Long noncoding RNA profiling revealed differentially expressed lncRNAs associated with disease activity in PBMCs from patients with rheumatoid arthritis

Long noncoding RNAs (lncRNAs) have recently emerged as important biological regulators, and the aberrant expression of lncRNAs has been reported in numerous diseases. However, the expression of lncRNAs in peripheral blood mononuclear cells (PBMCs) in rheumatoid arthritis (RA) has not been well documented. We applied a microarray analysis to profile the lncRNA and mRNA expression in 3 pairs of samples. Each sample was mixed with equivalent PBMCs from 9 female RA patients and 9 corresponding healthy controls, and the data were validated via qPCR using another cohort that comprised 36 RA patients and 24 healthy controls. A bioinformatic analysis was performed to investigate the potential functions of differentially expressed genes. Overall, 2,099 lncRNAs and 2,307 mRNAs were differentially expressed between the RA patients and healthy controls. The bioinformatic analysis indicated that the differentially expressed lncRNAs regulated the abnormally expressed mRNAs, which were involved in the pathogenesis of RA through several different pathways. The qPCR results showed that the expression levels of ENST00000456270 and NR_002838 were significantly increased in the RA patients, whereas the expression levels of NR_026812 and uc001zwf.1 were significantly decreased. Furthermore, the expression level of ENST00000456270 was strongly associated with the serum levels of IL-6 and TNF-a and the Simplified Disease Activity Index (SDAI) of the RA patients. Our data provided comprehensive evidence regarding the differential expression of lncRNAs in PBMCs of RA patients, which shed light on the understanding of the molecular mechanisms of lncRNAs in the pathogenesis of RA.