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)：真正静止和长期存活的干细胞已经被假设，但到目前为止还没有在肠道中鉴定出来。双重皮质醇样激酶1(Dclk1)被认为是肠道干细胞标记物，但也被发现在肠束细胞中表达。 最近，我们的团队培育出了Dclk1-Cre-ERT BAC转基因小鼠，我们明确地证明了Dclk1+丛状细胞是起源于神经脊的长寿、静止的干细胞，并且Dclk1还标记了肠道神经系统的节外前体细胞。我们的假设是，Dclk1+干细胞既可以作为神经干细胞，也可以作为储备肠道干细胞，这两种干细胞一起形成了肠道中其他干细胞群体的利基，主要是通过生成EN来实现的。我们将通过四个具体目标来探讨这一假设。(1)Dclk1+干细胞与Bmi1+肠道干细胞有什么关系？我们将利用Bmi1/GFP/+敲打小鼠和Lgr5/DTR敲打小鼠与Dclk1转基因系相结合来确定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细胞的动态平衡和对辐射损伤的反应？Dclk1-Cre-ERT小鼠与DTR F/F小鼠杂交后，将接受白喉毒素治疗，并评估其对辐射的再生反应。(3)。辐射损伤后Dclk1+祖细胞的激活是否会导致肠道增殖和再生增加？Dclk1祖细胞将通过有条件地删除PTEN或激活来激活 对IC-Notch1的辐射损伤反应进行了分析。(4)。Dclk1的消融 祖细胞在体外抑制ISC的生长，而Dclk1+祖细胞的激活在体外促进ISC的生长。我们将使用来自上述Dclk1杂交的全肠道培养物来探索Dclk1消融或激活对体外生长的影响。总体而言，这些研究应该会为Dclk1前体细胞在肠道中作为利基细胞和干细胞的作用以及它们对肠道再生的贡献提供新的见解。