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 - 对机械应力的细胞反应 - 被认为是在细胞质中发生的，对于许多基本细胞功能至关重要。然而，尚不清楚细胞质中施加的应力如何传播并转导为细胞反应。在此应用中，我们建议在细胞骨架（细胞质中推定的应激网络）中绘制负荷诱导的位移和应力。初步数据确定，我们可以使用同步检测方法跟踪带有绿色荧光蛋白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，并计算出响应于从外部施加在细胞上的小局部机械变形而产生的细胞内应力。我们惊讶地发现，在空间中，诱导的细胞内应变和应力场并未迅速衰减，正如当前所有细胞力学模型所预测的那样，而是在长距离内表现出集中的应力传播。在这里，我们提出了四个具体目标：目标1是进一步开发技术，以量化细胞骨架中三个维度的细胞内位移和应力场。目的2是检验假设的假设，即预应力介导了长距离应激的传播并确定细胞骨架中应力和应变浓度的起源。 AIM 3是响应局部振荡载荷响应于三个维度的细胞骨架结构的动态特征。 AIM 4是确定波形蛋白，细胞骨架交联蛋白质蛋白质的作用，局灶性粘附蛋白质蛋白和塔林在细胞骨架应激传播中的作用。提出的生物工程研究将收缩状态的新机械测量与细胞变形的数学分析相结合。实验方法是用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。当前的贫困可能对阐明特定基因座和结构途径有意义，以便在细胞质深处的位点进行机械汇。