Project 3: Intercepting Renal Damage following Skin Exposure to Arsenicals

军火库是化学武器的一个重要类别，因为它们对皮肤也有破坏性影响。 全身影响损害多个器官，包括肾脏和肺。这个项目是基于我们的 研究发现，皮肤接触路易斯汀，第一次世界大战期间首次合成的一种砷，不仅 损害皮肤，但也很快被吸收，并对肾脏产生毒性影响，导致急性和 延迟性肾损伤。初步研究表明，砷引起表观遗传性组蛋白重塑 通过BRD4的过度乙酰化和募集到诱导基因的启动子区域 炎症和组织损伤。BRD4是溴末端和超末端结构域家族的成员 蛋白质。此外，我们观察到细胞保护蛋白--血红素加氧酶-1(HO-1)显著上调。 1)局部暴露于路易氏剂后的肾脏。砷诱导BRD4和BRD4的高表达 HO-1基因敲除小鼠与野生型小鼠的炎症信号基因比较，表明 HO-1在炎症反应表观遗传调控中的重要性。总而言之，这些研究 强调单一皮肤砷中毒后急性和延迟性肾损害的重要性 暴露并确定两个潜在的相互关联的分子靶点BRD4和HO-1在肾脏损伤中的作用。 该项目的总体目标是制定基于机制的暴露后对策， 可以减轻砷引起的肾脏损伤。我们的假设是，有毒剂量的阿森纳会导致 蛋白质(组蛋白)的乙酰化和随后溴结构域蛋白的招募导致激活 阻断溴域信号或其下游效应物可以减轻肾脏 受伤。在目标1中，将表征砷介导的AKI小鼠模型以确定剂量-和 肾损害的时间依赖性。在目标2中，我们确定了阿司匹林引起AKI的机制 重点研究BRD4和HO-1对阿司匹林诱导的AKI的干预作用。在目标3中，我们将制定有针对性的 通过以下方法对砷致急性KI进行治疗干预以确定最佳的受益窗口 暴露于军火库的动物的暴露后治疗。FDA批准的和新型小分子都将 在这一目标中被评估。成功完成我们在此建议的研究不仅将提供 有效的化学损伤解毒剂，但也将有助于更广泛地了解内源性 表观遗传反应可用于开发AKI的新治疗策略。

Arsenicals are an important category of chemical weapons due to their devastating effects on the skin as well as systemic effects damaging multiple organs including the kidney and lung. This project is based on our findings that cutaneous exposure to lewisite, an arsenical first synthesized during world war I, not only damages skin but is also rapidly absorbed and exerts toxic effects in the kidney leading to both acute and delayed kidney damage. Preliminary studies demonstrate that arsenicals cause epigenetic histone remodeling by hyperacetylation and recruitment of BRD4 to promoter regions of inducible genes associated with inflammation and tissue damage. BRD4 is a member of the bromo- and extra-terminal domain family of proteins. In addition, we observed marked upregulation of the cytoprotective protein, heme oxygenase-1 (HO- 1) in the kidney following topical exposure to lewisite. Arsenicals induce higher expression of BRD4 and inflammatory signaling genes in HO-1 knockout mice as compared to wild-type littermates, suggesting the importance of HO-1 in epigenetic regulation of inflammatory responses. Taken together, these studies underscore the significance of both acute and delayed kidney damage following a single cutaneous arsenical exposure and identify two potential inter-related molecular targets, BRD4 and HO-1 in renal injury. The overall goal of this project is to develop mechanism-based post-exposure countermeasures that can mitigate arsenical-induced kidney damage. Our hypothesis is that toxic doses of arsenicals cause acetylation of proteins (histones) and subsequent recruitment of bromodomain proteins resulting in activation of injury pathways and that blocking bromodomain signaling or its downstream effectors can mitigate kidney injury. In Aim 1, an arsenical mediated murine model of AKI will be characterized to determine the dose- and time-dependence of kidney damage. In Aim 2, we determine the mechanisms by which arsenicals cause AKI focusing on BRD4 and HO-1 for intervention in arsenicals-induced AKI. In Aim 3, we will develop targeted therapeutic intervention in arsenical-induced AKI to determine the optimal window for the beneficial effects by post-exposure treatment in animals exposed to arsenicals. Both FDA approved and novel small molecules will be assessed in this aim. Successful completion of our research as proposed here will not only provide an effective antidote for chemical injury but will also contribute to a broader understanding of how endogenous epigenetic responses can be exploited towards developing new therapeutic strategies for AKI.