Objective To study the cytokines secreted by fibroblasts in the pathogenesis of psoriasis.Methods The healthy or psoriatic fibroblasts were co-cultured with keratinocytes in skin equivalents for15days.Changes in the expression pattern of268selected genes related to cytokines and their receptors were determined by comparing mRNA levels of fibroblasts under different culture conditions.Results Sixty-eight of268genes were found to be expressed on the fibroblasts.Compared with normal controls,a total of27genes was found to be differentially expressed at RNA level by a factor of twofold or greater,among which24genes were up-regulated,whereas3genes were down-regulated in psoriatic fibroblasts.These differentially expressed genes encoded interleukins,interferons,growth factors,chemokines,protein kinase receptors and chemokine receptors.Conclusions These results suggest that fibroblasts from psoriatic uninvolved skin strongly express cytokines which closely relate to the pathogenesis of psoriasis.It is indicated that dermal fibroblasts may play a potentially role in promoting keratinocyte proliferation and leading to the formation of psoriatic lesion.