Robustness of the Intestinal Stem Cell Niche

肠道干细胞生态位的稳健性

• 批准号: 9044805
• 负责人: Xiling Shen
• 金额: $ 30.61万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-06 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9044805
• 关键词: 3-Dimensional; 3D Print; Abdomen; Ablation; Address; Algorithms; Alleles; Animals; Area; Behavior; Biological Assay; Biological Models; Cell Lineage; Cells; Chronic; Colon Carcinoma; Columnar Cell; Development; Disease; Engraftment; Environment; Epithelium; Event; Feedback; Genetic Engineering; Health; Homeostasis; Image; Imaging Techniques; Implant; Individual; Injection of therapeutic agent; Intestines; Label; Laser Microscopy; Lasers; Left; Life; Ligands; Link; Microscopy; Modeling; Monitor; Movement; Mus; Mutation; Natural regeneration; Nature; Organoids; Paneth Cells; Pathway interactions; Physiologic pulse; Printing; Recovery; Reporter; Resolution; Role; Signal Pathway; Signal Transduction; Small Intestines; Specific qualifier value; Stem Cell Research; Stem cell transplant; Stem cells; System; Systems Analysis; Systems Biology; Techniques; Technology; Testing; Tissues; Transgenic Mice; Validation; adult stem cell; animal imaging; base; blastocyst; cancer stem cell; cell type; computer framework; coping; daughter cell; dynamic system; imaging system; improved; in vivo; innovation; insight; interdisciplinary approach; intestinal crypt; intestinal epithelium; multi-scale modeling; notch protein; novel; regenerative; resilience; spatiotemporal; stem cell biology; stem cell niche; stem cell population; theories; time use; tool; transcriptome

 DESCRIPTION (provided by applicant): The intestinal epithelium is one of the fastest regenerative tissues in the body. Regeneration is sustained by a group of stem cells, termed crypt base columnar cells (CBCs), at the bottom of the intestinal crypt. In the past 5 years, studies of CBCs have helped transform the dogma of stem cell biology. Rather than being largely quiescent, undergoing asymmetric division, and following the unidirectional differentiation hierarchy, CBCs are highly proliferative, capable of symmetric division, and replaceable by more differentiated cell types. Since then, similar stem cell populations and regulatory principles have been identified in many other tissues. However, all these discoveries converge on a central question: how does the stem cell niche control plasticity in order to keep a constant number of CBCs? Since proliferative CBCs have been linked to colon cancer, and stem cell transplants are being used clinically for treating a variety of diseases, it is importantto understand the underlying control. Cellular dynamics Innovative multiphoton imaging and laser ablation technologies will be used to investigate how cells divide, move and recover loss inside the stem cell niche, focusing on four fundamental questions: (1) are CBCs capable of both symmetric and asymmetric division, (2) do individual CBCs in the same niche have equal proliferative potential, (3) how does the niche recover from cell loss, and (4) how do cells outside the niche dedifferentiate and reenter the niche? Signaling dynamics Using the 3D intestinal organoid assay, a systematic study will be carried out to search for feedback and crosstalk mechanisms among major signaling pathways. Dynamical systems analysis will be performed to understand their impact on the niche control circuitry. Integration and Validation To integrate experimental findings and computational insights, a stochastic, multiscale model will be built that captures cellular division, movement and signaling events in the stem cell niche. This model will be used to test hypotheses on the niche control circuitry. A novel engraftment assay through injection of genetically engineered stem cells into blastocysts has been developed for in vivo validation. Innovation Novel in vivo GI imaging techniques have been developed by using openable abdominal window, 3-D printed intestinal support, labeled vasculature roadmap, and tracking algorithms. Through the window, a special laser can ablate a single cell inside the niche without damaging the surrounding tissue. A computational framework will integrate dynamical systems analysis and multiscale modeling to study the regulatory circuitry that controls cellular and signaling dynamics inside the niche. Predictions will be validated in novel chimeric mice with intestinal crypts derived from blastocyst-injected cells. Preliminary findings The stem cell niche undergoes extensive reorganization after loss of one CBC, attesting to its dynamic nature. Various feedback and crosstalk mechanisms have been identified to improve robustness.

 描述（由申请人提供）：肠上皮是体内再生速度最快的组织之一，其再生由位于肠隐窝底部的一组称为隐窝基底柱状细胞（CBC）的干细胞维持。过去 5 年，对 CBC 的研究帮助改变了干细胞生物学的教条，CBC 不是处于静止状态、经历不对称分裂并遵循单向分化层次，而是高度增殖、从那时起，在许多其他组织中发现了类似的干细胞群和调节原理，但所有这些发现都集中在一个核心问题上：干细胞生态位如何控制可塑性。为了保持恒定的 CBC 数量？ 由于增殖性 CBC 与结肠癌有关，并且干细胞移植在临床上用于治疗多种疾病，因此了解细胞动力学创新的多光子非常重要。成像和激光消融技术将用于研究干细胞生态位内细胞如何分裂、移动和恢复损失，重点关注四个基本问题：(1) CBC 是否能够进行对称和不对称分裂，(2) 单个 CBC 是否能够进行对称分裂和不对称分裂？相同的生态位具有相同的增殖潜力，(3) 生态位如何从细胞损失中恢复，以及 (4) 生态位外的细胞如何去分化并重新进入生态位？ 使用 3D 肠道类器官测定，将进行系统研究。进行动态系统分析，以了解它们对利基控制电路的影响。为了整合实验结果和计算见解，将建立一个随机的多尺度模型。捕获干细胞微环境中的细胞分裂、运动和信号传导事件，该模型将用于测试微环境控制电路的假设，该方法通过将基因工程干细胞注射到囊胚中来进行体内实验。创新通过使用可打开的腹部窗口、3D 打印的肠道支撑、标记的脉管系统路线图和跟踪，开发出了新颖的体内 GI 成像技术。计算框架将整合动力系统分析和多尺度建模，以研究控制微环境内细胞和信号动力学的调节电路，预测将在具有来自肠隐窝的新型嵌合小鼠中得到验证。初步发现 干细胞生态位在丢失一个 CBC 后会经历广泛的重组，证明了其动态特性已被确定以提高稳健性。