Mechanisms of Sulfur Mustard Toxicology

描述（由申请人提供）：我们提出的研究的总体目的是揭示芥菜剂如硫芥菜（2,2 '-二氯二乙基硫）诱导细胞毒性的分子机制。硫磺芥菜是一种强效的泡腾剂，已知会损害肺组织。毒性是维持肺完整性的关键蛋白质烷基化的结果，导致炎症和氧化应激。然而，介导芥菜作用的潜在机制尚不完全清楚。硫氧还蛋白（thioredoxin, Trx）系统由硫氧还蛋白还原酶（TrxR）和硫氧还蛋白组成，是细胞内主要的硫醇调节系统，在抗氧化防御、氧化还原调节、细胞生长控制等多种细胞功能中发挥重要作用。抑制该系统可导致氧化应激和抑制细胞增殖以及坏死和凋亡。在初步实验中，我们发现2-氯乙基乙基硫醚（GEES）是肺上皮细胞中硫氧还蛋白还原酶的有效抑制剂。我们假设，发酵剂靶向硫氧还蛋白还原酶和/或硫氧还蛋白中的关键巯基，导致酶抑制，进而在靶细胞中产生氧化应激。为了验证我们的假设，我们最初计划在肺上皮细胞中检测暴露于发泡剂（使用单功能发泡剂CEES和双功能氮芥HN-2）后细胞毒性与硫氧还蛋白系统功能之间的联系。然后，用纯化的酶来表征发酵剂与硫氧还蛋白还原酶和/或硫氧还蛋白之间的相互作用。公共卫生相关：硫磺芥菜，一种在第一次世界大战期间作为化学武器首次使用的发泡剂，仍然是一个重大的民用和军事威胁。目前还没有批准的治疗暴露于芥子气和相关的发泡剂。芥菜中毒的成功治疗将取决于针对其一个或多个作用位点的药物的开发。本研究旨在确定硫芥菜的作用部位，可以靶向药物治疗。

DESCRIPTION (provided by applicant): The overall aim of our proposed studies is to reveal the molecular mechanisms of cytotoxicity induced by mustard agents such as sulfur mustard (2, 2'-dichlorodiethyl sulfide). Sulfur mustard is a potent vesicant known to damage lung tissue. Toxicity is the result of alkylation of critical proteins that maintain the integrity of the lung, resulting in inflammation and oxidative stress. However, the underlying mechanisms mediating the actions of sulfur mustard are not fully understood. The thioredoxin (Trx) system, composed of thioredoxin reductase (TrxR) and thioredoxin, is a major thiol-regulating system in cells and plays an important role in many cellular functions including antioxidant defense, redox regulation, and cell growth control. Inhibition of this system can lead to oxidative stress and inhibition of cell proliferation as well as necrosis and apoptosis. In preliminary experiments we found that 2-chloroethyl ethyl sulfide (GEES), a model sulfur mustard vesicant, is a potent inhibitor of thioredoxin reductase in lung epithelial cells. We hypothesize that vesicants target critical sulfhydryl's in thioredoxin reductase and/or thioredoxin resulting in enzyme inhibition and in turn creating oxidative stress in target cells. To test our hypothesis, we initially plan to examine the link between cytotoxicity and the function of the thioredoxin system after vesicant exposure (using the monofunctional vesicant CEES and a bifunctional nitrogen mustard HN-2) in lung epithelial cells. Then, the interaction between vesicants and thioredoxin reductase and/or thioredoxin will be characterized using purified enzymes. PUBLIC HEALTH RELEVANCE: Sulfur mustard, a vesicant first employed during World War I as a chemical weapon, remains a significant civilian and military threat. There are currently no approved treatments for exposure to sulfur mustard and related vesicants. Successful therapy for sulfur mustard poisoning will depend on the development of drugs that target one or more of its sites of action. This research is designed to identify sites of action of sulfur mustard that can be targeted for drug treatment.