Hair follicle bulge cells in tumorigenesis and alopecia

该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、毛囊和角膜的持续再生。我们最初发现了 毛囊凸起处的上皮干细胞。然后，我们分离了一个角蛋白15启动子，其靶向转基因细胞中的隆突细胞。 小鼠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 结果表明，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。在这份赠款中， 应用程序，我们将： 1.评估隆突细胞中上调的基因是否对维持毛囊干细胞表型很重要： 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 就像毛囊干细胞一样。 B.使用我们的KlSCrePrl小鼠特异性阻断隆突细胞中的候选基因通路， 尤其是隆突细胞中的基因 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产生可诱导的转基因小鼠，其中候选基因在隆突细胞中过表达 诱导系统，和 B.使用以下方法在隆突细胞及其后代中特异性地删除候选“隆突激活”或谱系决定基因： KlSCrePRl小鼠。 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.我们将描绘毛囊干细胞和祖细胞在小鼠和人类毛囊的基础上， 细胞表面蛋白表达模式。毛囊内这些不同的细胞亚群将被 通过荧光激活细胞分选分离，以及它们的干细胞性质、基因表达模式和功能 特征将被发现。 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受益 从这项研究中。

The long term goal of this project is to better understand epithelial stem cell biology. Epithelial stem cells are responsible for the continual 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 importantfor maintaining the hair follicle stem cell phenotype by: a. overexpressing candidate genes in non-hairfollicle 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 KlSCrePrl 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 bulge cells using an RU486 inducible system, and b. deleting candidate "bulge activation" or lineage determining genes specifically in bulge cells and their progeny using theKlSCrePRl 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.