Objective: To investigate the effects of zinc oxide nanoparticles (ZnO-NPs) on neutrophil hypoxia and pyroptosis through nucleotide binding of oligomeric domain-like receptor protein 3 (NLRP3) inflammasome, and to analyze the role of pyroptosis on respiratory tract inflammotion induced by ZnO-NPs. Methods: In October 2022, primary cultured neutrophils were obtained from the abdominal aortic blood of SPF adult healthy SD rats. The neutrophils were treated with ZnO-NPs solution (0, 5, 10, 20 μg/ml) at different concentrations, and hypoxia group (5% O(2)) was set up. Hypoxia and reactive oxygen species (ROS) levels were detected by flow cytometry, and the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), cleaved Caspase-1 were measured by Western blot. The activity of lactic dehydrogenase (LDH) in the cell supernatant was measured by coloration, and the content of interleukin-1 beta (IL-1β) in cell culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA) . Results: Compared with the control group, hypoxia and ROS levels of neutrophils in hypoxia group and ZnO-NPs groups were significantly increased (P<0.05), and NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity and IL-1β content were significantly increased (P<0.05). Compared with hypoxia group, hypoxia and ROS levels of neutrophils in 5 μg/ml and 10 μg/ml ZnO-NPs groups were significantly decreased (P<0.05), NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1β content were decreased significantly (P<0.05). There were no significant differences in hypoxia, ROS levels, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1β content between the 20 μg/ml ZnO-NPs group and the hypoxia group (P>0.05) . Conclusion: ZnO-NPs treatment may activate the NLRP3 inflammasome to induce pyroptosis of neutrophils which may be related to ROS and hypoxia.
目的： 探讨纳米氧化锌（ZnO-NPs）可否通过核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）炎症小体对中性粒细胞缺氧和焦亡产生影响，分析细胞焦亡在ZnO-NPs诱发呼吸道炎症中的作用。 方法： 于2022年10月，采集SPF级成年健康SD大鼠腹主动脉血，分离并原代培养中性粒细胞，将不同浓度的ZnO-NPs溶液（0、5、10、20 μg/ml）作用于中性粒细胞，同时设缺氧（5% O(2)）组。用流式细胞仪检测缺氧和活性氧（ROS）水平，Western blot法检测细胞中NLRP3、凋亡相关斑点样蛋白（ASC）、活化半胱氨酸蛋白酶-1（cleaved Caspase-1）表达水平。采用比色法检测细胞培养上清液中乳酸脱氢酶（LDH）活力，采用酶联免疫吸附（ELISA）法检测细胞培养上清液中白细胞介素-1β（IL-1β）的含量。 结果： 与对照组比较，缺氧组和各浓度ZnO-NPs组中性粒细胞缺氧和ROS水平均明显升高（P<0.05），细胞NLRP3、ASC、cleaved Caspase-1蛋白表达水平、LDH活力和IL-1β含量均明显升高（P<0.05）。与缺氧组比较，5 μg/ml、10 μg/ml ZnO-NPs组中性粒细胞缺氧和ROS水平均明显下降（P<0.05），细胞NLRP3、ASC、cleaved Caspase-1蛋白表达水平、LDH活力和IL-1β含量均明显下降（P<0.05）。20 μg/ml ZnO-NPs组与缺氧组中性粒细胞缺氧、ROS水平、ASC、cleaved Caspase-1蛋白表达，以及LDH活力和IL-1β含量差异均无统计学意义（P>0.05）。 结论： ZnO-NPs可激活NLRP3炎症小体从而诱发中性粒细胞焦亡，可能与ROS和缺氧有关。.
Keywords: Hypoxia; Inflammasome; Neutrophils; Nucleotide binding of oligomeric domain-like receptor protein 3, NLRP3; Pyroptosis; Zinc oxide nanoparticles.