The mechanism of vesicant-induced ocular injury

眼睛比其他器官更容易暴露于水疱剂。这些后果 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 在暴露后很长时间才显现出来因此，据记载，在一个水泡攻击的幸存者， 两伊战争后30 h内角膜损伤明显， 40年后暗视和明视视网膜电图反应减弱。此外，延迟症状在 这些个体还包括视网膜中央静脉阻塞和泪液中可溶性VEGF-A的增加。 目前，还没有有效的解毒剂来对抗人类中由水疱剂引起的眼损伤和视力丧失。 因此，我们的长期目标是制定有效的医疗对策，以减轻 这样的暴露。这一目标将无法实现，除非我们增加我们的分子理解， 引起眼部损伤和进行性眼部损伤的潜在机制 exposure.因此，在本提案中，我们分析了直接眼部暴露（DOE）的水疱剂，以确定 驱动角膜、血管和视网膜病理学的急性和慢性阶段的分子信号传导。聚焦 未折叠蛋白反应（UPR）-TRIB 3下游信号传导，我们假设，在DOE后，不仅 角膜组织以及其他眼组织如血管和视网膜组织受到损伤， 根据严重程度，暴露于发泡剂激活角膜中的UPR-TRIB 3信号传导， 传播VEGF信号，引起血管功能障碍和视网膜损伤。为了剖析 在直接眼暴露和病理生理之间，我们提出了一个逐步的策略， and a wide广泛arsenal阿森纳of tools工具.这些工具包括不同的动物模型（小鼠和树鼩），角膜和 视网膜离体组织，角膜和视网膜培养细胞，两种不同的毒物（路易氏剂和氮芥）， 以及角膜、血管和视网膜组织中TRIB 3的基因消融以阻断TRIB 3-VEGF信号， 延缓眼部损伤的发生。后者将在实验中得到证实与发泡剂暴露的动物 使用小分子抑制剂VEGF-Trap-Eye进行治疗。因此，在目标#1中，我们建议调查是否 DOE致疱剂激活UPR-TRIB 3-VEGF轴，作为角膜组织损伤的分子驱动器。我们 将证明角膜起源的TRIB 3-VEGF轴激活的分子结果。在目标#2中，我们 目的是确定分泌的角膜TRIB 3介导的VEGF信号是否通过 评估角膜新生血管形成（NV）和视网膜血管破裂。在目标#3中，我们计划调查 分泌的角膜和血管介导的VEGF是否通过血管内皮生长因子驱动视网膜损伤的病理生理学， 激活UPR-TRIB 3。这些研究将确定一种新的和非常有趣的分子机制， 其中激活的UPR-TRIB 3-VEGF轴充当眼组织病理学的分子驱动器， 为今后在接触人群中进行眼毒性机理研究奠定基础。

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.