A global transcriptome analysis of human keratinocyte cell line HaCaT overexpressing the miR-21-3p.

Psoriasis is a chronic inflammatory skin disease that is mediated by a complex crosstalk between immune cells and keratinocytes (KCs). Emerging studies showed a specific psoriatic microRNAs signature where miR-21 is one of the most upregulated miRNAs. In this study, we focused our investigations on the passenger miR-21-3p strand that is poorly studied in skin and in psoriasis pathogenesis. Here, we transfected the HaCaT cells with synthetic oligoncucleotides form of miR-21-3p and evaluated the impact of the over-expression of this miRNA in these call by RNA-seq analysis. We identified a network of differentially expressed genes involved in abnormal proliferation control and immune regulatory genes implicated in the molecular pathogenesis of psoriasis in response to miR-21-3p overexpression in KCs. These results were confirmed by functional assays that validate the proliferative potential of miR-21-3p. All these findings highlight the importance of miR-21-3p, an underestimated miRNA, in psoriasis and provide novel molecular targets for therapeutic purposes. HaCaT cells were transfected with negative control or miR-21-3p mimics before extracting the total RNA fraction of cells 48h later and enriching polyA RNA. The samples are composed of 3 biological replicates from HaCaT cells transfected with a synthetic negative control miRNA (mimic CTL) as well as 3 biological replicates from HaCaT cells transfected with synthetic miR-21-3p mimics (mimic).