Yamada K, Yamada T, Sasaki T, Rahemtulla F, Takagi M
Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan.
Histochem J. 1997 Feb;29(2):167-75. doi: 10.1023/a:1026489506952.
The immunohistochemical localization of large hyaluronate-binding proteoglycans has been studied in human tooth germs at the bell stage using a monoclonal antibody, 5D5, which is derived from bovine sclera and specifically recognizes the core protein of large proteoglycans, such as versican, neurocan and brevican, but not that of aggrecan. In the early bell stage before predentine secretion, when the enamel organs consisted of the inner and outer enamel epithelia, stratum intermedium and stellate reticulum, the enamel organs were not stained by 5D5, but the dental papillae and follicles stained strongly. Concomitant with the secretion of predentine, dentine and subsequent enamel matrix, strong 5D5 immunostaining distributed over the entire cell surfaces of secretory ameloblasts was observed. The forming enamel matrix showed strong staining. While most of the inner and outer enamel epithelia and stratum intermedium lacked staining, the cervical loop region and stellate reticulum showed weak staining. Although the forming dentine and odontoblasts appeared to lack 5D5 affinity, the predentine, dental papilla and dental follicle demonstrated moderate to strong reactivity. At the ultrastructural level, specific immunoreaction by immunogold particle deposition was clearly detected over the basal lamina of presecretory ameloblasts, secretion granules of secretory ameloblasts and the forming enamel matrix. These results indicate that a marked increase in the large proteoglycan associated with secretory ameloblasts may correlate with cell differentiation and enamel matrix biosynthesis.
利用一种单克隆抗体5D5，对钟状期人牙胚中大型透明质酸结合蛋白聚糖的免疫组织化学定位进行了研究。该抗体源自牛巩膜，可特异性识别大型蛋白聚糖（如多功能蛋白聚糖、神经蛋白聚糖和短蛋白聚糖）的核心蛋白，但不能识别聚集蛋白聚糖的核心蛋白。在前期牙本质分泌之前的早期钟状期，当釉器由内釉上皮、外釉上皮、中间层和星网状层组成时，釉器未被5D5染色，但牙乳头和滤泡染色强烈。随着前期牙本质、牙本质及随后釉基质的分泌，观察到5D5免疫强染色分布于分泌性成釉细胞的整个细胞表面。正在形成的釉基质显示强染色。虽然大部分内釉上皮、外釉上皮和中间层缺乏染色，但颈环区和星网状层显示弱染色。尽管正在形成的牙本质和成牙本质细胞似乎缺乏5D5亲和力，但前期牙本质、牙乳头和牙滤泡表现出中度至强反应性。在超微结构水平上，在分泌前成釉细胞的基膜、分泌性成釉细胞的分泌颗粒和正在形成的釉基质上，通过免疫金颗粒沉积可清楚地检测到特异性免疫反应。这些结果表明，与分泌性成釉细胞相关的大型蛋白聚糖的显著增加可能与细胞分化和釉基质生物合成有关。
