CELLULAR MECHANISMS OF PULMONARY ENDOTHELIAL INJURY

肺内皮损伤的细胞机制

基本信息

批准号：
3346941
负责人：
BARBARA O MEYRICK
金额：
$ 20.66万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-05-01 至 1990-04-30
项目状态：
已结题

项目摘要

The general hypothesis that injury of pulmonary vascular endothelium involves direct responses of the endothelial cells themselves to toxic stimuli will be tested using endothelial cells grown in culture and explants of pulmonary artery intima. The endothelial responses may include intracellular generation of toxic oxygen radicals and generation of metabolites of arachidonic acid. These products may both alter the endothelial layer and affect its interaction with inflammatory cells. Activation of complement may also affect both the direct response of the endothelial cells to injurious stimuli and their interactions with inflammatory cells. Finally, inflammatory cells, per se, may potentiate the endothelial injury. To test the hypothesis, the barrier function of the endothelial layer of pulmonary artery intima and endothelial monolayers grown in culture will be measured by equilibration of isotopic tracers across the membrane and by direct measurement of hydraulic conductance. The effects of interventions on the structure of endothelial cells in both preparations will be followed and production of both lipoxygenase and cyclooxygenase products of arachidonic acid by endothelium over the course of the induced injury will be evaluated. The direct effects of various eicosanoids on endothelial structure, metabolism and function will be determined as will the question of whether an exogenous source of arachidonic acid causes the otherwise benign process of transendothelial migration of granulocytes to injure the endothelium. Measurements will be made of the effects of endotoxin and purified lipid-A on endothelial structure, metabolism and function. Measurements will also be made to determine how endotoxin alters the interactions of endothelium with leukocytes, to determine whether antioxidant enzymes delivered into cells by liposome encapsulation alter the endothelial response to endotoxin and to determine whether corticosteroids, nonsteroidal antiinflammatory drugs and free radical scavengers affect the endotoxin-induced injury. Susceptibility of different lines of cultured endothelial cells from several species to endotoxin will be examined and the role of complement in endotoxin-induced endothelial injury in the presence and absence of leukocytes will be studied. The proposed studies result from an extensive base of structural and functional information obtained in whole animal preparations and from a large amount of preliminary data suggesting that the goals of the studies are feasible. The studies will provide new information about cellular and humoral mechanisms of pulmonary vascular injury and provide a rationale for innovative approaches for prevention and therapy of diffuse lung injury.

肺血管内皮损伤的一般假设涉及内皮细胞本身对有毒物质的直接反应将使用在培养物中生长的内皮细胞来测试刺激肺动脉内膜外植体。内皮反应可能包括细胞内有毒氧自由基的产生和花生四烯酸的代谢物。这些产品都可能改变内皮层并影响其与炎症细胞的相互作用。补体的激活也可能影响补体的直接反应内皮细胞对伤害性刺激及其相互作用炎症细胞。最后，炎症细胞本身可能会增强内皮损伤。为了检验假设，势垒函数为肺动脉内膜内皮层和单层内皮培养物中的生长将通过同位素示踪剂的平衡进行测量跨膜并直接测量水力传导。干预措施对两种动物内皮细胞结构的影响随后将进行准备工作并产生脂氧合酶和整个过程中内皮细胞产生花生四烯酸的环氧合酶产物将评估诱发损伤的程度。各种因素的直接影响类二十烷酸对内皮结构、代谢和功能的影响确定是否存在外源性来源的问题花生四烯酸引起跨内皮细胞的良性过程粒细胞迁移损伤内皮。测量结果将是内毒素和纯化的脂质 A 对内皮细胞的影响结构、代谢和功能。还将进行测量确定内毒素如何改变内皮与细胞的相互作用白细胞，以确定抗氧化酶是否输送到细胞中通过脂质体封装改变内皮细胞对内毒素的反应确定是否使用皮质类固醇、非甾体类抗炎药自由基清除剂影响内毒素引起的损伤。不同细胞系培养的内皮细胞的敏感性将检查几种内毒素的种类以及补体在其中的作用在存在和不存在的情况下内毒素诱导的内皮损伤将研究白细胞。拟议的研究是广泛研究的结果从整个动物中获得的结构和功能信息的基础准备工作和大量初步数据表明研究的目标是可行的。这些研究将提供新的有关肺血管细胞和体液机制的信息伤害并为预防和预防创新方法提供依据弥漫性肺损伤的治疗。