Age Compromises Novel Motility and Repair Functions in Stem Cell Niche of Intestinal Crypts

年龄会损害肠隐窝干细胞生态位的新活力和修复功能

• 批准号: 9753843
• 负责人: Nozomi Nishimura
• 金额: $ 20.61万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9753843
• 关键词: Ablation; Address; Age; Aging; Animals; Antibodies; Autopsy; Biological Assay; Blood Vessels; Bromodeoxyuridine; Cell Count; Cell Nucleus; Cell Proliferation; Cell division; Cell physiology; Cells; Chronic; Colitis; Complement; Coupled; Development; Disease; Epithelial Cells; Epithelium; Equilibrium; Excision; Goals; Grant; Green Fluorescent Proteins; Health; Homeostasis; Image; Imagery; Immunofluorescence Immunologic; Impairment; Implant; Individual; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Inflammatory disease of the intestine; Injury; Intervention; Intestines; LGR5 gene; Label; Lasers; Left; Link; Location; Longevity; Measurement; Mechanics; Methods; Modeling; Molecular; Monitor; Motion; Mucous Membrane; Mus; Natural regeneration; Optics; Organism; Pathologic; Pathology; Pathway interactions; Pattern; Penetration; Positioning Attribute; Preparation; Process; Proteins; Reactive Oxygen Species; Recovery; Shapes; Sirolimus; Small Intestines; Stains; Stem cells; Techniques; Testing; Time; Tissues; Variant; age effect; base; cell behavior; cell injury; cell motility; cell type; crypt cell; daughter cell; expectation; imaging approach; imaging modality; improved; in vivo; in vivo imaging; injured; intestinal crypt; intestinal epithelium; macrophage; microscopic imaging; multiphoton microscopy; next generation; novel; preservation; repaired; response; response to injury; seal; self-renewal; stem cell niche; stem cell population; tissue repair; tool; tumorigenesis; young adult

As the primary controllers of epithelium regeneration, intestinal stem cells (ISCs) at the bottom of the crypt must maintain a balance between self-renewal and differentiation. However, it is still unclear how the stem cells maintain tissue homeostasis in response to daily variations in cell numbers or after injury. It is also well known that the ability to repair damage is reduced in aging, but it is not known what mechanism(s) underly this process. We have recently developed a chronic preparation for in vivo imaging with multiphoton microscopy which allows the monitoring the ISC niche in real-time in mice expressing green fluorescent protein in Lgr5+ ISCs. The goal is to directly track and identify how stem cells maintain their balance in the intestinal crypts. Next generation multiphoton microscopy with an in vivo imaging preparation with femtosecond laser ablation is used to ablate individual cells of a specific type to perturb the crypt. Time lapse imaging captures changes in cell number, position, motion and marker expression to identify how the various populations of stem cell respond. Upon ablation, the targeted cells lost their shape and moved out of the plane of the crypt base towards the intestinal lumen. Immediately adjacent cells appeared to move into the space left by the ablated cell, suggesting that the niche cells actively move around in response to the pattern disruption. This proposal tests the hypothesis that age and underlying pathology reduces the efficacy of these newly discovered dynamics, which can be rescued by age-delaying agents. The expectation is that these motions are involved in protecting the stem cells from damaging factors spilling from injured cells. The new optical tools have identified a potential new function of ISCs. In addition to generating daughter cells to replenish the epithelium, Lgr5+ ISCs appear to be mechanically active in eliminating damaged cells. This adds a new function to the repertoire of ISC actions. Collectively, the results suggest that there is an active process that involves cell migration in addition to cell division for maintaining homeostasis in the intestinal crypt and epithelium. !

作为上皮再生的主要控制者，位于隐窝底部的肠道干细胞(ISCs) 必须在自我更新和差异化之间保持平衡。然而，目前仍不清楚茎是如何 细胞维持组织动态平衡，以应对细胞数量的每日变化或损伤后。它也很好 已知损伤修复能力随着年龄的增长而降低，但具体是什么机制还不清楚(S) 这一过程。我们最近开发了一种用于体内多光子成像的慢性制剂 显微镜可以实时监测表达绿色荧光的小鼠的ISC生态位 Lgr5+ISCs中的蛋白质。我们的目标是直接跟踪和识别干细胞是如何在 肠道隐窝。下一代多光子显微镜，具有体内成像准备 飞秒激光消融用于消融特定类型的单个细胞，以扰乱隐窝。时间流逝 成像捕捉细胞数量、位置、运动和标记表达的变化，以识别不同的 干细胞群体会做出反应。消融后，目标细胞失去形状并移出平面。 隐窝底部朝向肠腔。紧接着，相邻的细胞似乎移动到了空间中 被消融的细胞留下的，这表明壁龛细胞对这种模式做出了积极的反应 颠覆。这一建议检验了年龄和潜在的病理降低这些疾病的疗效的假设。 新发现的动力学，可以通过延年剂来拯救。人们的期望是，这些 运动参与保护干细胞免受受损细胞溢出的破坏因素的影响。新的 光学工具已经发现了ISCs的一个潜在的新功能。除了生成子代细胞以 补充上皮，Lgr5+ISCs似乎在清除受损细胞方面具有机械活性。这 将新功能添加到ISC操作曲目中。总体而言，结果表明，有一种活跃的 除细胞分裂外还包括细胞迁移的过程，以维持肠道内的动态平衡 隐窝和上皮组织。 好了！