Dermal fibroblasts are strategically positioned underneath the basal epidermis layer to support keratinocyte proliferation and extracellular matrix production. In inflammatory conditions, these fibroblasts produce cytokines and chemokines that promote the chemoattraction of immune cells into the dermis and the hyperplasia of the epidermis, two characteristic hallmarks of psoriasis. However, how dermal fibroblasts specifically contribute to psoriasis development remains largely uncharacterized. In this study, we investigated through which cytokines and signaling pathways dermal fibroblasts contribute to the inflammatory features of psoriatic skin. We show that dermal fibroblasts from lesional psoriatic skin are important producers of inflammatory mediators, including IL-6, CXCL8, and CXCL2. This increased cytokine production was found to be regulated by ZFP36 family members ZFP36, ZFP36L1, and ZFP36L2, RNA-binding proteins with mRNA-degrading properties. In addition, the expression of ZFP36 family proteins was found to be reduced in chronic inflammatory conditions that mimic psoriatic lesional skin. Collectively, these results indicate that dermal fibroblasts are important producers of cytokines in psoriatic skin and that reduced expression of ZFP36 members in psoriasis dermal fibroblasts contributes to their inflammatory phenotype.
Butyrate Response Factor 1/metabolism , Fibroblasts/metabolism , Psoriasis/immunology , Transcription Factors/metabolism , Tristetraprolin/metabolism , Biopsy , Butyrate Response Factor 1/genetics , Case-Control Studies , Epidermis/immunology , Epidermis/metabolism , Epidermis/pathology , Gene Knockdown Techniques , Healthy Volunteers , Humans , Inflammation Mediators/metabolism , Keratinocytes/immunology , Keratinocytes/metabolism , Psoriasis/pathology , Transcription Factors/genetics , Tristetraprolin/genetics
