MiR-26a-5p enhances cells proliferation, invasion, and apoptosis resistance of fibroblast-like synoviocytes in rheumatoid arthritis by regulating PTEN/PI3K/AKT pathway.

Behavior alterations in fibroblast-like synoviocytes (FLS) contribute to a pivotal role in pathogenesis of rheumatoid arthritis (RA). MiRNAs are closely involved in a variety of pathologic conditions. In the present study, we aimed to screen for the aberrant expression of miRNAs in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) to further identify the altered expression of miR-26a-5p in RA-FLS and to investigate the role of miR-26a-5p in RA. The altered expression of miR-26a-5p in RA-FLS was screened by microarray analysis and confirmed by quantitative real time PCR. The effect of miR-26a-5p on proliferation, cell cycle, apoptosis, and invasion in RA-FLS were studied. The verification of miR-26a-5p target mRNA and downstream signaling pathway was elucidated by bioinformatics analysis, dual luciferase reporter assay, and western blot. Expression of miR-26a-5p was higher in RA-FLS than in fibroblast-like synoviocytes from osteoarthritis patients and trauma patients. Overexpression of miR-26a-5p RA-FLS promoted cells proliferation, G1/S transition, cells invasion, and resisted apoptosis in RA-FLS, whereas it led to contrary effects when inhibiting the expression of miR-26a-5p. The 3'UTR of tensin homolog (PTEN) was directly targetted by miR-26a-5p and activation of phosphoinositide 3-kinase (PI3K)/AKT pathway was observed when overexpression of miR-26a-5p. Our study suggested that miR-26a-5p has a complementary role in cells proliferation, invasion, and apoptosis of RA-FLS, which may be attributed to its activation effect on PI3K/AKT signaling pathway via targetting PTEN. MiR-26a-5p is likely to be a clinically helpful target for novel therapeutic strategies in RA.

Huang Z ，Xing S ，Liu M ，Deng W ，Wang Y ，Huang Z ，Huang Y ，Huang X ，Wu C ，Guo X ，Pan X ，Jiang J ，Feng F ，Li T ... -  《-》

MiR-199a-3p inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes via suppressing retinoblastoma 1.

Background Fibroblast-like synoviocytes (FLSs) that line the intimal synovium play a crucial role in the pathogenesis of rheumatoid arthritis (RA). miR-199a-3p is a highly conserved miRNA that has been shown to regulate a variety of growth behaviors in diverse cell types. However, the role of miR-199a-3p in RA-FLS is still unknown. Methods Here, we presented the first experimental evidence showing that miR-199a-3p was a critical regulator of RA-FLS function. Results miR-199a-3p expression was significantly reduced in RA-FLS compared with normal FLS. Ectopic expression of miR-199a-3p significantly inhibited RA-FLS proliferation and induced apoptosis, which was demonstrated by an increase in caspase-3 activity and Bax/Bcl-2 ratio. Our bioinformatics analysis identified Retinoblastoma 1 (RB1) gene to be a direct target of miR-199a-3p. In RA-FLS, miR-199a-3p directly targetted the 3'-UTR of RB1 mRNA and suppressed endogenous RB1 expression, whereas miR-199a-3p-resistant variant of RB1 was not affected. Silencing RB1 decreased cell proliferation and promoted apoptosis in RA-FLS, an effect comparable with miR-199a-3p overexpression. Enforced expression of RB1 partially restored cell proliferation and attenuated apoptosis in miR-199a-3p-overexpressing RA-FLSs. Conclusion In summary, miR-199a-3p is down-regulated in RA-FLS, and miR-199a-3p inhibits proliferation and induces apoptosis in RA-FLS, partially via targetting RB1. The miR-199a-3p/RB1 pathway may represent a new therapeutic target for RA.

Wangyang Y ，Yi L ，Wang T ，Feng Y ，Liu G ，Li D ，Zheng X ... -  《-》

Hypoxia-induced miR-191-C/EBPβ signaling regulates cell proliferation and apoptosis of fibroblast-like synoviocytes from patients with rheumatoid arthritis.

Yu S ，Lu Y ，Zong M ，Tan Q ，Fan L ... -  《-》

Lnc RNA ZFAS1 regulates the proliferation, apoptosis, inflammatory response and autophagy of fibroblast-like synoviocytes via miR-2682-5p/ADAMTS9 axis in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a frequent autoimmune disease. Emerging evidence indicated that ZNFX1 antisense RNA1 (ZFAS1) participates in the physiological and pathological processes in RA. However, knowledge of ZFAS1 in RA is limited, the potential work pathway of ZFAS1 needs to be further investigated. Levels of ZFAS1, microRNA (miR)-2682-5p, and ADAM metallopeptidase with thrombospondin type 1 motif 9 (ADAMTS9) were estimated using quantitative real-time polymerase chain reaction (qRT-PCR) assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to explore the ability of cell proliferation in fibroblast-like synoviocytes (FLS-RA). Cell apoptosis was measured via flow cytometry. Also, levels of ADAMTS9, apoptosis-related proteins, cleaved-caspase-3 (active large subunit), and autophagy-related proteins were identified adopting Western blot. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the productions of inflammatory cytokines. Beside, the interrelation between miR-2682-5p and ZFAS1 or ADAMTS9 was verified utilizing dual-luciferase reporter assay. High levels of ZFAS1 and ADAMTS9, and a low level of miR-2682-5p were observed in RA synovial tissues and FLS-RA. Knockdown of ZFAS1 led to the curbs of cell proliferation, inflammation, autophagy, and boost apoptosis in FLS-RA, while these effects were abolished via regaining miR-2682-5p inhibition. Additionally, the influence of miR-2682-5p on cell phenotypes and inflammatory response were eliminated by ADAMTS9 up-regulation in FLS-RA. Mechanically, ZFAS1 exerted its role through miR-2682-5p/ADAMTS9 axis in RA. ZFAS1/miR-2682-5p/ADAMTS9 axis could modulate the cell behaviors, inflammatory response in FLS-RA, might provide a potential therapeutic target for RA treatment.

Yang S ，Yin W ，Ding Y ，Liu F ... -  《-》

miR-124a inhibits the proliferation and inflammation in rheumatoid arthritis fibroblast-like synoviocytes via targeting PIK3/NF-κB pathway.

Abnormal hyperplasia of fibroblast-like synoviocytes (FLS) leads to the progression of rheumatoid arthritis (RA). This study aimed to investigate the role of miR-124a in the pathogenesis of RA. The viability and cell cycle of FLS in rheumatoid arthritis (RAFLS) were evaluated by Cell Counting Kit 8 and flow cytometry assay. The expression of PIK3CA, Akt, and NF-κB in RAFLS was examined by real-time PCR and Western blot analysis. The production of tumour necrosis factor (TNF)-α and interleukin (IL)-6 was detected by ELISA. The joint swelling and inflammation in collagen-induced arthritis (CIA) mice were examined by histological and immunohistochemical analysis. We found that miR-124a suppressed the viability and proliferation of RAFLS and increased the percentage of cells in the G1 phase. miR-124a suppressed PIK3CA 3'UTR luciferase reporter activity and decreased the expression of PIK3CA at mRNA and protein levels. Furthermore, miR-124a inhibited the expression of the key components of the PIK3/Akt/NF-κB signal pathway and inhibited the expression of pro-inflammatory factors TNF-α and IL-6. Local overexpression of miR-124a in the joints of CIA mice inhibited inflammation and promoted apoptosis in FLS by decreasing PIK3CA expression. In conclusion, miR-124a inhibits the proliferation and inflammation in RAFLS via targeting PIK3/NF-κB pathway. miR-124a is a promising therapeutic target for RA.

Yang B ，Ge Y ，Zhou Y ，Wang J ，Xie X ，Li S ，Tang M ，Xu L ，Tian J ... -  《-》