Systems-level role of GSK3 in colonic epithelium homeostasis and drug resistance

描述(由申请人提供)：自我更新的肠道上皮需要一层精确的动态平衡控制。令人惊讶的是，肠道上皮每五天就会完全更新一次，在人的整个一生中，多种细胞类型都会保持正确的比例。然而，我们对上皮细胞如何维持如此强健的组织的了解还远未完成。缺乏这种精细的体内平衡控制是各种疾病的基础，包括克罗恩病、肠易激综合征、溃疡性结肠炎和胃肠道癌症。GSK-3是肠道组织动态平衡的典型信号中枢：它接收和破译多种上游微环境信号，选择性地影响多种下游细胞过程，并改变细胞对药物的反应。尽管葛兰素史克-3的S参与了许多细胞过程，但其功能仍不清楚，研究也很少。我们缺乏对GSK-3在何时何地通过分子网络影响从微环境到复杂上皮组织中细胞决策的信号级联的系统了解。在这里，我们建议研究GSK-3作为信号转导和维持组织动态平衡的枢纽的作用，并识别其作用依赖于GSK-3在生理相关条件下的活性的药物类别。为了实现这一目标，我们开发了：创新的肠上皮器官型模型，适用于基于图像的扰动分析；GSK-3活性的活细胞报告；以及定量， 单细胞方法破译葛兰素史克-3‘S在将微环境信号转化为动态平衡决策中的作用。综上所述，我们建议：(1)鉴定调节肠道稳态的GSK-3相互作用网络；(2)了解GSK-3‘S在信号隔离和串扰中的作用；(目的3)阐明GSK-3活性如何影响药物反应。

DESCRIPTION (provided by applicant): Self-renewing intestinal epithelium requires layers of precise control for homeostasis. Amazingly, intestinal epithelium completely renews itself every five days, with multiple cell types maintained at just the right ratios throughout an individual's entire life. However, our understanding of how epithelium maintains such robust organization is far from complete. Lack of this exquisite homeostatic control is the basis for a variety of diseases, including Crohn's disease, irritable bowel syndrome, ulcerative colitis, and gastrointestinal cancers. GSK-3 is a quintessential signaling hub in intestinal tissue homeostasis: it receives and deciphers multiple upstream microenvironmental signals, selectively affects multiple downstream cellular processes, and alters cellular response to drugs. Despite GSK-3's presence in many cellular processes, its function remains unclear and understudied. We lack a systematic understanding of when and where GSK-3 affects the cascade of signals from the microenvironment through molecular networks to cellular decisions in the context of complex epithelial tissues. Here, we propose to study the role of GSK-3 as a hub for signal transduction and maintenance of tissue homeostasis as well as identify drug classes whose effects depend on GSK-3 activities in physiologically relevant conditions. To accomplish this, we have developed: innovative organotypic models of gut epithelium that are ideal for image-based perturbation assays; live-cell reporters of GSK-3 activity; and quantitative, single-cell approaches for deciphering GSK-3's role in transforming microenvironmental signals to homeostatic decisions. Together, we propose to: (Aim 1) identify GSK-3 interaction networks that regulate gut homeostasis; (Aim 2) understand GSK-3's role in signal insulation and crosstalk; and (Aim 3) elucidate how GSK-3 activity affects drug response.