Abstract
Purpose :
To explored the effects of particulate matter 2.5 (PM2.5) eye drops on the ocular surface structure and tear function in mice and established a novel animal model for dry eye research.
Methods :
Totally 90 BALB/c mice were used in this study and divided into three groups (right eye,4 times daily,14 consecutive days): Group A, negative control; Group B, PBS; Group C, 5.0 mg/ml PM2.5. The clinical manifestations of dry eye were measured before therapy and 1, 4, 7 and 14 days post-treatment respectively, which included the tear volume, tear break-up (BUT), corneal fluorescein staining, and inflammatory index. Eye samples were collected on D14 and examined by histologic light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM),PAS staining, apoptosis cells staining, Ki67 immunnostaining, and tumor necrosis factor-α (TNF-α), NF-κB-p65 and NF-κB Western Blot analysis.
Results :
Following treatment with PM2.5, the tear volume and, the tear film break-up time showed statistical differences at each time point (P <0.05). The FL score of the PM2.5-treated group was higher than that of others (P < 0.05). The average number of corneal epithelial layer cells in groups A and B was significantly lower than that in group C (P < 0.05).TEM and SEM revealed that the number of corneal epithelial microvilli and corneal desmosomes was drastically reduced in group C. PM2.5 induced apoptosis in the corneal superficial and basal epithelium and led to abnormal differentiation and proliferation of the ocular surface with higher expression levels of Ki67 and a reduced number of goblet cells in the conjunctival fornix in group C. PM2.5 significantly increased the levels of TNF-α, NF-κB p65 (phospho S536), and NF-κB in the cornea.
Conclusions :
The topical administration of PM2.5 in mice induces ocular surface changes that are similar to those of dry eye in humans, representing a novel model of dry eye.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.