Exploring Wnt-Fzd signaling specificities

项目摘要/摘要： 细胞间的交流是多细胞生命进化的核心：细胞发送特定的信号来指示 他们的邻居接受了与他们自己截然不同的命运。一类重要的发育信号由 WNT基因家族。WNT蛋白与其FrizzledFZD家族的同源受体相互作用以控制 无数的发育过程，从确定组织内单个细胞的极性到指定 生物体的前后轴。放松对WNT信号的管制可能会产生灾难性的后果 后果，包括胚胎致死、出生缺陷和疾病。他们多种多样而有力的活动 在发育和干细胞方面，Wnt蛋白在细胞和组织工程中具有很大的潜力。 我们研究的长期目标是更好地了解Wnt蛋白及其 下游信号事件影响细胞命运的决定，从而推动技术和治疗的进步 专门针对WNT信号的。多年来，我们为建设小康社会作出了重要贡献 WNTS作为研究级试剂处理人类多能干细胞和 产生具有潜在治疗价值的细胞群。然而，重大挑战需要 在WNTS作为治疗药物的全部潜力可以实现之前解决。尤其是，尽管它们的威力 尽管许多Wnt蛋白具有生物活性，但仍难以分离出具有生物活性且稳定的形式。此外， 有19个WNT和20多个WNT受体(包括Fzd1-10、LRP5/6、Ror1/2等)。在哺乳动物体内编码 基因组，目前尚不清楚信号特异性是如何建立的。最后，目前针对WNT的许多尝试 临床环境中的信号是高度非特异性的，会产生并发症和不良副作用。 未来五年的目标是利用我们实验室开发的一项创新技术，该技术利用 经过改造的Wnt激动剂，称为Wnt模拟剂，与 天然的Wnt蛋白。这些WNT模拟物将在包括HPS细胞在内的几个环境中进行效果测试 器官培养和整个动物(小鼠)的自我更新和分化。此外，建议的 研究将探索一种新的范例，即Wnt信号特异性是如何在体内建立的，从而 支持开发工具和方法，以精确定位单个WNT信号通路。这些 实验将使我们能够检验我们的假设，即个体WNT的选择性参与和激活 受体和受体复合体触发不同的信号输出和生物效应。 这项拟议的研究将显著推动干细胞研究和组织工程领域的发展 建立新的工具和方法在体外和体内操纵Wnt信号。凭借其在 对于人类的疾病和疾病，更好地了解Wnt信号对于发展Wnt信号是至关重要的 治疗目前不治之症的新疗法。

Project Summary/Abstract: Cell-cell communication lies at the heart of evolution of multi-cellular life: cells send specific signals to instruct their neighbors to adopt fates distinct of their own. An important class of developmental signals is encoded by the Wnt gene family. Wnt proteins interact with their cognate receptors of the Frizzled (Fzd) family to control countless developmental processes, from establishing the polarity of a single cell within a tissue to specifying the anterior-posterior body axis of an organism. Deregulation of Wnt signaling can have catastrophic consequences, including embryonic lethality, birth defects, and disease. With their diverse and potent activities in development and stem cells, Wnt proteins hold great promise as potent tools in cell and tissue engineering. The long-term objective of our research is to gain a better understanding of how Wnt proteins and their downstream signaling events influence cell fate decisions, and thereby advance technologies and treatments that specifically target Wnt signaling. Over the past years, we have made important contributions to the development of Wnts as research-grade reagents to manipulate human pluripotent stem (hPS) cells and generate cell populations with potential therapeutic value. However, significant challenges need to be addressed before the full potential of Wnts as therapeutics can be realized. In particular, despite their potent activities, many Wnt proteins remain difficult to isolate in a biologically active and stable form. Furthermore, with 19 Wnts and over 20 Wnt receptors (including Fzd1-10, Lrp5/6, Ror1/2, etc.) encoded in the mammalian genome, it is unclear how signaling specificity is established. Finally, many current attempts to target Wnt signaling in clinical settings are highly non-specific and produce complications and adverse side effects. The goal for the next five years is to leverage an innovative technology developed in our laboratory that utilizes engineered Wnt agonists, called Wnt mimetics, which exhibit superior biochemical properties compared to native Wnt proteins. These Wnt mimetics will be tested for their effects in several settings, including hPS cell self-renewal and differentiation, organoid cultures and in whole animals (mice). Furthermore, the proposed research will explore a new paradigm for how Wnt signaling specificity is established in vivo, and thereby enable the development of tools and approaches that pinpoint individual Wnt signaling pathways. These experiments will allow us to test our hypothesis that selective engagement and activation of individual Wnt receptors and receptor complexes trigger distinct signaling outputs and biological effects. The proposed research will significantly advance the field of stem cell research and tissue engineering by establishing new tools and methods to manipulate Wnt signaling in vitro and in vivo. With its abundant roles in human disorders and diseases, a better understanding of Wnt signaling is essential for the development of novel therapies for currently incurable diseases.