Transcriptomic profiling of human corneal epithelial cells exposed to airborne fine particulate matter (PM2.5)

Danni Lyu; Zhijian Chen; Siham Almansoob; Hui Chen; Yang Ye; Fan Song; Lifang Zhang; Zhenwei Qin; Qiaomei Tang; Houfa Yin; Wen Xu; Ke Yao; Qiuli Fu

doi:10.1016/j.jtos.2020.06.003

Transcriptomic profiling of human corneal epithelial cells exposed to airborne fine particulate matter (PM_2.5)

Ocul Surf. 2020 Oct;18(4):554-564. doi: 10.1016/j.jtos.2020.06.003. Epub 2020 Jun 19.

Authors

Danni Lyu¹, Zhijian Chen², Siham Almansoob¹, Hui Chen¹, Yang Ye¹, Fan Song¹, Lifang Zhang¹, Zhenwei Qin¹, Qiaomei Tang¹, Houfa Yin¹, Wen Xu¹, Ke Yao³, Qiuli Fu⁴

Affiliations

¹ Eye Center of the 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China.
² Department of Environmental and Occupational Health, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China.
³ Eye Center of the 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China. Electronic address: xlren@zju.edu.cn.
⁴ Eye Center of the 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China; Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China. Electronic address: 2313009@zju.edu.cn.

PMID: 32565256
DOI: 10.1016/j.jtos.2020.06.003

Abstract

Purpose: To explore the molecular mechanisms of PM_2.5-induced dysfunction in human corneal epithelial cells (HCECs) and the potential role of the plasminogen activator inhibitor type-2 (PAI-2) in PM_2.5-induced autophagy in vitro and in vivo.

Methods: RNA-Seq was performed to identify the differentially expressed genes (DEGs) in PM_2.5-exposed HCECs compared to unexposed condition, followed by validation via real-time PCR (qRT-PCR). Corneal fluorescein staining and tear secretion were assessed in the PM_2.5-exposed rat model. The expression of PAI-2 and autophagy-related markers were examined via immunoblotting, immunofluorescence staining and/or qRT-PCR in PM_2.5-exposed or unexposed HCECs and rat corneas. PAI-2-knockdown HCECs were generated to study PAI-2's role in the PM_2.5-induced autophagy in HCECs.

Results: A total of 434 DEGs-240 up-regulated and 194 down-regulated-were identified in PM_2.5-exposed HCECs rather than unexposed HCECs. The expression of a few genes related to proliferation, inflammation, and aryl hydrocarbon stimulation were significantly altered by PM_2.5 exposure. PAI-2 expression was up-regulated in PM_2.5-exposed HCECs, sharing a similar fluctuation trend with autophagy-related markers LC3B II and BECN1 according to various exposure periods. Moreover, PAI-2 knockdown significantly suppressed the expression of LC3B and BECN1 in PM_2.5-exposed HCECs. The corneal fluorescein staining was enhanced and tear secretion was significantly reduced in PM_2.5-exposed rat eyes. PAI-2 expression was also increased in PM_2.5-exposed rat corneas, together with the up-regulation of several autophagy-related markers.

Conclusion: The present study identified the altered expression of hundreds of genes in PM_2.5-exposed HCECs, which suggests the importance of PM_2.5 for cornea health. The involvement of PAI-2 was discovered in the PM_2.5-induced autophagy in HCECs as well as likely in rat corneas, which implied that PAI-2 may become a potential target of clinical treatment of PM_2.5-associated ocular surface diseases.

Keywords: Autophagy; Cornea; Human corneal epithelial cell; PAI-2; PM(2.5); Rat cornea.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Autophagy
Cornea
Epithelial Cells
Humans
Particulate Matter / toxicity
Rats
Transcriptome*

Substances

Particulate Matter