Dermal Papilla Regulation and Function for Stem Cell Activation in the Hair Cycle

毛乳头对毛发周期中干细胞激活的调节和功能

基本信息

批准号：
10132732
负责人：
Michael Rendl
金额：
$ 47.38万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10132732
关键词：
Ablation Adipocytes Adult Biological Models Biological Process Cell Separation Cells Cre driver Data Dermal Dermis Development Embryo Event Fibroblasts Future Gene Expression Gene Expression Profiling Gene Expression Regulation Gene Targeting Genes Genetic Germ Goals Hair Hair follicle structure Injections Instruction Investigation Knowledge Label Ligands Link Mediating Mesenchymal Mesenchyme Methods Molecular Molecular Analysis Molecular Profiling Mus Natural regeneration Periodicity Physiologic pulse Platelet-Derived Growth Factor Platelet-Derived Growth Factor alpha Receptor Play Publishing Regulation Resolution Rest Role Signal Pathway Signal Transduction Skin Study models Technology Testing Tissue Engineering Work adult stem cell cell type cytokine experimental study gene function genetic signature germline stem cells hair regeneration improved insight novel regenerative therapy stem cell function stem cells therapy development tongue papilla tool

项目摘要

Project Summary The hair follicle (HF) cycle is an excellent model for studying adult stem cell (SC) regulation by the microenvironment or niche, as it involves cyclical bouts of destruction (catagen), rest (telogen) and regrowth (anagen). Signals from the dermal papilla (DP) – a cluster of mesenchymal HF cells – are thought to induce a switch from a resting to an activated state in bulge/germ SCs during the telogen-to-anagen transition of the hair cycle. However, due to the lack of direct genetic tools for robust, inducible targeting of the telogen DP for gene ablation, the functional evidence for a role of the DP in SC activation is largely indirect. We also know little about the long-term fate and potential of the adult DP and its lineage relationships to the dermal sheath and fibroblasts. Finally, the precise molecular repertoire of the adult DP during the hair cycle has remained poorly defined, due to the limitations of DP isolation and gene expression analysis in previous studies. We recently established genetic labeling strategies for the specific isolation and molecular characterization of embryonic DP precursors and the DP from growing HFs, making it possible to identify their molecular signatures. We then developed embryonic DP-specific gene targeting tools and explored the role of DP signature genes during HF formation. We have now further established the conditions for the robust and inducible genetic targeting of the telogen DP, thus enabling exploration of the cellular turnover and clonal lineage relationships in the DP along with investigation into the molecular mechanisms underlying DP instruction of HF activation during the telogen- to-anagen transition. In these studies, we will rigorously test the hypothesis that the telogen DP serves as a SC-activating niche during the hair cycle. We will establish Crabp1 as the first robust, inducible genetic driver for Cre-mediated targeting of the telogen DP. We will then use Crabp1iCreER mice to determine, with spatial and temporal precision, the cellular turnover of the DP and its lineage relationship to the neighboring dermal sheath and the skin mesenchyme, through genetic fate mapping and pulse-chase label retention experiments, gaining insight into DP identity and lineage potential. We will use our novel driver to ablate PDGFRα and PDGFRβ in the telogen DP, assess SC activation status in the bulge/germ, the impact of the loss of PDGF signaling on hair regeneration, and decipher the molecular mechanisms underlying the PDGF signaling-driven DP functions regulating SC activation. We will isolate pure DP, bulge/germ SCs and related cell types at key hair cycle stages, and systematically define their molecular signatures throughout the hair cycle, with unprecedented cellular resolution and sensitivity of gene expression discovery. We will then investigate the functional role of Nr3c1 and other newly identified DP signature genes, by gene ablation with Crabp1iCreER in the telogen DP. With this work, we will greatly expand our knowledge of SC regulation by these niche cells, which will be essential for the development of treatments involving the regeneration of functional skin, including HFs.

项目概要毛囊 (HF) 周期是研究成体干细胞 (SC) 调节的绝佳模型微环境或生态位，因为它涉及破坏（退行期）、休息（休止期）和再生的周期性发作（生长期）来自真皮乳头 (DP)（一组间充质 HF 细胞）的信号被认为会诱导在头发的休止期到毛发生长初期的转变过程中，凸起/胚芽 SC 从静止状态切换到激活状态然而，由于缺乏直接的遗传工具来对基因的休止期 DP 进行稳健、诱导性靶向。消融方面，DP 在 SC 激活中的作用的功能证据在很大程度上是间接的，我们也知之甚少。关于成年 DP 的长期命运和潜力及其与真皮鞘的谱系关系最后，成体 DP 在毛发周期中的精确分子库仍然很差。定义，由于我们最近的研究中DP分离和基因表达分析的局限性。建立了胚胎特异性分离和分子表征的基因标记策略 DP 前体和来自生长 HF 的 DP，使我们能够识别它们的分子特征。开发了胚胎 DP 特异性基因靶向工具并探索了 DP 特征基因在 HF 期间的作用我们现在已经进一步建立了稳健和可诱导的基因靶向的条件。休止期 DP，从而能够探索 DP 中的细胞更新和克隆谱系关系研究休止期 DP 指令 HF 激活的分子机制在这些研究中，我们将严格检验休止期 DP 作为一个假设。我们将把 Crabp1 建立为第一个强大的、可诱导的遗传驱动因素。然后，我们将使用 Crabp1iCreER 小鼠来确定 Cre 介导的休止期 DP 的定位。时间精度、DP 的细胞更新及其与邻近真皮鞘的谱系关系和皮肤间质，通过遗传命运图谱和脉冲追踪标签保留实验，获得我们将使用我们的新型驱动程序来消除 DP 身份和谱系潜力。休止期 DP，评估凸起/胚芽中的 SC 激活状态，PDGF 信号传导丧失对头发再生，并破译 PDGF 信号驱动 DP 功能的分子机制我们将在关键毛发周期分离纯 DP、凸出/胚芽 SC 和相关细胞类型。阶段，并系统地定义其在整个头发周期中的分子特征，具有前所未有的然后我们将研究基因表达发现的细胞分辨率和敏感性。 Nr3c1 和其他新鉴定的 DP 特征基因，通过使用 Crabp1iCreER 在 DP 休止期进行基因消融。通过这项工作，我们将极大地扩展我们对这些利基细胞 SC 调节的了解，这将是对于开发涉及功能性皮肤再生（包括 HF）的治疗方法至关重要。