Identification of blood microRNA alterations in patients with severe active alopecia areata

Alopecia areata (AA) is a common inflammatory disease characterized by cellular infiltration of T cells targeting the anagen-stage hair follicle. Lack of efficacious treatment for AA may be due to little knowledge about its exact cellular mechanism. Studies have demonstrated that microRNAs (miRNAs) play an important role in the regulation of inflammatory skin diseases such as atopic dermatitis and psoriasis. However, little is known about the role of miRNAs in AA.

The present study aimed to explore the blood miRNAs alterations in patients with severe active AA.

We constructed a bipartite miRNA-messenger RNA (mRNA) regulatory network by the validated miRNA-mRNA relationships. Subsequently, the miRNA-miRNA synergistic network was formed in consideration of the Gene Ontology function enrichment of coregulated target genes. Lastly, the functional network was identified by the ingenuity pathway analysis.

By using an Agilent microarray that covers 2549 human miRNAs, we identified 36 significantly differentially expressed miRNAs in severe active AA patients. miRNA target gene prediction and functional annotation analysis showed significant enrichment in several pathways including the ribosome, cancer, cell cycle, insulin signaling, transforming growth factor-βsignaling, and p53 signaling pathways. Analysis of the three kinds of network showed that miR-185-5p, miR-125b-5p, and miR-186-5p might play important and synergistic roles in the active phase of AA. According to the receiver operating characteristic curve analysis, several miRNAs were selected for the quantitative real-time polymerase chain reaction validation. Among the miRNAs, miR-210 and miR-1246 had high prediction with high accuracy.

Blood dysregulated miRNAs are potentially associated with the severe active AA. These miRNAs could function synergistically and might be promising targets for the development of novel treatments for AA in the future.