Regulation of Active and Quiescent Intestinal Stem Cells

描述（由申请人提供）：越来越多的证据表明，活跃循环和静止肠道干细胞（ISCs）在小肠上皮内共存，并在组织更新中协同起作用。本研究探讨了这些ISC种群受不同的细胞外信号调节的假设，这些细胞外信号涉及器官大小控制和氧感应。这一假设通过三个特定目的进行评估：(1)探索参与控制器官大小的Hippo信号通路，调节活跃和静止ISC群体的再生反应；(2)通过氧感应途径研究活跃和静止ISCs的代谢调节；(3)通过比较基因表达谱确定活跃和静止ISCs的分子特征。这些特定目标将通过采用严格的小鼠遗传学来检查干细胞龛内的体内ISCs和验证的体外克隆培养技术来实现，这些技术允许单个分离的ISCs持续增殖和多谱系分化。这些目标的实现将有助于深入了解活性和静止ISCs在转录水平上的分子差异以及它们的差异调控

DESCRIPTION (provided by applicant): There is emerging evidence that distinct populations of actively cycling and quiescent intestinal stem cells (ISCs) co-exist within the small intestine epithelium and function cooperatively in tissue renewal. This proposal explores the hypothesis that these ISC populations are regulated by distinct sets of extracellular signals involved in organ size control and oxygen-sensing. This hypothesis is evaluated by three Specific Aims: (1) to explore the Hippo signaling pathway, implicated in controlling organ size, in regulating the regenerative responses of active and quiescent ISC populations, (2) to examine metabolic regulation of active and quiescent ISCs by the oxygen-sensing pathway, and (3) to determine the molecular signatures of active versus quiescent ISCs by comparative gene expression profiling. These Specific Aims will be achieved by employing rigorous mouse genetics to examine ISCs in vivo within their stem cell niches and validated ex vivo clonogenic culture techniques that allow for sustained proliferation and multi-lineage differentiation of single isolated ISCs. Achievement of these Aims should provide insight into the molecular differences between active and quiescent ISCs at the transcriptional level and their differential regulation by diverse pathways governing organ size and metabolism.