This study aimed to analyze long non-coding RNA (lncRNA) expression profiles in synovium tissue of patients with RA using RNA sequencing, and to further assess the clinical values of dysregulated lncRNAs in RA diagnosis and monitoring.
Thirty patients with RA who underwent knee arthroscopy and 30 controls with knee trauma who underwent surgery were consecutively enrolled and synovium tissue samples of both groups were obtained during surgery. In the exploration stage, lncRNA and mRNA expression profiles in three RA samples and three control samples were detected by RNA sequencing and bioinformatic analyses were then performed. In the validation stage, quantitative polymerase chain reaction (qPCR) was subsequently used to detect expression of five candidate lncRNAs in 30 patients with RA and 30 control patients.
A total of 349 lncRNAs and 1582 mRNAs were upregulated and 806 lncRNAs and 1295 mRNAs were downregulated in patients with RA compared with controls. Enrichment analyses revealed that these dysregulated lncRNAs and mRNAs were mainly involved in regulating immune response, leukocyte migration, complement activation, and B cell receptor signaling pathway. Subsequent qPCR validation discovered that lnc-AL928768.3 (P < 0.001) and lnc-AC091493.1 (P < 0.001) were elevated in patients with RA compared with controls and afford good predictive values for RA risk by receiver operating characteristic (ROC) curve analysis. Additionally, the two lncRNAs were positively associated with C-reactive protein level and disease activity score in 28 joints (ESR) (all P < 0.05).
Analysis of lncRNA expression profiles by sequencing reveals that lnc-AL928768.3 and lnc-AC091493.1 are novel biomarkers for RA risk and activity.