OXIDANT AND PROTEASE INTERACTION IN ACUTE LUNG INJURY

来自中性粒细胞和巨噬细胞的炎症介质 参与急性和慢性肺疾病的发病机制 伤害是不完全了解。 大多数研究都认为 分别在蛋白酶或氧自由基（氧化剂） 参与。 这些研究表明，氧化剂是至关重要的 参与多种类型的急性肺损伤和蛋白酶， 特别是弹性蛋白酶在慢性肺损伤中的作用。 但新兴 证据，特别是来自体外研究的证据表明， 这两类强有力的炎症反应之间的相互作用 介质在组织损伤的发展中可能是关键的。 该提案将以系统的方式解决氧化剂和 蛋白酶的相互作用，以及这与发病机制的关系 急性肺损伤 在体外初步研究中，我们将确定 大鼠中性粒细胞产生的蛋白酶和氧化剂谱 和巨噬细胞，因为我们使用大鼠进行体内研究 肺损伤。 我们感兴趣的是确定大鼠的白细胞 和人类细胞有相同类型的蛋白酶和氧化剂 在初步研究中，情况似乎是这样的。 大鼠 中性粒细胞产生次氯酸（HOCL），具有潜在的 金属酶就像人类的中性粒细胞， 大量的弹性蛋白酶。 在其他体外研究中，我们将 评估氧化剂-蛋白酶的相互作用， 细胞外基质蛋白 根据初步研究， 似乎氧化剂可以直接影响这些成分， 增强随后的蛋白水解，我们将详细研究如何 氧化剂和蛋白酶相互作用， 细胞外基质蛋白 在相关的体内研究中，我们将解决以下问题： 蛋白酶在两种实验性急性肺损伤模型中的作用 似乎需要氧化剂来启动组织的损伤 损伤 由于抗氧化剂的抑制作用似乎是时间 我们将做一个完整的时间过程研究，以确定 确切地说，在损伤开始后多久， 能有效抑制损伤。 蛋白酶的证据 参与这两种急性肺损伤模型将是 评估如下。 首先，在肺灌洗中，我们将寻找 受伤动物中游离蛋白酶活性的证据， 初步研究表明它们存在。 其次我们 将寻找细胞外基质蛋白的证据 灌洗液，特别是是否有证据表明 蛋白质分解 在初步研究中，我们发现， 这是事实。 在干预性研究中，我们将确定 抗氧化剂改变细胞外基质产物的水平， 蛋白酶在受伤大鼠的灌洗液中。 最后我们将 通过使用蛋白酶直接评估蛋白酶的作用 抑制剂的 这项研究应提供重要信息， 蛋白酶-氧化剂相互作用在糖尿病发病机制中的重要性 急性肺损伤

The inflammatory mediators derived from neutrophils and macrophages involved in the pathogenesis of acute as well as chronic lung injury are incompletely understood. Most studies have looked separately at either protease or oxygen radical (oxidant) involvement. These studies suggest that oxidants are critically involved in many types of acute lung injury and proteases, particularly elastase, in chronic lung injury. However, emerging evidence, particularly from in-vitro studies suggests that interactions between these two potent classes of inflammatory mediators may be critical in the evolution of the tissue injury. This proposal will address in a systematic fashion oxidant and protease interactions and how this relates to the pathogenesis of acute lung injury. In initial studies in-vitro we will identify the spectrum of proteases and oxidants produced by rat neutrophils and macrophages since we are using the rat for the in-vivo studies of lung injury. We are interested in determining if rat leukocytes have the same types of proteases and oxidants as the human cells and in preliminary studies this appears to be the case. Rat neutrophils produce hypochlorous acid (HOCL), have latent metalloenzymes just like the human neutrophil and produce significant amounts of elastase. In other in-vitro studies we will assess oxidant-protease interactions in the destruction of extracellular matrix proteins. Based on preliminary studies it appears as if oxidants can directly affect these components to enhance subsequent proteolysis and we will study in detail how oxidants and proteases interact to enhance the breakdown of these extracellular matrix proteins. In correlative in-vivo studies we will address the question of the role that proteases play in two experimental models of acute lung injury which appear to require oxidants to initiate the tissue injury. Since inhibition by antioxidants appears to be time dependent we will do a complete time course study to determine precisely how long after initiation of the injury that antioxidants can effectively suppress the injury. Evidence of protease involvement in these two models of acute lung injury will be assessed as follows. First, in lung lavage we will look for evidence of free protease activity in the injured animals with preliminary studies revealing that they are present. Secondly, we will be looking for evidence of extracellular matrix proteins in the lavage fluid and specifically whether or not they show evidence of proteolysis. In preliminary studies we find that this appears to be the case. In interventional studies we will determine if antioxidants alter the levels of extracellular matrix products and proteases in the lavage fluid of injured rats. Finally, we will assess directly the role that proteases play by the use of protease inhibitors. This study should provide important information on the importance of protease-oxidant interactions in the pathogenesis of acute lung injury.