Real-ambient PM induced corneal epithelial barrier disruption through Wnt/β-catenin signaling.

Continued daily exposure to fine particulate matter (PM) is linked to increasing risks of ocular surface diseases. However, further study is needed to understand how real-ambient PM disrupts the barrier function of the corneal epithelial layers and its underlying mechanism. In our study, we utilized a real-ambient PM exposure system to investigate its effects on the corneal epithelial barrier in C57BL/6Jmice over 4 and 8 weeks. The mean concentration of PM in the exposure chambers over 8 weeks was 140.18 μg/m. Following 4 and 8 weeks of continuous PM exposure, we observed disorganized cellular arrangements in the corneal epithelium of mice. Moreover, PM exposure led to a significant loss of microvilli on the surface of corneal epithelial cells and noticeable disconnections among epithelial cell layers. Subsequent in vitro analysis revealed that 100 μg/mL PM activated the Wnt/β-catenin signaling pathway in corneal epithelium, resulting in decreased expression 1.81 fold and 2.25 fold of E-cadherin and ZO-1, respectively, ultimately impairing the corneal epithelial barrier function. Our findings provide the knowledge base for promoting eye health in the context of atmospheric pollution.