Transcriptional Regulation of Stem Cell Differentiation into Motor Neurons

我们建议进一步了解在神经发育过程中指导干细胞的分子机制，最终目标是使基于干细胞的再生医学能够用于神经退行性疾病。我们将研究脊髓性肌萎缩症（SMA）的发病机制， 我们阐明的目标是为这种发育性疾病的潜在治疗靶点提供线索。为了了解外部线索如何指导发展，我们将阐明神经发育的转录调控网络，并在预测计算模型中表示这种理解。我们的研究将开始与未分化的胚胎干细胞（ES），并使用 通过我们开创的实验方案，我们将阐明特定神经元亚型中ES细胞发育和命运承诺的机制。我们的工作分为三个项目。项目1将确定可能参与运动神经元身份的转录因子，迭代定义转录因子， 网络，并表征SMA的转录后果。利用这些结果，项目2将发现关键的转录和染色质调节因子如何控制小鼠和人类胚胎干细胞的基因表达程序，并发现这种调节回路在分化为脊髓祖细胞和特定类别的中枢神经系统细胞（如运动神经元）后如何变化。利用这两个项目的数据，项目3将建立一个神经发育过程中的转录调控模型，该模型整合了人类和小鼠的表达数据、因子结合数据、染色质数据、shRNA敲低数据和基因组序列，在推导的调控网络的背景下检查我们的SMA模型的基因表达结果，探讨小鼠ES细胞分化模型的有效性。项目1和项目2都将测试项目3中生成的模型。

We propose to further our understanding of the molecular mechanisms that direct stem cells during neural development with the ultimate goal of enabling stem cell based regenerative medicine for neurodegenerative diseases. We will study the etiology of Spinal Muscular Atrophy (SMA) in the context of the mechanisms that we elucidate with the goal of developing clues to potential therapeutic targets for this developmental disease. To understand how external cues direct development, we will elucidate the transcriptional regulatory networks underlying neural development and represent this understanding in predictive computational models. Our studies will begin with undifferentiated embryonic stem (ES) cells, and using protocols that we have pioneered, we will elucidate the mechanism of ES cell development and fate commitment in specific neuron subtypes. Our work is structured into three projects. Project 1 will identify the transcription factors potentially involved in motor neuron identity, iteratively define transcriptional networks, and characterize the transcriptional consequences of SMA. Drawing upon these results, Project 2 will discover how key transcriptional and chromatin regulators control the gene expression programs of mouse and human embryonic stem cells and discover how this regulatory circuitry changes upon differentiation into spinal progenitor cells and then specific classes of central nervous system cells such as motor neurons. Using data from both of these projects, Project 3 will build a model of transcriptional regulation during neural development that integrates expression data, factor binding data, chromatin data, shRNA knock down data, and genome sequence in both human and mouse, examine the gene expression consequences of our SMA model in the context of the deduced regulatory networks, and explore the validity of the mouse model for human ES cell differentiation. Both Project 1 and 2 will test the models produced in Project 3.