转化生长因子β1和E-钙黏附分子在人牙胚发育过程中的表达及意义

Expressions of TGF-β1 and E-cadherin in human tooth germ development and their significances

目的：观察转化生长因子β1（TGF-β1）和E-钙黏附分子（E—cadherin）在人牙胚发育过程中的表达，探讨其对牙齿发育的作用及意义。方法：胎龄8～34周胎儿尸体36例，取连牙胚的下颌骨，制成4μm厚的连续石蜡切片。采用SABC免疫组化方法，观察TGF-β1和E—cadherin在人牙胚中的分布。结果：TGF-β1和E-cadherin在人牙胚发育的不同时期均有表达。TGF-β1在蕾状期和帽状期的牙蕾上皮、牙板、内釉细胞和外釉细胞均呈阳性表达，钟状期在内釉细胞、釉结、中间层、牙板、成釉细胞、成牙本质细胞呈强阳性表达，靠近成牙本质细胞的牙乳头细胞和牙囊呈阳性表达。E—cadherin在蕾状期和帽状期的牙蕾上皮、牙板上皮、钟状早期的成釉细胞、外釉细胞中呈阳性表达，在钟状中期成釉细胞、成牙本质细胞中呈强阳性表达，外釉上皮和靠近成牙本质细胞的牙乳头细胞中呈阳性表达，在钟状晚期接近硬组织处的成釉细胞、成牙本质细胞、上皮根鞘呈强阳性表达。结论：TGF-β1是参与牙胚细胞分化及形态发生的重要调节因子，E—cadherin与牙釉质和牙本质的发育、分泌及矿化密切相关。

Objective To observe the expressions of TGF-β1 and E-cadherin in human tooth germ development and explore the function and significance. Methods The mandible containing the tooth germs from 36 foetus bodys aged 8- 34 weeks were gotten. SABC immunohistochemistry was used to detect the distribution of TGF-β1 and E-cadherin on human tooth germs. Results TGF-β1 and E-cadherin expressed in different stages of tooth development. During bud stage and cap stage, the TGF-β1 expression was positive in tooth bud epithelium, dental lamina, outer enamel epithelium and inner enamel epithelium. During bell stage, the TGF-β1 expression was strongly positive in inner enamel epithelium, enamel knot, stratum intermedium, dental lamina, odontoblast, ameloblast and positively expressed in the dental papilla ceils which neared to odontoblast and dental sac. During bud stage and cap stage, the E-cadherin expression was positive in tooth bud epithelium and dental lamina. During early bell stage, the E-cadherin expression was positive in ameloblast and outer enamel epithelium. During middle bell stage, the E-cadherin expression was strongly positive in ameloblast, odontoblast and positively expressed in outer enamel epithelium and the dental papilla cells which neared to the odontoblast. During late bell stage, the expression of E-cadherin strongly positive in odontoblast, ameloblast which neared to the hard tissue and epithelial root sheath. Conclusion TGF-β1 is an important regulatory factor which participants in tooth germ cell differentiation and morphous development. E-cadherin has close correlation with development, secretion and mineralization of enamel and dentin.