跨膜蛋白Syndecan-1在不同发育时期小鼠磨牙组织中的表达

目的以小鼠磨牙为发育模型，研究其不同发育时期跨膜蛋白Syndecan- 1的表达特点，进而分析Syndecan-1在牙齿发育中的作用。方法取不同胎龄的胎鼠，制作其下颌第一磨牙的切片，进行免疫荧光染色，并在荧光显微镜下观察Syndecan- 1的表达情况。结果Syndecan- 1的表达随牙胚发育的时期不同而变化：蕾状期时在牙源性上皮和间充质中有弱的阳性分布，帽状期时成釉器上皮阳性表达减弱，而牙乳头及周围的间充质的阳性反应明显增强，钟状期时成釉器上皮又呈阳性表达，并以在中间细胞层的反应更为强烈，而牙乳头间充质的染色则很弱，同时前成釉细胞以及下方的成牙本质细胞的顶端也呈Syndecan- 1的阳性表达。结论Syndecan- 1参与了成釉器和牙乳头的发育和分化过程的调节，并与牙胚细胞的增殖以及成釉细胞和成牙本质细胞的分化相关。

Study of the expression pattern of Syndecan-1 in different developing molar stage of mouse

Objective Developing mouse molar was used as a model for the study of Syndecan-1,a transmembrane heparan sulfate proteoglycans,in order to approach the possible mechanism and function of this macromolecule during tooth development.Methods Mouse embryos were removed at different days of gestation.The frozen sections of the first lower molar were made from the embryonic mouse heads and then indirect immunofluorescence was performed on these sections.The altered distribution pattern of Syndecan-1 in embryonic mouse first lower molars at different stages of development from the bud to the late bell stage was observed under a conventional fluorescence microscope.Results There was a ubiquitous staining in the dental tissues at bud stage: Both the epithelium and mesenchyme were weakly positive for Syndecan-1.From the bud to the cap stage,there was a strong decrease of the staining for Syndecan-1 in the epithelial compartment,while an intense staining in dental mesenchyme was observed at cap stage.At bell stage,Syndecan-1 was again detected in dental epithelium including the stratum intermedium and the outer enamel epithelium,and it was found having some intense signal in the stratum intermedium.However,the staining for Syndecan-1 in dental mesenchyme of this stage became weaker and finally disappeared.Furthermore,a positive expression for Syndecan-1 was also found at the top of pre-ameloblasts as well as odontoblasts.Conclusion These changes in the patterning of Syndecan-1 during tooth development might be related with cell proliferation during morphogenesis and later be involved in the differentiation of ameloblast and odontoblast.