Possible role of heat shock protein (Hsp) 25 in the enamel organ during amelogenesis in the rat molar
Possible role of heat shock protein (Hsp) 25 in the enamel organ during amelogenesis in the rat molar
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DOI：
10.1679/aohc.64.369
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发表时间：
2001-10-01
影响因子：
--
通讯作者：
Ohshima, H
中科院分区：
文献类型：
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作者：
Otsuka, Y;Nakakura-Ohshima, K;Ohshima, H
用免疫细胞化学和共聚焦显微镜观察了大鼠磨牙成釉过程中热休克蛋白（Hsp） 25的表达。热休克蛋白25免疫反应在大鼠磨牙内釉质上皮和成釉细胞层的定位模式与我们之前报道的大鼠门牙中的定位模式几乎相同：强烈的热休克蛋白25免疫反应首先出现在成釉前细胞中，在分泌型成釉细胞和皱端成釉细胞中被识别出具有特定阶段的免疫强度。用hsp25抗体和罗丹明标记的phalloidin共聚焦显微镜清楚地显示了hsp25和肌动蛋白丝在成釉细胞层中的共定位，支持了我们的假设，即该分子可能在牙釉质形成过程中加强成釉细胞层，并在褶边端成釉细胞中形成和维持褶边。有趣的是，本质上缺乏牙釉质形成能力的无牙釉质区细胞在4-11天出现皱边时显示出Hsp - 25免疫反应性，但在出生后15天凋亡后免疫反应性下降。由于hsp25已被证明是一种特异性的细胞凋亡抑制剂，无牙釉质区细胞有助于确定牙本质尖角区域的轮廓。这些数据支持了我们之前关于hsp25在淀粉体发育中的多种功能的假设。
The postnatal expression of heat shock protein (Hsp) 25 during the amelogenesis of rat molars was investigated by immunocytochemistry and confocal microscopy. The localization pattern of Hsp 25-immunoreactivity in the inner enamel epithelium and ameloblast cell layer of the rat molars was almost identical to that in the rat incisors which we have previously reported: an intense Hsp 25-immunoreactivity, which first appeared in the preameloblasts, was recognized in secretory ameloblasts and ruffle-ended ameloblasts with stage-specific immunointensity. Confocal microscopy with Hsp 25-antibody and rhodamine-labeled phalloidin clearly demonstrated the co-localization of Hsp 25 and actin filaments in the ameloblast layer, supporting our hypothesis that this molecule might serve to reinforce the ameloblast layer during enamel formation as well as the formation and maintenance of the ruffled border in ruffle-ended ameloblasts. Interestingly, the enamel free area cells, which essentially lack the ability for enamel formation, showed the Hsp 25-immunoreactivity during 4-11 days when they developed a ruffled border, but decreased in that immunoreactivity after postnatal 15 days following apoptosis. Since Hsp 25 has been shown to be a specific inhibitor of apoptosis, the enamel-free area cells contribute to determine the outline of dentin at the cusped area. These data support our previous hypothesis on the diverse functions of Hsp 25 in amelogenesis.