A Murine Model of Acute Allergic Conjunctivitis Induced by Continuous Exposure to Particulate Matter 2.5

Abstract

PURPOSE. Several pieces of epidemiologic evidence have indicated PM2.5 (particulate matter with a diameter of 2.5 lm or less) as a causing factor of allergic conjunctivitis, but without experimental elucidation of mechanism. In the present study, PM2.5 in solution was directly applied to the mouse ocular surface to elucidate whether PM2.5 might cause allergic conjunctivitis, and its underlying mechanisms were analyzed. METHODS. ICR mice were challenged for 18 consecutive days with eye drops containing PM2.5 at 3.2, 6.4, and 12.8 mg/mL in 0.9% NaCl saline, along with the controls prepared in parallel without PM2.5 and another control group treated with both PM2.5 at 12.8 mg/mL and artificial tears. On day 19, the whole eyes and meibomian glands were harvested for histopathological analyses and assessment of clinical scoring, tear volume, tear breakup time, and tear ferning. Furthermore, goblet cells by periodic acid Schiff stain and infiltrated eosinophils by Giemsa stain were quantified and compared among study groups. RESULTS. Clinical scoring showed more eyelid edema, tearing, and scratching behaviors, with longer tear breakup time under the influence of increased PM2.5 concentrations. Tear ferning assay showed less tear crystal formation and decreased crystal branches after exposure to PM2.5. In addition, higher goblet cell density in the upper palpebral conjunctiva and extensive eosinophil infiltration in the entire conjunctiva and in the meibomian glands were induced by PM2.5. CONCLUSIONS. These results demonstrate that PM2.5 can induce symptoms similar to clinical allergic conjunctivitis and that the murine acute allergic conjunctivitis model can be induced by direct exposure to PM2.5.

The Role of Th17 Cells and IL-17 in Th2 Immune Responses of Allergic Conjunctivitis

“…is discrepancy could be attributed to indoor and outdoor air pollution and the increased pollen due to climate change and global warming [11][12][13][14]. Several reports have shown that AC is closely related to asthma, rhinitis, and other allergic diseases, which seriously affects the quality of life of patients and productivity [5][6][7][15][16][17].…”

Conditioned Medium of Human Amniotic Epithelial Cells Alleviates Experimental Allergic Conjunctivitis Mainly by IL-1ra and IL-10

“…When treated with AECM, the immune cells and eosinophils in the conjunctival tissue of mice were reduced by 28.23% ± 5.1% and 60% ± 4.5%, respectively, compared to EAC mice ( Figure 2D ). When conjunctival goblet cells (one typical type of mucus-secreting cells) ( 38 – 40 ) were examined, similar patterns of the SRW-induced increase in EAC group and the inhibitory effects of AECM were observed ( Figures 2E, F ).…”

Environmental and Air Pollution Factors Affecting Allergic Eye Disease in Children and Adolescents in India

“…Among the six sources that contributed to the PM 2.5 in the city, “soil” had a significant positive association with ocular symptoms. Tang et al [ 15 ] described a murine model of acute allergic conjunctivitis induced by continuous exposure to particulate matter (PM 2.5 ). The mice that were challenged with eye drops containing PM 2.5 in increasing concentrations displayed more eyelid edema, tearing, and scratching behavior, and also had a higher goblet cell density in the upper palpebral conjunctiva, showing extensive eosinophil infiltration in the meibomian glands and ocular surface as well.…”