Analyzing the role of Wnt signaling during reprogramming.

描述（由申请人提供）：细胞通信是多细胞生命进化的核心：细胞发送特定信号以指示它们的邻居采用与它们自己不同的命运。一类重要的发育信号由Wnt基因家族编码。Wnt蛋白及其信号级联几乎涉及到每一个发育过程，从建立组织内单个细胞的极性到指定生物体的前后体轴。Wnt信号的失调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。由于它们在发育和疾病中的多样性和有效性，Wnt吸引了许多寻求指导和指导细胞命运选择的研究人员的注意。这项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机制的理解，这是一个成熟细胞获得胚胎干细胞样状态的过程。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，但对细胞外环境（如Wnt信号）在这一过程中的作用知之甚少。这里提出的研究建立在关键和未发表的观察基础上，即Wnt信号传导是重编程所必需的。具体而言，在Wnt加工酶PORCN中携带突变的成纤维细胞（从具有罕见遗传缺陷的患者获得，称为局灶性皮肤发育不全）不能重编程，除非在重编程过程中用生物活性Wnt蛋白处理细胞。拟议的研究将详细研究Wnt信号在重编程中的作用和要求。使用最近发现的诱导多能性的方法，本提案的第一个目的将检查将人成纤维细胞转化为iPS细胞的Wnt信号传导的要求和时机。在第二个目标中，将检查由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，将采用下一代测序技术来鉴定重编程过程中Wnt途径的分子靶标。影响：这项创新性的研究将通过建立一个新的范式来显著推进干细胞研究领域，即从成熟细胞到诱导多能干细胞（iPS）细胞的转变需要Wnt信号传导。由于其在人类疾病和疾病（如癌症）中的丰富作用，更好地了解Wnt信号传导对于开发目前无法治愈的疾病的新疗法至关重要。

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 The research proposed here builds on the critical and unpublished observation that Wnt signaling is required for reprogramming.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.