Regulators of epidermal growth and differentiation

项目总结/摘要 背景：表皮分化的流行模型是转录调控， RNA聚合酶II因子仅在分化基因启动子启动。 诱导分化。有可能转录的下游机制 转录起始如转录延伸可以对调节 表皮生长和分化。我们已经证明，比延伸因子 如ELL和ELL 2是表皮生长所必需，而SPT 6是 通过控制转录延伸来分化。 目的/假设：该提案旨在了解表皮细胞的调节， 干细胞和祖细胞通过转录延伸自我更新和分化。 我们已经发现高达30%的诱导表皮分化基因含有 在干细胞和祖细胞中启动子近端暂停的RNA聚合酶II。后 分化，特异性延伸因子如SPT 6是促进细胞分化所必需的。 这些暂停的分化基因的转录延伸。在干细胞和祖细胞中 细胞中也有延伸因子，促进生长的转录， 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分化中的作用 （2）延伸因子如何控制表皮生长和分化的机制 分化 研究设计：为了在更临床相关的环境中研究表皮稳态，我们 生成三维完整的人类皮肤，包含人类表皮细胞（其 已被永久敲除的转录延伸因子） 人真皮基质和基底膜，免疫再生 妥协的老鼠通过使用该模型，我们可以对 转录延伸因子在再生人皮肤中的作用 在表皮生长和分化中的作用。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伸因子 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.