Effects of collected road dusts on cell viability, inflammatory response, and oxidative stress in cultured human corneal epithelial cells

Most studies on the adverse effects of air pollution have focused on respiratory and cardiovascular diseases, and there are relatively few studies on eye diseases following exposure of ambient particulate matter (PM). Epidemiological and clinical researches correlating the eye and PMs have recently received attention. PMs are complex mixture of particles that vary in chemical composition and size. This study investigated the influence of collected road dust on cell viability, inflammatory responses, and oxidative stress in human corneal epithelial cells. The collected road dust was classified with respect to aerodynamic diameter and solubility. Exposure concentration was calculated based on the particle deposition rate. We observed a dose-dependent decrease in cell viability at total PM_2.5 and PM₁₀. The pellet fractions of total PM_2.5 and PM₁₀ mainly contributed to the mitochondrial activity. Although both total PM_2.5 and PM₁₀ did not change the membrane integrity, the supernatant fractions significantly affected cell membrane integrity. Both total and fractions induced nitric oxide production and interleukin 8 expression. In addition, total PM_2.5 and PM₁₀ increased the oxidative stress; the pellet fractions of total PM_2.5 and PM₁₀ also induced higher oxidative stress. However, there was no significant difference between the cellular responses of total PM_2.5 and PM₁₀. We observed that the effects of collected road dust on cellular responses were strongly dependent on their concentration and solubility.