Possible Role of Lysine Demethylase 2A in the Pathophysiology of Psoriasis

BACKGROUND: Psoriasis is a common chronic inflammatory skin disease. The development of psoriasis is dependent on many intercellular events such as innate immunity and T cell-mediated inflammation. Furthermore, genetic factors are strongly implicated in the pathophysiology of psoriasis. Although a variety of susceptible genes are identified, it is likely that many important genes remain undisclosed. OBJECTIVE: The aim of this study is to investigate the possible role of lysine demethylase 2A (KDM2A) in the pathophysiology of psoriasis. METHODS: We examined the expression of KDM2A using a well established imiquimod-induced psoriasiform dermatitis model. RESULTS: Immunohistochemistry analysis showed that expression of KDM2A was increased in imiquimod-induced psoriasiform dermatitis. Consistent with this result, KDM2A level was markedly increased in the epidermis of psoriatic patient. When keratinocytes were stimulated with TLR3 agonist poly(I:C), KDM2A was increased at both the mRNA and protein levels. Poly(I:C) increased the expression of psoriasis-related cytokines including tumor necrosis factor-α, interleukin-8, and CCL20, and KDM2A inhibitor daminozide enhanced the poly(I:C)-induced cytokine expression. Finally, topical co-application of imiquimod and daminozide exacerbated the imiquimod-induced psoriasiform dermatitis. CONCLUSION: Together, these results suggest that KDM2A is increased to negatively regulate the inflammatory reaction of epidermal keratinocytes in psoriasis.