Air Pollution and Atopic Dermatitis (AD): The Impact of Particulate Matter (PM) on an AD Mouse-Model.

Air pollution reportedly contributes to the development and exacerbation of atopic dermatitis (AD). However, the exact mechanism underlying this remains unclear. To examine the relationship between air pollution and AD, a clinical, histological, and genetic analysis was performed on particulate matter (PM)-exposed mice. Five-week-old BALB/c mice were randomly divided into four groups (control group, ovalbumin (OVA) group, PM group, OVA + PM group; = 6) and treated with OVA or PM alone or together. Cutaneous exposure to OVA and PM alone resulted in a significant increase in skin severity scores, trans-epidermal water loss (TEWL) and epidermal thickness compared to the control group at Week 6. The findings were further accentuated in the OVA + PM group showing statistical significance over the OVA group. A total of 635, 501, and 2149 genes were found to be differentially expressed following OVA, PM, and OVA + PM exposure, respectively. Strongly upregulated genes included , , , , (OVA vs. control), , , , , , (PM vs. control) and , , , , (OVA + PM vs. control). In comparing the groups OVA + PM with OVA, 818 genes were differentially expressed with , , , , being the most highly upregulated in the OVA + PM group. Taken together, our study demonstrates that PM exposure induces/aggravates skin inflammation via the differential expression of genes controlling skin barrier integrity and immune response. We provide evidence on the importance of public awareness in PM-associated skin inflammation. Vigilant attention should be paid to all individuals, especially to those with AD.