Inflammation and particularly interleukin-1β (IL-1β), a pro-inflammatory cytokine highly secreted by activated immune cells during early AMD pathological events, contribute significantly to retinal neurodegeneration. Here, we identify specific cell types that generate IL-1β and harbor the IL-1 receptor (IL-1R) and pharmacologically validate IL-1β’s contribution to neuro-retinal degeneration using the IL-1R allosteric modulator composed of the amino acid sequence rytvela (as well as the orthosteric antagonist, Kineret) in a model of blue light–induced retinal degeneration. Mice were exposed to blue light for 6 h and sacrificed 3 days later. Mice were intraperitoneally injected with rytvela, Kineret, or vehicle twice daily for 3 days. The inflammatory markers F4/80, NLRP3, caspase-1, and IL-1β were assessed in the retinas. Single-cell RNA sequencing was used to determine the cell-specific expression patterns of retinal Il1b and Il1r1. Macrophage-induced photoreceptor death was assessed ex vivo using retinal explants co-cultured with LPS-activated bone marrow–derived macrophages. Photoreceptor cell death was evaluated by the TUNEL assay. Retinal function was assessed by flash electroretinography. Blue light markedly increased the mononuclear phagocyte recruitment and levels of inflammatory markers associated with photoreceptor death. Co-localization of NLRP3, caspase-1, and IL-1β with F4/80+ mononuclear phagocytes was clearly detected in the subretinal space, suggesting that these inflammatory cells are the main source of IL-1β. Single-cell RNA sequencing confirmed the immune-specific expression of Il1b and notably perivascular macrophages in light-challenged mice, while Il1r1 expression was found primarily in astrocytes, bipolar, and vascular cells. Retinal explants co-cultured with LPS/ATP-activated bone marrow–derived macrophages displayed a high number of TUNEL-positive photoreceptors, which was abrogated by rytvela treatment. IL-1R antagonism significantly mitigated the inflammatory response triggered in vivo by blue light exposure, and rytvela was superior to Kineret in preserving photoreceptor density and retinal function. These findings substantiate the importance of IL-1β in neuro-retinal degeneration and revealed specific sources of Il1b from perivascular MPs, with its receptor Ilr1 being separately expressed on surrounding neuro-vascular and astroglial cells. They also validate the efficacy of rytvela-induced IL-1R modulation in suppressing detrimental inflammatory responses and preserving photoreceptor density and function in these conditions, reinforcing the rationale for clinical translation.

中文翻译：

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一种变构白介素-1 受体调节剂可减轻视网膜变性模型中的炎症和光感受器毒性

炎症，尤其是白细胞介素 1β (IL-1β)，一种在早期 AMD 病理事件期间由活化的免疫细胞高度分泌的促炎细胞因子，对视网膜神经变性有显着影响。在这里，我们鉴定了产生 IL-1β 并含有 IL-1 受体 (IL-1R) 的特定细胞类型，并使用由氨基酸序列 rytvela 组成的 IL-1R 变构调节剂在药理学上验证了 IL-1β 对神经视网膜变性的贡献（以及正畸拮抗剂 Kineret）在蓝光诱导的视网膜变性模型中。小鼠暴露在蓝光下 6 小时，3 天后处死。小鼠腹膜内注射 rytvela、Kineret 或载体，每天两次，共 3 天。在视网膜中评估炎症标志物 F4 / 80、NLRP3、caspase-1 和 IL-1β。单细胞 RNA 测序用于确定视网膜 Il1b 和 Il1r1 的细胞特异性表达模式。使用与 LPS 激活的骨髓衍生的巨噬细胞共培养的视网膜外植体，在体外评估了巨噬细胞诱导的光感受器死亡。通过 TUNEL 测定评估光感受器细胞死亡。通过闪光视网膜电图评估视网膜功能。蓝光显着增加了单核吞噬细胞的募集和与光感受器死亡相关的炎症标志物的水平。在视网膜下间隙清晰地检测到 NLRP3、caspase-1 和 IL-1β 与 F4 / 80 + 单核吞噬细胞的共定位，表明这些炎症细胞是 IL-1β 的主要来源。单细胞 RNA 测序证实了 Il1b 的免疫特异性表达，尤其是光激发小鼠的血管周围巨噬细胞，而 Il1r1 表达主要存在于星形胶质细胞、双极细胞和血管细胞中。与 LPS / ATP 激活的骨髓衍生的巨噬细胞共培养的视网膜外植体显示出大量的 TUNEL 阳性光感受器，这被 rytvela 治疗消除了。IL-1R 拮抗作用显着减轻了体内由蓝光照射引发的炎症反应，rytvela 在保留光感受器密度和视网膜功能方面优于 Kineret。这些发现证实了 IL-1β 在神经视网膜变性中的重要性，并揭示了来自血管周围 MP 的 Il1b 的特定来源，其 Ilr1 受体分别在周围的神经血管和星形胶质细胞上表达。