Characterisation of the circular RNA landscape in mesenchymal stem cells from psoriatic skin lesions.

Circular RNAs (circRNAs) have recently emerged as novel non-coding regulatory RNAs, reportedly involved in many biological processes and human diseases. However, the role of circRNAs in the pathogenesis of psoriasis is unclear. Additionally, mesenchymal stem cells (MSCs) are involved in pathological processes associated with immune diseases, including psoriasis. In this study, we determined the circRNA expression profile of MSCs from psoriatic skin lesions and investigated possible mechanisms associated with psoriasis. RNA sequencing was used to detect circRNA expression in MSCs from psoriatic skin lesions and normal skin, and detailed bioinformatic analysis was performed. Our results allowed us to predict a circRNA-microRNA (miRNA) interaction network and subsequently validate seven differentially expressed circRNAs and three miRNAs by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, we analysed circRNA expression in plasma to determine the extent of abnormal circRNA circulation in patients with psoriasis. In total, 6,323 circRNAs were detected, of which 3,227 constituted previously unreported circRNAs. We identified 129 circRNAs that exhibited significantly different expression patterns between the psoriasis and control groups, and established a circRNA-miRNA interaction network through bioinformatic analysis that indicated circRNA interaction with miRNAs associated with psoriasis. Additionally, qRT-PCR results confirmed the differential expression of seven circRNAs as well as the stable expression of three circRNAs in plasma from psoriasis patients, consistent with trends observed in cells. This is the first study of circRNA expression in psoriasis, indicating possible circRNA involvement in the pathogenesis of psoriasis.