Identification of changed expression of mRNAs and lncRNAs in osteoarthritic synovium by RNA-sequencing

Long non-coding RNAs (lncRNAs) are recently reported to regulate the homeostasis of cartilage in osteoarthritis (OA), but their regulatory roles in OA synovium remain elusive. This study aimed to identify the differentially expressed mRNAs and lncRNAs in OA synovium and further explore the function of differentially expressed lncRNAs in OA progression through bioinformatics analysis. We started with RNA-sequencing in 5 OA synovium samples and 5 healthy controls to compare the expression of mRNAs and lncRNAs. GO analysis and KEGG pathway analysis were performed to annotate the function of differentially expressed mRNAs. Then real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was admitted in 17 osteoarthritic synovium and 18 healthy controls to confirm the changes of the expression of the selected lncRNAs. LncRNA-mRNA co-expression network was constructed to predict the potential molecular regulatory mechanisms of specifically expressed lncRNAs in OA synovium. 384 mRNAs and 17 lncRNAs were detected to be differentially expressed in OA synovium. The expressions of 4 lncRNAs were confirmed by qRT-PCR. We found the differentially expression lncRNAs could potentially regulate OA progression through pathways regarding to immune response through the lncRNA-mRNA network and further annotation for co-expression mRNAs. Our results indicated that lncRNAs may play key roles in OA synovitis and may have potential value in OA diagnosis.