Cellular and Molecular Mechanisms of Dermal Sheath Formation and Function

真皮鞘形成和功能的细胞和分子机制

基本信息

批准号：
9191501
负责人：
Nicholas Heitman
金额：
$ 3.88万
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：
2016
资助国家：
美国
起止时间：
2016-07-06 至 2019-07-05
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9191501
关键词：
Ablation Age Biological Biological Models Biology Cell Maintenance Cell Separation Cells Data Dermal Development Diphtheria Toxin Disease Embryo Epithelial Cells Fibroblasts Future Gene Expression Profile Gene Expression Regulation Gene Targeting Genes Genetic Goals Growth Hair Hair Diseases Hair follicle structure Hair shaft structure Homeostasis Knockout Mice Knowledge Label Longevity Maintenance Mesenchymal Mesenchyme Methods Molecular Molecular Profiling Morphogenesis Multipotent Stem Cells Mus Natural Killer Cells Natural regeneration Physiologic pulse Population Proliferating Regulation Reporter Role Signal Transduction Skin Source Specific qualifier value Stem cells System Technology Testing Time Work clinical application cytotoxic genetic signature in vivo innovation insight molecular dynamics novel novel therapeutics progenitor regenerative therapy research study stem stem cell niche tongue papilla tool transcription factor transcriptome sequencing

项目摘要

Summary The hair follicle (HF) is an excellent model system to study the molecular cross-talk between stem/progenitor cells with their niche microenvironment. During early hair morphogenesis, hair follicle-specified epithelial cells in hair placodes receive directive niche signals from specialized cells in dermal condensates (DC) that are the precursors of the mature HF mesenchyme, the dermal papilla (DP) and the dermal sheath (DS). After embryonic hair follicle formation, cells in the DP continue to send signals to rapidly proliferating transit amplifying cells during hair growth, and are critical for activating stem cells to initiate hair follicle regeneration during the hair cycle. The role of DS is much less clear, but recently DS has been implicated as a source of new DP over a lifespan by contributing cells to the DP compartment. Despite these insights, several fundamental questions remain to be answered: (1) What is the lineage and functional relationship between DS and DP? (2) What are essential functions of the DS for hair follicle growth? (3) What are the molecular mechanisms that govern DS identity and function? The goal of this work is to answer these fundamental questions by employing our recently established genetic tools to specifically label and target the mature DS and its embryonic precursors. We have previously established the methods to lineage-trace the DS and its precursors, purify for the first time DS cells separately from DP, define a DS-specific gene signature, test the requirement of DS for hair follicle growth, and target the DS for gene ablation, thereby altogether opening up the opportunity to study the core biological DS functions. This proposal aims to define the cellular dynamics and molecular mechanisms of the formation of the DS and its functions as a niche component. I will determine the clonal and proliferative dynamics with pulse- chase label retention experiments and lineage tracing of single-cell labeled DCs using established genetic targeting tools with reporter mice. I will also use an inducible labeling system to determine the proliferative dynamics of niche cells during follicle formation and growth. Additionally, I will selectively ablate the DS in hair follicles to determine their role in follicle growth and maintenance using genetic targeting tools and the inducible diphtheria toxin cytotoxic ablation system. Further, I will define the gene expression signature of the DS through systems-level analysis of our lab’s recently generated RNA-sequencing data from in vivo isolated cells. Finally, I will further investigate the role of the DS in the HF by gene ablation of the recently identified sheath transcription factor, Satb2, using genetic targeting tools and a conditional knock-out mouse line of Satb2. The strengths of this proposal lies in its innovation of using novel mouse tools to target mesenchymal niche cells within the hair follicle, and its potential to generate translatable findings for the development of future clinical applications.

概括毛囊（HF）是研究干/祖细胞之间分子串扰的优秀模型系统细胞及其生态位微环境在早期毛发形态发生过程中，毛囊特异的上皮细胞。毛发基板接收来自真皮凝结物 (DC) 中的特殊细胞的指令性生态位信号，这些细胞是成熟 HF 间充质、真皮乳头 (DP) 和真皮鞘 (DS) 的前体。胚胎毛囊形成时，DP中的细胞不断向快速增殖的转运发送信号在毛发生长过程中放大细胞，对于激活干细胞以启动毛囊再生至关重要 DS 在头发周期中的作用尚不清楚，但最近 DS 被认为是头发周期的一个来源。尽管有这些见解，但在整个生命周期中通过向 DP 室贡献细胞来形成新的 DP。有待回答的基本问题是：（1）DS 之间的谱系和功能关系是什么？和 DP？ (2) DS 对毛囊生长的基本功能是什么？这项工作的目标是回答这些基本原理？通过使用我们最近建立的遗传工具来专门标记和定位成熟的 DS 来解决问题我们之前已经建立了 DS 及其胚胎前体的谱系追踪方法。前体，首次与 DP 分开纯化 DS 细胞，定义 DS 特异性基因特征，测试 DS对毛囊生长的要求，从而针对DS进行基因消融，完全开放研究 DS 核心生物功能的机会。该提案旨在定义细胞动力学和形成的分子机制 DS 及其作为利基组件的功能我将通过脉冲确定克隆和增殖动力学。使用已建立的遗传追踪单细胞标记 DC 的追踪标记保留实验和谱系追踪我还将使用诱导标记系统来确定增殖情况。此外，我将选择性地消除头发中的 DS。使用遗传靶向工具和方法来确定它们在卵泡生长和维持中的作用此外，我将定义诱导白喉毒素细胞毒性消融系统的基因表达特征。 DS 通过对我们实验室最近生成的体内分离的 RNA 测序数据进行系统级分析最后，我将通过最近鉴定的基因消融来进一步研究 DS 在 HF 中的作用。鞘转录因子 Satb2，使用遗传打靶工具和条件性敲除小鼠品系 Satb2.该提案的优点在于其创新性地使用新颖的小鼠工具来靶向间充质。毛囊内的生态位细胞，及其为发展产生可转化发现的潜力未来的临床应用。