lncRNA expression profiles related to apoptosis and autophagy in peripheral blood mononuclear cells of patients with rheumatoid arthritis

Mir22hg facilitates ferritinophagy-mediated ferroptosis in sepsis by recruiting the m6A reader YTHDC1 and enhancing Angptl4 mRNA stability

BACKGROUND

Ferritinophagy-mediated ferroptosis plays a crucial role in fighting pathogen aggression. The long non-coding RNA Mir22hg is involved in the regulation of ferroptosis and aberrantly overexpression in lipopolysaccharide (LPS)-induced sepsis mice, but whether it regulates sepsis through ferritinophagy-mediated ferroptosis is unclear.

METHODS

Mir22hg was screened by bioinformatics analysis. Ferroptosis was assessed by assaying malondialdehyde (MDA), reactive oxygen species (ROS), and Fe2+ levels, glutathione (GSH) activity, as well as ferroptosis-related proteins GPX4 and SLC3A2 by using matched kits and performing western blot. Ferritinophagy was assessed by Lyso tracker staining and FerroOrange staining, immunofluorescence analysis of Ferritin and LC-3, and western blot analysis of LC-3II/I, p62, FTH1, and NCOA4. The bind of YTH domain containing 1 (YTHDC1) to Mir22hg or angiopoietin-like-4 (Angptl4) was verified by RNA pull-down and/or immunoprecipitation (RIP) assays.

RESULTS

Mir22hg silencing lightened ferroptosis and ferritinophagy in LPS-induced MLE-12 cells and sepsis mouse models, as presented by the downregulated MDA, ROS, Fe2+, NCOA4, and SLC3A2 levels, upregulated GPX4, GSH, and FTH1 levels, along with a decrease in autophagy. Mir22hg could bind to the m6A reader YTHDC1 without affecting its expression. Mechanistically, Mir22hg enhanced Angptl4 mRNA stability through recruiting the m6A reader YTHDC1. Furthermore, Angptl4 overexpression partly overturned Mir22hg inhibition-mediated effects on ferroptosis and ferritinophagy in LPS-induced MLE-12 cells.

CONCLUSION

Mir22hg contributed to in ferritinophagy-mediated ferroptosis in sepsis via recruiting the m6A reader YTHDC1 and strengthening Angptl4 mRNA stability, highlighting that Mir22hg may be a potential target for sepsis treatment based on ferroptosis.

Integrated DNA methylation analysis reveals a potential role for PTPRN2 in Marfan syndrome scoliosis

Background

Marfan syndrome (MFS) is a rare genetic disorder caused by mutations in the Fibrillin-1 gene (FBN1) with significant clinical features in the skeletal, cardiopulmonary, and ocular systems. To gain deeper insights into the contribution of epigenetics in the variability of phenotypes observed in MFS, we undertook the first analysis of integrating DNA methylation and gene expression profiles in whole blood from MFS and healthy controls (HCs).

Methods

The Illumina 850K (EPIC) DNA methylation array was used to detect DNA methylation changes on peripheral blood samples of seven patients with MFS and five HCs. Associations between methylation levels and clinical features of MFS were analyzed. Subsequently, we conducted an integrated analysis of the outcomes of the transcriptome data to analyze the correlation between differentially methylated positions (DMPs) and differentially expressed genes (DEGs) and explore the potential role of methylation-regulated DEGs (MeDEGs) in MFS scoliosis. The weighted gene co-expression network analysis was used to find gene modules with the highest correlation coefficient with target MeDEGs to annotate their functions in MFS.

Results

Our study identified 1253 DMPs annotated to 236 genes that were primarily associated with scoliosis, cardiomyopathy, and vital capacity. These conditions are typically associated with reduced lifespan in untreated MFS. We calculated correlations between DMPs and clinical features, such as cobb angle to evaluate scoliosis and FEV1% to assess pulmonary function. Notably, cg20223687 (PTPRN2) exhibited a positive correlation with cobb angle of scoliosis, potentially playing a role in ERKs inactivation.

Conclusions

Taken together, our systems-level approach sheds light on the contribution of epigenetics to MFS and offers a plausible explanation for the complex phenotypes that are linked to reduced lifespan in untreated MFS patients.

m6A-mediated lncRNA MAPKAPK5-AS1 induces apoptosis and suppresses inflammation via regulating miR-146a-3p/SIRT1/NF-κB axis in rheumatoid arthritis

To investigate the role of m6A-mediated lncRNA MAPKAPK5-AS1 (MK5-AS1) in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs) and its underlying molecular mechanism. RT-qPCR, western blot, flow cytometry (FCM), and enzyme-linked immunosorbent assay (ELISA) were utilized for evaluating inflammation and apoptosis. Next, RIP, RNA pull-down, dual-luciferase reporter gene assay, and a series of rescue experiments were performed to explore the regulatory mechanisms of MK5-AS1 and its sponge-like action in RA-FLSs. The regulatory relationships between MK5-AS1 and WTAP were explored using the MeRIP-qPCR assay and RT-qPCR. Finally, the critical RNAs in the ceRNA axis were verified in the clinical cohort. MK5-AS1 was poorly expressed and miR-146a-3p was overexpressed in co-cultured RA-FLSs. MK5-AS1 overexpression could inhibit inflammatory responses and promote cell apoptosis in the co-cultured RA-FLSs. MK5-AS1 bound to miR-146a-3p to target SIRT1, thereby affecting inflammatory responses and cell apoptosis in the co-cultured RA-FLSs. SIRT1 knockdown or miR-146a-3p overexpression reversed the impacts of MK5-AS1 overexpression on co-cultured RA-FLSs inflammation and apoptosis. Moreover, WTAP was downregulated, and induced the inhibition of MK5-AS1 by promoting its RNA transcript stability. Clinically, MK5-AS1 was downregulated in RA-PBMCS and correlated with the clinical characteristics of RA. Our study elucidated that m6A-mediated MK5-AS1 sequestered miR-146a-3p to suppress SIRT1 expression in co-cultured RA-FLSs, thus providing a new insight into the treatment of rheumatoid arthritis.

Long noncoding RNA/circular RNA regulates competitive endogenous RNA networks in rheumatoid arthritis: molecular mechanisms and traditional Chinese medicine therapeutic significances

Rheumatoid arthritis (RA) is a systemic and autoimmune disease that is mainly featured abnormal fibroblast-like synoviocyte (FLS) proliferation and inflammatory cell infiltration. Abnormal expression or function of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are closely related to human diseases, including RA. There has been increasing evidence showing that in the competitive endogenous RNA (ceRNA) networks, both lncRNA and circRNA are vital in the biological functions of cells. Nevertheless, the exact mechanism of ceRNA in RA remains to be investigated. Herein, we summarized the molecular potencies of lncRNA/circRNA-mediated ceRNA networks in RA, with emphasis on the phenotypic regulation of ceRNA in the progression of RA, including regulation of proliferation, invasion, inflammation and apoptosis, as well as the role of ceRNA in traditional Chinese medicine (TCM) in the treatment of RA. In addition, we also discussed the future direction and potential clinical value of ceRNA in the treatment of RA, which may provide potential reference value for clinical trials of TCM therapy for the treatment of RA.Key messagesLong noncoding RNA/circular RNA can work as the competitive endogenous RNA sponge and participate in the pathogenesis of rheumatoid arthritis.Traditional Chinese medicine and its agents have shown potential roles in the prevention and treatment of rheumatoid arthritis via competitive endogenous RNA.

LncRNA-mediated cell autophagy: An emerging field in bone destruction in rheumatoid arthritis

In recent years, research on the mechanism of bone destruction in rheumatoid arthritis (RA) has remained in the initial stages, and the mechanism has not been fully elucidated to date. Recent studies have shown that long noncoding RNAs (lncRNAs) participate in RA bone destruction via autophagy, but the specific regulatory mechanism of lncRNA-mediated autophagy is unclear. Therefore, in this article, we review the mechanisms of lncRNA-mediated autophagy in fibroblast-like synoviocytes and chondrocytes in RA bone destruction. We explain that lncRNAs mediate autophagy and participate in many specific pathological processes of RA bone destruction by regulating signalling pathways and the expression of target genes. Specific lncRNAs can be used as markers for molecular diagnosis, mechanistic regulation, treatment and prognosis of RA.

Competing endogenous RNA analysis identified lncRNA DSCR9 as a novel prognostic biomarker associated with metastasis and tumor microenvironment in renal cell carcinoma

Distant metastasis is the main cause of death in patients with clear cell renal carcinoma (ccRCC). The dysregulation of the tumor microenvironment is responsible for tumorigenesis and metastasis in ccRCC. The role of long non-coding RNAs in the tumor immune of ccRCC remains unclear. The present study screened differentially expressed protein-coding genes and non-coding genes between ccRCC and normal tissues based on three datasets. The commonly deregulated genes were used to identify distant metastasis-related long non-coding RNAs (lncRNAs) and prognostic lncRNAs. Pearson correlation analysis was used to identify immune-related lncRNAs. A competing endogenous RNA network was constructed and hub lncRNAs were identified. A total of 1650 coding genes, 821 lncRNAs and 62 miRNAs were commonly deregulated in the three datasets. A total of 408 lncRNAs associated with the overall survival of patients with ccRCC were identified. Among them, 82 lncRNAs were distant metastasis-related. Further analysis identified 52 lncRNAs associated with the immune pathway. Functional analyses concordantly demonstrated the role of the 52 lncRNAs in metastasis and tumor immunology. The ceRNA network analysis indicated lncRNA DSCR9 as the key lncRNA regulator. Univariate and multivariate analysis in two independent cohorts validated that DSCR9 could be an independent risk factor for the progression-free survival of patients with ccRCC. Further analyses indicated that DSCR9 might be associated with the immunotherapeutic response. reverse transcription-quantitative PCR demonstrated that the RNA expression level of DSCR9 was upregulated in ccRCC compared with normal kidney samples. The present study demonstrated the potential of LncRNA DSCR9 in assessing the prognosis and developing future immunotherapy for patients with metastatic ccRCC.

Biomarkers (mRNAs and non-coding RNAs) for the diagnosis and prognosis of rheumatoid arthritis

In recent years, diagnostic and therapeutic approaches for rheumatoid arthritis (RA) have continued to improve. However, in the advanced stages of the disease, patients are unable to achieve long-term clinical remission and often suffer from systemic multi-organ damage and severe complications. Patients with RA usually have no overt clinical manifestations in the early stages, and by the time a definitive diagnosis is made, the disease is already at an advanced stage. RA is diagnosed clinically and with laboratory tests, including the blood markers C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) and the autoantibodies rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA). However, the presence of RF and ACPA autoantibodies is associated with aggravated disease, joint damage, and increased mortality, and these autoantibodies have low specificity and sensitivity. The etiology of RA is unknown, with the pathogenesis involving multiple factors and clinical heterogeneity. The early diagnosis, subtype classification, and prognosis of RA remain challenging, and studies to develop minimally invasive or non-invasive biomarkers in the form of biofluid biopsies are becoming more common. Non-coding RNA (ncRNA) molecules are composed of long non-coding RNAs, small nucleolar RNAs, microRNAs, and circular RNAs, which play an essential role in disease onset and progression and can be used in the early diagnosis and prognosis of RA. In this review of the diagnostic and prognostic approaches to RA disease, we provide an overview of the current knowledge on the subject, focusing on recent advances in mRNA-ncRNA as diagnostic and prognostic biomarkers from the biofluid to the tissue level.

LncRNA-mRNA co-expression analysis revealed 8 core lncRNAs in rheumatoid arthritis of collagen-induced arthritis rats

BACKGROUNDS

Rheumatoid arthritis (RA) is a chronic inflammatory and autoimmune disease. Current studies suggest that long noncoding RNAs (lncRNAs) may be key regulators in pathogenesis.

METHODS

Analyzed lncRNAs and mRNAs using microarrays to find key differentially expressed lncRNAs in RA. GO and KEGG enrichment analysis together with coding non-coding co-expression (CNC) network was used for comprehensive analysis. Verify that their expression levels are consistent with the chip results by qRT-PCR.

RESULTS

There are 268 differentially expressed lncRNAs (DELs) and 286 differentially expressed mRNAs (DEMs). We found 8 core lncRNAs through the CNC network. Eight highly significantly differentially expressed lncRNAs corrected with microarray profiles. The functions and associated pathways of significantly differentially expressed lncRNAs were predicted by GO and KEGG analysis. They may be involved in the pathogenesis of RA.

CONCLUSION

The differential expression profiles of lncRNAs and mRNAs in the collagen-induced arthritis rat model preliminarily predicted functions through comprehensive analysis. However, its exact role and specific mechanism remain to be further studied.

lncRNA-mediated synovitis in rheumatoid arthritis: A perspective for biomarker development

Long noncoding RNAs (lncRNAs) are a regulatory class of noncoding RNAs with a wide range of activities such as transcriptional and post-transcriptional regulations. Emerging evidence has demonstrated that various lncRNAs contribute to the initiation and progression of Rheumatoid Arthritis (RA) through distinctive mechanisms. The present study reviews the recent findings on lncRNA role in RA development. It focuses on the involvement of different lncRNAs in the main steps of RA pathogenesis including T cell activation, cytokine dysregulation, fibroblast-like synoviocyte (FLS) activation and joint destruction. Besides, it discusses the current findings on RA diagnosis and the potential of lncRNAs as diagnostic, prognostic and predictive biomarkers in Rheumatology clinic.

Functional Interactions Between lncRNAs/circRNAs and miRNAs: Insights Into Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases that affect synovitis, bone, cartilage, and joint. RA leads to bone and cartilage damage and extra-articular disorders. However, the pathogenesis of RA is still unclear, and the lack of effective early diagnosis and treatment causes severe disability, and ultimately, early death. Accumulating evidence revealed that the regulatory network that includes long non-coding RNAs (lncRNAs)/circular RNAs (circRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNA) plays important roles in regulating the pathological and physiological processes in RA. lncRNAs/circRNAs act as the miRNA sponge and competitively bind to miRNA to regulate the expression mRNA in synovial tissue, FLS, and PBMC, participate in the regulation of proliferation, apoptosis, invasion, and inflammatory response. Thereby providing new strategies for its diagnosis and treatment. In this review, we comprehensively summarized the regulatory mechanisms of lncRNA/circRNA-miRNA-mRNA network and the potential roles of non-coding RNAs as biomarkers and therapeutic targets for the diagnosis and treatment of RA.

LncRNA Expression Profiles in Systemic Lupus Erythematosus and Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common multisystem autoimmune diseases that share, among others, many clinical manifestations and serological features. The role of long non-coding RNAs (lncRNAs) has been of particular interest in the pathogenesis of autoimmune diseases. Here, we aimed to summarize the roles of lncRNAs as emerging novel biomarkers and therapeutic targets in SLE and RA. We conducted a narrative review summarizing original articles on lncRNAs associated with SLE and RA, published until November 1, 2021. Based on the studies on lncRNA expression profiles in samples (including PBMCs, serum, and exosomes), it was noted that most of the current research is focused on investigating the regulatory mechanisms of these lncRNAs in SLE and/or RA. Several lncRNAs have been hypothesized to play key roles in these diseases. In SLE, lncRNAs such as GAS5, NEAT1, TUG1, linc0949, and linc0597 are dysregulated and may serve as emerging novel biomarkers and therapeutic targets. In RA, many validated lncRNAs, such as HOTAIR, GAS5, and HIX003209, have been identified as promising novel biomarkers for both diagnosis and treatment. The shared lncRNAs, for example, GAS5, may participate in SLE pathogenesis through the mitogen-activated protein kinase pathway and trigger the AMP-activated protein kinase pathway in RA. Here, we summarize the data on key lncRNAs that may drive the pathogenesis of SLE and RA and could potentially serve as emerging novel biomarkers and therapeutic targets in the coming future.

Long noncoding RNA LINC01189 is associated with HCV-hepatocellular carcinoma and regulates cancer cell proliferation and chemoresistance through hsa-miR-155-5p

INTRODUCTION AND OBJECTIVES

Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) may be closely associated with Hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). In this study, we investigated the expression and functions of a lncRNA, LINC01189, in HCV-associated HCC.

PATIENTS OR MATERIALS AND METHODS

LINC01189 expression was measured in HCC tumors, HCV-infected HCC tumors and HCV-infected HCC cells. LINC01189 was overexpressed in HCV-infected HepG2 cells to measure its function on HCV-correlated cancer proliferation. In HCC cell lines of Huh7 and Hep3B, LINC01189 was upregulated to investigate its effects on cancer cell proliferation and 5-FU chemoresistance. The competing endogenous RNA (ceRNA) target of LINC01189, human microRNA-155-5p (hsa-miR-155-5p) was probed by dual-luciferase assay and qRT-PCR. Hsa-miR-155-5p was upregulated in LINC01189-overexpessed Huh7 and Hep3B cells to investigate their epigenetic correlation on HCC development regulation.

RESULTS

LINC01189 is downregulated in HCV-infected HCC tumors and cell lines. LINC01189 overexpression inhibited HCC cancer cell proliferation and 5-FU chemoresistance. Hsa-miR-155-5p was confirmed to be a ceRNA target of LINC01189 in HCC. Upregulating hsa-miR-155-5p reversed the LINC01189-mediated inhibition on HCC proliferation and 5-FU chemoresistance.

CONCLUSIONS

LINC01189 downregulation is associated with HCV infection in HCC, and it has tumor-suppressing effects on HCC development through hsa-miR-155-5p.

Triptolide promotes the apoptosis and attenuates the inflammation of fibroblast-like synoviocytes in rheumatoid arthritis by down-regulating lncRNA ENST00000619282

Rheumatoid arthritis (RA), recognized as a common chronic autoimmune disease, is characterized by the excessive proliferation and inflammatory infiltration of fibroblast-like synoviocytes (FLS). In this study, our purpose is to elucidate the mechanisms of triptolide (TPL) in the treatment of RA by regulating the long non-coding RNA (lncRNA) ENST00000619282, which promoted apoptosis and reduced inflammatory infiltration of FLS in RA (RA-FLS). RA-FLS was treated with different concentrations of TPL at different time points. CCK-8 assay, ELISA, RT-qPCR, immunofluorescence, TUNEL assay, and the transmission electron microscopy were used to measure the changes of cell viability, apoptosis, and the release of inflammatory cytokines. Next, the involvement of ENST00000619282 in TPL-mediated protection against RA was explored. ENST00000619282 expression was significantly increased in the peripheral blood mononuclear cells (PBMCs) of RA patients. ENST0000061928 expression in RA PBMCs was positively associated with ESR, RF, CCP, and DAS28, while TPL treatment led to a downregulation of ENST00000619282. In addition, ENST00000619282 was significantly increased in RA-FLS. Furthermore, overexpression of ENST00000619282 elevated the levels of pro-apoptotic and pro-inflammatory factors, while reduced the levels of anti-apoptotic proteins and antiinflammatory factors. Besides, TPL treatment could reverse these effects by ENST00000619282 overexpression. The anti-RA potential of TPL might be achieved by downregulating ENST00000619282, thereby promoting apoptosis, and reducing the inflammatory response in RA.

The role of miRNAs in the regulation of autophagy in autoimmune diseases

Autoimmune diseases (AD), which are classified as chronic injuries, are caused by a specific auto-reactive reaction. The etiology of most ADs is not well understood. Meanwhile, Autophagy is a protective response defining as a catabolic method by lysosomes tending to maintain homeostasis acts by recycling and discrediting cell compartments. Autophagy plays a crucial role in controlling immune homeostasis by eliminating intracellular pathogens and presenting antigens to immune cognition. MicroRNAs are commonly known as endogenous non-coding small RNAs, which span 18-25 nt and take part in the gene expression at the post-transcriptional level regulation. miRNAs play important roles in different processes like, cell differentiation, duplicating, and apoptosis. Moreover, miRNAs are the critical molecules for the regular function of the immune system by modulating immune tolerance mechanisms and autoimmunity. Recent findings support the role of dysregulated miRNAs in the pathogenesis of ADs and in the regulation of autophagy. In this review, we will focus on the role of the miRNAs in the regulation of autophagy and then will explain the role of dysregulated miRNAs in the initiation of the ADs by modulating autophagy.

Identification of crucial noncoding RNAs and mRNAs in hypertrophic scars via RNA sequencing

Hypertrophic scarring (HS) is a dermal fibroproliferative disorder characterized by excessive deposition of collagen and other extracellular matrix components. The aim of this study is to explore crucial long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) associated with HS and provide a better understanding of the molecular mechanism of HS. To investigate the lncRNA, circRNA and mRNA expression profiles, we performed RNA sequencing of human HS and normal skin tissues. After the identification of differentially expressed mRNAs (DEmRNAs), lncRNAs (DElncRNAs) and circRNAs (DEcircRNAs), we performed functional enrichment of DEmRNAs. Further on, we constructed DElncRNA/DEcircRNA–DEmRNA coexpression networks and competing endogenous RNA regulatory networks, and performed functional analyses of the DEmRNAs in the constructed networks. In total, 487 DEmRNAs, 92 DElncRNAs and 17 DEcircRNAs were identified. DEmRNAs were significantly enriched in processes such as collagen fibril organization, extracellular matrix–receptor interaction and the phosphatidylinositol 3‐kinase (PI3K)–Akt signaling pathway. In addition, we detected 580 DElncRNA–DEmRNA and 505 DEcircRNA–DEmRNA coexpression pairs. The competing endogenous RNA network contained 18 circRNA–microRNA (miRNA) pairs, 18 lncRNA–miRNA pairs and 409 miRNA–mRNA pairs, including 10 circRNAs, 5 lncRNAs, 15 miRNAs and 160 mRNAs. We concluded that MIR503HG/hsa‐miR‐204‐3p/ACAN, MIR503HG/hsa‐miR‐431‐5p/TNFRSF9, MEG3/hsa‐miR‐6884‐5p/ADAMTS14, AC000035.1‐ADAMTS14 and hsa_circ_0069865‐COMP/ADAM12 interaction pairs may play a central role in HS.

Dysregulation of lncRNAs in Rheumatoid Arthritis: Biomarkers, Pathogenesis and Potential Therapeutic Targets

Rheumatoid arthritis (RA) is a chronic autoimmune disease of unknown etiology, mainly manifested by persistent abnormal proliferation of fibroblast-like synoviocytes (FLSs), inflammation, synovial hyperplasia and cartilage erosion, accompanied by joint swelling and joint destruction. Abnormal expression or function of long noncoding RNAs (lncRNAs) are closely related to human diseases, including cancers, mental diseases, autoimmune diseases and others. The abnormal sequence and spatial structure of lncRNAs, the disorder expression and the abnormal interaction with the binding protein will lead to the change of gene expression in the way of epigenetic modification. Increasing evidence demonstrated that lncRNAs were involved in the activation of FLSs, which played a key role in the pathogenesis of RA. In this review, the research progress of lncRNAs in the pathogenesis of RA was systematically summarized, including the role of lncRNAs in the diagnosis of RA, the regulatory mechanism of lncRNAs in the pathogenesis of RA, and the intervention role of lncRNAs in the treatment of RA. Furthermore, the activated signal pathways, the role of DNA methylation and other mechanism have also been overview in this review.

Expression and clinical significance of circular RNAs related to immunity and inflammation in patients with rheumatoid arthritis

The aim of this study was to investigate the changes in and clinical significance of circular RNAs (circRNAs) expression related to immunity and inflammation in patients with rheumatoid arthritis (RA). We analyzed the circRNAs related to immunity and inflammation in peripheral blood mononuclear cells (PBMCs) from three RA patients and three healthy controls using high-throughput sequencing and bioinformatics analysis. Subsequently, four differentially expressed circRNAs were verified by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). We selected hsa_circ_0003353 for functional phenotype analysis in fibroblast-like synoviocytes (FLS) according to correlation tests and logistic regression analysis. The results identified and verified the expression of circRNAs (0003353, 0005732, 0072428, 0091685) that were significantly changed in PBMCs from RA patients. ROC analysis suggested that these circRNAs have significant value in RA diagnosis. Spearman analysis revealed that significant relationships between these circRNAs and clinical indicators as well as SPP. The logistic regression analysis showed that clinical indicators and SPP were risk factors for hsa_circ_0003353 expression, which is worthy of further investigation. As predicted, hsa_circ_0003353 had significantly higher expression in RA-FLS. The cell proliferation, migration, invasion, apoptosis, and inflammatory cytokine production of RA-FLS showed significant alterations after hsa_circ_0003353 suppression and overexpression. Our results indicate that hsa_circ_0003353 may play an essential role in promoting immunity, inflammation, synovial invasion, and joint destruction and that hsa_circ_0003353 may act as a biomarker of RA.