Department of Ophthalmology, Xi'an Fourth Hospital, Affiliated Xi'an Fourth Hospital, Northwestern Polytechnical University, Affiliated Guangren Hospital of Xi'an JiaoTong University Health Science Center, Xi'an, 710004, Shaanxi Province, China.
Basic Medicine, Xi'an Medical University, Xi'an, 710021, Shaanxi Province, China; Laboratory Animal Center, Xi'an JiaoTong University School of Medicine, Xi'an, 710061, Shaanxi Province, China; Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Xi'an, 710021, Shaanxi Province, China.
Free Radic Biol Med. 2020 Jun;153:187-201. doi: 10.1016/j.freeradbiomed.2020.04.007. Epub 2020 Apr 19.
Exposure to cigarette smoke (CS) pollution has previously associated with dry eye symptoms but without detailed experimental data and elucidation of the mechanism. We aimed to evaluate the effects of CS on the ocular surfaces of mice and the extraction of DMSO lipid-soluble cigarette smoke particles (DCSP) on cultured human corneal epithelial cells (HCECs), and explore to elucidate the probable mechanism. C57BL mice were exposed to CS challenging. In vivo clinical evaluations, including corneal fluorescein staining, tear film break-up time, and confocal microscopic observations, were performed before exposure and post-exposure. At the end of the in vivo study, changes in corneal and conjunctival histology, corneal ultrastructure, and conjunctival goblet cell intensity were examined, expression of TUNLE and Ki67 in tissue were also detected. In vitro, cell confluence and caspase3/7 were assessed in DCSP treated HCECs. Production of TNF-α, IL-1β and IL-6, activation of NF-κB and Ki67 were evaluated by means of ELISA and Western blot respectively in HCECs cultured with 0.6 μL/mL DCSP. We found that longer-term CS exposure induced dry eye symptoms in mice. Additionally, corneal and conjunctival epithelial damage occurred, the corneal ultrastructure changed, and the density of goblet cells decreased. Apoptosis and Ki67 increased in both the conjunctiva and the cornea of CS-exposed animals. Furthermore, although DCSP inhibited the proliferation of HCECs, expression of Ki67 increased and apoptosis was only induced significantly by 2.0 μL/mL DCSP. The release of IL-1β and IL-6, activation of NF-κB were prompted by DCSP. The results indicated that CS is toxic to the ocular surface of mice and HCECs. Longer-term CS exposure in mice stimulates ocular surface changes that resemble those observed with dry eye. The mechanism may relate to inflammation and activation of NF-κB. In this study, we established a novel animal model to study dry eye, with the experimental data and elucidation of mechanism facilitating further research.
暴露于香烟烟雾（CS）污染以前与干眼症症状有关，但没有详细的实验数据和阐明其机制。我们旨在评估 CS 对小鼠眼表面的影响，以及 DMSO 脂溶性香烟烟雾颗粒（DCSP）对培养的人角膜上皮细胞（HCEC）的提取，并探索阐明可能的机制。C57BL 小鼠暴露于 CS 刺激。在暴露前和暴露后进行体内临床评估，包括角膜荧光素染色、泪膜破裂时间和共聚焦显微镜观察。在体内研究结束时，检查角膜和结膜组织学变化、角膜超微结构和结膜杯状细胞强度，还检测组织中的 TUNEL 和 Ki67 表达。在体外，用 DCSP 处理 HCEC 评估细胞汇合和 caspase3/7。通过 ELISA 和 Western blot 分别评估培养有 0.6 μL/mL DCSP 的 HCEC 中 TNF-α、IL-1β 和 IL-6 的产生、NF-κB 和 Ki67 的激活。我们发现，较长时间的 CS 暴露会导致小鼠出现干眼症症状。此外，角膜和结膜上皮损伤发生，角膜超微结构改变，杯状细胞密度降低。CS 暴露动物的结膜和角膜中，细胞凋亡和 Ki67 增加。此外，尽管 DCSP 抑制 HCEC 的增殖，但仅 2.0 μL/mL DCSP 可显著诱导 Ki67 增加和细胞凋亡。DCSP 促使 IL-1β 和 IL-6 的释放和 NF-κB 的激活。结果表明，CS 对小鼠眼表面和 HCEC 具有毒性。小鼠较长时间的 CS 暴露会刺激眼表面变化，类似于干眼症的观察结果。其机制可能与炎症和 NF-κB 激活有关。在这项研究中，我们建立了一种新的动物模型来研究干眼症，其实验数据和机制阐明有助于进一步研究。
