Screening and biological function analysis of inflammation-related circRNAs in synovial tissue of patients with primary knee osteoarthritis
Qiao Linghui1, Yuan Tao1, Han Jie2, Wang Guancheng1, Gu Yanglin1
1Wuxi Second Affiliated Hospital of Nanjing Medical University, Wuxi 214000, Jiangsu Province, China; 2Wuxi Clinical College of Nantong University, Wuxi 214000, Jiangsu Province, China
Abstract: BACKGROUND: Primary knee osteoarthritis is one of the most common chronic diseases among the elderly, which brings a heavy burden on society and families. Current clinical treatments only focus on surgeries such as total knee replacement, but it is difficult to prevent cartilage tissue degeneration at an early stage. The formation mechanism of knee osteoarthritis, especially the influence of inflammation in disease progression, has been reported to some extent, but its specific mechanism is still unclear.
OBJECTIVE: To investigate the differentially expressed circRNA sites of primary knee osteoarthritis and rheumatoid arthritis and their effects on the pathogenesis of the disease.
METHODS: In this study, we collected the synovial tissues from eight patients with primary knee osteoarthritis and two patients with rheumatoid arthritis (control group). The expression profile of circRNAs in the tissue was detected by RNA-seq technique, trying to find the differentially expressed genes and key biological function pathways.
RESULTS AND CONCLUSION: Compared with patients with rheumatoid arthritis, 185 differentially expressed circRNAs were detected in patients with knee osteoarthritis, of which 14 were up-regulated and 171 were down-regulated. Through the pathway enrichment and functional annotation of these target genes, a variety of enrichment pathways were identified, including protein H3-K36 dimethylation, glycosphingolipid biosynthesis process, and positive regulation of Toll-like receptor 9 signaling pathway. Based on the above sequencing results, a circRNA-miRNA interaction network was created, contributing to understanding the effect of differentially expressed circRNAs. In this study, we determined the differential expression of inflammation-related circRNAs in synovial tissue and the control group. These differentially expressed transcripts may elucidate the effect of circRNA and its relationship network in synovial tissue on the progression of osteoarthritis. Findings from this study will be helpful to explore the pathogenesis and key therapeutic targets of osteoarthritis.
Key words: osteoarthritis, rheumatoid arthritis, circRNA, inflammation, synovial tissue, RNA-seq