Circular <scp>RNA</scp> expression profile analysis of severe acne by <scp>RNA</scp> ‐Seq and bioinformatics

Acne is a common chronic skin disease with a multifactorial aetiology and pathogenesis. Recently, circular RNAs (circRNAs) have been identified as a key factor in regulating gene expression through circRNA-miRNA-mRNA networks in many biological processes and human diseases. However, the circRNAs expression in patients with acne is still unknown.To investigate circRNA expression profile in severe acne.The expression profile of circRNAs in three paired lesional skin and adjacent non-lesional skin in severe acne was detected by high-throughput RNA sequencing technology and bioinformatics analysis. The candidate circRNAs were validated by PCR, Sanger sequencing and qRT-PCR in the separate group (n = 4). The circRNA-miRNA-mRNA interaction networks were predicted.A total of 538 circRNAs including 271 up- and 267 downregulated circRNAs were differentially expressed in lesional skin compared with adjacent non-lesional skin in severe acne. Gene Ontology and KEGG pathway enrichment analyses revealed that the aberrantly expressed circRNAs were primarily involved in inflammatory, metabolism and immune responses. Five candidate circRNAs (circRNA_0084927, circRNA_0001073, circRNA_0005941, circRNA_0086376 and circRNA_0018168) were validated to have significant decrease in severe acne by PCR, Sanger sequencing and qRT-PCR, in agreement with the results from RNA-Seq data analysis. The five identified circRNAs were predicted to interact with 213 miRNAs and regulated target gene expression.This study firstly showed that circRNAs were differentially expressed in severe acne and suggested that circRNAs could be used as a potential biomarker for the drug targets of acne.