Full Sail Ahead: How Membranes Move and Respond to Flow

全速前进：膜如何移动和响应流动

• 批准号: 10630916
• 负责人: Aurelia R Honerkamp-Smith
• 金额: $ 35.13万
• 依托单位: LEHIGH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10630916
• 关键词: Affect; Arterial Fatty Streak; Atherosclerosis; Biochemical; Biological Models; Biological Process; Biophysics; Blood Pressure; Blood Vessels; Blood flow; Bone Density; Cell Line; Cell membrane; Cell physiology; Cells; Communication; Complex; Confocal Microscopy; Coupling; Development; Endothelial Cells; Environment; Extracellular Domain; Friction; Glass; Glypican; Goals; Health; Heparan Sulfate Proteoglycan; Homing Behavior; Human; Individual; Label; Lateral; Lesion; Lipids; Liquid substance; Malignant Neoplasms; Measures; Mechanics; Mediating; Membrane; Membrane Lipids; Membrane Proteins; Membrane Transport Proteins; Methodology; Microfluidics; Mission; Modeling; Molecular; Motion; Movement; Neoplasm Metastasis; Nitric Oxide; Nitric Oxide Synthase; Oncogenes; Pathology; Physics; Physiological; Plasma Cells; Play; Process; Production; Property; Protein Sortings; Proteins; Proteoglycan; Publishing; Reporting; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Solid; Sorting; Surface; Tertiary Protein Structure; Testing; Tissues; Translating; Transmembrane Transport; United States National Institutes of Health; Visualization; Work; angiogenesis; aqueous; biophysical properties; cardiovascular health; cell motility; drug discovery; experience; experimental study; extracellular; fluid flow; fluidity; healing; interest; lens; link protein; mechanical stimulus; mechanotransduction; membrane model; monolayer; neural growth; novel therapeutics; protein function; protein transport; reconstitution; response; self-renewal; shear stress; transmission process; tumor

PROJECT SUMMARY A remarkable feature of lipid membranes is their fluidity: they can self-heal, bend, and circulate. Individual cells also experience and respond to the flows in their environment. Flow responses regulate diverse processes such as blood pressure, bone density, and neural growth. This is particularly apparent in blood vessels, where a monolayer of endothelial cells forms the interface between flowing blood and stationary tissue. Correlation between regions of low flow and atherosclerotic plaques was observed a century ago, leading to the hypothesis that shear flow impacts endothelial cell function. Understanding how cells accomplish mechanotransduction of shear stress into cellular signals is of wide interest. However, the molecular determinants behind flow mechanotransduction remain unclear. Particularly, we lack information on the lateral movement of extracellular membrane proteins located at the cell-fluid interface. While flow has been observed to transport membrane proteins, how this transport affects protein function and cell responses remains unknown. The goal of the proposed studies is to quantitatively measure the physical interactions specific to lipid membranes that determine how lipids and proteins move in response to flow and test whether flow transport of a membrane protein activates intracellular signaling in endothelial cells. Our central hypothesis is that physiologically significant protein and lipid concentration gradients arise from physical interactions between fluid flow and complex membranes. This hypothesis is based on the premise that extracellular lipid-anchored proteoglycans like glypican-1 can be transported along the plasma membrane by external flow, with the aqueous part of the protein acting as a molecular sail. We will accomplish three specific aims: Our first aim is to identify the fundamental properties and principles that govern flow transport of membrane-linked proteins in model membranes and to build a model to predict protein motion in physiological contexts. In the second aim, we will determine how the flow-mediated lateral transport of a physiologically important membrane protein (glypican-1) initiates the short-term flow response in endothelial cells. In our third aim, we will investigate how lipid sorting by flow contributes to flow signaling in our model system and living cell membranes. Our approach is to conduct parallel experiments in model membranes and living cells, allowing us to directly relate physiological function to molecular biophysics. The experiments rely on the PI's expertise using experimental microfluidics and confocal microscopy to determine fundamental membrane properties. While the model protein studied here is specific to endothelial cells, the principles of fluid mechanics that we will uncover are universal. We, therefore, anticipate that our models will apply to multiple cell lines and flow conditions, and will lay the groundwork for future research directions.

项目摘要 脂质膜的一个显着特征是它们的流动性：它们可以自我修复，弯曲和循环。 单个细胞还会经历并响应其环境中的流量。流动响应调节多样化 血压，骨密度和神经生长等过程。这在血液中尤其明显 血管，内皮细胞的单层形成流动和静止的界面 组织。一个世纪前观察到低流量和动脉粥样硬化斑块之间的相关性， 导致假设剪切流动会影响内皮细胞功能。了解细胞如何完成 将剪切应力转导到细胞信号中的机械转导引起了广泛的关注。但是，分子 流动转导背后的决定因素尚不清楚。特别是，我们缺乏有关横向的信息 位于细胞流体界面的细胞外膜蛋白的运动。虽然观察到流动 要运输膜蛋白，该转运如何影响蛋白质功能和细胞反应仍然存在 未知。 拟议的研究的目的是定量测量特定于脂质的物理相互作用 确定脂质和蛋白质如何以流动和测试是否流动转运的膜的膜 膜蛋白激活内皮细胞中细胞内信号传导。我们的中心假设是 生理意义的蛋白质和脂质浓度梯度是由物理相互作用引起的 流体流动和复杂的膜。该假设是基于细胞外脂质锚定的前提 像Glypican-1这样的蛋白聚糖可以通过外流沿质膜运输， 蛋白质的水部分充当分子帆。我们将完成三个具体目标：我们的第一个目标是 确定控制膜连接蛋白在流动中的基本特性和原理 建模膜并建立一个模型，以预测生理环境中的蛋白质运动。在第二个目标中 我们将确定流动介导的生理上重要膜蛋白的横向转运 （Glypican-1）启动内皮细胞中的短期流动反应。在我们的第三个目标中，我们将研究如何 流量通过流量分类有助于我们的模型系统和活细胞膜中的流动信号传导。 我们的方法是在模型膜和活细胞中进行并行实验，从而使我们能够 直接将生理功能与分子生物物理学联系起来。实验依赖于PI的专业知识 实验性微流体和共聚焦显微镜，以确定基本膜特性。而 这里研究的模型蛋白质是特定于内皮细胞的，这是流体力学原理，我们将发现这些原理 是普遍的。因此，我们预计我们的模型将适用于多个单元线和流动条件，并且 将为未来的研究方向奠定基础。