Bioengineering to map stress propagation in cytoskeleton

生物工程绘制细胞骨架中的应力传播图

• 批准号: 7105062
• 负责人: Ning Wang
• 金额: $ 25.68万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7105062
• 关键词: actin binding protein; bioengineering /biomedical engineering; bioimaging /biomedical imaging; biophysics; crosslink; cytoplasm; cytoskeletal proteins; cytoskeleton; flow cytometry; fluorescence microscopy; green fluorescent proteins; human tissue; magnetic field; mathematical model; mechanical stress; mechanoreceptors; mitochondria; molecular /cellular imaging; muscle cells; protein structure function; smooth muscle; technology /technique development; three dimensional imaging /topography; vimentin; vinculin

DESCRIPTION (provided by applicant): Mechanotransduction - the cellular response to mechanical stress - is thought to occur in the cytoplasm and is vital to many fundamental cell functions. However, how applied stresses are propagated within the cytoplasm and transduced into cellular responses is unknown. In this application we propose to map load-induced displacements and stresses in the cytoskeleton, the putative stress-bearing network in the cytoplasm. Preliminary data establish that we can track intracellular cytoskeletal structures marked with green fluorescent protein using a synchronous detection method. We can also measure the spatial distribution of displacements of these structures and compute intracellular stresses that arise in response to a small localized mechanical deformation imposed on the cell from the outside. We were surprised to find that the induced fields of intracellular strain and stress did not decay rapidly in space, as would be predicted from all current models of cell mechanics, but rather exhibited focused stress propagation over long distances. Here we propose four Specific Aims: Aim 1 is to further develop the technology to quantify intracellular displacement and stress fields in three dimensions in the cytoskeleton. Aim 2 is to test the hypothesis that the prestress mediates long distance stress propagation and to identify the origin of stress and strain concentration in the cytoskeleton. Aim 3 is to map the dynamic features of the cytoskeletal structures in three dimensions in response to localized oscillatory loads. Aim 4 is to determine the roles of vimentin, cytoskeletal crosslinking protein plectin, and focal adhesion proteins vinculin and talin in cytoskeletal stress propagation. The proposed bioengineering research combines novel mechanical measurements of the contractile state with mathematical analysis of cell deformation. The experimental method is to measure with high spatial and temporal resolution the intracellular deformation field in response to localized mechanical loading, and to characterize the mechanical state and cytoskeletal structure during specific interventions. The current poject may have implications in elucidating specific loci and structural pathways for mechanotranduction at sites deep in the cytoplasm.

描述（由申请人提供）：机械转导——细胞对机械应力的反应——被认为发生在细胞质中，并且对于许多基本细胞功能至关重要。然而，所施加的应激如何在细胞质内传播并转化为细胞反应尚不清楚。在此应用中，我们建议绘制细胞骨架中负载引起的位移和应力，即细胞质中假定的应力承受网络。初步数据表明，我们可以使用同步检测方法追踪用绿色荧光蛋白标记的细胞内细胞骨架结构。我们还可以测量这些结构位移的空间分布，并计算响应从外部施加在细胞上的微小局部机械变形而产生的细胞内应力。我们惊讶地发现，细胞内应变和应力的感应场并没有像当前所有细胞力学模型所预测的那样在空间中迅速衰减，而是表现出长距离的集中应力传播。在这里，我们提出了四个具体目标： 目标 1 是进一步开发量化细胞骨架中三个维度的细胞内位移和应力场的技术。目标 2 是检验预应力介导长距离应力传播的假设，并确定细胞骨架中应力和应变集中的起源。目标 3 是在三个维度上绘制细胞骨架结构响应局部振荡载荷的动态特征。目标 4 是确定波形蛋白、细胞骨架交联蛋白凝集素以及粘着斑蛋白纽蛋白和踝蛋白在细胞骨架应激传播中的作用。拟议的生物工程研究将收缩状态的新颖机械测量与细胞变形的数学分析结合起来。实验方法是以高空间和时间分辨率测量响应局部机械载荷的细胞内变形场，并表征特定干预期间的机械状态和细胞骨架结构。当前的项目可能对阐明细胞质深处的机械传导的特定位点和结构途径具有影响。