Cellular Modulation of Microvessel Permeability in vivo

描述（由申请人提供）：急性炎症的特征是微血管对血浆蛋白的渗透性增加，白细胞聚集到炎症部位。微血管壁通透性的大幅增加是导致水肿形成和器官功能障碍的关键事件。我们研究的长期目标是研究炎症条件下微血管通透性的调节机制。本研究旨在探讨完整微血管在不同刺激下，血管结构变化、转运途径形成、信号转导途径与通透性变化的幅度和时间过程之间的直接关系。提出三个具体目标：1)研究急性和慢性炎症条件下完整微血管内皮间隙形成和炎症介质诱导的通透性增加的细胞机制；2)探讨急性和慢性炎症条件下周细胞和基底膜在微血管通透性调节中的作用；3)明确急性和慢性炎症条件下ros诱导通透性增加的细胞机制。这些目标将通过联合共聚焦显微镜、电子显微镜以及对完整微血管的微血管渗透性的定量评估来实现。我们新建立的方法使我们能够三维可视化和量化炎症介质诱导的间隙形成，表征内皮粘附蛋白的变化，以及检测单个灌注微血管内皮细胞和周细胞中肌动蛋白细胞骨架的变化。电子显微镜研究允许超微结构变化与共聚焦图像结果相关。该研究将为更好地理解炎症条件下通透性增加时调节流体和溶质运输的机制提供新的信息和可能的新概念。所获得的见解将直接应用于识别有效的目标，以防止渗透性增加，并有助于开发靶向和临床应用的抗炎疗法。

DESCRIPTION (provided by applicant): Acute inflammation is characterized by increased microvascular permeability to plasma proteins and leukocyte recruitment into inflammatory sites. A large increase in permeability of the microvessel wall is a critical event resulting in edema formation and organ dysfunction. The long-term goal of our research is to investigate the mechanisms that regulate microvessel permeability under inflammatory conditions. The objective of this proposal is to investigate the direct correlation between vascular structural changes, transport pathway formations, signal transduction pathways, and the magnitude and time course of the permeability changes in intact microvessels in response to different stimuli. Three specific aims are proposed: 1) Investigate the cellular mechanisms of endothelial gap formation and inflammatory mediator-induced permeability increases in intact microvessels under acute and chronic inflammatory conditions; 2) Investigate the role of pericytes and the basement membranes in the regulation of microvessel permeability under acute and chronic inflammatory conditions; and 3) Identify the cellular mechanisms responsible for ROS-induced permeability increases under acute and chronic inflammatory conditions. These aims will be accomplished using combined confocal microscopy, electron microscopy, with quantitative assessments of microvessel permeability in intact microvessels. Our newly established methods enable us to three- dimensionally visualize and quantify inflammatory mediator-induced gap formation, characterize the changes in endothelial adhesion proteins, as well as to detect changes in actin cytoskeleton in endothelial cells and pericytes in individually perfused microvessels. The electron microscopy study allows ultrastructural changes to be correlated with confocal image findings. The proposed research will provide new information and possibly new concept for a better understanding of the mechanisms that regulate fluid and solute transport when permeability is increased under inflammatory conditions. The insight gained will be directly applied to the identification of an effective target to prevent the permeability increase and contribute to the development of targeted and clinically applicable anti-inflammatory therapies.