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

摘要：目前的抗VEGF-A治疗在一部分患者中抑制脉络膜新生血管（CNV） 新生血管性年龄相关性黄斑变性（NV-AMD）。然而，长期使用这种抗- VEGF-A治疗可能损害VEGF-A所针对的脉络膜毛细血管和视网膜的生理功能。 needed.此外，尽管持续抗VEGF-A治疗，仍可能发生疾病进展。因此，小说 迫切需要特异性靶向疾病相关机制的NV-AMD疗法， 损害视网膜稳态功能所需的生长因子和细胞途径， 脉络膜抑制促进CNV的炎症途径将是一种很有前途的新方法， 不会干扰健康视网膜和脉络膜细胞的正常功能。在这方面 炎性体是一种促炎蛋白复合物，通过血管生成促进病理性血管生成。 IL-1b的产生，并且据报道其在AMD中被激活，已经成为非常感兴趣的领域 在AMD领域。然而，先前的研究主要集中在RPE细胞中的NLRP 3炎性体， 相互矛盾的数据导致炎性小体在AMD发病机制中的作用不清楚。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关键开放的新数据， AMD领域的问题，并帮助解释一些相互矛盾的数据。我们的研究结果表明， 在活化的巨噬细胞和小胶质细胞中而不是在RPE细胞中的炎性体活化促进CNV。因此 RPE中炎性体活性的缺乏并不意味着炎性体在AMD中不起作用 发病机制此外，我们提供的证据表明，炎症小体激活可以发生在CNV巨噬细胞 和小胶质细胞，尽管NLRP 3缺陷。基于这些发现，我们提出，NLRP 3的激活 巨噬细胞/小胶质细胞中的炎性小体以及非NLRP 3炎性小体促进CNV。我们的新数据 在Vegfahyper小鼠和NV-AMD患者的眼睛中，表明AIM 2炎性体是一个关键的 在这些巨噬细胞和/或小神经胶质细胞中的总体炎性体活化的贡献者。因此，我们假设 NLRP 3和AIM 2炎性小体都通过它们在巨噬细胞中的活化促进NV-AMD 和小胶质细胞浸润并诱导早期CNV。值得注意的是，AIM2炎性小体对AMD的作用 发病机制以前没有考虑过。因此，我们的初步数据和发表的工作提供了一个 这些假设有很强的科学前提，所提出的实验具有很高的新颖性， 严格性和强临床相关性，因为它们的结果将作为靶向 NV-AMD患者的炎性小体活化。我们的建议将利用遗传学和药理学 在两种成熟的NV-AMD小鼠模型以及在人AMD眼睛中的实验中， 定义AIM 2和NLRP 3炎性小体对NV-AMD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.