Quiescent Dclk1+ stem cells in the mouse intestine

小鼠肠道中的静态 Dclk1 干细胞

• 批准号: 8547458
• 负责人: Timothy Cragin Wang
• 金额: $ 34.78万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-25 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8547458
• 关键词: Ablation; Adult; Behavior; Cell Count; Cell Lineage; Cells; Cloning; Columnar Cell; Data; Diphtheria Toxin; Embryo; Endoderm; Enteral; Enteric Nervous System; Epithelial; Epithelial Cells; Gastrointestinal tract structure; Gene Expression; Generations; Genes; Genetic; Growth; Homeostasis; Image; In Vitro; Injury; Intestines; Knock-in Mouse; Label; Laboratories; Life; Maintenance; Modeling; Molecular Profiling; Mus; Natural regeneration; Nerve; Nervous system structure; Neural Crest; Organ; PTEN gene; Phosphotransferases; Play; Positioning Attribute; Radiation; Radiation Injuries; Regulation; Reserve Stem Cell; Role; Secretory Cell; Signal Transduction; Stem cells; Stromal Cells; System; Testing; Time; Tissues; Toxin; Transgenic Mice; Transgenic Organisms; Tumor Suppressor Proteins; base; bone; cell type; doublecortin protein; insight; mouse model; neglect; nerve stem cell; notch protein; progenitor; regenerative; response; stem; stem cell niche; stem cell population

DESCRIPTION (provided by applicant): Truly quiescent and long-lived stem cells have been postulated but to date not identified in the gut. Doublecortin-like kinase 1 (Dclk1) was proposed as a stem cell marker in the intestine but was also found to be expressed in intestinal tuft cells. Recently, our group has generated Dclk1- Cre-ERT BAC transgenic mice, and we have shown unequivocally that Dclk1+ tuft cells are long-lived, quiescent stem cells that originate from the neural crest, and that Dclk1 also labels extraganglionic progenitors of the enteric nervous system. Our hypothesis is that Dclk1+ stem cells play a role both as neural stem cells and also as reserve intestinal stem cells, which together form a niche for other stem cell populations in the intestine, primarily through generation of the ENS. We will explore this hypothesis through four specific aims. (1) What is the relationship between Dclk1+ stem cells and Bmi1+ intestinal stem cells? We will utilize Bmi1/GFP/+ knockin mice and Lgr5/DTR knockin mice in combination with Dclk1 transgenic lines to determine whether there is overlap between Dclk1 and Bmi1. (2) Does ablation of Dclk1+ progenitors inhibit normal intestinal epithelial homeostasis and the response to radiation injury? Dclk1-Cre-ERT mice crossed to DTR F/F mice will be treated with diptheria toxin and the regenerative response to radiation assessed. (3). Does activation of Dclk1+ progenitors result in intestinal proliferation and increased regeneration following radiation injury? Dclk1 progenitors will be activated by conditional deletion of PTEN or activation of IC-Notch1, followed by analysis of the response to radiation injury. (4). Does ablation of Dclk1 progenitors inhibit in vitro ISC growth, and does activation of Dclk1+ progenitors accelerate in vitro ISC growth. We will use whole intestinal cultures derived from the Dclk1 crosses above to explore the effect of Dclk1 ablation or activation on in vitro growth. Overall, these studies should provide new insights into the role of Dclk1 progenitors as both niche and stem cells in the intestine, and their contribution to intestinal regeneration.

描述（由申请人提供）：已经假设存在真正静止且长寿的干细胞，但迄今为止尚未在肠道中发现。双皮质素样激酶 1 (Dclk1) 被提议作为肠道干细胞标记物，但也发现在肠道簇细胞中表达。 最近，我们的团队培育出了 Dclk1-Cre-ERT BAC 转基因小鼠，并且我们明确地表明 Dclk1+ 簇细胞是源自神经嵴的长寿、静止干细胞，并且 Dclk1 还标记肠神经系统的节外祖细胞。我们的假设是，Dclk1+ 干细胞既充当神经干细胞，又充当储备肠道干细胞，它们主要通过 ENS 的产生，共同形成肠道中其他干细胞群的生态位。我们将通过四个具体目标来探讨这一假设。 （1）Dclk1+干细胞和Bmi1+肠道干细胞有什么关系？我们将利用 Bmi1/GFP/+ 敲入小鼠和 Lgr5/DTR 敲入小鼠与 Dclk1 转基因系组合来确定 Dclk1 和 Bmi1 之间是否存在重叠。 (2) Dclk1+祖细胞的消融是否会抑制正常肠上皮稳态和对辐射损伤的反应？与 DTR F/F 小鼠杂交的 Dclk1-Cre-ERT 小鼠将接受白喉毒素治疗，并评估对辐射的再生反应。 （3）。 Dclk1+ 祖细胞的激活是否会导致辐射损伤后肠道增殖和再生增加？ Dclk1祖细胞将通过PTEN的条件删除或激活而被激活 IC-Notch1，然后分析对辐射损伤的反应。 （4）。是否消融 Dclk1 祖细胞抑制体外 ISC 生长，并且 Dclk1+ 祖细胞的激活是否加速体外 ISC 生长。我们将使用源自上述 Dclk1 杂交的全肠培养物来探索 Dclk1 消除或激活对体外生长的影响。总的来说，这些研究应该为 Dclk1 祖细胞作为肠道中的生态位细胞和干细胞的作用及其对肠道再生的贡献提供新的见解。