Cell dynamics in cervical loop epithelium during transition from crown to root: implications for Hertwig's epithelial root sheath formation
Cell dynamics in cervical loop epithelium during transition from crown to root: implications for Hertwig's epithelial root sheath formation
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DOI：
10.1111/jre.12003
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发表时间：
2013-04-01
影响因子：
3.5
通讯作者：
Harada, H.
中科院分区：
文献类型：
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作者：
Sakano, M.;Otsu, K.;Harada, H.
背景与目的一些牙根发育不良的临床病例是先天性的。由于Hertwig‘s上皮根鞘(HERS)的形成是根发育和生长的重要事件，我们认为了解HERS的发育机制有助于阐明该病的病因。为了寻找她发育和生长的构成因素和现象，我们研究了颈环(CL)的增殖和活动。材料与方法用DiI标记和器官培养系统观察CL的细胞运动。为了检测细胞增殖，我们用抗Ki67抗体对CL和HERS进行了免疫组织化学染色。用绿色荧光蛋白小鼠牙胚片培养法观察CL细胞的运动情况。我们还检测了与细胞运动相关的巴西林的表达。结果DiI标记的图像显示，在CL的顶端，上皮随着外釉上皮(OEE)的生长而延长。Ki67免疫组织化学染色细胞增殖分析显示，在HERS形成初期，OEE比内釉上皮(IEE)分裂更活跃。活体成像显示CL尖部的OEE和细胞的活动度比IEE活跃。在OEE和CL的顶端有较强的Paxlin表达。结论在抑制IEE生长后，OEE细胞的生长和运动更为活跃，从而促进了HERS的形成。Paxlin的表达模式参与了OEE和HERS的主动运动。这一结果将有助于了解HERS的形成机制，阐明HERS异常的根源。
Background and Objective Some clinical cases of hypoplastic tooth root are congenital. Because the formation of Hertwig's epithelial root sheath (HERS) is an important event for root development and growth, we have considered that understanding the HERS developmental mechanism contributes to elucidate the causal factors of the disease. To find integrant factors and phenomenon for HERS development and growth, we studied the proliferation and mobility of the cervical loop (CL). Material and Methods We observed the cell movement of CL by the DiI labeling and organ culture system. To examine cell proliferation, we carried out immunostaining of CL and HERS using anti-Ki67 antibody. Cell motility in CL was observed by tooth germ slice organ culture using green fluorescent protein mouse. We also examined the expression of paxillin associated with cell movement. Results Imaging using DiI labeling showed that, at the apex of CL, the epithelium elongated in tandem with the growth of outer enamel epithelium (OEE). Cell proliferation assay using Ki67 immunostaining showed that OEE divided more actively than inner enamel epithelium (IEE) at the onset of HERS formation. Live imaging suggested that mobility of the OEE and cells in the apex of CL were more active than in IEE. The expression of paxillin was observed strongly in OEE and the apex of CL. Conclusion The more active growth and movement of OEE cells contributed to HERS formation after reduction of the growth of IEE. The expression pattern of paxillin was involved in the active movement of OEE and HERS. The results will contribute to understand the HERS formation mechanism and elucidate the cause of anomaly root.