Lee Hun, Kim Eung Kweon, Kim Hee Young, Kim Tae-Im
Department of Ophthalmology, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, South Korea.
Department of Ophthalmology, The Institute of Vision Research, Yonsei University College of Medicine, Seoul, South Korea.
PLoS One. 2017 Jan 3;12(1):e0169209. doi: 10.1371/journal.pone.0169209. eCollection 2017.
Based on previous findings that ozone can induce an inflammatory response in the ocular surface of an animal model and in cultured human conjunctival epithelial cells, we investigated whether exposure to ozone exacerbates symptoms of allergic conjunctivitis. We evaluated the effects of exposure to ozone on conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, production of inflammatory cytokines in tears, and aqueous tear production in a mouse model of allergic conjunctivitis. To validate our in vivo results, we used interleukin (IL)-1α-pretreated conjunctival epithelial cells as an in vitro substitute for the mouse model. We evaluated whether exposure to ozone increased the inflammatory response and altered oxidative status and mitochondrial function in IL-1α-pretreated conjunctival epithelial cells. In the in vivo study, ozone induced increases in conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, and production of inflammatory cytokines, accompanied by a decrease in tear volume. In the in vitro study, exposure to ozone led to additional increases in IL-6 and tumor necrosis factor-α mRNA levels, which were already induced by treatment with IL-1α. Ozone did not induce any changes in cell viability. Pretreatment with IL-1α increased the expression of manganese superoxide dismutase, and exposure to ozone led to additional increments in the expression of this antioxidant enzyme. Ozone did not induce any changes in mitochondrial activity or expression of mitochondrial enzymes and proteins related to mitochondrial function, with the exception of phosphor-mammalian target of rapamycin. Treatment with butylated hydroxyanisole, a free radical scavenger, attenuated the ozone-induced increases in IL-6 expression in IL-1α-pretreated conjunctival epithelial cells. Therefore, we conclude that exposure to ozone exacerbates the detrimental effects on the integrity of the ocular surface caused by conjunctival allergic reactions, and further increases the inflammatory response in IL-1α-pretreated conjunctival epithelial cells.
基于先前的研究发现，即臭氧可在动物模型的眼表以及培养的人结膜上皮细胞中诱导炎症反应，我们研究了暴露于臭氧是否会加重过敏性结膜炎的症状。我们在过敏性结膜炎小鼠模型中评估了暴露于臭氧对结膜水肿、结膜充血、角膜和结膜荧光素染色评分、泪液中炎性细胞因子的产生以及泪液分泌量的影响。为了验证我们的体内实验结果，我们使用白细胞介素（IL）-1α预处理的结膜上皮细胞作为小鼠模型的体外替代物。我们评估了暴露于臭氧是否会增加IL-1α预处理的结膜上皮细胞中的炎症反应，并改变氧化状态和线粒体功能。在体内研究中，臭氧导致结膜水肿、结膜充血、角膜和结膜荧光素染色评分增加以及炎性细胞因子产生增加，同时泪液量减少。在体外研究中，暴露于臭氧导致IL-6和肿瘤坏死因子-α mRNA水平进一步升高，这些水平在IL-1α处理后已经被诱导升高。臭氧未诱导细胞活力发生任何变化。用IL-1α预处理可增加锰超氧化物歧化酶的表达，而暴露于臭氧会导致这种抗氧化酶的表达进一步增加。除了磷酸化雷帕霉素靶蛋白外，臭氧未诱导线粒体活性或与线粒体功能相关的线粒体酶和蛋白质表达发生任何变化。用自由基清除剂丁基羟基茴香醚处理可减弱臭氧诱导的IL-1α预处理的结膜上皮细胞中IL-6表达的增加。因此，我们得出结论，暴露于臭氧会加重结膜过敏反应对眼表完整性的有害影响，并进一步增加IL-1α预处理的结膜上皮细胞中的炎症反应。
