Establishment of a mouse model of atopic dermatitis induced by topical application of ovalbumin and calcipotriol / 中华皮肤科杂志

ABSTRACT

Objective To explore a method for rapidly establishing a mouse model of atopic dermatitis (AD).Methods C57BL/6 mice served as model animals,and were randomly divided into 3 groupscalcipotriol + ovalbumin (OVA) group (n =6) topically treated with calcipotriol and OVA on the mouse ears,calcipotriol group (n =6) topically treated with calcipotriol on the ears,and control group (n =3) topically treated with 75％ alcohol on the ears.The treatment lasted 12 days.Before the model establishment and on day 14,the photos of the mouse ears were taken,and ear thickness was measured;moreover,blood samples were obtained from the mouse caudal vein,and serum levels of total IgE and OVAspecific IgE were detected.On day 14,the skin tissues of mouse auricles were resected and subjected to histopathological examination.Results On day 14,erythematous swelling,dryness and desquamation occurred on the mouse ear skin in the calcipotriol + OVA group and calcipotriol group,and both the two groups showed significantly increased ear thickness compared with those before the model establishment (both P ＜ 0.001).However,there was no significant difference in the ear thickness between the calcipotriol + OVA group (0.355 ± 0.03 mm) and calcipotriol group (0.370 ± 0.05 mm,q =0.674,P =0.231).Histopathological examination of the ear skin showed more obvious epidermal hyperplasia and infiltration of dermal inflammatory cells including eosinophils and mastocytes in the calcipotriol + OVA group compared with the calcipotriol group and control group.Immunohistochemical study revealed that there was no significant difference in the expression of thymic stromal lymphopoietin (TSLP) and interferon (IFN)-γ among the 3 groups (both P ＞ 0.05),while the expression of interleukin (IL)-13 significantly differed among the 3 groups (F =5.159,P =0.032),and was significantly higher in the calcipotriol + OVA group (77.12 ± 5.46) than in the control group (55.49 ± 9.92,q =3.170,P =0.021).On day 14,the calcipotriol + OVA group and calcipotriol group both showed markedly increased total serum IgE levels compared with those before the treatment,and the calcipotriol + OVA group showed a more significant increase (8 278.56 ± 3 297.68 vs.892.64 ± 82.83 μ g/L,t =4.132,P =0.026).Meanwhile,the serum level of OVA-specific IgE was significandy higher in the calcipotriol + OVA group (192.846 ± 15.391 μg/L) than in the calcipotriol group (8.492 ±3.879 μg/L,q =22.476,P ＜ 0.001) on day 14.Conclusion The mouse model of allergeninduced AD can be rapidly established by topical application of calcipotriol and OVA for 12 consecutive days,which lays a foundation for further study on allergen-related pathogenesis of AD.