GENE MANIPULATION IN ACUTE LUNG INJURY FROM SMOKE

烟雾吸入是火灾中发病和死亡的主要原因- 每年造成至少20，000人死亡。 一个迟到的- 非心源性肺水肿常发生于火灾受害者 吸入了浓烟 这种现象不是由热引起的，而是由 烟雾中的化学毒素似乎间接导致细胞损伤， 释放第二信使。 花生四烯酸的代谢产物 级联反应是一组参与烟雾诱导的第二信使 急性长期损伤。 我们假设花生四烯酸级联中的酶的激活， 特别是磷脂酶A2（PLA 2）和白三烯A4（LTA 4）家族， 水解酶介导烟雾吸入性急性肺损伤 这些第二信使。 基因治疗提供了一种独特的方法， 抑制LTA 4水解酶或PLA 2家族的单个成员， 细胞溶质或分泌型PLA 2，对它们没有选择性药理学作用 抑制剂的 通过基因治疗操纵这些关键酶将 有助于阐明它们在急性肺损伤中作用， 治疗选择 为了检验假设，我们建立了一个大鼠模型，显示出对肺损伤的剂量反应， 将使用烟雾吸入法。 这些关键酶的生产将是 基因疗法控制的 过表达编码 胞质或分泌型PLA 2或LTA 4水解酶将与 脂质体并通过气管吹入递送至肺。 在不同 时间后交付给肺这些酶的水平，以及 将在支气管肺泡灌洗液中测量它们的代谢物。 的 将评估烟雾诱导的急性肺损伤的剂量反应， 通过测量肺动脉压，过度表达这些基因的动物 血流动力学和血管外肺水以及组织学检查。 最后，将在动物中研究急性肺损伤，其中这些酶 会被反义抑制剂下调 这些反义基因 将与脂质体复合并在吸烟前递送至肺 吸入和吸入烟雾后的不同时间，以确定其 治疗效果。

Smoke inhalation is a major cause of morbidity and mortality in fire- related injuries causing at least 20,000 fatalities per year. A delayed- onset noncardiogenic pulmonary edema frequently develops in fire victims with smoke inhalation. This phenomenon is not caused by heat, but by chemical toxins in smoke that appear to indirectly cause cell injury by the release of secondary messengers. The metabolites of the arachidonic cascade are one group of secondary messengers involved in smoke induced acute long injury. We hypothesize that activation of enzymes in the arachidonic acid cascade, especially the family of phospholipase A2 (PLA2) and leukotriene A4(LTA4) hydrolase mediate acute lung injury in smoke inhalation through production of these secondary messengers. Gene therapy offers a unique approach to inhibiting LTA4 hydrolase or individual members of the PLA2 family such as cytosolic or secretory PLA2 for which there are not selective pharmacologic inhibitors. Manipulation of these key enzymes through gene therapy will help delineate their role in acute lung injury and may well lead to new therapeutic options. To test hypothesis, a rat model showing a dose response lung injury to smoke inhalation will be used. The production of these key enzymes will be manipulated by gene therapy. Plasmids which overexpress the genes encoding cytosolic or secretory PLA2 or LTA4 hydrolase will be complexed with liposomes and delivered to the lung by tracheal insufflation. At various times after delivery to the lung the levels of these enzymes as well as their metabolites will be measured in bronchoalveolar lavage fluid. The dose response to smoke induced acute lung injury will be assessed in animals that overexpress these genes by measurement of pulmonary hemodynamics and extravascular lung water, and examination of histology. Finally acute lung injury will be studied in animals in which these enzymes will be downregulated by antisense-based inhibitors. These antisense genes will be complexed with liposomes and delivered to the lung prior to smoke inhalation and at various times after smoke inhalation to determine their therapeutic effect(s).