P169 : The influence of inhaled particulate matter on oxazolone-induced atopic dermatitis mouse model

Background: Previous studies have shown that particulate matter (PM) triggers skin inflammatory conditions including atopic dermatitis (AD). However, it is not well investigated whether inhaled PM significantly exacerbates acute AD. Objectives: This study aimed to analyze the effect of inhaled PM on the inflammation of acute AD skin lesion by using a mouse model. Methods: The mice were divided into four groups: the normal group, normal group with PM, AD group without PM, and AD group with PM. Visual examination of ear thickness and histological analysis were performed. On harvested ear tissue, mRNA and protein expression of inflammatory cytokines and chemokines, growth factor, epidermal differentiation marker and barrier function were assessed by RT-PCR and Western blot. Protein expression of serum IgE was assessed by ELISA. Results: The ear thickness increased significantly in the AD group with PM compared to the AD group without PM. IL-4, -13, -1β and serum IgE were increased in both AD group without PM and with PM but there was no significant difference between the two groups. Compared to the AD group without PM, CXCL1 and CXCL5 were increased significantly in the AD group with PM. Conclusion: In this study, the results suggest that there is no definite evidence whether the inhaled PM aggravates the acute AD.