GENE MANIPULATION IN ACUTE LUNG INJURY FROM SMOKE

吸入烟雾是火灾中发病率和死亡率的主要原因- 每年造成至少20,000人死亡的相关伤害。一辆延迟的- 起病的非心源性肺水肿常见于火灾受害者 吸入浓烟。这种现象不是由高温引起的，而是由 烟雾中的化学毒素似乎通过 释放第二信使。花生四烯酸的代谢物 级联是参与烟雾诱导的一组次要信使 急性长时间损伤。 我们假设花生四烯酸级联反应中的酶的激活， 尤其是磷脂酶A2(PLA2)和白三烯A4(LTA4)家族 水解酶通过产物介导烟雾吸入所致急性肺损伤 这些第二信使。基因疗法提供了一种独特的方法 抑制LTA4水解酶或PLA2家族的个别成员，如 无选择性药理作用的胞浆或分泌型PLA2 抑制剂。通过基因疗法操纵这些关键酶将 有助于阐明它们在急性肺损伤中的作用，并很可能导致新的 治疗选择。 为了检验假设，一个显示肺损伤的剂量反应的大鼠模型 将使用烟雾吸入。这些关键酶的生产将是 通过基因治疗来操纵。过度表达编码基因的质粒 胞浆或分泌型PLA2或LTA4水解酶将与 脂质体经气管注入后进入肺内。在各种不同的 产后进入肺的时间，这些酶的水平以及 他们的代谢物将在支气管肺泡灌洗液中进行测量。这个 将评估对烟雾引起的急性肺损伤的剂量反应 通过测量肺组织来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，将在动物身上研究急性肺损伤，在这些动物中，这些酶 会被反义抑制剂下调。这些反义基因 将与脂质体形成络合物，并在吸烟前被输送到肺部 并在吸入烟雾后的不同时间测定其 疗效(S)。

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).