The regulation of keratinocyte stem cells

描述(申请人提供)：角质形成细胞干细胞在维持表皮和毛囊的正常结构和功能方面具有毋庸置疑的作用，被认为是遗传性和获得性皮肤病的重要参与者。因此，识别调控其数量和增殖能力的基因是皮肤生物学中的一个关键问题。我们在这里提出了一种新的策略来识别涉及角质形成细胞干细胞调控的基因。这一策略利用了我们实验室最近取得的几个重要进展：1)毛囊干细胞上可选择的标记的鉴定，2)克隆性角质形成干细胞体外灵敏和定量的检测，3)与干细胞基因表达的干细胞数量分析连锁的多个基因座的遗传作图，以及4)角质形成细胞干细胞基因表达的分析。这项拟议的研究的目的是确定调节角质形成细胞干细胞数量的主要基因。我们的假设是，存在特定的基因和途径来调节角质形成细胞干细胞的数量，这些基因和途径可能不同于那些调节转运放大细胞的基因和途径。具体目标1的重点是使用遗传工具来完善我们已经确定的连锁间隔。在具体目标2中，我们将使用候选基因方法进行干细胞基因鉴定；包括已鉴定的BMPS基因中序列变体的功能意义。在目标3中，我们将使用互补的全球基因组方法来确定相关的分子途径，并在数量性状基因座内没有编码序列差异的情况下评估导致基因表达差异的调控多态。我们在这项提案中详细介绍的研究将使我们能够识别角质形成细胞干细胞中的主要基因和调控途径。这项研究将对皮肤生物学和干细胞研究领域产生影响，并将为皮肤癌的发生机制提供新的见解。干细胞调控基因的鉴定对于基因治疗以及慢性增生性皮肤病、无法愈合的伤口和皮肤癌的新治疗方式的设计都是重要的。

DESCRIPTION (provided by applicant): Keratinocyte stem cells have an unquestioned role in maintaining the normal structure and function of the epidermis and hair follicles and are thought to be important players in inherited and acquired skin disease. Hence, identification of genes regulating their number and proliferative potential is a critical problem in cutaneous biology. We propose here a novel strategy for identifying genes involved in keratinocyte stem cell regulation. This strategy takes advantage of several recent important advances made in our laboratory: 1) identification of a selectable marker on hair follicle stem cells, 2) development of a sensitive and quantitative in vitro assay for clonogenic keratinocyte stem cells, 3) genetic mapping of several loci with linkage to stem cell number analysis of stem cell gene expression, and 4) analysis of keratinocyte stem cell gene expression. The objective of this proposed research is to identify major genes regulating the number of keratinocyte stem cells. Our hypothesis is that there are specific genes and pathways that regulate the number of keratinocyte stem cells that may be different from those regulating transit-amplifying cells The focus of Specific Aim 1 is to use genetic tools to refine the linkage intervals we have already identified. In Specific Aim 2 we will use a candidate gene approach for stem cell gene identification; including the functional significance of the sequence variant in the Bmps gene already identified. In Aim 3, we will use a complementary global genomic approach to identify associated molecular pathways, and to assess regulatory polymorphisms causing differences in gene expression in the absence of coding sequence differences within the quantitative trait locus. The investigation we detail in this proposal will enable the identification of major genes and regulatory pathways in keratinocyte stem cells. This research will impact the fields of cutaneous biology and stem cell research and should provide new insight into the mechanism of skin carcinogenesis. Identification of stem cell regulatory genes is important for gene therapy as well as for the design of new therapeutic modalities for chronic hyperproliferative skin disease, for wound that do not heal, and for skin cancer.