Slowly cycling cells and hair follicle stem cells

缓慢循环细胞和毛囊干细胞

• 批准号: 7275617
• 负责人: Tudorita Tumbar
• 金额: $ 1.59万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-16 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7275617
• 关键词: Mus musculus; cell differentiation; cell growth regulation; cell sorting; gene expression; genetically modified animals; hair follicle; microarray technology; regeneration; skin; stem cells; tissue /cell culture; wound healing

DESCRIPTION (provided by applicant): We are interested in elucidating the molecular mechanisms involved in tissue stem cell self-renewal and fate choice, in normal tissue development and homeostasis. Stem cells hold great promises for future therapies of numerous deadly diseases, yet their basic properties are not well understood. Progress in the field has been hampered by the difficulty of identifying tissue stem cells in the absence of specific biochemical markers. Increasing evidence suggested that stem cells are infrequently dividing cells, that could be identified in many mouse tissues as DMA label retaining cells (or LRCs). Recently we developed a strategy applicable to many self-regenerating tissues to pulse-label LRCs with the green fluorescent protein (GFP) fused to histone H2B. We have used the mouse skin and the hair follicle as model systems, since the relation between LRCs and skin epithelial stem cells had been investigated in most depth. In our preliminary work we tracked and isolated GFP LRCs and demonstrated that at least a fraction of these cells had a stem cell phenotype. In this proposal we describe in three Specific Aims strategies to examine in more detail the relation between LRCs and stem cells. We will: 1) classify LRCs into distinct sub- populations and investigate their sternness; 2) examine their special cell cycle properties; 3) characterize their distinct patterns of gene expression. To accomplish these goals we use in vivo cell tracking and in vitro cell sorting methods combined with a variety of assays which include: hair regeneration and skin wounding; cell culture and skin reconstitution; cell cycle kinetics; and microarrays. First, our data will have global relevance for the isolation and characterization of putative stem cells with LRCs properties from many tissues. Although we focus on the skin, our work will lead the way for similar approaches in many systems which lack the specific means to separate stem cells from other cells of their tissue of residence. Second, stem cell proliferation must be tightly controlled in tissues to regulate the balance between normal and abnormal growth. Our studies will unravel some of the mechanisms developed by putative SCs to control their proliferation, an important first step in understanding such perturbation in the diseased tissues. Finally, our work will provide some of the basic knowledge necessary for more efficient manipulation of skin stem cells for clinical applications such as cell transplantation on burn victims.

描述（由申请人提供）：我们感兴趣的是阐明在正常组织发育和稳态中，组织干细胞自我更新和命运选择所涉及的分子机制。干细胞为未来治疗许多致命疾病提供了巨大的希望，但其基本特性尚未得到很好的理解。在缺乏特异性生化标记的情况下，组织干细胞的识别困难阻碍了该领域的进展。越来越多的证据表明，干细胞是很少分裂的细胞，可以在许多小鼠组织中鉴定为DMA标记保留细胞（或LRC）。最近，我们开发了一种适用于许多自我再生组织的策略，用与组蛋白H2 B融合的绿色荧光蛋白（GFP）脉冲标记LRC。由于LRC与皮肤上皮干细胞之间的关系已被研究得最为深入，因此我们以小鼠皮肤和毛囊作为模型系统。在我们的初步工作中，我们跟踪和分离GFP LRC，并证明这些细胞中至少有一部分具有干细胞表型。在本提案中，我们在三个特定目标中描述了更详细地研究LRC和干细胞之间关系的策略。我们将：1）将LRC分类为不同的亚群并研究它们的干性; 2）检查它们特殊的细胞周期特性; 3）表征它们不同的基因表达模式。为了实现这些目标，我们使用体内细胞跟踪和体外细胞分选方法结合各种测定，包括：毛发再生和皮肤损伤;细胞培养和皮肤重建;细胞周期动力学;和微阵列。 首先，我们的数据将具有全球性的相关性，从许多组织中分离和表征具有LRC特性的假定干细胞。虽然我们专注于皮肤，但我们的工作将为许多系统中的类似方法开辟道路，这些系统缺乏将干细胞与其居住组织的其他细胞分离的特定方法。其次，干细胞增殖必须在组织中受到严格控制，以调节正常和异常生长之间的平衡。我们的研究将解开推定的干细胞控制其增殖的一些机制，这是了解患病组织中这种扰动的重要第一步。最后，我们的工作将提供一些必要的基础知识，更有效地操纵皮肤干细胞的临床应用，如烧伤患者的细胞移植。