Atopic dermatitis (AD) is a chronic, recurrent, itchy, inflammatory skin disease. The coexistence of anxiety, depression, and social withdrawal is problematic in AD. Although an association between AD and anxiety and depressive behavior has been observed in humans and in a few mouse models, the detailed mechanisms are unknown. To address this issue, we analyzed the mental state of mice using AD models. We sensitized mice with 3% oxazolone (OXA) and then repeatedly applied 0.6% OXA to the ears of mice 3 times per week for 4 weeks. In these mice, the auricule changed to an AD-like appearance, and scratching behavior was observed. Followingly, we conducted the behavioral tests to evaluate depression and anxiety. We evaluated anxiety by the open field test and the light/dark transition test, and evaluated depression by the forced swim test and the tail suspension test. OXA applied mice showed anxiety-like behavior in the open field test, whereas control mice did not. No significant difference was found in the other three tests. We hypothesized that the itching of atopic dermatitis cause anxiety-like behaviors in mice. To address this question, we focused on IL-31, a cytokine that is strongly associated with itching in AD. IL-31 was administered continuously at a dose of 2µg per day for 3 weeks by the osmotic pump and was evaluated anxiety-like behavior. The IL-31-treated mice showed severe scratching behavior and associated alopecia. IL-31 administered mice showed anxiety tendencies in the open field test and light/dark transition test and no significant differences were found in the depressive tendencies, which was consistent with the results in mice with OXA-induced AD model. These findings suggest that anxiety-like behavior is induced in the AD model, possibly via IL-31-induced pruritus.

ESDR059 - IL-31 causes anxiety-like behavior in a mouse model of atopic dermatitis

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.