LOCALIZATION OF ACTIN DURING DIFFERENTIATION OF THE AMELOBLAST, ITS RELATED EPITHELIAL-CELLS AND ODONTOBLASTS IN THE RAT INCISOR USING NBD-PHALLACIDIN
LOCALIZATION OF ACTIN DURING DIFFERENTIATION OF THE AMELOBLAST, ITS RELATED EPITHELIAL-CELLS AND ODONTOBLASTS IN THE RAT INCISOR USING NBD-PHALLACIDIN
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DOI：
10.1111/j.1432-0436.1986.tb00786.x
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发表时间：
1986-01-01
期刊：
影响因子：
2.9
通讯作者：
KITAMURA, H
中科院分区：
文献类型：
--
作者：
NISHIKAWA, S;KITAMURA, H
使用NBD-鬼笔毒肽，它特异性地结合到F-肌动蛋白，我们研究了在大鼠切牙成釉细胞，相关上皮细胞和成牙本质细胞的分化过程中肌动蛋白的定位变化。在用NBD-鬼笔毒肽处理的冷冻切片中，在顶环中的未分化上皮细胞和未分化的内釉上皮细胞的近端观察到强烈的荧光。在分化过程中，远端开始表现出强烈的荧光。在分泌型成釉细胞的横截面中，荧光在近端呈均匀强度的多边形，在远端呈不均匀强度的矩形。在远端，与切牙长轴成直角的荧光更强。在远端，这种模式是在釉质层出现之前建立的。这些模式在成釉细胞的分泌期得以维持。这些位点的出现位置、方式和时间与成釉细胞的终末网相同。NBD-鬼笔毒肽弱标记成釉细胞胞体周围的胞质，也标记Tomes突。形成中间层的细胞主要在其周边标记（即形成较大的多边形），而覆盖的上皮细胞在其整个细胞质中显示标记。除终网外，成牙本质细胞胞体在整个分化过程中均呈弱标记。分泌前牙本质的年轻成牙本质细胞首先标记在末端网上，随着牙本质厚度的增加，荧光逐渐变得更强。线样荧光-可能表明肌动蛋白定位在成牙本质细胞的过程中，其分支-只看到在未脱钙部分的前牙本质中，在脱钙部分的前牙本质和牙本质。成釉细胞和成牙本质细胞分化过程中F-actin分布的变化可能与切牙的形态发生以及釉质和牙本质的形成有关。肌动蛋白在脱钙切片牙本质中的定位支持了成牙本质细胞突几乎延伸到釉质牙本质交界处的观点。
Using NBD-phallacidin, which specifically binds to F-actin, we investigated changes in the localization of actin during the differentiation of ameloblasts, related epithelial cells and odontoblasts in rat incisors. In cryosections treated with NBD-phallacidin, intense fluorescence was observed in undifferentiated epithelial cells in the apical loop and at the proximal extremity of undifferentiated inner enamel epithelial cells. During differentiation, the distal extremity began to exhibit strong fluorescence. In cross-sections of secretory ameloblasts, the fluorescence took the form of polygons of uniform intensity at the proximal end, and of rectangles of non-uniform intensity at the distal end. At the distal end, the fluorescence was more intense at right angles to the long axis of the incisor. At the distal end, this pattern was established just before the appearance of the enamel layer. These patterns were maintained during the secretory stage of ameloblasts. The location, pattern and time of appearance of these sites were identical to those of the terminal webs in ameloblasts. NBD-phallacidin weakly labelled the peripheral cytoplasm of the cell body of ameloblasts, and also labelled Tomes'' process. The cells forming the stratum intermedium were mainly labelled at their periphery (i.e. forming larger polygons), while the overlying epithelial cells exhibited labelling throughout their cytoplasm. Except for the terminal webs, the cell bodies of odontoblasts were weakly labelled throughout the period of differentiation. Young odontoblasts secreting predentin were first labelled on the terminal web, with the fluorescence becoming gradually more intense as the thickness of the dentin increased. Thread-like fluorescence-probably indicating actin localization in the odontoblast process and its branch-was seen only in the predentin in undecalcified sections, and in both the predentin and dentin in decalcified sections. The observed changes in the distribution of F-actin during the differentiation of ameloblasts and odontoblasts might be involved in the morphogenesis of incisor teeth as well as in the formation of enamel and dentin. The localization of actin in the dentin of decalcified sections supports the view that the odontoblast process extends almost as far as the enamel-dentin junction.