Elucidating the cytoskeletal mechanics in stem cell niche morphogenesis

阐明干细胞生态位形态发生中的细胞骨架力学

• 批准号: 10386101
• 负责人: Bailey Nicole Warder
• 金额: $ 4.68万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10386101
• 关键词: Actomyosin; Address; Adherens Junction; Adopted; Affect; Anterior; Area; Automobile Driving; Behavior; Biological Assay; Biology; Cell Polarity; Cell Shape; Cells; Centrosome; Cues; Cytoskeletal Proteins; Data; Daughter; Defect; Dominant-Negative Mutation; Drosophila genus; Dynein ATPase; Educational process of instructing; Embryonic Development; Ensure; Equilibrium; Exposure to; F-Actin; Feedback; Genetic; Goals; Gonadal structure; Health; Human; Image; Imaging Techniques; Journals; Kinesin; Lasers; Lead; Link; Maintenance; Measures; Mechanics; Mentors; Mentorship; Microtubules; Mitotic spindle; Modeling; Morphogenesis; Morphology; Motor; Myosin ATPase; Myosin Light Chain Kinase; Myosin Type II; Pathway interactions; Play; Process; Proteins; RNA Interference; Reproducibility; Rho-associated kinase; Role; Shapes; Signal Transduction; Source; Structure; Suggestion; System; Techniques; Testing; Time; Tissues; Training; Transgenic Organisms; Work; cell behavior; cell cortex; experimental study; germline stem cells; kinase inhibitor; male; mechanical force; meetings; non-muscle myosin; response; self-renewal; stem cell division; stem cell function; stem cell niche; stem cells; symposium; tissue degeneration; tumor; tumorigenesis

Project Abstract: Defects in stem cell function severely impact human health by inducing tumor formation or tissue degeneration. To maintain a proper balance of self-renewal and differentiation, stem cells rely on signaling cues from their niche, which is the microenvironment in which they reside. It is imperative to understand the intricacies that underlie niche biology to reveal mechanisms that promote normal stem cell function and minimize defects in human health. In many tissues, the niche has a precise and reproducible morphology. However, not much is known about how niche morphology is controlled or how it impacts niche function. This project will use the Drosophila gonad to study the mechanics of niche formation, combining genetic tractability with powerful live- imaging techniques pioneered in the DiNardo lab. In this system, the niche has a distinct morphology defined by a smoothened boundary between the niche and the adjacent stem cells. This boundary is further referred to as the niche periphery. Functionally, the niche plays key roles in regulating stem cell behavior: 1) it is the source for self-renewal cues, 2) it restricts access of these cues to only adjacent cells, and 3) it regulates stem cell division orientation. Preliminary evidence suggests that the smooth niche periphery is crucial to ensure proper division angles for germline stem cells (GSCs), suggesting a link between niche structure and function. Furthermore, F-actin and Myosin II (MyoII) are enriched at the niche periphery, accompanied by tensile forces, suggestive of actomyosin contractility. A key goal for this project is to unveil the role of actomyosin contractility in niche morphogenesis and function (Aim 1). Since niche morphogenesis is highly reproducible, this project will also address upstream mechanisms that robustly polarize F-actin and MyoII to the niche periphery (Aim 2). An intriguing possibility is that mechanical forces exerted on the niche by adherent GSCs induce cytoskeletal polarization along the niche periphery. Preliminary evidence suggests GSC divisions are required for proper niche morphology, and it is known that multiple forces act in concert to drive spindle elongation in a dividing cell. This project will address the Hypothesis that F-actin and MyoII enrichment along the niche periphery is induced by GSC spindle elongation, and is necessary for niche formation and function. A combination of transgenic techniques will be used to manipulate actomyosin contractility, as well as inhibit microtubule motors involved in spindle elongation. This project will potentially unveil a feedback mechanism where stem cells shape the niche that guides their behavior, and will be among the first to describe the mechanisms of shaping a functional niche. The training plan for this project consists of lab work, conference attendance, journal clubs, lab meetings, graduate group seminars, and exposure to teaching and mentoring roles. This work will be completed under the mentorship of Dr. Stephen DiNardo, an expert in Drosophila biology and morphogenesis, with co-mentorship by Dr. Erfei Bi, an expert on Myosin, actomyosin ring formation, and cell polarity.

项目摘要： 干细胞功能的缺陷通过诱导肿瘤形成或组织变性严重影响人类健康。 为了保持自我更新和分化的适当平衡，干细胞依赖于信号提示 利基，这是它们居住的微环境。必须理解复杂的 利基生物学基础是揭示促进正常干细胞功能并最大程度减少缺陷的机制 人类健康。在许多组织中，利基市场具有精确且可重复的形态。但是，没有什么是 知道如何控制利基形态或如何影响利基功能。这个项目将使用 果蝇性果蝇研究利基形成的力学，将遗传障碍性与强大的活性相结合 成像技术在Dinardo实验室中开创了。在该系统中，利基市场具有独特的形态定义 通过利基和相邻干细胞之间的平滑边界。这个边界进一步提到 作为利基周边。在功能上，利基在调节干细胞行为中起关键作用：1） 自我更新线索的来源，2）它仅限于相邻单元格的访问权限，3）它调节茎 细胞分裂方向。初步证据表明，光滑的利基外围对于确保 生殖干细胞（GSC）的适当分裂角度，表明利基结构与功能之间有联系。 此外，F-肌动蛋白和肌球蛋白II（MyOII）在小众外围富含，并由拉伸力伴随 暗示肌动球蛋白收缩力。该项目的关键目标是揭示Actomyosin收缩性的作用 在小众形态发生和功能中（AIM 1）。由于利基形态发生高度可重复，因此该项目 还将解决上游机制，将F-肌动蛋白和myoII稳健地将其偏向于利基外围（AIM 2）。 一种有趣的可能性是，依从gscs在利基上施加的机械力诱导细胞骨架 沿利基周围的极化。初步证据表明，适当的GSC分区需要 利基形态，众所周知，多力量共同行动以驱动主轴伸长率 细胞。该项目将解决以下假设：F-肌动蛋白和迈奥伊沿何处的富集是 由GSC纺锤伸长诱导，对于小众形成和功能是必需的。组合 转基因技术将用于操纵肌球蛋白的收缩力，并抑制微管电机 参与主轴伸长。该项目可能会推出干细胞的反馈机制 塑造指导其行为的利基市场，并将成为第一个描述塑造机制的人之一 功能性利基。该项目的培训计划包括实验室工作，会议出勤，期刊俱乐部， 实验室会议，研究生小组研讨会以及接触教学和指导角色。这项工作将是 在果蝇生物学和形态发生专家斯蒂芬·迪纳多（Stephen Dinardo）的指导下完成 在肌球蛋白，肌动蛋白环形成和细胞极性的专家Erfei Bi博士的同时。