MiR-330 inhibits IL-22-induced keratinocyte proliferation through targeting CTNNB1.

Psoriasis is a common chronic inflammatory skin disease which is characterized by hyperproliferation and aberrant differentiation of keratinocytes; however the exact pathogenesis is largely unknown. Interleukin-22 (IL-22) has demonstrated its vital role in T cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. The microRNAs (miRNAs) are a class of small non-coding RNA molecules that play important roles in cellular processes by regulating gene expression at the post-transcriptional level. MiR-330 has been reported to inhibit the proliferation and migration of mouse keratinocytes. In the present study, we indicated that miR-330 expression in lesion tissue of psoriasis patients was specifically down-regulated, and could inhibit IL-22-induced proliferation of HaCaT and HKC cell. Wnt/β-catenin pathway plays an essential role in the pathogenesis of psoriasis. By direct targeting CTNNB1, miR-330 could significantly downregulate IL-22-induced CTNNB1 expression. In addition, we found that the downstream targets of β-catenin, CyclinD1 and Axin2, could be affected by miR-330; miR-330 could suppress CyclinD1 protein expression and rescue Axin2 protein expression. Taken together, we indicated miR-330 inhibits IL-22-induced proliferation of HaCaT and HKC cell by targeting CTNNB1 and subsequently affect the downstream factors, CyclinD1 and Axin2 for the first time, and provide diagnostic markers and a novel target for psoriasis treatment.