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 脂膜的一个显著特征是它们的流动性：它们可以自愈、弯曲和循环。 单个细胞也会经历并响应其环境中的流动。流动反应调节多种 血压、骨密度和神经生长等过程。这在血液中表现得尤为明显 血管，其中单层内皮细胞形成流动的血液和静止的血液之间的界面。 组织.世纪前就观察到低血流区域和动脉粥样硬化斑块之间的相关性， 导致剪切流影响内皮细胞功能的假设。了解细胞如何完成 剪切应力到细胞信号的机械传导受到广泛关注。然而，分子 流动机械转导的决定因素仍不清楚。特别是，我们缺乏关于 位于细胞-液体界面的细胞外膜蛋白的运动。虽然观察到流动 运输膜蛋白，这种运输如何影响蛋白质功能和细胞反应仍然存在 未知 拟议研究的目标是定量测量特定于脂质的物理相互作用 膜，确定脂质和蛋白质如何移动，以响应流动，并测试是否流动运输 膜蛋白激活内皮细胞中的细胞内信号传导。我们的核心假设是， 生理学上显著的蛋白质和脂质浓度梯度由蛋白质和脂质之间的物理相互作用引起。 流体流动和复杂的膜。这一假设是基于这样的前提，即细胞外脂质锚定的 蛋白聚糖如磷脂酰肌醇蛋白聚糖-1可以通过外部流动沿着质膜运输， 蛋白质的水性部分充当分子帆。我们将实现三个具体目标：第一个目标是 确定的基本属性和原则，支配流动运输的膜连接蛋白质， 模型膜，并建立模型来预测蛋白质在生理环境中的运动。第二个目标， 我们将确定一种生理上重要的膜蛋白的流动介导的横向转运 磷脂酰肌醇蛋白聚糖-1（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 通过流动的脂质分选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平行实验，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， 实验微流体和共聚焦显微镜来确定基本的膜特性。而 这里研究的模型蛋白是内皮细胞特有的，我们将揭示流体力学的原理， 是普遍的。因此，我们预计我们的模型将适用于多种细胞系和流动条件， 将为未来的研究方向奠定基础。