The mechanism of vesicant-induced ocular injury

眼睛对发泡剂的敏感性是其他器官的10倍。这些事件的后果 暴露及其对人类视力的影响很容易被低估，因为许多眼部症状可能 暴露很久后才显露出来。因此，有记录表明，在发泡剂袭击中的幸存者 伊伊战争不仅在袭击后的前30小时内经历了角膜损伤，而且还表现为 40年后，暗视和明视视网膜电波反应减弱。此外，延迟症状在 这些人还包括视网膜中央静脉阻塞和泪液中可溶性血管内皮生长因子-A的增加。 目前，还没有有效的解毒剂来对抗发泡剂引起的人类眼损伤和视力丧失。 因此，我们的长期目标是制定有效的医学对策，以减轻 这样的曝光。这一目标是不可能实现的，除非我们增加我们对 发泡剂致眼部损伤和进行性眼部损伤的机制 曝光。因此，在这项建议中，我们分析发泡剂的直接眼部暴露(DOE)以确定 分子信号驱动角膜、血管和视网膜病理生物学的急性和慢性阶段。调焦 关于未折叠蛋白反应(UPR)-TRIB3下游信号，我们假设，在DOE之后，不仅 角膜组织以及其他眼组织，如血管和视网膜组织，也受到损害，以及 根据严重程度的不同，接触发泡剂会激活角膜中的UPR-TRIB3信号，从而进一步 传播血管内皮生长因子信号，导致血管功能障碍和视网膜损伤。剖析机械连杆 在直接眼睛暴露和病理生理学之间，我们提出了一系列不同的循序渐进的策略。 以及广泛的工具库。这些工具包括不同的动物模型(小鼠和树鼠)、角膜和 视网膜体外组织、角膜和视网膜培养细胞，两种不同的毒物(路威特和氮芥末)， 并在角膜、血管和视网膜组织中进行TRIB3的基因消融，以阻断TRIB3-VEGF信号和 延缓眼部损伤的发生。后者将在暴露于发泡剂的动物实验中得到证实。 用小分子抑制剂VEGF-Trap-Eye治疗。因此，在目标1中，我们建议调查 DOE到发泡剂激活UPR-TRIB3-VEGF轴，作为角膜组织损伤的分子驱动因素。我们 将展示角膜起源的TRIB3-血管内皮生长因子轴激活的分子后果。在目标2中，我们 目的探讨分泌型角膜TRIB3介导的血管内皮细胞生长因子信号是否通过 评估角膜新生血管(NV)和视网膜血管破裂。在目标3中，我们计划调查 分泌型角膜和血管介导的血管内皮生长因子是否通过 激活UPR-TRIB3。这些研究将确定一种新的和非常有趣的分子机制，通过 其中激活的UPR-TRIB3-VEGF轴作为眼组织病理生物学的分子驱动因素，将 为未来暴露人群眼毒性的机制研究奠定基础。

The eye is 10 times more susceptible to exposure to vesicants than other organs. The aftermath of these exposures and their impacts on human vision are easy to underestimate since many ocular symptoms may manifest long after exposure. Thus, it has been documented that the survivors of a vesicant attack during the Iraq–Iran War not only experienced corneal damage in the first 30 h after the attack but also manifested diminished scotopic and photopic electroretinogram responses 40 years later. In addition, delayed symptoms in these individuals also included central retinal vein occlusion and an increase of soluble VEGF-A in their tears. Currently, there is no effective antidote to combat vesicant-induced ocular damage and vision loss in humans. Therefore, our long-term goal is to generate effective medical countermeasures to mitigate the consequences of such exposures. This goal will not be achievable unless we increase our molecular understanding of the underlying mechanism responsible for the ocular damage and progressive ocular injuries caused by vesicant exposure. Therefore, in this proposal, we analyze direct ocular exposure (DOE) to vesicants to identify the molecular signaling driving the acute and chronic stages of corneal, vascular, and retinal pathobiology. Focusing on the unfolded protein response (UPR)-TRIB3 downstream signaling, we hypothesize that, upon DOE, not only the corneal tissue but also other ocular tissues, such as vascular and retinal tissues, are damaged, and depending on the severity, vesicant exposure activates UPR-TRIB3 signaling in the cornea, which further propagates the VEGF signal, causing blood vessel dysfunction and retinal injury. To dissect the mechanistic link between direct ocular exposure and pathophysiology, we propose a diverse spectrum of step-by-step strategies and a broad arsenal of tools. These tools include different animal models (mice and tree shrews), corneal and retinal ex vivo tissue, corneal and retinal cultured cells, two different toxicants (lewisite and nitrogen mustard), and genetic ablation of TRIB3 in the corneal, vascular, and retinal tissue to block the TRIB3-VEGF signal and delay the onset of ocular injuries. The latter will be confirmed in experiments with vesicant-exposed animals treated with a small-molecule inhibitor VEGF-Trap-Eye. Therefore, in Aim #1, we propose to investigate whether DOE to vesicants activates the UPR-TRIB3-VEGF axis, acting as a molecular driver of corneal tissue injury. We will demonstrate the molecular consequences of corneal-originated TRIB3-VEGF axis activation. In Aim #2, we intend to determine whether secreted corneal TRIB3-mediated VEGF signal drives vascular pathogenesis by assessing corneal neovascularization (NV) and retinal blood vessel disruption. In Aim #3, we plan to investigate whether secreted cornea- and vascular-mediated VEGF drives the pathophysiology of retinal injury through the activation of UPR-TRIB3. These studies will identify a novel and highly interesting molecular mechanism by which the activated UPR-TRIB3-VEGF axis acts as a molecular driver of ocular tissue pathobiology and will establish a groundwork for future mechanistic studies of ocular toxicity in exposed populations.