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. 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.
Abstract
PURPOSE: To explore the molecular mechanisms of PM2.5-induced dysfunction in human corneal epithelial cells (HCECs) and the potential role of the plasminogen activator inhibitor type-2 (PAI-2) in PM2.5-induced autophagy in vitro and in vivo. METHODS: RNA-Seq was performed to identify the differentially expressed genes (DEGs) in PM2.5-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 PM2.5-exposed rat model. The expression of PAI-2 and autophagy-related markers were examined via immunoblotting, immunofluorescence staining and/or qRT-PCR in PM2.5-exposed or unexposed HCECs and rat corneas. PAI-2-knockdown HCECs were generated to study PAI-2's role in the PM2.5-induced autophagy in HCECs. RESULTS: A total of 434 DEGs-240 up-regulated and 194 down-regulated-were identified in PM2.5-exposed HCECs rather than unexposed HCECs. The expression of a few genes related to proliferation, inflammation, and aryl hydrocarbon stimulation were significantly altered by PM2.5 exposure. PAI-2 expression was up-regulated in PM2.5-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 PM2.5-exposed HCECs. The corneal fluorescein staining was enhanced and tear secretion was significantly reduced in PM2.5-exposed rat eyes. PAI-2 expression was also increased in PM2.5-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 PM2.5-exposed HCECs, which suggests the importance of PM2.5 for cornea health. The involvement of PAI-2 was discovered in the PM2.5-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 PM2.5-associated ocular surface diseases.
PURPOSE: To explore the molecular mechanisms of PM2.5-induced dysfunction in human corneal epithelial cells (HCECs) and the potential role of the plasminogen activator inhibitor type-2 (PAI-2) in PM2.5-induced autophagy in vitro and in vivo. METHODS: RNA-Seq was performed to identify the differentially expressed genes (DEGs) in PM2.5-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 PM2.5-exposed rat model. The expression of PAI-2 and autophagy-related markers were examined via immunoblotting, immunofluorescence staining and/or qRT-PCR in PM2.5-exposed or unexposed HCECs and rat corneas. PAI-2-knockdown HCECs were generated to study PAI-2's role in the PM2.5-induced autophagy in HCECs. RESULTS: A total of 434 DEGs-240 up-regulated and 194 down-regulated-were identified in PM2.5-exposed HCECs rather than unexposed HCECs. The expression of a few genes related to proliferation, inflammation, and aryl hydrocarbon stimulation were significantly altered by PM2.5 exposure. PAI-2 expression was up-regulated in PM2.5-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 PM2.5-exposed HCECs. The corneal fluorescein staining was enhanced and tear secretion was significantly reduced in PM2.5-exposed rat eyes. PAI-2 expression was also increased in PM2.5-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 PM2.5-exposed HCECs, which suggests the importance of PM2.5 for cornea health. The involvement of PAI-2 was discovered in the PM2.5-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 PM2.5-associated ocular surface diseases.