Project 2: Attenuating Pulmonary Toxicity of Cutaneous Exposure to Arsenicals

皮肤暴露于高活性和有毒的砷化物，如路易氏剂、二苯氯胂、二乙基 氯胂和二苯氰胂可能是偶然发生的，也可能是故意释放的。急性皮肤 暴露会导致远端器官（如肺）严重的局部起泡和炎症，造成损伤， 呼吸衰竭砷致肺损伤的发病机制尚不完全清楚， 有效的治疗方案一直是一个挑战。使用从皮肤获得的肺的RNA-Seq 暴露的砷，我们鉴定了几个改变的溴结构域4（BRD 4）靶基因。BRD 4是一个 蛋白质的溴末端和末端外（BET）结构域家族的成员，在与乙酰化组蛋白结合时 引发炎症级联反应这项提案的重点是了解BET蛋白质的作用， 皮肤砷诱导的急性肺损伤（ALI）和迟发性肺损伤中的相关炎症通路 （德新社）。我们的初步数据表明，皮肤给药后，肺中BRD 4蛋白和组蛋白乙酰化增加， 砷暴露我们还证明，JQ 1，BRD 4抑制剂，减轻肺损伤和减少 炎性细胞因子如IL-6，在皮肤暴露于氧化苯砷（PAO;一种替代物）后， 砷）。因此，我们假设毒性剂量的砷剂会导致蛋白质的乙酰化， 随后与BET蛋白结合，导致损伤途径的激活，并阻断BET信号传导 或其下游效应物可减轻砷剂引起的肺损伤。拟议的研究分为 三个具体目标。目的1将描述皮肤暴露后砷诱导的小鼠肺损伤 砷剂。这些曝光将在MRIGlobal进行，MRIGlobal是一家专门从事 这样的暴露。对于机制研究和治疗测试，aim 1还将开发内部PAO 皮肤砷诱导的ALI模型和三氧化二砷（ATO）吸入模型。研究目的2 将确定砷剂引起急性肺毒性的机制。这些体外和体内研究 将在原代肺细胞中使用与战争有关的砷剂和砷剂替代物， 小鼠，并将确定下游治疗靶点和分子，可以减轻毒性诱导的 这些化学品。这些研究将利用药物开发核心获得新的合成或FDA- 用于测试治疗效果的批准分子。目标3中的研究将确定小分子 布罗莫结构域信号传导抑制剂可以减轻砷诱导的肺损伤和相关的发病率。这些 体内小鼠研究最初将使用ATO或PAO进行。成功的候选分子，获得 通过我们的药物开发中心，然后将用更有效的砷剂进行测试。拟议预算的结果 研究将有助于确定皮肤砷中毒引起的肺损伤的治疗方案， 其他与起泡和炎症有关的潜在有毒化学物质。

Cutaneous exposure to highly reactive and toxic arsenicals such as lewisite, diphenyl chloroarsine, diethyl chloroarsine and diphenyl cyanoarsine may occur accidently or by deliberate release. Acute cutaneous exposures cause severe local blistering and inflammation in distal organs, such as the lung, causing injury and respiratory failure. The pathogenesis of arsenical-induced lung injury is incompletely understood and a search for effective treatment regimens has been a challenge. Using RNA-Seq of lungs obtained from cutaneous exposed arsenical we identified several bromodomain 4 (BRD4) target genes that were altered. BRD4 is a member of the bromo- and extra-terminal (BET) domain family of proteins that on binding to acetylated histones initiates the inflammatory cascade. This proposal focuses on understanding the role of BET proteins and associated inflammatory pathways in cutaneous arsenical-induced acute lung injury (ALI) and delayed lung injury (DLI). Our preliminary data indicates increased BRD4 protein and histone acetylation in lung following cutaneous arsenical exposures. We also demonstrate that JQ1, a BRD4 inhibitor, mitigates lung injury and decreases inflammatory cytokines such as IL-6, following cutaneous exposure to phenyl arsineoxide (PAO; a surrogate arsenical). Therefore, we hypothesize that toxic doses of arsenicals cause acetylation of proteins and subsequent binding to BET proteins, resulting in activation of injury pathways, and that blocking BET signaling or its downstream effectors can mitigate arsenicals-induced lung injury. The proposed studies are divided into three specific aims. Aim 1 will characterize arsenical-induced lung injury in mice following cutaneous exposures to arsenicals. These exposures will be carried out at MRIGlobal, a contract organization specializing in carrying out such exposures. For mechanistic studies and testing of therapies, aim 1 will also develop an in-house PAO model of cutaneous arsenical-induced ALI and an inhalation model of arsenic trioxide (ATO). Studies in Aim 2 will determine mechanisms by which arsenicals cause acute pulmonary toxicity. These in vitro and in vivo studies will be carried out using both warfare-related arsenicals and surrogates of arsenicals in primary lung cells and mice and will identify downstream therapeutic targets and molecules that can mitigate the toxicity induced by these chemicals. These studies will utilize the Drug Development Core in acquiring novel synthetic or FDA- approved molecules to test for therapeutic efficacy. Studies in Aim 3 will determine whether small molecule inhibitors of bromodomain signaling can mitigate arsenical-induced lung injury and associated morbidity. These in vivo mouse studies will initially be carried out using ATO or PAO. Successful candidate molecules, obtained through our Drug Development Core, will then be tested with more potent arsenicals. Results of the proposed research will help identify treatment options for cutaneous arsenical exposure-induced lung injury as well as for other potentially toxic chemicals associated with blistering and inflammation.