IL6R is a target of miR-197 in human keratinocytes

Background: Psoriasis is a chronic inflammatory disorder with cutaneous and systemic manifestations and substantial negative effects on patients' life quality. MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Evidence suggests that miRNAs play a role in the pathogenesis of psoriasis. Previously studies, from others and by us, show-specific miRNAs that are differentially expressed between the psoriasis lesion and healthy skin. One of those miRNAs is miR-197-3p whose expression is down-regulated in the psoriatic lesions compared to normal or uninvolved psoriatic skin. In order to understand miR-197's role in psoriasis, we found that it could modulate IL-22 and IL-17 signaling. Objectives: We aimed to identify additional biochemical targets of miR-197 in psoriasis. Methods: We have chosen to apply a transcriptome-wide biochemical approach (PAR-CLIP) to search for new targets of miR-197 in keratinocytes. Results: in this work, using PAR-CLIP, we found an additional biochemical target of miR-197, one of the subunits of the receptor to IL-6. IL-6R is known to be up-regulated in psoriasis and even was considered as a possible therapeutic target. Conclusions: From the present data and our previous studies it appears that miR-197 is a major regulator of the interaction between immune system cells and keratinocytes. Overall design: AGO2 PAR-CLIP experiments in wild-type and miRNA-transfected skin cells in culture to identify miRNA targets