Changing patterns of localization of putative stem cells in developing human hair follicles
Changing patterns of localization of putative stem cells in developing human hair follicles
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DOI：
10.1046/j.1523-1747.2000.00857.x
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发表时间：
2000-02-01
影响因子：
6.5
通讯作者：
Shimizu, H
中科院分区：
文献类型：
--
作者：
Akiyama, M;Smith, LT;Shimizu, H
在啮齿类动物中，毛囊干细胞位于外根鞘中一个明确的隆起处;然而，作为人类毛囊上皮干细胞部位的隆起处仍然存在争议。表皮干细胞被认为表达高水平的β 1整联蛋白和低水平的E-钙粘蛋白和β-和γ-连环蛋白。为了阐明毛囊发育过程中可能的干细胞的个体发生分布，检测了一系列估计胎龄（EGA）的人胎儿皮肤样本中β 1整联蛋白亚基、E-钙粘蛋白、β-和γ-连环蛋白的表达模式。富含β 1整联蛋白、E-钙粘蛋白和β-和γ-连环蛋白贫乏的细胞（可能的干细胞）定位于整个毛胚（65-84天EGA），随后定位于发栓的最外层细胞（85-104天EGA）。在球根毛栓（105-135 d EGA）和分化的胎毛毛囊（>135 d EGA）中，它们主要位于外根鞘的隆突和最外层。这种顺序定位与富含表皮生长因子受体表达的细胞相似，并且与表皮干细胞的假定标记物角蛋白19阳性。此外，这些富含β 1整合素、E-钙粘蛋白以及β-和γ-连环蛋白缺乏的细胞通过电子显微镜显示出相似的未分化形态学特征，这些毛囊干细胞的个体发育定位信息有助于进一步理解人类毛囊形态发生的机制，并支持人类胎儿毛囊隆突是干细胞的一个部位的观点滤泡上皮细胞。
In rodents, the hair follicle stem cells lie in a well-defined bulge in the outer root sheath; however, the bulge as a stem cell site of human hair follicle epithelium is still controversial. Epidermal stem cells are thought to express high levels of beta 1 integrin and low levels of E-cadherin and beta- and gamma-catenin. In order to clarify the ontogenic distribution of possible stem cells during hair follicle development, the expression patterns of beta 1 integrin subunits, E-cadherin, and beta- and gamma-catenins in the skin samples from human fetuses of a series of estimated gestational ages (EGA) were examined. beta 1 integrin-rich, E-cadherin-, and beta- and gamma-catenin-poor cells, possible stem cells, were localized to the entire hair germ (65-84 d EGA) and later to the outermost cells of hair peg (85-104 d EGA). In the bulbous hair peg (105-135 d EGA) and in the differentiated lanugo hair follicle (>135 d EGA), they were settled in the bulge and the outermost layer of the outer root sheath. This sequential localization was similar to that of cells rich in epidermal growth factor receptor expression and positive with keratin 19, a putative marker of epidermal stem cells, In addition, these beta 1 integrin-rich, E-cadherin-, and beta- and gamma-catenin-poor cells showed similar, undifferentiated morphologic features by electron microscopy, This information of ontogenic localization of possible hair follicle stem cells contributes to the further understanding of mechanisms of human hair follicle morphogenesis and supports the idea that the human fetal hair follicle bulge is a site of stem cells for follicular epithelium.