Mechanical force and response during stem cell divisions in a self-renewing epithelial organ

自我更新上皮器官干细胞分裂过程中的机械力和反应

• 批准号: 8907633
• 负责人: XinXin Du
• 金额: $ 5.42万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8907633
• 关键词: Actins; Actomyosin; Adhesions; Adult; Animals; Architecture; Behavior; Behavior Control; Biological Assay; Cell Communication; Cell Proliferation; Cell model; Cell physiology; Cells; Complex; Computer Simulation; Crowding; Disease; Drosophila genus; Dysplasia; E-Cadherin; Environment; Epithelial; Epithelial Cells; Epithelium; Feedback; Fluorescence Resonance Energy Transfer; Future; Genetic; Geometry; Goals; Image; Insecta; Invertebrates; Investigation; Knowledge; Life; Light; Maintenance; Malignant Neoplasms; Mammals; Measurement; Mechanics; Midgut; Modeling; Molecular; Myosin Type II; Organ; Organ Size; Outcome; Pathology; Physiological; Reporting; Research; Research Design; Research Training; Resolution; Role; Shapes; Small Intestines; Source; Staging; Stem cells; System; Technology; Testing; Therapeutic; Time; Tissues; Tube; Tumor Suppressor Proteins; Vertebrates; Work; base; behavior change; biophysical model; cell behavior; cell type; density; experience; genetic manipulation; in vivo; insight; interdisciplinary approach; non-muscle myosin; notch protein; novel; public health relevance; research study; response; self-renewal; sensor; skills; stem cell division; stem cell therapy; temporal measurement; tissue fixing; tumor; tumor growth; tumorigenesis; tumorigenic

 DESCRIPTION (provided by applicant): Multicellular tissues, and the stem cells that renew them, continuously experience and exert mechanical forces. Although applied force is known to direct stem cell behavior in culture, the role of physiological forces in regulating stem cells witin organs is little explored. Elucidating these roles in a simple invertebrate organ will reveal basic information about the in vivo mechanobiology of stem cells and lay groundwork for future studies in more complex systems. The midgut of adult Drosophila provides such a reductionist system. The epithelium of this digestive, tube-shaped organ is continually renewed by resident stem cells, highly genetically tractable, and amenable to live imaging. Taking advantage of these features, the long-range goal of this research is to understand how stem cells exert and respond to mechanical force during midgut epithelial renewal and tumorigenesis. The central hypothesis of this proposal is that stem cell divisions are sensitive to epithelial tension forces, and that altered responses to these forces underlie stem cell-driven tumorigenesis. To investigate this hypothesis, an interdisciplinary strategy will be used that combines molecular tension sensors, targeted manipulation of actomyosin contractility, and biophysical modeling of cellular mechanics. First, the mechano-sensitivity of normal stem cell divisions will be ascertained by examining real-time dynamics of E-cadherin based tension forces around dividing stem cells, determining how force dynamics and division behavior change when actomyosin contractility is perturbed, and evaluating the long-term impact of perturbed contractility on epithelial renewal. Second, the mechano-sensitivity of tumor-generating stem cells will be assessed by applying similar experimental strategies to stem cells lacking the Notch tumor suppressor, and examining early and late stages of tumor growth. Third, guided by the outcomes of these experiments, computational models will be developed to simulate the roles of tension forces during normal and tumor-generating stem cell divisions. By modeling mechanical feedback and different sources of tension force in silico, new hypotheses will be generated to direct future investigation. The study design has high research training potential because it enables the acquisition of wet lab proficiency while expanding prior skills in computational modeling. Altogether, the proposed work will provide new knowledge of how epithelial tension forces influence divisions of midgut stem cells during renewal and tumorigenesis, advancing understanding of the mechanobiology of epithelial stem cells in vivo.

 描述（由适用提供）：多细胞组织以及更新它们的干细胞，不断体验并发挥机械力。尽管已知施加的力是在培养中引导干细胞行为的，但物理力在确定干细胞赢得器官中的作用却很少探索。在简单的无脊椎动物器官中阐明这些角色将揭示基本 有关体内机理细胞的信息，并为更复杂的系统中的未来研究奠定基础。成年果蝇的中肠提供了这样的还原主义系统。该消化，管状器官的上皮是由居民干细胞不断更新的，该干细胞高度易于拖动，并且可以进行现场成像。利用这些特征，这项研究的远距离目标是了解干细胞在中肠上皮更新和肿瘤发生过程中如何发挥和响应机械力。该提议的中心假设是干细胞分裂对上皮张力敏感， 这改变了对这些力的反应是干细胞驱动的肿瘤发生。为了研究这一假设，将使用跨学科的策略，该策略结合了分子张力传感器，靶向肌球蛋白收缩力的有针对性操纵以及细胞机械的生物物理模型。首先，通过检查围绕干细胞的E-钙粘着蛋白的张力力的实时动力学来确定正常干细胞分裂的机理敏感性，确定当肌动蛋白收缩性受到扰动并评估对上皮renewal的触及收缩性对上​​皮renewal的长期影响时，力动力学和分裂行为如何改变。其次，将通过对缺乏Notch肿瘤抑制剂的干细胞应用类似的实验策略来评估对肿瘤生成的干细胞的机理敏感，并检查肿瘤生长的早期和晚期。第三，在这些实验的结果的指导下，将开发计算模型，以模拟在正常和产生肿瘤的干细胞分裂过程中张力的作用。通过对硅的机械反馈和不同张力来源进行建模，将产生新的假设以指导未来的研究。研究设计具有很高的研究培训潜力，因为它可以在扩大计算建模的先前技能的同时获得湿实验室的熟练程度。总的来说，提出的工作将提供有关上皮张力在更新和肿瘤发生过程中如何影响中肠干细胞分裂的新知识，从而促进了对体内上皮干细胞机械生物学的理解。