159 Downregulation of serum exosome miR-1305 contribute to the development of psoriasis through non-canonical Wnt signaling pathway

Abstract

Background: The extensive involvement of microRNAs (miRNAs) in the pathogenesis of psoriasis is well documented. However, whether the serum exosome derived miRNAs play a role in psoriasis remains unclear. Objectives: To explore the role of serum exosome microRNA-1305 (miR-1305) in psoriasis. Methods: Exosomes were isolated from serum by differential ultracentrifugation. The morphology was identified by transmission electron microscope (TEM). Observation of serum exosomes uptake by keratinocytes though confocal fluorescence microscopy. MiRNA microarray was performed in serum exosomes from 4 patients with psoriasis and 4 controls. qRT-PCR were used to identify the differential expression miRNAs. Using bioinformatic predicted the signaling pathways related to mir-1305. Western blot was used to investigate the protein levels of Wnt5a and its downstream effectors. Normal human epidermal keratinocytes (NHEKs) and HaCat cells were transfected with miR-1305 mimic/Ctrl (50 nM) or miR-1305 inhibitor/Ctrl (100 nM); or siWnt5a/ctrl (60 nM) with Lipofectamine 2000. Results: The diameter of serum exosomes were around 100 nm. Serum exosomes could be uptake by keratinocytes after co-culture for 12h. Using miRNA microarray, we found 16 differentially expressed miRNAs in serum exosomes; 14 (87.5%) were downregulated and 2 (12.5%) were upregulated (fold change>2, P<0.05). Among these differentially expressed miRNAs, miR-1305 was down-regulated in serum exosomes from psoriasis patients (fold change=0.20, P<0.01, n=4). Through the methods of bioinformatics analysis, qRT-PCR and Western blot, we found that miR-1305 was closely related to non-canonical WNT signaling pathway (P<0.01), and miR-1305 regulated the expression of Wnt5a in Normal human epidermal keratinocytes (NHEKs) and HaCat cells. Conclusions: MiR-1305 was downregulated in serum exosomes from psoriasis patients. Downregulation of serum exosomes miR-1305 was involved in the pathogenesis of psoriasis through regulating non-canonical WNT pathways. However, much work remains to be done in the future to test our point of view.