Molecular & cellular biology of hair follicle stem cells

描述(由申请人提供)：本项目的总体目标是 鉴定毛囊干细胞内基因的表达，并 研究特定基因在维持干细胞表型中的作用。这个 毛囊是研究上皮干细胞和理解 维持毛囊干细胞动态平衡的机制 可能导致在肿瘤发生、伤口愈合和头发领域取得进展 精神错乱。类似于其他自我更新的组织，如骨髓， 胃肠道和表皮，毛囊内含有缓慢循环 具有高增殖能力和生产能力的干细胞 分化的细胞以再生组织。然而，与其他组织不同的是， 毛囊生长(生长期)被退化期(退化期)打断 和休眠(休眠)，随后再生。因为下层卵泡 在退化期退化，只留下休止期的杆状结构，这 俱乐部毛发周围残留的上皮帽代表着丰富的来源 负责再生新的较低卵泡的干细胞 阿尼根。他们从富含干细胞的端粒酶原区域提取了核糖核酸。 以及从生长期卵泡球部区域分离出来的卵泡 人类头皮。通过cdna表达阵列，一些基因似乎是 在干细胞区表达，而在基质角质形成细胞中不表达 生长期的灯泡。其中几个基因已被证明在 其他实验动物的增殖行为和分化途径 系统。 在这项提议中要检验的假设是特定的基因 在毛囊干细胞中的表达对维持 干细胞的特性。具体目标是：1.对表情进行特色化 通过原位表达阵列鉴定的特定基因 共聚焦杂交、免疫组织化学和免疫荧光 显微镜。三个可能对维持干细胞有作用的基因 将检查属性。2.检验这三个基因的显著性 毛囊干细胞体外维持特性的实验研究 逆转录病毒转染人毛囊干细胞野生型和 突变的基因结构。克隆性测定及其他体外实验 天然的和转基因的干细胞将被用于研究这些基因的作用。 克隆性和其他干细胞属性。3.测试服务器的功能 毛囊发育和体外循环过程中的特异性基因 和活体方法。用天然和非天然的头发重建分析 转基因干细胞将被用来分析 卵泡发生和周期。除了已经建立的老鼠毛 重建系统，他们将尝试开发一个人类毛囊 毛囊干细胞与显微解剖真皮构建系统的研究 应用脱细胞真皮类似物移植到裸体上的乳头 老鼠。

DESCRIPTION (provided by applicant): The overall goal of this project is to characterize the expression of genes within hair follicle stem cells and to study the role of specific genes in maintaining the stem cell phenotype. The hair follicle is a model for studying epithelial stem cells and understanding the mechanisms which maintain the homeostasis of hair follicle stem cells and may lead to advances in the areas of tumorigenesis, wound healing and hair disorders. Similar to other self renewing tissues, such as bone marrow, gastrointestinal tract and epidermis, the hair follicle contains slowly cycling stem cells with a high proliferative capacity and the ability to produce differentiated cells to regenerate the tissue. Unlike other tissues, however, hair follicle growth (anagen) is interrupted by periods of regression (catagen) and rest (telogen), with subsequent regeneration. Since the lower follicle degenerates in the catagen phase, leaving only the telogen club structure, this residual epithelial cap surrounding the club hair represents an enriched source of stem cells which are responsible for regenerating a new lower follicle in anagen. They have extracted RNA from the stem cell rich area of telogen follicles as well as from the bulb area of anagen follicles dissected from human scalp. Through cDNA expression arrays, a number of genes appear to be expressed in the stem cell area that are not expressed in matrix keratinocytes of the anagen bulb. Several of the genes have been shown to mediate proliferative behavior and differentiation pathways in other experimental systems. The hypothesis that will be tested in this proposal is that specific genes expressed in the stem cells of the hair follicle are important in maintaining stem cell properties. The specific aims are: 1. To characterize the expression of specific genes identified by the expression array through in situ hybridization, immunohistochemistry and immunofluorescence with confocal microscopy. Three genes which likely have roles in maintaining stem cell properties will be examined. 2. To test the significance of these three genes in maintaining in vitro properties of hair follicle stem cells through retroviral transfection of human hair follicle stem cells with wild type and mutant gene constructs. Clonogenicity assays and other in vitro experiments of native and transfected stem cells will be used to study the role of these genes in clonality and other stem cell attributes. 3. To test the function of the specific genes during hair follicle development and cycling through in vitro and in vivo methods. Hair reconstitution assays performed with native and genetically altered stem cells will be used to analyze potential functions in folliculogenesis and cycling. In addition to the established mouse hair reconstitution system, they will attempt to develop a human hair follicle reconstitution system from hair follicle stem cells and microdissected dermal papillae using acellular dermal analogues with transplantation onto athymic mice.