Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China.
Department of Geriatric Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China.
Mol Med. 2024 Sep 27;30(1):159. doi: 10.1186/s10020-024-00938-0.
Retinal ischemia/reperfusion (IR) injury is a common pathological process in many ophthalmic diseases. Interleukin-1β (IL-1β) is an important inflammatory factor involved in the pathology of retinal IR injury, but the mechanism by which IL-1β is regulated in such injury remains unclear. Caspase-11 non-canonical inflammasomes can regulate the synthesis and secretion of IL-1β, but its role in retinal IR injury has not been elucidated. This study aimed to evaluate the role of caspase-11 non-canonical inflammasomes in retinal IR injury.
Retinal IR injury was induced in C57BL/6J mice by increasing the intraocular pressure to 110 mmHg for 60 min. The post-injury changes in retinal morphology and function and in IL-1β expression were compared between caspase-11 gene knockout (caspase-11) mice and wild-type (WT) mice. Morphological and functional changes were evaluated using hematoxylin-eosin staining and retinal whole mount staining and using electroretinography (ERG), respectively. IL-1β expression in the retina was measured using enzyme-linked immunosorbent assay (ELISA). The levels of caspase-11-related protein were measured using western blot analysis. The location of caspase-11 in the retina was determined via immunofluorescence staining. Mouse type I astrocytes C8-D1A cells were used to validate the effects of caspase-11 simulation via hypoxia in vitro. Small-interfering RNA targeting caspase-11 was constructed. Cell viability was evaluated using the MTT assay. IL-1β expression in supernatant and cell lysate was measured using ELISA. The levels of caspase-11-related protein were measured using western blot analysis.
Retinal ganglion cell death and retinal edema were more ameliorated, and the ERG b-wave amplitude was better after retinal IR injury in caspase-11 mice than in WT mice. Further, caspase-11 mice showed lower protein expressions of IL-1β, cleaved caspase-1, and gasdermin D (GSDMD) in the retina after retinal IR injury. Caspase-11 protein was expressed in retinal glial cells, and caspase-11 knockdown played a protective role against hypoxia in C8-D1A cells. The expression levels of IL-1β, cleaved caspase-1, and GSDMD were inhibited after hypoxia in the si-caspase-11 constructed cells.
Retinal IR injury activates caspase-11 non-canonical inflammasomes in glial cells of the retina. This results in increased protein levels of GSDMD and IL-1β and leads to damage in the inner layer of the retina.
视网膜缺血/再灌注（IR）损伤是许多眼科疾病中的一种常见病理过程。白细胞介素-1β（IL-1β）是一种参与视网膜 IR 损伤病理过程的重要炎症因子，但 IL-1β在这种损伤中的调节机制尚不清楚。半胱天冬酶-11 非经典炎性小体可调节 IL-1β的合成和分泌，但它在视网膜 IR 损伤中的作用尚未阐明。本研究旨在评估半胱天冬酶-11 非经典炎性小体在视网膜 IR 损伤中的作用。
通过将眼内压升高至 110mmHg 持续 60min 诱导 C57BL/6J 小鼠发生视网膜 IR 损伤。比较 caspase-11 基因敲除（caspase-11）小鼠和野生型（WT）小鼠视网膜形态和功能以及 IL-1β表达的变化。分别采用苏木精-伊红染色和视网膜全铺片染色、视网膜电图（ERG）评估形态和功能变化。采用酶联免疫吸附试验（ELISA）检测视网膜中 IL-1β的表达。采用 Western blot 分析检测半胱天冬酶-11 相关蛋白水平。采用免疫荧光染色检测半胱天冬酶-11 在视网膜中的定位。采用体外缺氧法验证 C8-D1A 细胞中 caspase-11 模拟的作用，并构建靶向半胱天冬酶-11 的小干扰 RNA。采用 MTT 法评估细胞活力。采用 ELISA 检测上清液和细胞裂解液中 IL-1β的表达。采用 Western blot 分析检测半胱天冬酶-11 相关蛋白水平。
与 WT 小鼠相比，caspase-11 小鼠视网膜 IR 损伤后视网膜神经节细胞死亡和视网膜水肿减轻，ERG b 波振幅较高。此外，caspase-11 小鼠视网膜 IR 损伤后 IL-1β、裂解的半胱天冬酶-1 和天冬氨酸特异性半胱氨酸蛋白酶-11（GSDMD）的蛋白表达水平较低。半胱天冬酶-11 蛋白在视网膜神经胶质细胞中表达，C8-D1A 细胞中 caspase-11 敲低对缺氧具有保护作用。构建的 si-caspase-11 细胞缺氧后，IL-1β、裂解的半胱天冬酶-1 和 GSDMD 的表达水平受到抑制。
视网膜 IR 损伤激活了视网膜神经胶质细胞中的半胱天冬酶-11 非经典炎性小体，导致 GSDMD 和 IL-1β蛋白水平升高，进而导致视网膜内层损伤。
