Regulators of epidermal growth and differentiation

项目摘要/摘要 背景：表皮分化的普遍模式是转录 因子仅在分化基因启动子上招募RNA聚合酶II 诱导分化。有可能转录下游的机制 转录延伸等启动可能对调控产生重大影响 表皮生长和分化。我们已经证明了特定的伸长系数 如ELL和ELL2是表皮生长所必需，而SPT6是表皮生长所必需的 通过控制转录伸长进行分化。 目的/假设：这项提议试图了解表皮的调节 干细胞和祖细胞通过转录延伸进行自我更新和分化。 我们发现，高达30%的诱导表皮分化基因含有 启动子近端暂停了干细胞和祖细胞中的RNA聚合酶II。vt.在.的基础上 分化，特殊的伸长因子如SPT6是必要的促进 这些暂停的分化基因的转录延长。在茎和祖细胞中 细胞也有伸长因子，可以促进转录生长和 增殖基因，以允许表皮更新。 具体目的：(1)转录延伸因子在表皮生长和生长中的作用 分化(2)伸长因子控制表皮生长的机制 差异化。 研究设计：为了在更具临床相关性的环境中研究表皮动态平衡，我们 生成三维完整的人类皮肤，包含人类表皮细胞(即 已经被永久地去除转录延伸因子)在上下文中 人体真皮基质和基底膜，免疫后再生 受损的老鼠。利用这一模型，我们可以进行功能损失实验。 人再生皮肤中转录延伸因子的作用研究 在表皮的生长和分化中。我们还将使用染色质免疫沉淀 然后进行下一代测序，以确定哪些基因是延长因子 约束和规范。

Project Summary/Abstract Background: The prevailing model of epidermal differentiation is that transcription factors recruit RNA Polymerase II to differentiation gene promoters only upon the induction of differentiation. It is possible that mechanisms downstream of transcription initiation such as transcriptional elongation can have major impacts on regulating epidermal growth and differentiation. We have shown that specific elongation factors such as ELL and ELL2 are necessary for epidermal growth while SPT6 is essential for differentiation through the control of transcription elongation. Objective/hypothesis: This proposal seeks to understand the regulation of epidermal stem and progenitor cell self-renewal and differentiation through transcription elongation. We have found that up to 30% of induced epidermal differentiation genes contain promoter proximal paused RNA polymerase II in stem and progenitor cells. Upon differentiation, specific elongation factors such as SPT6 are necessary to promote the transcriptional elongation of these paused differentiation genes. In stem and progenitor cells there are also elongation factors that promote the transcription of growth and proliferation genes to allow for epidermal renewal. Specific Aims: (1) The role of transcription elongation factors on epidermal growth and differentiation (2) Mechanisms on how elongation factors control epidermal growth and differentiation. Study Design: To study epidermal homeostasis in a more clinically relevant setting, we generate 3-dimensionally intact human skin, containing human epidermal cells (that have been permanently knocked down for transcription elongation factors) in the context of human dermal stroma and basement membrane, regenerated on immune compromised mice. By using this model, we can perform loss of function experiments on the transcription elongation factors in regenerated human skin to characterize their role in epidermal growth and differentiation. We will also use chromatin immunoprecipitations followed by next generation sequencing to determine which genes the elongation factors bind and regulate.