Hair Follicle Stem Cells
Hair Follicle Stem Cells
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DOI：
10.1007/978-94-007-2415-0_5
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
E. Legué;I. Sequeira;J. Nicolas
中科院分区：
文献类型：
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作者：
E. Legué;I. Sequeira;J. Nicolas
毛囊的周期性更新为研究干细胞的行为提供了一个独特的机会，即它们的贡献和维护模式。毛囊更新包括形态发生和伸长的生长阶段，其被大量凋亡阶段中断，随后是静止阶段。毛囊含有两种类型的干细胞：在生长阶段发挥作用并确保毛囊持续延长的干细胞和在周期内维持毛囊的干细胞。谱系追踪分析表明，到目前为止，长期干细胞对不同毛囊谱系的贡献存在意想不到的异质性。然而，这种异质性并不反映迄今为止鉴定的干细胞标志物的异质性，并且细胞的贡献可能取决于其后代所采用的位置。此外，最近的研究表明，长期干细胞库是高度动态的，通过对称分裂和来自先前称为毛囊的非永久性分化部分的细胞的贡献而经历多轮的消耗和补充。相反，在毛囊的伸长过程中，具有定型行为的不对称分裂细胞维持毛囊生长。它们的功能被细胞凋亡的干预中断。因此，毛囊利用两种策略来维持自身。这说明了这样一种观点，即干细胞性与其说是细胞的特性，不如说是一个系统的特性，这个系统可以采取各种策略来实现其功能，即一个器官的长期维持。
The cyclic renewal of hair follicles offers an exclusive opportunity to study stem cells behaviors, that is their contributions and mode of maintenance. The hair follicle renewal comprises a growth phase of morphogenesis and elongation that is interrupted by a phase of massive apoptosis followed by a resting phase. The hair follicle contains two types of stem cells: stem cells that function during the growth phase and ensure the continuous elongation of the hair follicle and stem cells that maintain the hair follicle over cycles. Lineage-tracing analyses demonstrated a so far unexpected heterogeneity of contribution to the diverse hair follicle lineages among the long-term stem cells. This heterogeneity however does not reflect the heterogeneity of the stem cell markers identified to date and the contribution of a cell likely depends on the position adopted by its descendants. Moreover, recent studies demonstrated that the pool of long-term stem cells was highly dynamic, undergoing rounds of depletion and replenishment by symmetrical division and contribution of cells from the previously called non-permanent differentiated part of the hair follicle. In contrast, during the elongation of the hair follicle, asymmetrically dividing cells with stereotypical behaviors sustain hair follicle growth. Their functioning is interrupted by the intervention of apoptosis. Therefore, the hair follicle utilizes two strategies to maintain itself. This illustrates the notion that stemness is not so much the properties of a cell but the properties of a system that can adopt various strategies to achieve its function, the long-term maintenance of an organ.