CELL MEMBRANE FLUIDITY UNDER FLUID SHEAR STRESS

流体剪切应力下的细胞膜流动性

• 批准号: 6135467
• 负责人: MARK Andreas HAIDEKKER
• 金额: $ 2.06万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6135467
• 关键词: biological signal transduction; biomechanics; cell membrane; fluid flow; fluidity; fluorescence microscopy; hemodynamics; membrane activity; vascular endothelium

The overall goal of the proposed research is to determine the primary mechanosensor of mammalian cells for fluid flow. Various responses of different cell types to fluid shear stress have been explored on a biochemical basis, e.g. nitric oxide production or activation of G proteins. The hypothesis is that fluid shear stress increases membrane fluidity, thus activating heterotrimetric G proteins. Preliminary experiments using fluorescent membrane probes strongly support the hypothesis. The proposed project will focus on microscopic techniques that build on fluorescence and real-time computer image processing. Three alternative methods well be applied: Fluorescence recovery after photobleaching, fluorescence polarization anisotropy, and environment-specific fluorescent probes. All three methods allow the probing of fluidity properties on a sub- cellular scale, although the physical principles are fundamentally different. Therefore, the individual results will be used to mutually support and complete the overall findings. Furthermore, location specific effects, e.g. force accumulation at the cell-cell junction, can be investigated. If successful, the study will provide a fundamental understanding on how the endothelium senses hemodynamic forces as well as an insight into the shear-induced force distribution within the cell and on a macroscopic scale.

拟议的研究的总体目标是确定哺乳动物细胞的流体流动的主要mechanosensor。已经在生物化学基础上探索了不同细胞类型对流体剪切应力的各种响应，例如一氧化氮的产生或G蛋白的活化。假设是流体剪切应力增加了膜流动性，从而激活了异型G蛋白。使用荧光膜探针的初步实验强烈支持这一假设。拟议的项目将侧重于建立在荧光和实时计算机图像处理的显微技术。有三种方法可供选择：光漂白后的荧光恢复、荧光偏振各向异性和环境特异性荧光探针。所有这三种方法都允许在亚细胞尺度上探测流动性性质，尽管物理原理根本不同。因此，单个结果将用于相互支持和完成总体结果。此外，位置特定的影响，例如在细胞-细胞连接处的力积累，可以进行研究。如果成功，该研究将提供关于内皮如何感知血液动力学力的基本理解，以及对细胞内和宏观尺度上的剪切诱导力分布的深入了解。