Assessment of DNA Damage and Cell Senescence in Corneal Epithelial Cells Exposed to Airborne Particulate Matter (PM2.5) Collected in Guangzhou, China.
To assess the genotoxic effect of airborne particulate matter on corneal epithelial cells and investigate the role of reactive oxygen species (ROS) formation in this process.



Immortalized human corneal epithelial cells (HCECs) and primary bovine corneal epithelial cells were exposed to airborne particulate matter collected from Guangzhou for 24 hours. The cell viability and toxicity were measured by the CCK-8 test and lactate dehydrogenase (LDH) release, respectively. The DNA breaks and DNA repair were examined by alkaline comet assay and by immunofluorescence staining of the phosphorylated histone variant H2AX (γH2AX), respectively. Reactive oxygen species production was assessed by the fluorescent probe, CM-H2DCFDA. Cell senescence was evaluated with senescence-associated β-Galactosidase staining, and cell ultrastructure was observed with transmission electron microscopy.



Exposure to PM2.5 at the concentration of 20 μg/mL to 200 μg/mL decreased cell viability and increased LDH release. Remarkably increased DNA double-stand breaks, increased expression of DNA repair-related protein γH2AX, elevated ROS formation, and altered cell ultrastructure were observed in HCECs after treatment with PM2.5. The genotoxic effect of PM2.5 was attenuated by the ROS inhibitor N-acetyl-l-cysteine (NAC).



Particulate matter 2.5 could induce DNA damage and cell senescence in corneal epithelial cells, probably by promoting ROS formation. Thus, whether long-term exposure of PM2.5 might be related to potential risk of abnormality in corneal epithelium renewal and regeneration should be further investigated.
Institute of Ophthalmology School of Medicine, Jinan University, Guangzhou, China 2Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China.
Zi-Xun
ZX
Gao
Department of Public Health and Preventive Medicine, Jinan University, Guangzhou, China.
Xi-Ling
XL
Song
Department of Clinical Medicine, School of Medicine, Jinan University, Guangzhou, China.
Shan-Shan
SS
Li
Department of Clinical Medicine, School of Medicine, Jinan University, Guangzhou, China.
Xiao-Rong
XR
Lai
Department of Clinical Medicine, School of Medicine, Jinan University, Guangzhou, China.
Yu-Lan
YL
Yang
Department of Public Health and Preventive Medicine, Jinan University, Guangzhou, China.
Guang
G
Yang
Institute of Ophthalmology School of Medicine, Jinan University, Guangzhou, China 2Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China.
Zhi-Jie
ZJ
Li
Department of Histology and Embryology, Guangzhou Medical University, Guangzhou, China.
Yu-Hong
YH
Cui
Institute of Ophthalmology School of Medicine, Jinan University, Guangzhou, China 2Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China 3Department of Public Health and Preventive Medicine, Jinan University.
Hong-Wei
HW
Pan
D000397:Air Pollution / Q000009:adverse effects*; D000818:Animals; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D002681:China; D004249:DNA Damage / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D019573:Epithelium, Corneal / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism
D052638:Particulate Matter; D017382:Reactive Oxygen Species