INDUCTION AND MAINTENANCE OF PLURIPOTENT-PLASTIC STATE

描述(由申请人提供)： 最近，传统观点认为体细胞干细胞仍然忠实于 它们的起源组织受到了挑战。肌肉衍生的能力， 和神经来源的培养，以产生能够造血的细胞 移植后的重建以及造血能力 培养出肌肉细胞引发了关于 体细胞的可塑性。这种可塑性可能是 挖掘治疗潜力是令人信服的，并使 对其性质和可能对其进行监管的方式的理解 利息。可塑性，或我们认为的细胞的能力 血统承诺，要产生替代组织或细胞类型必须需要 细胞重新编程并选择另一条发育路径。这一定是 即使对组织中的干细胞群体也是如此。一种理解 定义多能性和可塑性体细胞状态的基本机制 干细胞是这项提案的重点。我们的假设是 干细胞的可塑性是翻译抑制因子的功能 多能干细胞中存在关键的转录因子。 我们还假设，可塑性包括对血统表达的抑制 定义细胞中已经存在的转录本，重置发育 沿着另一条发展道路进行规划。到目前为止，一个蛋白质组 定义基因表达的方法还没有被采用。我们有 探索了一种新颖而健壮的方法来定义 干细胞的分化。使用这种方法，我们将能够 识别和研究在翻译中被抑制的抄本 塑性/多能状态，并了解其基本机制 缺乏可塑性和多能性。具体地说，我们将1)确定 关键的翻译调控的mRNA转录本和定义准确的 定量分析基因在多能细胞中的整体表达 多聚体相关转录本及其快速翻译状态的研究 干细胞可塑性体外模型的全程筛选试验2) 定义翻译调控机制在转录中对 可塑性和多能性；3)定义了翻译的作用 调节和维持多能性的规则。

DESCRIPTION (provided by applicant): Recently, the traditional view that somatic stem cells remain faithful to their tissue of origin has been challenged. The capability of muscle-derived, and neural-derived cultures to produce cells capable of hematopoietic reconstitution following transplant, as well as the ability of hematopoietic cultures to give rise to muscle cells raises profound questions about the plasticity of somatic cells. The possibility that such plasticity might be exploited for therapeutic potential is compelling and makes a better understanding of its nature and the ways in which might be regulated of great interest. Plasticity, or the ability of cells that we think of as being lineage committed, to generate an alternative tissue or cell type must require the cells to reprogram and take an alternative developmental path. This must be true even of the stem cell populations within a tissue. An understanding of the basic mechanisms that define the pluripotent and plastic state somatic stem cells is the focus of this proposal. Our hypothesis is that the plasticity of stem cells a function of the translational repression of critical transcription factors present in the pluripotent stem cell. Plasticity, we also hypothesize, involves inhibition of expression of lineage defining transcripts already present within a cell resetting the developmental program along an alternative developmental pathway. To date, a proteomic approach to defining gene expression has not been undertaken. We have explored a novel and robust method for defining the change in translation upon the differentiation of stem cells. Using this approach we will be able to identify and study transcripts that are translationally repressed in the plastic/pluripotent state and gain an understanding of the basic mechanisms that underly plasticity and pluripotency. Specifically we will 1) identify critical translationally regulated mRNA transcripts and define an accurate picture of overall gene expression in the pluripotent cell by quantitating polysome-associated transcripts and their translational state using a rapid throughout screening assay in an in vitro model of stem cell plasticity; 2) define the mechanisms of translational regulation in transcripts critical to plasticity and pluripotency; and 3) define the role of translational regulation in modulating and maintaining pluripotency.