Ocular exposure to particulate matter (PM) causes local inflammation; however, the influence of neutrophils on PM-induced ocular inflammation is still not fully understood. In this study, we constructed a system to investigate the role of PM in ocular inflammation using a co-culture of human corneal epithelial cells (HCE-T) and differentiation-induced neutrophils (dHL-60). To investigate whether HCE-T directly endocytosed PM, we performed a holographic analysis, which showed the endocytosis of PM in HCE-T. The cytokines and chemokines produced by HCE-T were measured using an ELISA. HCE-T treated with PM produced IL-6 and IL-8, which were inhibited by N-Acetyl-L-cysteine (NAC), suggesting the involvement of ROS. Their co-culture with dHL-60 enhanced their production of IL-6, IL-8, and MCP-1. This suggests an inflammatory loop involving intraocular corneal epithelial cells and neutrophils. These cytokines and chemokines are mainly regulated by NF-κB. Therefore, this co-culture system was examined in the presence of an IKK inhibitor known to downregulate NF-κB activity. The IKK inhibitor dramatically suppressed the production of these factors in co-culture supernatants. The results suggest that the inflammatory loop observed in the co-culture is mediated through ROS and the transcription factor NF-κB. Thus, the co-culture system is considered a valuable tool for analyzing complex inflammations.

中文翻译：

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在颗粒物存在下，角膜上皮细胞和中性粒细胞样细胞共培养，以 ROS 依赖性方式协同诱导炎症细胞因子和趋化因子

眼睛接触颗粒物 (PM) 会导致局部炎症；然而，中性粒细胞对 PM 引起的眼部炎症的影响仍不完全清楚。在这项研究中，我们构建了一个系统，通过人角膜上皮细胞 (HCE-T) 和分化诱导的中性粒细胞 (dHL-60) 的共培养来研究 PM 在眼部炎症中的作用。为了研究 HCE-T 是否直接内吞 PM，我们进行了全息分析，结果显示 HCE-T 中 PM 的内吞作用。使用 ELISA 测量 HCE-T 产生的细胞因子和趋化因子。用 PM 处理的 HCE-T 产生 IL-6 和 IL-8，它们被 N-乙酰基-L-半胱氨酸 (NAC) 抑制，表明 ROS 的参与。他们与 dHL-60 共培养增强了 IL-6、IL-8 和 MCP-1 的产生。这表明涉及眼内角膜上皮细胞和中性粒细胞的炎症循环。这些细胞因子和趋化因子主要受NF-κB调节。因此，在存在已知可下调 NF-κB 活性的 IKK 抑制剂的情况下检查了该共培养系统。 IKK 抑制剂显着抑制了共培养上清液中这些因子的产生。结果表明，共培养物中观察到的炎症循环是通过 ROS 和转录因子 NF-κB 介导的。因此，共培养系统被认为是分析复杂炎症的有价值的工具。