Hsp27在大鼠磨牙及其发育中的分布研究

目的 探讨Hsp27在大鼠磨牙及其发育中的分布及意义。方法 建立大鼠牙胚发育模型，用免疫组化方法检测HsD27在磨牙发育不同时期的表达。结果 在成釉细胞形成过程中，Hsp27首先出现在前成釉细胞中，在成釉细胞分泌阶段和成熟阶段，Hsp27的阳性免疫反应逐步增强。正在分化和已分化的成牙本质细胞中，有Hsp27的阳性反应。21天时，冠部成牙本质细胞仍保持强烈的Hsp27免疫反应，而髓室底和牙根的成牙本质细胞为弱或无Hsp27反应。但是在以后牙根发育阶段，髓室底和牙根侧的成牙本质细胞对Hsp27反应增强。值的注意的是，不能形成牙釉质的无釉区细胞，在牙胚发育5～11天时，有显著的Hsp27表达。但在14天以后又伴随凋亡而减少。结论 Hsp27可以看作区别内釉上皮细胞和前成釉细胞的有用标志物，并与成牙本质细胞分化程度有关。Hsp27作为凋亡抑制剂与无釉区牙本质在牙冠尖端处轮廓的形成有关。

Distribution of Hsp27 in development of rat molars

Objective To examine the distribution of Hsp27 in the development of rat molar. Methods Model of rat tooth development was established to examine Hsp27 by immunohistochemical technique. Results During amelogenesis, Hsp27 immunoreactivity first appeared in the preameloblasts, and increased in immunoreactivity in secretory stage and maturation stage. Hsp27 immunoreactivity positive staining was found in the differentiating and differentiated odontoblasts. At 21 days, the coronal odontoblasts retained intensive Hsp27 immunoreactivity, whereas the odontoblasts in the root and floor pulp showed weak I-Isp27 immunoreactivity or negative. However, odontoblasts showed Hsp27 immunoreativity in the later stages. Interestingly, the enamel free area cells, which essentially lack the ability for enamel formation, showed the Hsp27 immunoreactivity during 5 - 11 days, but decreased in Hsp27 immunoreactivity after 14 days following apoptosis. Conclusion Hsp27 might be a useful marker for distinguishing preameloblasts from inner enamel epithelial cells. Expression of Hsp27 also reflects the differentiation status of odontoblasts. Hsp27 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.