Examination of measurement of cytokines in an Imiquimod-induced psoriasis mice model

Abstract

Psoriasis is a chronic inflammatory skin disease of unknown etiology with red rash and scaly patches appear on the skin. Although the psoriasis was a rare disease in the past Japan, recently the prevalence of the psoriasis is increased due to the changes in lifestyle (for example, Euro-American dietary habit). The precise mechanisms and causes of psoriasis have not been identified. In this study, we analyzed the cytokines expression pattern known to be contributed to psoriasis using Imiquimod-induced psoriasis mice model. Imiquimod were administered transdermally to BALB/c mice once daily for 6 days to make the psoriasis model. Steroid drugs were administered transdermally 4 hours after administration of Imiquimod. The model was evaluated by the increase in skin thickness and erythema score (Draize test). After the administration of Imiquimod for 3, 5 and 7 days, plasma and skin were collected and the expression of cytokines was measured with Cytometric bead array (CBA assay) or real time PCR. In results of CBA assay in plasma, the concentration of cytokines (IL-17A, TNF-alpha and IL-6) significantly increased in the psoriasis model group in comparison with the normal group. On the other hand, steroid drugs significantly decreased the concentration of cytokines compared with those in the psoriasis model group. Correspondingly, the results of cytokines expression pattern in skin with RT-PCR in the psoriasis model group and steroid drugs administrated groups significantly changed in comparison with the normal group. Thus, it is considered that the result of this study is useful for investigation of psoriasis therapeutic drugs in Imiquimod-induced psoriasis mice model.