人釉成熟蛋白诱导下的釉质原位晶体生长

In situ crystal growth of enamel induced by human amelotin

目的研究釉成熟蛋白(amelotin)在牙体原位对牙釉质再矿化的诱导能力。方法从釉质发育期第三磨牙牙囊中提取牙胚细胞总RNA,反转录、扩增得到釉成熟蛋白c DNA。使用限制性内切酶剪切得到釉成熟蛋白全长基因,将其与p MD18-T载体相连构建质粒,以大肠杆菌BL21(DE3)感受态细胞表达得到釉成熟蛋白。将2 mg/ml的釉成熟蛋白涂布于处理后的牙釉质表面,过饱和矿化液中37℃孵育14天,扫描电子显微镜观察新生矿物结晶。结果釉成熟蛋白能在脱矿釉质表面诱导生成珠状晶体,它们首尾相接排列成串状小棒,相互平行的小棒垂直于脱矿釉面向外延伸生长。结论相互平行的串珠棒状晶体模拟了平行排列的釉柱,特征串珠结构证实釉成熟蛋白在釉质生长过程中的重要作用。

Objective To study the ability of amelotin to induce the enamel remineralization in situ.Methods The total RNA of tooth germ cells was extracted from dental follicles of the third molar during enamel development, and the mature protein cDNA of dental germ cells was obtained by reverse transcription and amplification.The full-length gene of amelotin was obtained by restriction endonuclease digestion and ligated into the pMD18-T vector to construct a plasmid.The plasmid was transformed into E.coli Top10 and then,E.coli BL21 （DE3） competent cells were used to express the amelotin.Amelotin （2 mg/ml） was adhered to the demineralized enamel surface and incubated in supersaturated mineralized solution at 37 for 14 days- Scanning electron microscopy was used to observe the crystallization of newborn minerals.Results Amelotin induced neonatal pearl crystals on the surface of demineralized enamel.Beaded crystals were arranged side by side to form a string of small rods.Small parallel rods were extended from the demineralized glaze.Conclusion The parallel beaded rod-like crystals mimic the parallel arrangement of the enamel columns, and the characteristic beaded structure confirms the important role of amelotin in the enamel growth process.