MOLECULAR MECHANISMS OF TAZAROTENE ACTION IN PSORIASIS

Psoriasis is a chronic immune-mediated disease that is characterized b y the hyperproliferation and abnormal differentiation of keratinocytes and by inflammation. The epidermal changes associated with psoriasis may be due to the infiltration of inflammatory T lymphocytes and the r elease of cytokines in response to antigenic stimulation. Tazarotene i s a retinoic acid receptor-specific retinoid with demonstrated efficac y in the topical treatment of psoriasis. Tazarotene downregulates mark ers of keratinocyte differentiation, keratinocyte proliferation, and i nflammation. The drug also upregulates three novel genes TIG-1 (tazaro tene-induced gene-1), TIG-2, and TIG-3, which may mediate an antiproli ferative effect. The effect of tazarotene on these markers is probably a direct effect on gene expression rather than an indirect effect ass ociated with disease improvement.