell with bonedevelopment. The mesenchymal of dental embryo was alsopositive expression. The objective of this research is to observethe expression site of Osx during tooth development by theimmunohistochemistry method in order to explore the functionand significiance of Osx. And reveal the signal network in toothdevelopment. Nevertheless,there are not reports on the functionalexpresstion of Osx and tooth germ development.The specimens of human tooth germ in different stages wereobtained from aborted embryos in second hospital of Jilinuniversity and HongQi community clinic . the stage of mandibleand maxillary speciments from aborted embryo range 7 weeks-28weeks. The speciments were paraffined. Immunohistochemistrystaining technique was used to test the expression of Osx duringhuman tooth germ development ..The results suggest that Osx gene expresses in the cytoplasm.There are different distribution in different stage of toothdevelopment .In the bud stage, the epithelial express Osx protein,the dental lamina epithelial was less expression .In the cap stage,the expression of Osx in the enamel organ contained the outerenamel epithelium, inner enamal epithelium and stellate reticulumwere strongly positive expressions, and the expression of Osxin the inner enamal epithelium and enamel knot obviouslyconcentrated. The expression dental papilla was observed inweakly.In the bell stage, odontoblast, ameloblast and the adjacentdental papilla highly express the Osx, enamel-dentinal junction,the new formative enamel and dentinal tubule also express theOsx protein.Conclusion: The expression of Osx has its own specificityin different stage of human dental germ development.Osxparticipates in the differentiation and mature of odontoblast,ameloblast, the signal transmission between cells, it regulating thesecreting of enamel ,dentin and the process of biologicalmineralizing. Osx may plays an important roly in human toothdevelopment.更多还原