Cellular Modulation of Microvessel Permeability in vivo

描述（由申请方提供）：急性炎症的特征是微血管对血浆蛋白的渗透性增加和白细胞募集到炎症部位。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调节微血管通透性的机制。本提案的目的是调查血管结构变化，运输途径的形成，信号转导途径，和完整的微血管中的渗透性变化的幅度和时间过程中，响应于不同的刺激之间的直接相关性。本论文的主要目的是：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）研究周细胞和基底膜在急性和慢性炎症条件下微血管通透性调节中的作用;和3）鉴定在急性和慢性炎症条件下负责ROS诱导的渗透性增加的细胞机制。这些目标将使用共聚焦显微镜、电子显微镜以及完整微血管中微血管通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，以及检测单独灌注微血管中内皮细胞和周细胞中肌动蛋白细胞骨架的变化。电子显微镜研究允许超微结构的变化与共聚焦图像的结果。这项研究将为更好地理解炎症条件下渗透性增加时调节液体和溶质转运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鉴定有效靶点，以防止渗透性增加，并有助于开发靶向和临床适用的抗炎疗法。公共卫生相关性：我们研究的长期目标是研究调节完整微血管通透性的细胞机制。大量的临床和实验证据表明，炎症相关的血管通透性增加是多种心血管疾病（如动脉粥样硬化、糖尿病等）的始动事件，同时也促进了肿瘤的生长和转移。更好地了解调节微血管通透性的机制对于确定许多疾病的发病机制至关重要，并有助于开发新的治疗方法。

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. PUBLIC HEALTH RELEVANCE: The long-term goal of our research is to investigate the cellular mechanisms that regulate permeability in intact microvessels. Accumulated clinical and experimental evidence indicate that an inflammation-associated increase in vascular permeability is the initiating event for a variety of cardiovascular diseases (such as atherosclerosis, diabetes) as well as promoting tumor growth and tumor metastasis. A better understanding of the mechanisms that regulate microvessel permeability is crucial to defining the pathogenesis of many disease conditions, and to aid in the development of novel therapeutic approaches.