Cigarette smoke extract (CSE), a complex mixture of compounds, contributes to a range of eye diseases; however, the underlying pathophysiological responses to tobacco smoke remain ambiguous. The purpose of the present study was to evaluate the cigarette smoke-induced phenotypic and transcriptomic changes in the corneal epithelium with a view to elucidating the likely underlying mechanism. Accordingly, for the first time, we characterized the genome-wide effects of CSE on the corneal epithelium. The ocular surface of the mice in the experimental groups was exposed to CSE for 1 h per day for a period of one week, while mice in the control group were exposed to preservative-free artificial tears. Corneal fluorescein staining, confocal microscopy and scanning electron microscopy were performed to examine the corneal ultrastructure. Transcriptome sequencing and bioinformatics analysis were performed followed by RT-qPCR to validate gene expression changes. The results indicate that CSE exposure disrupted the structural integrity of the superficial epithelium, decreased the density of microvilli, and compromised the corneal epithelial barrier intactness. RNA-seq revealed 667 differentially expressed genes, and functional analysis highlighted the enhancement of several biological processes such as antioxidant activity and the response to oxidative stress. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that glutathione metabolism and drug metabolism cytochrome P450 were the most relevant pathways contributing to the effects of CSE on the corneal epithelium. Protein–protein interaction (PPI) network analysis illustrated that GCLC, NQO1, and HMOX1 were the most relevant nodes. In conclusion, the present study indicates that CSE exposure induces changes in the phenotype and genotype of the corneal epithelium. The antioxidant response element is essential for counteracting the effects of cigarette smoke on this tissue layer. These results shed novel insights into how cigarette smoke damages this ocular surface.

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接触香烟烟雾后角膜上皮的表型和转录组变化

香烟烟雾提取物（CSE）是一种复杂的化合物混合物，会导致一系列眼部疾病；然而，对烟草烟雾的潜在病理生理反应仍然不明确。本研究的目的是评估香烟烟雾引起的角膜上皮表型和转录组变化，以期阐明可能的潜在机制。因此，我们首次描述了 CSE 对角膜上皮的全基因组影响。实验组小鼠的眼表每天暴露于CSE 1小时，持续一周，而对照组小鼠则暴露于不含防腐剂的人工泪液。采用角膜荧光素染色、共聚焦显微镜和扫描电镜检查角膜超微结构。进行转录组测序和生物信息学分析，然后进行 RT-qPCR 以验证基因表达变化。结果表明，CSE 暴露破坏了浅表上皮的结构完整性，降低了微绒毛的密度，并损害了角膜上皮屏障的完整性。 RNA-seq揭示了667个差异表达基因，功能分析强调了多种生物过程的增强，例如抗氧化活性和对氧化应激的反应。此外，京都基因与基因组百科全书（KEGG）通路富集分析表明，谷胱甘肽代谢和药物代谢细胞色素P450是CSE对角膜上皮影响最相关的通路。蛋白质-蛋白质相互作用 (PPI) 网络分析表明 GCLC、NQO1 和 HMOX1 是最相关的节点。总之，本研究表明 CSE 暴露会引起角膜上皮表型和基因型的变化。抗氧化反应元素对于抵消香烟烟雾对该组织层的影响至关重要。这些结果为香烟烟雾如何损害眼表提供了新的见解。