Genomic-wide Analysis of Oct 3/4 and Nanog Targets

描述(申请人提供)：从小鼠水泡内细胞团中分离出的胚胎干细胞是多能性的，能够无限对称的细胞分裂，并可以产生嵌合体动物。最近分离的人类ES细胞为治疗各种退行性疾病带来了巨大的希望，包括但不限于帕金森氏症和糖尿病。同源结构域转录因子Oct3/4和Nanog被认为在维持ES细胞的多能性方面发挥关键作用。令人惊讶的是，Nanog的目标完全未知，10月3日/4日提出的目标也很少。因此，抑制ES细胞分化和促进自我更新的分子机制尚不清楚。我们开发了一种新的方法来识别复杂的后生动物调节子，称为染色质占用序列分析(SACO)，它结合了染色质免疫沉淀和Long SAGE的修饰。我们将使用SACO在小鼠ES细胞中识别完整的Nanog和Oct3/4基因组靶标。这些知识不仅将有助于确定干细胞控制细胞命运承诺的机制，而且还可能使现有人类干细胞系的无限期繁殖成为可能。对这些转录网络的洞察也可能导致从成人组织或细胞产生多能干细胞。我们的研究旨在为多能干细胞中的Nanog和Oct3/4靶点提供完整的定义。通过表征相应转录本的调控，我们期望表征控制ES细胞自我更新和多能性的分子途径。代表新的Nanog和Oct3/4驱动转录本的微阵列以及基因组结合位点的目录将被提供给干细胞研究社区。代表新的Nanog和Oct3/4靶点的微阵列的创建将有助于高通量分析它们在早期胚胎发育过程中的表达，并通过调节分化和多能性的途径来调节它们。这套研究将是迄今为止对任何后生动物系统中转录因子结合调节的最全面的分析。

DESCRIPTION (provided by applicant): Embryonic stem (ES) cells isolated from the inner cell mass of murine blostocysts are pluripotent, capable of indefinite symmetric cell division, and can generate chimeric animals. The recent isolation of human ES cells holds great promise for the treatment of a variety of degenerative disorders including, but not limited to, Parkinson's disease and diabetes. The homeodomain transcription factors, Oct3/4 and Nanog, are believed to play critical roles in sustaining ES cell pluripotency. Surprisingly, targets of Nanog are completely unknown and few Oct3/4 targets have been proposed. Thus, the molecular mechanisms that repress differentiation of ES cells and promote self-renewal are poorly defined. We have developed a novel approach for identifying complex metazoan regulons called SACO (Serial Analysis of Chromatin Occupancy), which combines chromatin immunoprecipitation with a modification of Long SAGE. We will use SACO to identify the entire complement of Nanog and Oct3/4 genomic targets in mouse ES cells. Such knowledge would not only aid efforts to characterize mechanisms that govern cell-fate commitment of stem cells, but could also enable the indefinite propagation of existing human stem cell lines. Insight into these transcriptional networks could also lead to the generation of pluripotent stem cells from adult tissues or cells. Our studies are designed to provide a complete definition of Nanog and Oct3/4 targets in pluripotent stem cells. By characterizing the regulation of the corresponding transcripts, we expect to characterize the molecular pathways that control self-renewal and pluripotency of ES cells. The microarrays representing novel Nanog and Oct3/4 driven transcripts and the catalog of genomic binding sites will be provided to the stem cell research community. The creation of microarrays representing novel Nanog and Oct3/4 targets will facilitate high-throughput analysis of their expression during early embryogenesis and their regulation by pathways that regulate differentiation and pluripotency. This set of studies will represent the most comprehensive analysis to date of the regulation of transcription factor binding in any metazoan system.