Analyzing the role of Wnt signaling during reprogramming.

描述(申请人提供)：细胞通讯是多细胞生命进化的核心：细胞发出特定的信号，指示它们的邻居接受自己的命运。一类重要的发育信号是由Wnt基因家族编码的。WNT蛋白及其信号级联几乎涉及每一个发育过程，从确定组织内单个细胞的极性到确定生物体的前后BOD轴。放松对Wnt信号的管制可能会产生灾难性的后果，包括胚胎死亡、出生缺陷和疾病，最明显的是癌症。由于其在发育和疾病方面的多样和强大的活动，WNTS吸引了许多试图指导和指导细胞命运选择的研究人员的注意。这项拟议研究的长期目标是提高目前对Wnt蛋白及其信号通路调节重编程的机制的理解，在重编程过程中，成熟细胞获得类似胚胎干细胞的状态。虽然大多数关于重编程的研究都集中在核事件和表观基因组的变化上，但对于细胞外环境在这一过程中的作用，如Wnt信号，知之甚少。这里提出的研究建立在关键的和未发表的观察结果的基础上，即WNT信号是重新编程所必需的。具体地说，携带Wnt加工酶PORCN突变的成纤维细胞(从患有罕见的遗传缺陷，称为局灶性真皮发育不良的患者中获得)无法重新编程，除非在重新编程过程中用具有生物活性的Wnt蛋白处理细胞。这项拟议的研究将非常详细地研究Wnt信号在重新编程中的作用和要求。利用最近发现的诱导多能性的方法，这项建议的第一个目标将检查Wnt信号在将人成纤维细胞转化为iPS细胞过程中的需求和时机。在第二个目标中，将研究由FZD基因家族编码的Wnt受体的作用，以确定协调iPS细胞生成过程的Wnt信号环的确切性质。在第三个目标中，将使用下一代测序技术在重新编程过程中识别Wnt途径的分子靶点。影响：提出的创新性研究将极大地推动干细胞研究领域的发展，因为它建立了一个新的范式，即从成熟细胞到诱导多能干细胞(IPS)的转变需要Wnt信号。由于它在人类疾病和疾病(如癌症)中的广泛作用，对Wnt信号的更好理解对于开发目前无法治愈的疾病的新疗法是至关重要的。

DESCRIPTION (provided by applicant): Cell communication lies at the core of evolution of multi-cellular life: cells send specific signals to instruct their neighbors to adopt fates distinc of their own. An important class of such developmental signals is encoded by the Wnt gene family. Wnt proteins and their signaling cascades touch on virtually every developmental process, from establishing the polarity of a single cell within a tissue to specifying the anterior-posterior bod axis of an organism. Deregulation of Wnt signaling can have catastrophic consequences, including embryonic lethality, birth defects, and disease, most notably cancer. With their diverse and potent activities in development and disease, Wnts have captivated the attention of many researchers seeking to instruct and guide cellular fate choices. The long-term objective of the proposed research is to elevate the current understanding of the mechanisms by which Wnt proteins and their signaling pathways regulate reprogramming, a process in which mature cells acquire an embryonic stem cell-like state. While the majority of research on reprogramming has focused on nuclear events and changes in the epigenome, relatively little is known about the role of the extracellular environment, such as Wnt signals, in this process. The research proposed here builds on the critical and unpublished observation that Wnt signaling is required for reprogramming. Specifically, fibroblasts harboring mutations in the Wnt processing enzyme PORCN (obtained from patients with a rare genetic defect, called Focal Dermal Hypoplasia) fail to reprogram unless the cells are treated with biologically active Wnt protein during the course of reprogramming. The proposed research will examine in great detail the role and requirement of Wnt signaling in reprogramming. Using the recently discovered method for inducing pluripotency, the first aim of this proposal will examine the requirement and timing of Wnt signaling in converting human fibroblasts to iPS cells. In the second aim, the role of Wnt receptors encoded by the FZD gene family will be examined to identify the precise nature of the Wnt signaling loop that orchestrates the process of iPS cell generation. In a third aim, next generation sequencing technologies will be employed to identify the molecular targets of the Wnt pathway during the process of reprogramming. IMPACT: The proposed and innovative research will significantly advance the field of stem cell research by establishing a new paradigm that Wnt signaling is required for the transition from mature cell to induced pluripotent stem (iPS) cell. With its abundant roles in human disorders and diseases, such as cancer, a better understanding of Wnt signaling is essential for the development of novel therapies for currently incurable diseases.