Transcriptional regulation of skin stem cells and their niche

项目摘要： 这项研究的首要目标是了解皮肤干细胞是如何维持 当响应细胞内在和外在信号进行自我更新时， 分化干细胞的自我更新是通过对称或不对称的细胞 分裂，通过分裂产生新一代的干细胞以补充干细胞 人口然而，成体干细胞的DNA复制和细胞分裂也可导致 DNA突变的产生和积累损害干细胞功能， 有些情况下是肿瘤形成在皮肤中，毛囊干细胞获得静止， 细胞更新和分裂。然而，人们对这些干细胞是如何产生的仍然知之甚少。 自我更新和静止阶段之间的过渡和静止的要求， 干细胞的长期维持。这些问题对调查人员提出了挑战，因为 这些自我更新和静止的干细胞在大多数成年人中是罕见的， 组织，使其分离和表征困难。在早期成年小鼠的皮肤中， 毛囊干细胞高度同步地进行自我更新和静止。此属性使 毛囊干细胞是研究干细胞中这一基本问题的理想系统 生物学最近，我们发现了一种转录因子Foxc 1，它可以诱导自我更新，但 而不是静止的毛囊干细胞和它们的小生境来加强静止。这一发现 揭示了静止干细胞在自我激活过程中对干细胞激活的适应性反应。 更新，并阐明了进一步研究控制细胞状态的机制的途径 成体干细胞的转变在这项提案中，我们将利用我们创新的基因组工具， 了解干细胞静止和自我更新的适应性控制的小鼠模型 由转录因子介导。我们将首先确定多种转录因子 调节干细胞静止通过协调转录控制的共同和独特的 目标的我们将确定长期保持头发静止的要求 卵泡干细胞（Aim 1）。然后，我们将研究开放染色质的差异， 自我更新和静止的干细胞。我们将研究BMP信号是如何被 转录因子（Aim 2）。最后，我们将探讨棒毛锚定的机制 由转录因子介导（Aim 3）。从这些研究中获得的知识将 增强我们对毛囊干细胞静止控制的理解。

Project Summary: The overarching goal of the proposed research is to understand how skin stem cells maintain their identity when responding to cell intrinsic and extrinsic signals for self-renewal or differentiation. Self-renewal of stem cells is achieved by either symmetrical or asymmetrical cell division, through which new generations of stem cells are produced to replenish the stem cell population. However, DNA replication and cell division of adult stem cells can also lead to generation and accumulation of DNA mutations that compromise stem cell function and, in some cases, tumorigenesis. In the skin, hair follicle stem cells acquire quiescence to minimize cell turnover and division. However, it remains poorly understood how these stem cells transition between self-renewing and quiescent phases and the requirement of quiescence for long-term maintenance of stem cells. These questions have challenged investigators, because these self-renewing and quiescent stem cells are rare and usually heterogeneous in most adult tissues, making their isolation and characterization difficulty. In the skin of early adult mice, hair follicle stem cells are highly synchronized for self-renewal and quiescence. This property makes hair follicle stem cells an ideal system to investigate this fundamental question in stem cell biology. Recently, we have identified a transcription factor, Foxc1, induced in self-renewing but not quiescent hair follicle stem cells and their niche to reinforce quiescence. This finding uncovers an adaptive response of quiescent stem cells to stem cell activation during self- renewal and illuminates a path to further investigate mechanisms that control cellular state transitions in adult stem cells. In this proposal, we will utilize our innovative genomic tools and mouse models to understand adaptive control of stem cell quiescence and self-renewal mediated by transcription factors. We will first determine how multiple transcription factors regulate stem cell quiescence by coordinating transcriptional control of common and unique targets. We will determine the requirement of quiescence for long-term maintenance of hair follicle stem cells (Aim 1). We will then investigate the differences in open chromatin between self-renewing and quiescent stem cells. We will examine how the BMP signaling is controlled by transcription factors (Aim 2). Finally, we will investigate the mechanism of club hair anchorage mediated by transcription factors (Aim 3). The knowledge gained from these studies will enhance our understanding of quiescence control in hair follicle stem cells.