Comprehensive circular RNA profiles in plasma reveals that circular RNAs can be used as novel biomarkers for systemic lupus erythematosus

Circular RNAs (circRNAs), a novel class of widespread endogenous noncoding RNAs, have been involved in the development of various diseases, including atherosclerosis, Alzheimer's disease and several types of cancers, but there is little knowledge about their associations with systemic lupus erythematosus (SLE). This study is aimed to identify the expression profiles of circRNAs in 6 paired SLE and normal participants plasma samples by using a circRNA microarray. The microarray analysis showed that 207 circRNAs were differentially expressed between these two groups, including 113 upregulated and 94 downregulated circRNAs. Then, we selected 8 circRNAs as candidate biomarkers from the microarray analysis and further verified them in another group of subjects consisting of 24 SLE patients and 24 normal controls using quantitative real-time polymerase chain reaction assays (qRT-PCR). Finally, we confirmed four circRNAs that were consistent with the microarray results. In addition, bioinformatics was employed to predict the interaction between validated circRNAs and potential miRNA targets. Taken together, we firstly illustrate the comprehensive expression profiles of circRNAs in SLE patients plasma and lay the foundations to develop circRNAs as novel non-invasive biomarkers for SLE disease in the future.