Roles of microRNAs in psoriasis: Immunological functions and potential biomarkers

Abstract

MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in RNA silencing and post-transcriptional regulation of gene expression. Psoriasis is an inflammatory skin disease characterized by the dysfunction of keratinocytes, with the immune dysregulation. We reviewed the recent studies on the roles of miRNAs in psoriasis and showed that miRNAs play key roles in psoriasis, including the regulation of hyperproliferation, cytokine and chemokine production in keratinocyte, as well as mediating immune dysfunction in psoriasis. Furthermore, miRNAs, particularly, circulating miRNAs may serve as novel biomarkers for diagnosis, monitoring therapy response and reflecting the disease severity. Thus, targeting specific miRNAs may be used to develop new therapeutic methods for psoriasis.

Keywords: biomarkers; immunological mechanisms; miRNA; psoriasis.

FIGURE 1

Biogenesis of miRNAs. RNA polymerase II transcribes miRNA genes, generating long primary transcripts (pri-miRNAs). In the nucleus, the RNase III-type enzyme Drosha processes the long primary transcripts (pri-miRNAs), yielding hairpin precursors (pre-miRNA). Exportin 5 transports the pre-miRNAs from the nucleus into the cytoplasm. The pre-miRNA hairpins are further processed by Dicer into mature miRNAs, which are incorporated into the Argonaute (Ago) protein and form the RNA-induced silencing complex (RISC) together with Dicer. Once incorporated into the RISC, the miRNAs then guide the RISC to the target genes and repress target gene expression by destabilizing the target mRNAs or suppressing protein translation (Refer to our paper [50])

FIGURE 2

Materials for miRNA extraction and process of miRNA profiles, including the sample preparation, miRNA extraction, detection, data analysis and results application

FIGURE 3

Roles of miRNAs in the modulation of immunological mechanism of psoriasis. Both the cells interaction network and the cytokines and chemokines network are regulated by miRNA, which indicates a critical role of miRNA playing in the immunopathogenesis of psoriasis. KC, keratinocyte; imDC, immature dendritic cell; mDC, mature dendritic cell; LC, Langerhans cell; TC, T cell; NK, natural killer cell; NKT, natural killer T cell; Treg, regulatory T cell; miR, microRNA