Nature: 指甲控制指头再生

2013/07/23 21:43:09

小鼠和人类的指尖再生是哺乳动物器官再生的一个引人注目的例子。然而，这种能力是非常有限的：如果指头在超过指甲的地方被截掉的话是从不会再生的。 Mayumi Ito及其同事为这一过程提供了新见解。他们发现，控制小鼠指甲干细胞分化的机制直接耦合到其协调指头再生的能力上。位于指甲干细胞区域远端的指甲祖细胞在一个依赖于Wnt信号作用的过程中分化成指甲。Wnt信号作用的激发也是指甲再生以及吸引那些促进整个指头在切除后再生的神经所必需的。作者提出，指甲干细胞也许可用于为截肢者开发新的治疗方法。

Wnt activation in nail epithelium couples nail growth to digit regeneration

doi: 10.1038/nature12214

Makoto Takeo, Wei Chin Chou, Qi Sun, Wendy Lee, Piul Rabbani, Cynthia Loomis, M. Mark Taketo, Mayumi Ito

The tips of mammalian digits can regenerate after amputation1, 2, like those of amphibians. It is unknown why this capacity is limited to the area associated with the nail2, 3, 4. Here we show that nail stem cells (NSCs) reside in the proximal nail matrix and that the mechanisms governing NSC differentiation are coupled directly with their ability to orchestrate digit regeneration. Early nail progenitors undergo Wnt-dependent differentiation into the nail. After amputation, this Wnt activation is required for nail regeneration and also for attracting nerves that promote mesenchymal blastema growth, leading to the regeneration of the digit. Amputations proximal to the Wnt-active nail progenitors result in failure to regenerate the nail or digit. Nevertheless, β-catenin stabilization in the NSC region induced their regeneration. These results establish a link between NSC differentiation and digit regeneration, and suggest that NSCs may have the potential to contribute to the development of novel treatments for amputees.