LncRNA PICSAR promotes cell proliferation, migration and invasion of fibroblast-like synoviocytes by sponging miRNA-4701-5p in rheumatoid arthritis.

Long non-coding RNAs (lncRNAs) have drawn increasing attention because they play a pivotal role in various types of autoimmune diseases, including rheumatoid arthritis (RA). Fibroblast-like synoviocytes (FLSs), a prominent component of hyperplastic synovial pannus tissue, are the primary effector cells in RA synovial hyperplasia and invasion which can lead to joint destruction. In this study, we investigated whether lncRNAs could act as competing endogenous RNAs to regulate the pathological behaviors of RA-FLSs. LncRNA microarray was conducted to establish lncRNA expression profiles in FLSs isolated from RA patients and healthy controls (HCs). Differentially expressed lncRNAs were verified by quantitative real-time PCR (qRT-PCR) on RA-FLSs and synovial fluid. The functional role of lncRNA PICSAR downregulation was evaluated in RA-FLSs. We conducted molecular biological analysis to predict miRNAs which have a potential binding site for PICSAR and further refined the results by qRT-PCR. Luciferase reporter assay was adopted to validate the interaction of lncRNA PICSAR and miR-4701-5p. Western Blot and qPCR were used to identify the target gene and protein. The functional role of miR-4701-5p upregulation was examined in RA-FLSs. We identified a long intergenic non-protein-coding RNA162 (LINC00162), also known as lncRNA PICSAR (p38 inhibited cutaneous squamous cell carcinoma associated lincRNA), has significantly higher expression in RA-FLSs and RA synovial fluid. The cell proliferation, migration, invasion and proinflammatory cytokines production of RA-FLSs showed significant alterations after the lncRNA PICSAR suppression. Mechanistically, lncRNA PICSAR functioned through sponging miR-4701-5p in RA-FLSs. Our results reveal PICSAR may exert an essential role in promoting synovial invasion and joint destruction by sponging miR-4701-5p in RA and that lncRNA PICSAR may act as a biomarker of RA.

Bi X ，Guo XH ，Mo BY ，Wang ML ，Luo XQ ，Chen YX ，Liu F ，Olsen N ，Pan YF ，Zheng SG ... -  《EBioMedicine》

LncRNA NEAT1 regulates the proliferation and production of the inflammatory cytokines in rheumatoid arthritis fibroblast-like synoviocytes by targeting miR-204-5p.

Xiao J ，Wang R ，Zhou W ，Cai X ，Ye Z ... -  《Human Cell》

Influences of the lncRNA TUG1-miRNA-34a-5p network on fibroblast-like synoviocytes (FLSs) dysfunction in rheumatoid arthritis through targeting the lactate dehydrogenase A (LDHA).

Rheumatoid arthritis (RA) is a systemic and chronic inflammatory disease. The cellular glucose metabolism of fibroblast-like synoviocytes (FLSs) of RA has been revealed to be essential to the pathogenesis and development of RA. To date, the precise roles and molecular mechanisms of long noncoding RNA TUG1 in RA have not been elucidated. TUG1 and miR-34a-5p were detected by qRT-PCR. Interactions between lncRNA-miRNA and miRNA-mRNA were validated by RNA pull-down assay and luciferase assay. The glucose metabolism was evaluated by glucose uptake and extracellular acidification rate (ECAR). Cell viability was determined by MTT assay and Annexin V assay. TUG1 expression was significantly upregulated in synovial fibroblast-like synoviocytes (FLSs) compared with normal FLSs. Functional assays uncovered that silence of TUG1 suppressed FLSs-RA invasion, migration, glucose metabolism, and increased apoptosis. Bioinformatics analysis indicated that TUG1 interacted with miR-34a-5p. RNA pull-down assay and luciferase assay validated that TUG1 sponged miR-34a-5p in FLSs-RA. Overexpression of miR-34a-5p effectively inhibited glucose metabolism of FLSs-RA. Furthermore, the glucose metabolism of FLSs-RA was significantly elevated compared with normal FLSs. The glucose metabolism enzyme, LDHA, was directly targeted by miR-34a-5p in FLSs. Rescue experiments validated that the miR-34a-5p-inhibited glucose metabolism of FLSs-RA was through targeting LDHA. Finally, we showed restoration of miR-34a-5p in TUG1-overexpressing FLSs-RA successfully overcame the TUG1-promoted glucose metabolism and apoptosis resistance via targeting LDHA. The present study uncovered critical roles and molecular mechanisms underlying the TUG1-mediated glucose metabolism and apoptosis of FLSs-RA through modulating the miR-34a-5p-LDHA pathway in fibroblast-like synoviocytes of rheumatoid arthritis.

Zhang M ，Lu N ，Guo XY ，Li HJ ，Guo Y ，Lu L ... -  《-》

LncRNA HOTAIR inhibits the progression of fibroblast-like synoviocytes by sponging miRNA-106b-5p in rheumatoid arthritis.

Qiu H ，Liu M ，Shi X ，Ma M ，Zhang J ，Liu H ... -  《-》

Long non-coding RNA PVT1 can regulate the proliferation and inflammatory responses of rheumatoid arthritis fibroblast-like synoviocytes by targeting microRNA-145-5p.

Tang J ，Yi S ，Liu Y 《Human Cell》