釉原蛋白、釉蛋白及成釉蛋白在小鼠牙胚组织发育过程中的表达

目的:比较小鼠釉原蛋白(amelogenin,AMELX)、成釉蛋白(ameloblastin,AMBN)和釉蛋白(enamelin,ENAM)在牙胚组织发育过程中表达的差异,从而揭示其不同的功能。方法:选择牙胚发育期分别位于钟状期、钟状晚期、釉质成熟期的昆明小鼠头颅切片,使用抗鼠AMELX、AMBN和ENAM多克隆抗体(由美国德州大学健康科学中心Dr.Sim-mer赠送),行免疫组织化学EnVision二步法染色,观察三种蛋白在处于三个不同发育阶段小鼠头颅切片中的表达情况。结果:免疫组化结果显示,三种蛋白在三种小鼠牙胚的成釉细胞、釉质、牙本质中的表达存在时空顺序差异,随着牙胚发育和釉质成熟,AMELX呈递减表达,而AMBN和ENAM则较恒定表达。AMELX在周围发育中的编织状骨组织中也有微弱表达。结论:AMELX、AMBN和ENAM为主要的釉质基质蛋白,在牙胚发育的不同阶段有不同的调节矿化的作用,AMELX在釉质矿化早期促进晶体生长,而其在骨中的表达则进一步表明其在骨修复中可能的作用;AMBN促进釉质基质矿化,并维持晶体形状、大小;ENAM促进和维持晶体生长,并与再矿化有关。

Expression of Amelogenin, Ameloblastin and Enamelin in Developing Tooth Germs of Mouse

Objective: To compare the different expression of amelogenin(AMELX), ameloblastin(AMBN) and enamelin(ENAM) in tooth germs, thus to clarify the functions of these proteins in the development of tooth. Methods: The mice whose tooth germs were in bell stage, late bell stage and enamel mature stage were selected. The expression of these three proteins in the sagital sections of these mice was detected by immunohistochemistry, and EnVision two steps method was applied. The antibodies were presented from Dr. Simmer. Results: Immunohistochemistry showed that the temporal and spatial expression patterns of AMELX, AMBN and ENAM in ameloblasts and enamel matrix were different. With the mineralization of enamel matrix, expression of AMELX decreased, but it weakly expressed in adjacent bone. At the same time, expression of AMBN and ENAM were more stable. Conclusion: AMELX, AMBN and ENAM are the major matrix proteins of enamel, and play different roles during different developing stages of tooth germs. AMELX may facilitate the growth of crystals in the early mineral stage, and act in the repairing of bone. AMBN may promote the mineralization of enamel matrix, and also keep the shape and size of crystals. ENAM may act in remineralization and promoting the growth of crystals.