Université Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium.
Nature. 2012 Sep 13;489(7415):257-62. doi: 10.1038/nature11393.
The skin interfollicular epidermis (IFE) is the first barrier against the external environment and its maintenance is critical for survival. Two seemingly opposite theories have been proposed to explain IFE homeostasis. One posits that IFE is maintained by long-lived slow-cycling stem cells that give rise to transit-amplifying cell progeny, whereas the other suggests that homeostasis is achieved by a single committed progenitor population that balances stochastic fate. Here we probe the cellular heterogeneity within the IFE using two different inducible Cre recombinase–oestrogen receptor constructs targeting IFE progenitors in mice. Quantitative analysis of clonal fate data and proliferation dynamics demonstrate the existence of two distinct proliferative cell compartments arranged in a hierarchy involving slow-cycling stem cells and committed progenitor cells. After wounding, only stem cells contribute substantially to the repair and long-term regeneration of the tissue, whereas committed progenitor cells make a limited contribution.
皮肤毛囊间表皮（IFE）是抵御外部环境的第一道屏障，其维持对于生存至关重要。有两种看似相反的理论被提出来解释 IFE 的稳态。一种认为 IFE 是由产生过渡扩增细胞后代的长寿慢循环干细胞维持的，而另一种则认为稳态是通过平衡随机命运的单一定向祖细胞群体来实现的。在这里，我们使用两种不同的诱导型 Cre 重组酶-雌激素受体构建体在小鼠中靶向 IFE 祖细胞，来探测 IFE 内的细胞异质性。克隆命运数据的定量分析和增殖动力学表明，存在两个不同的增殖细胞区室，它们按涉及慢循环干细胞和定向祖细胞的层次排列。在创伤后，只有干细胞对组织的修复和长期再生做出重大贡献，而定向祖细胞的贡献有限。
