Cellular Modulation of Microvessel Permeability in vivo

描述(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，白细胞重新聚集到炎症部位。微血管壁通透性的大幅增加是导致浮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。本研究的目的是探讨血管结构变化、运输途径的形成、信号转导途径与完整微血管对不同刺激反应的通透性变化的幅度和时程之间的直接关系。提出了三个具体的目标：1)研究急性和慢性炎症条件下完整微血管内皮细胞间隙形成和炎症介质诱导的通透性增加的细胞机制；2)研究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；以及3)确定在急性和慢性炎症条件下ROS诱导通透性增加的细胞机制。这些目标将通过结合使用共聚焦显微镜、电子显微镜以及对完整微血管的微血管通透性进行定量评估来实现。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缝隙形成，表征内皮细胞黏附蛋白的变化，以及检测单独灌流的微血管中内皮细胞和周细胞中肌动蛋白细胞骨架的变化。电子显微镜研究使超微结构的变化与共聚焦图像发现相关联。这项拟议的研究将提供新的信息，并可能提供新的概念，以更好地理解炎症条件下渗透性增加时调节流体和溶质运输的机制。所获得的洞察力将直接用于确定有效的靶点，以防止通透性增加，并有助于开发有针对性的临床适用的抗炎疗法。

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.