Hair follicle bulge cells in tumorigenesis and alopecia

描述（由申请人提供）：本项目的长期目标是更好地了解上皮干细胞生物学。上皮干细胞负责自我更新组织如表皮、毛囊和角膜的再生。我们最初在毛囊的隆起处发现了假定的上皮干细胞。然后，我们分离出一个角蛋白15启动子，在转基因小鼠的目标隆突细胞。K15启动子允许毛囊干细胞的分离、谱系分析和分子表征。我们发现，隆突细胞具有干细胞的特性，分离的隆突细胞可以重建毛囊、表皮和皮脂腺。我们现在已经确定了一些基因，我们假设保持干细胞表型。在此补助金申请中，我们将： 1. 通过以下方式评估隆突细胞中上调的基因对于维持毛囊干细胞表型是否重要： a. 在转基因小鼠的非毛囊干细胞中过表达候选基因，然后测试这些细胞是否表现为毛囊干细胞。 B. 使用我们的Kl 5CrePrl小鼠特异性地阻断隆突细胞中的候选基因途径，以在隆突细胞中特异性地缺失或过表达基因。 2. 通过以下方式确定在休止期隆突细胞中下调的基因是否参与干细胞活化和/或谱系确定： a.使用RU 486诱导系统产生诱导型转基因小鼠，其中候选基因在凸出细胞中过表达，和 B.特异性地在隆突细胞中删除候选“隆突激活”或谱系决定基因 和它们的后代。 3. 开发用于分离和表征人类毛囊干细胞的方法。 a.我们将确定在小鼠隆突中鉴定的基因是否也在人类隆突中表达。 B.我们将描述小鼠和小鼠体内的毛囊干细胞和祖细胞， 基于细胞表面蛋白表达模式的人毛囊。毛囊内这些不同的细胞亚群将通过荧光激活细胞分选分离，并识别其干细胞性质、基因表达模式和功能特征。 患有脱发、毛干疾病、基底细胞癌、毛囊肿瘤或慢性伤口的患者可能会从这项研究中受益。

DESCRIPTION (provided by applicant): The long term goal of this project is to better understand epithelial stem cell biology. Epithelial stem cells are responsible for the regeneration of self-renewing tissues such as epidermis, hair follicle, and cornea. We originally identified putative epithelial stem cells in the bulge of the hair follicle. We then isolated a keratin 15 promoter that targets bulge cells in transgenic mice. The K15 promoter allowed for the isolation, lineage analysis and molecular characterization of hair follicle stem cells. We showed, that bulge cells have properties of stem cells, and isolated bulge cells can reconstitute hair follicles, epidermis and sebaceous glands. We have now identified a number of genes which we hypothesize maintain the stem cell phenotype. In this grant application we will: 1. evaluate whether genes upregulated in the bulge cells are important for maintaining the hair follicle stem cell phenotype by: a. overexpressing candidate genes in non-hair follicle stem cells of transgenic mice, and then testing whether these cells behave as hair follicle stem cells. b. blocking candidate gene pathways specifically in the bulge cells using our Kl5CrePrl mice to delete or overexpress genes specifically in the bulge cells. 2. determine if genes downregulated in telogen bulge cells are involved in stem cell activation and/or lineage determination by: a. generating inducible transgenic mice in which candidate genes are over-expressed in bulgecells using an RU486 inducible system, and b. deleting candidate "bulge activation" or lineage determining genes specifically in bulge cells and their progeny using theKlSCrePR l mice. 3. develop means for isolating and characterizing human hair follicle stem cells. a. We will establish whether genes identified in mouse bulge are also expressed in human bulges. b. We will delineate hair follicle stem and progenitor cells within both the mouse and human hair follicle based on cell surface protein expression patterns. These distinct subpopulations of cells within the hair follicle will be isolated by fluorescent activated cell sorting, and their stem cell nature, gene expression patterns and functional characteristics will be discerned. Patients with alopecia, hair shaft disorders, basal cell carcinoma, hair follicle tumors, or chronic wounds could potentially benefit from this research.