Dynamics of Actin in Normal and Transformed Cells

正常细胞和转化细胞中肌动蛋白的动态

• 批准号: 7623044
• 负责人: Yu-li Wang
• 金额: $ 48.23万
• 依托单位: CARNEGIE-MELLON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7623044
• 关键词: Ablation; Actins; Address; Adhesions; Adhesives; Affect; Atomic Force Microscopy; Cancerous; Cell Shape; Cells; Centrosome; Chemicals; Cytoskeleton; Differentiation and Growth; Dimensions; Dorsal; Embryonic Development; Environment; Extracellular Matrix; Fluorescence; Fluorescence Resonance Energy Transfer; Focal Adhesions; Gene Combinations; Genes; Goals; Health; Home environment; Image; Imaging Techniques; Integrins; Lead; Life; Location; Malignant Neoplasms; Maps; Mechanics; Mediating; Medical; Methods; Microfabrication; Micromanipulation; Microtubules; Molecular; Morphology; Muscle Rigidity; Normal Range; Optics; Outcome; Pathologic Processes; Pattern; Physical environment; Physiological; Play; Positioning Attribute; Process; Proteins; Public Health; Regenerative Medicine; Regulation of Cell Shape; Research; Resolution; Role; Screening procedure; Shapes; Signal Transduction; Site; Surface; Testing; Tissues; Traction; UV sensitive; Wound Healing; base; cell motility; cell transformation; cellular imaging; density; image processing; in vivo; innovation; mathematical model; migration; molecular scale; novel; particle; research study; response; sensor; stem cell differentiation

DESCRIPTION (provided by applicant): The long-term objective of this project is to understand the mechanisms of a wide range of functions performed by the actin cytoskeleton. The proposed research will focus on the basic principles that control cell shape and migration, which play an important role in numerous physiological and pathological processes including embryonic development, wound healing, and metastatic invasion. In addition, control of cell shape and migration represents a bottleneck in regenerative medicine with few effective strategies. While rapid advances have been made on identifying and characterizing the molecular components, the fundamental rules governing the responses of these functions to the physical environment remain largely unknown. The study will combine powerful optical, mechanical, chemical, microengineering, and mathematical approaches to address the responses of adherent cells to substrate rigidity and topography, which are known to have profound effects on cell shape and migration, as well as downstream processes including growth and differentiation. The first aim will characterize cellular responses to rigidity, by determining the size scale of the sensor. The experiments will also test a hypothetical universal mechanism for sensing mechanical signals, and investigate the possible role of rigidity sensing in cancer invasion. The second aim will identify key parameters that determine cellular responses to the geometry of adhesive substrates. In addition, the experiments will test potential mechanisms of geometry sensing, including one based on differential tension at adhesion sites and the other on differential microtubule density and/or dynamics. The third aim will probe the mechanism that allows cells to distinguish 3D environments from 2D surfaces. The experiments will address the topographic requirements and the possible involvement of contractile forces, cortical rigidity, and microtubule positioning. The project will take full advantage of microfabricated substrates, in addition to other innovative approaches from photo- modulation, micromanipulation, to image processing. Cells will be manipulated with pharmacological and gene ablation/silencing techniques, and imaged with high-resolution confocal and total internal reflection fluorescence optics. The fundamental principles revealed by these experiments will impact a broad range of medical issues related directly or indirectly to the regulation of cell shape and migration. PUBLIC HEALTH REVELANCE: There is now extensive evidence that physical and topographical signals, including mechanical forces, rigidity, and geometric patterns, have profound effects on cell shape and migration, which in turn affect a wide range of normal and pathological processes from cancer invasion to stem cell differentiation. However, while cellular responses to chemical interactions have been studied extensively, much less is known about their responses to these non-chemical signals, partially due to the limitations in conventional experimental methods. The proposed experiments will apply highly innovative approaches to overcome the barrier, and to obtain crucial information for understanding and treating many health issues related to cell shape control and cell migration.

描述（由申请人提供）：该项目的长期目标是了解肌动蛋白细胞骨架广泛功能的机制。我们的研究将集中在控制细胞形状和迁移的基本原理上，它们在许多生理和病理过程中发挥重要作用，包括胚胎发育、伤口愈合和转移性侵袭。此外，细胞形状和迁移的控制是再生医学的瓶颈，目前还没有有效的策略。虽然在识别和表征分子成分方面取得了迅速进展，但控制这些功能对物理环境反应的基本规则在很大程度上仍然未知。该研究将结合强大的光学、机械、化学、微工程和数学方法来解决贴壁细胞对基质硬度和地形的反应，这些对细胞形状和迁移以及下游过程（包括生长和分化）有深远的影响。第一个目标是通过确定传感器的尺寸来表征细胞对刚度的反应。实验还将测试一种假设的感知机械信号的通用机制，并研究刚性感知在癌症侵袭中的可能作用。第二个目标将确定关键参数，决定细胞响应的几何形状的粘合剂基质。此外，实验将测试几何传感的潜在机制，包括一种基于粘附位点的差异张力，另一种基于差异微管密度和/或动力学。第三个目标是探索细胞区分3D环境和2D表面的机制。实验将解决地形要求和可能涉及的收缩力、皮质刚度和微管定位。该项目将充分利用微加工基板，以及从光调制、微操作到图像处理等其他创新方法。细胞将使用药理学和基因消融/沉默技术进行操作，并使用高分辨率共聚焦和全内反射荧光光学成像。这些实验揭示的基本原理将影响与细胞形状和迁移调节直接或间接相关的广泛医学问题。