Retinoic Acid Promotes Interleukin-4 Plasmid-Dimethylsulfoxide Topical Transdermal Delivery for Treatment of Psoriasis

BACKGROUND: Psoriasis is an autoimmune disease that is caused by a shift in the Th1/Th2 balance toward Th1-dominant immunity. It has been established as an effective treatment to counteract psoriasis by subcutaneous injection of recombinant interleukin (IL)-4, and IL-4 gene therapy by topical transdermal penetration has shown its antipsoriatic effect in mice. Retinoic acid (RA) and dimethylsulfoxide can increase the efficiency of gene transfection in the topical transdermal delivery system. OBJECTIVE: We investigated whether RA could improve anti-psoriasis efficiency using IL-4 expression plasmid pORF-mIL-4 (pIL-4) via transdermal delivery system in K14-vascular endothelial growth (K14-VEGF) factor transgenic mice. METHODS: After pretreatment with RA, plasmid pIL-4 in 10% dimethylsulfoxide was applied to the ear skin by topical transdermal penetration. Hematoxylin- eosin staining and immunohistochemistry were performed with ear samples to evaluate anti-psoriasis efficiency in mice. RESULTS: The psoriasis pathological features were relieved and psoriasis-associated factors were significantly reduced. CONCLUSION: Our results reveal that topical application of pIL-4 in dimethylsulfoxide by transdermal delivery with RA pretreatment can improve psoriasis significantly.