A morphogenetic concept of salivary duct regeneration and metaplasia
A morphogenetic concept of salivary duct regeneration and metaplasia
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DOI：
10.1007/s004280100537
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发表时间：
2002-05-01
期刊：
影响因子：
3.5
通讯作者：
Löhrs, U
中科院分区：
文献类型：
--
作者：
Ihrler, S;Zietz, C;Löhrs, U
唾液管的生理再生和化生过程的确切机制尚未明确确定，尽管长期以来人们一直倾向于推定的未定型干细胞群的再生。在本研究中，分别对 Ki 67 和 α-肌动蛋白或不同细胞角蛋白亚型进行双重免疫组织化学标记，使得常规唾液管和不同类型化生中细胞增殖的精确定位和定量成为可能。我们的数据证明了唾液管所有五种细胞类型的基线增殖能力。腺泡和闰管的管腔分泌细胞独立于肌上皮或基底细胞再生。相反，横纹管和排泄管中嗜氧细胞的更新是通过基底细胞的增殖和分化来维持的。绝大多数化生是由横纹管/排泄管的未定型、Bcl-2 阳性基底细胞发展而来，这些细胞具有多向形态发生分化的巨大能力。尽管基底细胞发挥着重要作用，但我们的研究结果表明，所有细胞类型原则上都必须被视为唾液腺肿瘤的潜在祖细胞。对唾液管再生和化生过程的深入了解可能有助于更好地理解复杂的正式致癌过程。
The exact mechanisms of physiological regeneration and of metaplastic processes of the salivary duct have not been definitely established, although regeneration from a putative uncommited stem cell population has long been favored. In the present study, double immunohistochemical labeling for Ki 67 and alpha-actin or different cytokeratin subtypes, respectively, made possible an exact localization and quantification of cellular proliferation in the regular salivary duct and in different types of metaplasia. Our data demonstrate a baseline proliferative capacity in all five cell types of the salivary duct. Luminal secretory cells of the acinus and intercalated duct regenerate independently from myoepithelial or basal cells. In contrast, the renewal of oxyphilic cells in the striated and excretory duct is maintained by proliferation and differentiation of basal cells. The great majority of metaplasias develops from uncommitted, Bcl-2 positive basal cells of striated/excretory ducts which possess an enormous capacity for pluridirectional morphogenetic differentiation. Despite this important role of basal cells, our findings demonstrate that all cell types principally have to be considered as potential progenitor cells for salivary gland tumors. The improved insight into regenerative and metaplastic processes of the salivary duct may contribute to a better understanding of the complex formal carcinogenesis.