Cellular and molecular mechanisms of AIM2 and NLRP3 inflammasome activation in age-related macular degeneration

摘要：目前抗血管内皮生长因子-A的治疗方法抑制了部分患者的脉络膜新生血管(CNV) 患有新生血管性老年性黄斑变性(NV-AMD)。然而，长期使用这种抗癌药物治疗 血管内皮生长因子-A治疗可能损害血管内皮生长因子-A所代表的脉络膜毛细血管和视网膜的生理功能 需要的。此外，尽管持续接受抗血管内皮生长因子-A治疗，疾病仍可继续发展。因此，小说 NV-AMD的治疗迫切需要针对特定的疾病相关机制，而不是 损害视网膜内稳态功能所需的生长因子和细胞通路 脉络膜。抑制促进CNV的炎症途径将是一种非常有希望的新方法，以至于 不会干扰健康的视网膜和脉络膜细胞的正常功能。在这方面， 炎性小体是一种促炎蛋白复合体，通过 IL-1b的产生，据报道在AMD中被激活，已经成为一个非常感兴趣的领域 在AMD字段中。然而，以前的研究主要集中在RPE细胞中的NLRP3炎症体和 相互矛盾的数据导致对炎性小体在AMD发病机制中的作用尚不清楚。通过 利用NV-AMD的遗传小鼠模型，Vegfahyper小鼠，我们现在提供了解决密钥打开的新数据 AMD领域的问题，并有助于解释一些相互矛盾的数据。我们的发现表明 激活的巨噬细胞和小胶质细胞中的炎性小体激活而不是RPE细胞中的炎性小体激活促进CNV。因此，一个 RPE中炎性小体缺乏活性并不意味着炎性小体在AMD中不起作用 发病机制。此外，我们还提供了cnv巨噬细胞中可以发生炎性小体激活的证据。 和小胶质细胞，尽管NLRP3缺乏。基于这些发现，我们认为NLRP3的激活 巨噬细胞/小胶质细胞中的炎性小体以及非NLRP3炎性小体促进CNV的发生。我们的新数据 在Vegfahyper小鼠和NV-AMD患者的眼睛中表明AIM2炎症小体是关键 这些巨噬细胞和/或小胶质细胞中的炎性小体激活。因此，我们假设 NLRP3和AIM2炎性小体均通过激活巨噬细胞促进NV-AMD 和小胶质细胞，渗透并诱导早期CNV。值得注意的是，AIM2炎症体在AMD中的作用 发病机制以前没有被考虑过。因此，我们的初步数据和发表的工作提供了一个 这些假设具有很强的科学性前提，所提出的实验具有较高的新颖性、较高的 严谨性和很强的临床相关性，因为他们的结果将作为目标为目标的新疗法的框架 NV-AMD患者的炎性小体激活。我们的提案将同时利用遗传学和药理学 在两种已建立的NV-AMD小鼠模型以及在人类AMD眼睛中的实验中， 明确AIM2和NLRP3炎性小体在NV-AMD中的作用。

SUMMARY: Current anti-VEGF-A therapies inhibit choroidal neovascularization (CNV) in a subset of patients with neovascular age-related macular degeneration (NV-AMD). However, long-term treatment with such anti- VEGF-A therapies may impair physiological functions of the choriocapillaris and retina for which VEGF-A is needed. Moreover, disease progression can occur despite continuous anti-VEGF-A treatment. Thus, novel therapies for NV-AMD are urgently needed that target specifically disease-associated mechanisms without impairing growth factors and cellular pathways that are required for homeostatic functions of the retina and choroid. Inhibiting the inflammatory pathways that promote CNV would be such a promising novel approach that would not interfere with the normal functions of healthy retinal and choroidal cells. In this context, the inflammasome, a proinflammatory protein complex that promotes pathologic angiogenesis through the generation of IL-1b and which has been reported to be activated in AMD, has become an area of much interest in the AMD field. However, previous studies have focused mainly on the NLRP3 inflammasome in RPE cells and conflicting data have resulted in an unclear picture of the role of the inflammasome for AMD pathogenesis. By utilizing a genetic mouse model of NV-AMD, Vegfahyper mice, we provide now new data that resolve key open questions in the AMD field and help explain some of the conflicting data. Our findings demonstrate that inflammasome activation in activated macrophages and microglia but not in RPE cells promotes CNV. Thus, a lack of inflammasome activity in the RPE does not mean that the inflammasome does not play a role in AMD pathogenesis. Furthermore, we provide evidence that inflammasome activation can occur in CNV macrophages and microglia despite NLRP3 deficiency. Based on these findings we propose that activation of both NLRP3 inflammasomes as well as non-NLRP3 inflammasomes in macrophages/microglia promotes CNV. Our new data in Vegfahyper mice and in eyes from patients with NV-AMD suggest that the AIM2 inflammasome is a key contributor to overall inflammasome activation in these macrophages and/or microglia. Thus, we hypothesize that both the NLRP3 and the AIM2 inflammasomes promote NV-AMD through their activation in macrophages and microglia that infiltrate and induce early CNV. Notably, a role of the AIM2 inflammasome for AMD pathogenesis has previously not been considered. Thus, our preliminary data and published work provide a strong scientific premise for these hypotheses, and the proposed experiments have a high novelty, high rigor, and strong clinical relevance, as their outcome will serve as a framework for novel therapies that target inflammasome activation in patients with NV-AMD. Our proposal will utilize both genetic as well as pharmacologic approaches in two well-established mouse models of NV-AMD as well as experiments in human AMD eyes, to define the roles of AIM2 and NLRP3 inflammasomes for NV-AMD.