Identification of AMD3100 (Plerixafor) as a potential lead compound for chlorine toxicity

项目摘要/摘要 问题陈述：氯(Cl2)气体是美国最常见的吸入性刺激物， 导致严重的不良反应，包括肺损伤和死亡。PI和其他人之前的研究已经 证明了白细胞(中性粒细胞和巨噬细胞)迁移和归巢到肺中起关键作用。 Cl2气体暴露后肺部发病率和死亡率的作用。趋化因子配体基质的结合- 衍生因子-1(SDF-1)与C-X-C趋化因子受体4(CXCR4)对肺免疫、上皮细胞和肺组织的影响 内皮细胞促进白细胞从循环到肺的迁移。SDF-1/CXCR4轴还 促进肺内白细胞的激活和存活。我们的初步数据显示，SDF-1 而CXCR4水平在接触Cl2的动物的肺中升高。因此，我们的假设是SDF- 1/CXCR4轴参与Cl2和CXCR4暴露后肺内白细胞的迁移、归巢和存活 因此，FDA批准的化合物AMD3100(Plerixafor)抑制这一轴将减弱Cl2- 诱发肺部发病率和死亡率。具体目标：1)确定SDF-1/CXCR4轴在Cl2诱导中的作用 肺内白细胞的迁移、激活和存活。2)优化AMD3100的Cl2毒性给药方案。 3)阐明了Cl2暴露后SDF-1/CXCR4的调控机制。实验方法： 将C57BL/6小鼠暴露于Cl2气体(500ppm，30min)，然后将SDF-1浓度 支气管肺泡灌洗液及CXCR4在肺泡白细胞和全肺表面的表达 组织将随着时间的推移进行测量。还将分析SDF-1/CXCR4轴是否中介Cl2 肺白细胞的依赖性迁移、激活和存活。接下来，接触Cl2的小鼠将被 临床安全剂量(0.01-0.16 mg/kg)的AMD3100肌肉注射后，急性和 将测量慢性肺损伤和死亡率。最后，Cl2诱导的溶血和缺氧在 将在体外和体内研究Cl2暴露后肺SDF-1和CXCR4水平的调节。预期的 结果：我们预计AMD3100将减少白细胞向肺的移位，从而减轻 对暴露在Cl2中的小鼠的肺损伤和提高存活率。创新：这项研究是第一次提出使用 FDA批准的一种新型小分子化合物AMD3100，用于减轻术后肺损伤和死亡率 暴露在Cl2气体中。AMD3100可能有益于减轻暴露于其他有毒气体后的肺损伤 如溴和光气，也与溶血和增加的迁移有关 白细胞进入肺部。

PROJECT SUMMMARY/ABSTRACT Statement of problem: Chlorine (Cl2) gas is the most common inhalational irritant in the United States, which results in serious adverse effects including lung injury and death. Previous studies by the PI and others have demonstrated that migration and homing of leukocytes (neutrophils and macrophages) into lungs play a critical role in lung morbidity and mortality post Cl2 gas exposure. The binding of the chemokine ligand, stromal- derived-factor-1 (SDF-1), to the C-X-C chemokine receptor type 4 (CXCR4) on lung immune, epithelial, and endothelial cells promote the migration of leukocytes from the circulation to lungs. The SDF-1/CXCR4 axis also propagates the activation and survival of leukocytes in the lungs. Our preliminary data shows that both SDF-1 and CXCR4 levels are elevated in the lungs of Cl2 exposed animals. Therefore, our hypothesis is that SDF- 1/CXCR4 axis is involved in the migration, homing, and survival of leukocytes in lung post exposure to Cl2 and therefore inhibiting this axis by an FDA approved compound, AMD3100 (Plerixafor), would attenuate Cl2- induced lung morbidity and mortality. Specific aims: 1) Establish the role of SDF-1/CXCR4 axis in Cl2-induced lung leukocyte migration, activation, and survival. 2) Optimize the dosage regimen of AMD3100 for Cl2 toxicity. 3) Delineate the mechanisms of SDF-1/CXCR4 regulation post-Cl2 exposure. Experimental approach: C57BL/6 mice will be exposed to Cl2 gas (500ppm, 30min) and then the SDF-1 concentration in broncholaveolar lavage fluid and the CXCR4 surface expression on the alveolar leukocytes and whole lung tissue will be measured over time. It will also be analyzed whether, the SDF-1/CXCR4 axis mediates Cl2 dependent migration, activation, and survival of lung leukocytes. Next the Cl2 exposed mice will be administered a clinically safe dose (0.01-0.16 mg/kg) of AMD3100 intramuscularly and the indices of acute and chronic lung injury and mortality will be measured. Finally, the role of Cl2-induced hemolysis and hypoxia in the regulation of lung SDF-1 and CXCR4 levels post Cl2 exposure will be studied in vitro and in vivo. Anticipated results: We anticipate that AMD3100 will attenuate leukocyte translocation to lungs and subsequently mitigate lung injury and improve survival in mice exposed to Cl2. Innovation: The study is the first to propose the use of a novel, FDA-approved, small molecule compound, AMD3100, to mitigate lung injury and mortality post exposure to Cl2 gas. AMD3100 may be beneficial in mitigating lung injury post exposure to other toxic gases such as bromine and phosgene, which are also associated with hemolysis and increased migration of leukocytes into lung.