The regulation of keratinocyte stem cells

描述（由申请人提供）：角化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，并且被认为是遗传性和获得性皮肤病的重要参与者。因此，识别调节其数量和增殖潜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参与角化细胞干细胞调控的基因。该策略利用了我们实验室最近取得的几项重要进展：1)鉴定毛囊干细胞的可选择标记，2)开发克隆性角化细胞干细胞的敏感和定量体外检测，3)与干细胞数量相关的几个位点的遗传定位，干细胞基因表达分析，以及4)角化细胞干细胞基因表达分析。本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，有特定的基因和途径调节角质细胞干细胞的数量，这可能不同于那些调节转运扩增细胞的基因和途径。specific Aim 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Specific Aim 2中，我们将使用候选基因方法进行干细胞基因鉴定；包括已经确定的Bmps基因序列变异的功能意义。在目标3中，我们将使用互补的全球基因组方法来识别相关的分子途径，并评估在数量性状位点缺乏编码序列差异的情况下导致基因表达差异的调控多态性。我们在本提案中详细的研究将使角化细胞干细胞的主要基因和调控途径的鉴定成为可能。这项研究将影响皮肤生物学和干细胞研究领域，并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设计慢性增殖性皮肤病、无法愈合的伤口和皮肤癌的新治疗方式非常重要。

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.