Central Role of Heme Oxygenase in Reversing Bromine Morbidity and Mortality

描述（由申请人提供）：溴（Br2）是一种卤素，用作水消毒剂，用于漂白纤维，用于制造抗癫痫药物、染料、阻燃剂、杀虫剂、钻井液和汽油添加剂。在运输事故、集装箱间转移或恐怖主义行动中，高浓度吸入溴会导致呼吸衰竭死亡。很少有已发表的研究评估吸入Br2的急性和慢性后遗症；治疗仍然是症状性的，没有有效的对策。我们令人兴奋和高度新颖的初步数据表明，与野生型的同窝小鼠相比，过度表达人类血红素加氧酶(HO)-1基因和蛋白（hHO-1 BAC）的小鼠在暴露于Br2后返回室内空气时，死亡率显着降低。相比之下，缺乏HO-1基因（HO-1-/-）的小鼠在暴露于Br2后显示出明显增加的死亡率。我们还通过高通量筛选鉴定了五种化合物，它们是人类HO-1基因的有效诱导剂。本应用的目的是：(1)确定HO-1在保护小鼠免受Br2诱导的损伤中的作用；(2)测试这些化合物在Br2暴露后全身给药的小鼠中上调HO-1的功效，并降低死亡率和肺损伤。SA # 1。我们将hHO-1 BAC、HO-1-/-小鼠及其野生型幼崽在环境室中暴露于Br2 （600 ppm， 30分钟），然后将它们放回室内空气中，测量两周的死亡率和肺损伤。SA #2:(i)我们将人类气道克拉拉细胞样细胞（H441）的融合单层暴露于Br2中，并将其返回到室内空气中；然后，我们将测试通过高通量筛选鉴定的五种化合物的功效，以增加HO-1并减少Br2诱导的细胞坏死和凋亡。（ii）我们将分析这些化合物，以确定那些与肌肉给药有关的最佳药代动力学特性。（iii）我们将体外表现出最佳细胞保护作用的化合物在hHO-1 BAC和野生型小鼠肌肉内注射，并在注射后2、24和72测量肺mRNA和hHO-1活性。（iv）我们将hHO-1 BAC、HO-1 -/-小鼠及其野生型幼崽（均为C57BL/6背景）暴露于Br2 （600 ppm）中30分钟，将它们送回室内空气中，并在暴露后2小时开始肌内注射该化合物。如SA #1所述，我们将测量所有组的死亡率和14 d的肺损伤指数和肺hHO1活性。

DESCRIPTION (provided by applicant): Bromine (Br2) is a halogen used as a water disinfectant, for bleaching fibers, in the manufacture of antiepileptic drugs, dyestuffs, flame retardants, insecticides, drilling fluids, and gasoline additives When inhaled at higher concentrations, as may occur during transportation accidents, transfers among containers or acts of terrorisms, Br2 has caused death from respiratory failure. There are very few published studies evaluating acute and chronic sequelae of Br2 inhalation; treatment remains symptomatic and no effective countermeasures exist. Our exciting and highly novel preliminary data show that mice overexpressing the human form of the heme oxygenase (HO)-1 gene and protein (hHO-1 BAC) exhibit significantly lower mortality when returned to room air post Br2 exposure as compared to their wild-type littermate controls. In contrast, mice deficient in the HO-1 gene (HO-1-/-), display markedly increased mortality following Br2 exposure. We have also identified five compounds that are potent inducers of the human HO-1 gene using high-throughput screening. The goals of this application are: (1) to establish the role of HO-1 in protecting mice from Br2 induced injury and (2) test the efficacy of these compounds, administered in mice systemically, post Br2 exposure, to upregulate HO-1, and decrease mortality and lung injury. SA #1. We will expose hHO-1 BAC, HO-1-/- mice and their wild-type littermates to Br2 (600 ppm for 30 min) in environmental chambers, and return them to room air and measure mortality and lung injury for two weeks. SA #2: (i) We will expose confluent monolayers of human airway Clara-cell like cells (H441) to Br2 and return them to room air; we will then test the efficacy of the five compounds identified by high throughput screening, to increase HO-1 and decrease Br2 induced cellular necrosis and apoptosis. (ii) We will profile these compounds to determine those with the best pharmacokinetic properties related to intramuscular dosing. (iii) We will inject hHO-1 BAC and wild-type mice intramuscularly with the compound that exhibits the best cytoprotective effects in vitro and measure lung mRNA and hHO-1 activity at two, 24 and 72 post injection. (iv) We will expose hHO-1 BAC, HO- 1-/- mice and their wild-type littermates (all in C57BL/6 background) to Br2 (600 ppm for 30 min), return them to room air and inject them intramuscularly starting at 2 h post-exposure with this compound. We will measure mortality in all groups and indices of lung injury and lung hHO1 activity for 14 d as described in SA #1.