Silencing long non-coding RNA NEAT1 attenuates rheumatoid arthritis via the MAPK/ERK signalling pathway by downregulating microRNA-129 and microRNA-204

Unveiling Novel Drug Targets and Emerging Therapies for Rheumatoid Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disease, that causes joint damage, deformities, and decreased functionality. In addition, RA can also impact organs like the skin, lungs, eyes, and blood vessels. This autoimmune condition arises when the immune system erroneously targets the joint synovial membrane, resulting in synovitis, pannus formation, and cartilage damage. RA treatment is often holistic, integrating medication, physical therapy, and lifestyle modifications. Its main objective is to achieve remission or low disease activity by utilizing a "treat-to-target" approach that optimizes drug usage and dose adjustments based on clinical response and disease activity markers. The primary RA treatment uses disease-modifying antirheumatic drugs (DMARDs) that help to interrupt the inflammatory process. When there is an inadequate response, a combination of biologicals and DMARDs is recommended. Biological therapies target inflammatory pathways and have shown promising results in managing RA symptoms. Close monitoring for adverse effects and disease progression is critical to ensure optimal treatment outcomes. A deeper understanding of the pathways and mechanisms will allow new treatment strategies that minimize adverse effects and maintain quality of life. This review discusses the potential targets that can be used for designing and implementing precision medicine in RA treatment, spotlighting the latest breakthroughs in biologics, JAK inhibitors, IL-6 receptor antagonists, TNF blockers, and disease-modifying noncoding RNAs.

Role of miRNAs in Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by autoimmunity, synovial inflammation and joint destruction. Pannus formation in the synovial cavity can cause irreversible damage to the joint and cartilage and eventually permanent disability. Current conventional treatments for RA have limitations regarding efficacy, safety and cost. microRNA (miRNA) is a type of non-coding RNA (ncRNA) that regulates gene expression at the post-transcriptional level. The dysregulation of miRNA has been observed in RA patients and implicated in the pathogenesis of RA. miRNAs have emerged as potential biomarkers or therapeutic agents. In this review, we explore the role of miRNAs in various aspects of RA pathophysiology, including immune cell imbalance, the proliferation and invasion of fibroblast-like synovial (FLS) cell, the dysregulation of inflammatory signaling and disturbance in angiogenesis. We delve into the regulatory effects of miRNAs on Treg/Th17 and M1/M2 polarization, the activation of the NF-κB/NLRP3 signaling pathway, neovascular formation, energy metabolism induced by FLS-cell-induced energy metabolism, apoptosis, osteogenesis and mobility. These findings shed light on the potential applications of miRNAs as diagnostic or therapeutic biomarkers for RA management. Furthermore, there are some strategies to regulate miRNA expression levels by utilizing miRNA mimics or exosomes and to hinder miRNA activity via competitive endogenous RNA (ceRNA) network-based antagonists. We conclude that miRNAs offer a promising avenue for RA therapy with unlimited potential.

The Diagnostic Value of miR-124a Expression in Peripheral Blood and Synovial Fluid of Patients with Rheumatoid Arthritis

INTRODUCTION

Rheumatoid arthritis (RA), a chronic autoimmune disorder, is currently a severe health threat. Previous studies have documented the altered expression of various miRNAs in RA patients. This study determined the expression of miR-124a in RA patients and estimated its diagnostic value for RA.

METHODS

A total of 80 RA patients were enrolled as the study subjects, and 36 patients with osteoarthritis were included, with another 36 healthy people as the controls. miR-124a expression levels in peripheral blood plasma, peripheral blood mononuclear cells (PBMCs), and synovial fluid were measured using reverse transcription quantitative polymerase chain reaction, followed by Pearson correlation analysis. Additionally, the association between miR-124a and major clinical indicators was assessed, such as rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and disease activity score of 28 joints (DAS28). The diagnostic efficacy of miR-124a expression in plasma, PBMCs, and synovial fluid for RA was evaluated by the receiver operating characteristic curve, and the difference in the area under the curve (AUC) was analyzed.

RESULTS

miR-124a was downregulated in RA patients, and the expression levels of miR-124a in plasma, PBMCs, and synovial fluid showed a certain degree of positive correlation. miR-124a was inversely linked with RF, ESR, and DAS28. For the diagnosis of RA patients, the AUC of plasma miR-124a was 0.899 and the cut-off value was 0.800, with 68.75% sensitivity and 94.44% specificity; the AUC of miR-124a in PBMCs was 0.937 and the cut-off value was 0.805, with 82.50% sensitivity and 91.67% specificity; the AUC of miR-124a in plasma combined with PBMCs was 0.961, with a higher diagnostic value than independent plasma or PBMCs; the AUC of miR-124a in synovial fluid was 0.929 and the cut-off value was 0.835, with 80.00% sensitivity and 88.89% specificity.

CONCLUSION

miR-124a expression is downregulated in the plasma, PBMCs, and synovial fluid of RA patients and has a high diagnostic value for RA.

Personalized medicine in rheumatoid arthritis: Combining biomarkers and patient preferences to guide therapeutic decisions

The last few decades have seen major therapeutic advancements in rheumatoid arthritis (RA) therapeutics. New disease-modifying antirheumatic drugs (DMARDs) have continued to emerge, creating more choices for people. However, no therapeutic works for all patients. Each has its own inherent benefits, risks, costs, dosing, and monitoring considerations. In parallel, there has been a focus on personalized medicine initiatives that tailor therapeutic decisions to patients based on their unique characteristics or biomarkers. Personalized effect estimates require an understanding of a patient's baseline probability of response to treatment and data on the comparative effectiveness of the available treatments. However, even if accurate risk prediction models are available, trade-offs often still need to be made between treatments. In this paper, we review the history of RA therapeutics and progress that has been made toward personalized risk predictive models for DMARDs, outlining where knowledge gaps still exist. We further review why patient preferences play a key role in a holistic view of personalized medicine and how this links with shared decision-making. We argue that a "preference misdiagnosis" may be equally important as a medical misdiagnosis but is often overlooked.

Mechanism Underlying the Action of Berberine in the Treatment of Gouty Arthritis Based on Network Pharmacology

Introduction: Gouty arthritis (GA) is induced by a purine metabolism disorder and monosodium urate (MSU) crystal-related inflammation. Berberine (BBR), extracted from Coptis chinensis, ameliorates MSU-induced GA. However, the mechanisms of BBR against GA remain to be fully elucidated. This study aimed to identify the key targets and pathways mediating the effects of BBR against GA using network pharmacology. Methods: BBR and GA targets were obtained from several databases, and the network of BBR-GA common targets was visualized using Cytoscape software. Protein–protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using the STRING and Database for Annotation, Visualization, and Integrated Discovery databases, respectively. Animal experiments were performed to determine the outcomes of the BBB intervention. The serum levels of IL-1β, IL-8, and IL-6 were detected using enzyme-linked immunosorbent assay. Results: Thirty-three common targets (including NF-κB, RelA, MAPK1, IL-6, and IL-1β) of BBR and GA were identified, and a network of common targets between BBR and GA was constructed. PPI analysis demonstrated that IL-1β, IL-6, TNF, MAPK, and RelA are key targets with high degree values. GO and KEGG pathway analyses revealed the involvement of inflammation-related biological processes and signaling pathways, such as the NF-κB, MAPK, and TNF signaling pathways. Animal experiments demonstrated that the uric acid, IL-1β, IL-6, and IL-8 serum levels were significantly lower in the BBR group compared with those in hyperuricemic rats. Conclusions: Using systematic network analysis, potential targets mediating the effects of BBR on GA were detected. The pathways and inflammatory factors involved were identified using in vivo experiments, thus providing a reference for further basic research and clinical applications of BBR in the treatment of GA.

Absent in melanoma 2 (AIM2) in rheumatoid arthritis: novel molecular insights and implications

Absent in melanoma 2 (AIM2), a member of the Pyrin and HIN domain protein family, is a cytoplasmic receptor that recognizes double-stranded DNA. AIM2 exhibits limited expression under physiological conditions but is widely expressed in many human diseases, including autoimmune diseases, and plays an essential role in the immune response. Rheumatoid arthritis (RA) is an autoimmune disease that poses a severe threat to physical and mental health, and is caused by several genetic and metabolic factors. Multiple immune cells interact to form a complex inflammatory network that mediates inflammatory responses and bone destruction. Abnormal AIM2 expression in multiple immune cell populations (T cells, B cells, fibroblast-like synoviocytes, monocytes, and macrophages) may regulate multiple functional responses in RA through mechanisms such as pyroptosis, PANoptosis, and regulation of other molecules. In this review, we describe and summarize the functional regulation and impact of AIM2 expression in immune cells to improve our understanding of the complex pathological mechanisms. These insights may provide potential directions for the development of new clinical diagnostic strategies for RA.

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.

The role of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in immune diseases

The long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) has been shown to be involved in the pathogenesis of several diseases. Herein, we discuss recent developments and insights into NEAT1 and its contribution to a variety of immune disorders. Our evaluations revealed that NEAT1's function in immune diseases seems to be focused on the modulation of paraspeckle expression and it is primarily associated with the nuclear retention of its mRNA. NEAT1 is also involved in the sequestration of paraspeckle proteins and in affecting the transcriptional expression of specific immune regulators. The expression of NEAT1 may be aberrantly upregulated in several immune pathologies, indicating that it could serve as a potential prognostic biomarker in these conditions. We summarized describing the expression changes and the role of NEAT1 in several immune diseases. We also described the mechanism of its regulation of the immune cell differentiation and function of NEAT1 in different disease.

Naringenin as a natural immunomodulator against T cell-mediated autoimmune diseases: literature review and network-based pharmacology study

T cells, especially CD4+ T helper (Th) cells, play a vital role in the pathogenesis of specific autoimmune diseases. Naringenin, a citrus flavonoid, exhibits anti-inflammatory, anti-oxidant, and antitumor properties, which have been verified in animal autoimmune disease models. However, naringenin's possible effects and molecular mechanisms in T cell-mediated autoimmune diseases are unclear. This review summarizes the findings of previous studies and predicts the target of naringenin in T cell-mediated autoimmune disorders such as multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis through network pharmacology analysis. We performed DAVID enrichment analysis, protein-protein interaction analysis, and molecular docking to predict the positive effect of naringenin on T cell-mediated autoimmune disorders. Sixteen common genes were screened, among which the core genes were PTGS2, ESR1, CAT, CASP3, MAPK1, and AKT1. The possible molecular mechanism relates to HIF-1, estrogen, TNF, and NF-κB signaling pathways. Our findings have significance for future naringenin treatment of T cell-mediated autoimmune diseases.

Construction of a ceRNA Network Related to Rheumatoid Arthritis

(1) Background: Rheumatoid arthritis (RA) is a common systemic autoimmune disease affecting many people and has an unclear and complicated physiological mechanism. The competing endogenous RNA (ceRNA) network plays an essential role in the development and occurrence of various human physiological processes. This study aimed to construct a ceRNA network related to RA. (2) Methods: We explored the GEO database for peripheral blood mononuclear cell (PBMC) samples and then analyzed the RNA of 52 samples (without treatment) to obtain lncRNAs (DELs), miRNAs (DEMs), and mRNAs (DEGs), which can be differentially expressed with statistical significance in the progression of RA. Next, a ceRNA network was constructed, based on the DELs, DEMs, and DEGs. At the same time, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis were used to validate the possible function of the ceRNA network. (3) Results: Through our analysis, 389 DELs, 247 DEMs, and 1081 DEGs were screened. After this, a ceRNA network was constructed for further statistical comparisons, including 16 lncRNAs, 1 miRNA, and 15 mRNAs. According to the GO and KEGG analysis, the ceRNA network was mainly enriched in the mTOR pathway, the dopaminergic system, and the Wnt signaling pathway. (4) Conclusions: The novel ceRNA network related to RA that we constructed offers novel insights into and targets for the underlying molecular mechanisms of the mTOR pathway, the dopaminergic system, and the Wnt signaling pathway (both classic and nonclassic pathways) that affect the level of the genetic regulator, which might offer novel ways to treat RA.

Long Non-Coding RNA NR-133666 Promotes the Proliferation and Migration of Fibroblast-Like Synoviocytes Through Regulating the miR-133c/MAPK1 Axis

Long non-coding RNA (lncRNA) is involved in the regulation of rheumatoid arthritis (RA) and many other diseases. In this study, a new lncRNA, NR-133666, was identified to be highly expressed in the adjuvant-induced arthritis rat model using the Agilent lncRNA microarray assay. qRT-PCR verified that NR-133666 was upregulated in fibroblast-like synoviocyte of a collagen-induced arthritis (CIA) rat model. Fluorescence in situ hybridization analysis showed that NR-133666 is mainly expressed in the cytoplasm of collagen-induced arthritis FLS. MTT assay and EdU staining results showed that the proliferation of CIA FLS was inhibited after NR-133666 was knocked down, and the wound healing assay showed that the migration of CIA FLS was also suppressed. Dual luciferase detection was used to confirm the relationship among NR-133666, miR-133c and MAPK1. MAPK1 is the target gene of miR-133c, where NR-133666 acts as a sponge of miR-133c to reduce the inhibitory effect of miR-133c on MAPK1. Overexpression of NR-133666 and MAPK1 can promote the proliferation and migration of CIA FLS, and overexpression of miR-133c can reverse this phenomenon. Western blot indicated that it may be related to the ERK/MAPK signaling pathway. Collectively, we identified that lncRNA NR-133666 acted as a miR-133c sponge that can promote the proliferation and migration of CIA FLS through regulating the miR-133c/MAPK1 axis.

LncRNAs and Rheumatoid Arthritis: From Identifying Mechanisms to Clinical Investigation

Rheumatoid arthritis (RA) is a systemic chronic autoinflammatory disease, and the synovial hyperplasia, pannus formation, articular cartilage damage and bone matrix destruction caused by immune system abnormalities are the main features of RA. The use of Disease Modifying Anti-Rheumatic Drugs (DMARDs) has achieved great advances in the therapy of RA. Yet there are still patients facing the problem of poor response to drug therapy or drug intolerance. Current therapy methods can only moderate RA progress, but cannot stop or reverse the damage it has caused. Recent studies have reported that there are a variety of long non-coding RNAs (LncRNAs) that have been implicated in mediating many aspects of RA. Understanding the mechanism of LncRNAs in RA is therefore critical for the development of new therapy strategies and prevention strategies. In this review, we systematically elucidate the biological roles and mechanisms of action of LncRNAs and their mechanisms of action in RA. Additionally, we also highlight the potential value of LncRNAs in the clinical diagnosis and therapy of RA.

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.

Inter‐alpha‐trypsin inhibitor heavy chain 4: A serologic marker relating to disease risk, activity, and treatment outcomes of rheumatoid arthritis

Objective

Inter‐alpha‐trypsin inhibitor heavy chain 4 (ITIH4) regulates immunity and inflammation, but its clinical role in rheumatoid arthritis (RA) patients remains unclear. Hence, this study was conducted to explore the association of circulating ITIH4 with disease risk, clinical features, inflammatory cytokines, and treatment outcomes of RA.

Methods

After the enrollment of 93 active RA patients and 50 health controls (HCs), their serum ITIH4 level was analyzed by enzyme‐linked immunosorbent assay (ELISA). For RA patients only, serum ITIH4 level at week (W) 6 and W12 after treatment was also analyzed. Besides, serum tumor necrosis factor‐alpha (TNF‐α), interleukin (IL)‐1β, IL‐6, and IL‐17A at baseline of RA patients were also detected by ELISA.

Results

ITIH4 was downregulated in RA patients (151.1 (interquartile range (IQR): 106.2–213.5) ng/mL) than in HCs (306.8 (IQR: 238.9–435.1) ng/mL) (p < 0.001). Furthermore, ITIH4 was negatively related to C‐reactive protein (CRP) (r_s = −0.358, p < 0.001) and 28‐joint disease activity score using erythrocyte sedimentation rate (DAS28‐ESR) (r_s = −0.253, p = 0.014) in RA patients, but not correlated with other clinical features (all p > 0.05). Besides, ITIH4 was negatively linked with TNF‐α (r_s = −0.337, p = 0.001), IL‐6 (r_s = −0.221, p = 0.033), and IL‐17A (r_s = −0.368, p < 0.001) in RA patients, but not correlated with IL‐1β (r_s = −0.195, p = 0.061). Moreover, ITIH4 was gradually elevated in RA patients from baseline to W12 after treatment (p < 0.001). Additionally, the increment of ITIH4 at W6 and W12 was linked with treatment response and remission in RA patients (all p < 0.05).

Conclusion

Circulating ITIH4 possesses clinical utility in monitoring disease risk, inflammation, disease activity, and treatment outcomes of RA.

Long Non-Coding RNA PVT1 and Its Target miRNA-146a as Potential Prognostic Biomarkers in Rheumatoid Arthritis Patients

Objective: Long non-coding RNAs (lncRNAs) and their target microRNAs were documented in multiple studies to have a significant role in different joint disorders such as rheumatoid arthritis (RA) and osteoarthritis (OA). The current work aimed to determine the potential role of lnc-PVT1 and miR-146a as promising biomarkers to distinguish between RA, OA patients, and healthy individuals. Methods: The expression levels of lnc-PVT1 and its target miR-146a in the serum were measured for three different groups, including patients with RA (40), OA patients (40), and healthy controls (HCs) (40). Participating individuals were subjected to a full history investigation and clinical examination. Blood samples were tested for ESR, RF, CBC, as well as liver and renal functions. Serum was used to detect the relative expression levels of lnc-PVT1 and miR-146a and we correlated the levels with RA and OA activity and severity signs. Results: Lnc-PVT1 expression level was greater among patients with RA compared to that of OA patients, with a fold change median of 2.62 and 0.22, respectively (p = 0.001). The miR-146a fold change was significantly demonstrated between the RA, OA, and HCs groups. There was no correlation between both biomarkers with the disease activity scales (DAS28) of RA, the Knee injury Osteoarthritis Outcome Score (KOOS), or any sign of detection of the disease severity of OA. Conclusions: lnc-PVT1 and miR-146a could be considered as promising biomarkers for the diagnosis of RA and OA and may have an important role as therapeutic targets in the future.

LncRNA NEAT1 Recruits SFPQ to Regulate MITF Splicing and Control RPE Cell Proliferation

Purpose

Retinal pigment epithelium (RPE) cell proliferation is precisely regulated to maintain retinal homoeostasis. Microphthalmia-associated transcription factor (MITF), a critical transcription factor in RPE cells, has two alternatively spliced isoforms: (+)MITF and (-)MITF. Previous work has shown that (-)MITF but not (+)MITF inhibits RPE cell proliferation. This study aims to investigate the role of long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in regulating MITF splicing and hence proliferation of RPE cells.

Methods

Mouse RPE, primary cultured mouse RPE cells, and different proliferative human embryonic stem cell (hESC)-RPE cells were used to evaluate the expression of (+)MITF, (-)MITF, and NEAT1 by reverse-transcription PCR (RT-PCR) or quantitative RT-PCR. NEAT1 was knocked down using specific small interfering RNAs (siRNAs). Splicing factor proline- and glutamine-rich (SFPQ) was overexpressed with the use of lentivirus infection. Cell proliferation was analyzed by cell number counting and Ki67 immunostaining. RNA immunoprecipitation (RIP) was used to analyze the co-binding between the SFPQ and MITF or NEAT1.

Results

NEAT1 was highly expressed in proliferative RPE cells, which had low expression of (-)MITF. Knockdown of NEAT1 in RPE cells switched the MITF splicing pattern to produce higher levels of (-)MITF and inhibited cell proliferation. Mechanistically, NEAT1 recruited SFPQ to bind directly with MITF mRNA to regulate its alternative splicing. Overexpression of SFPQ in ARPE-19 cells enhanced the binding enrichment of SFPQ to MITF and increased the splicing efficiency of (+)MITF. The binding affinity between SFPQ and MITF was decreased after NEAT1 knockdown.

Conclusions

NEAT1 acts as a scaffold to recruit SFPQ to MITF mRNA and promote its binding affinity, which plays an important role in regulating the alternative splicing of MITF and RPE cell proliferation.

LncRNAs as a new regulator of chronic musculoskeletal disorder

Objectives

In recent years, long non‐coding RNAs (lncRNAs) have been found to play a role in the occurrence, progression and prognosis of chronic musculoskeletal disorders.

Design and methods

Literature exploring on PubMed was conducted using the combination of keywords 'LncRNA' and each of the following: 'osteoarthritis', 'rheumatoid arthritis', 'osteoporosis', 'osteogenesis', 'osteoclastogenesis', 'gout arthritis', 'Kashin‐Beck disease', 'ankylosing spondylitis', 'cervical spondylotic myelopathy', 'intervertebral disc degeneration', 'human muscle disease' and 'muscle hypertrophy and atrophy'. For each disorder, we focused on the publications in the last five years (5/1/2016‐2021/5/1, except for Kashin‐Beck disease). Finally, we excluded publications that had been reported in reviews of various musculoskeletal disorders during the last three years. Here, we summarized the progress of research on the role of lncRNA in multiple pathological processes during musculoskeletal disorders.

Results

LncRNAs play a crucial role in regulating downstream gene expression and maintaining function and homeostasis of cells, especially in chondrocytes, synovial cells, osteoblasts, osteoclasts and skeletal muscle cells.

Conclusions

Understanding the mechanisms of lncRNAs in musculoskeletal disorders may provide promising strategies for clinical practice.

LncRNA ZNF667-AS1 alleviates rheumatoid arthritis by sponging miR-523-3p and inactivating the JAK/STAT signalling pathway

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease, which compromises the synovial membrane resulting in chronic inflammation. Increasing evidence has demonstrated that long non-coding RNAs (lncRNAs) are implicated in the pathogenesis of RA. This study investigated the role of lncRNA ZNF667-AS1 in RA progression.

METHODS

Synovial tissues and fibroblast-like synoviocytes (FLSs) were obtained from patients with RA. Gene expression was measured using RT-qPCR. Chondrocytes were treated with lipopolysaccharide (LPS) to establish in vitro models of OA. Cell counting kit-8 (CCK-8), western blot, and enzyme-linked immunosorbent assay (ELISA) were used to examine the proliferation and inflammatory cytokine production in chondrocytes. Animal models of OA were established in SD rats. Peripheral blood mononuclear cells (PBMCs) were isolated from the OA rats. Flow cytometry was used to measure the changes of the inflammatory T-helper cell 17 (Th17) cells. The relationship between ZNF667-AS1 and miR-523-3p was verified by luciferase reporter assay.

RESULTS

ZNF667-AS1 was downregulated in RA-FLSs and LPS-stimulated chondrocytes. ZNF667-AS1 overexpression significantly promoted cell proliferation and inhibited the production of IL-6, IL-17 and TNF-α in LPS-stimulated chondrocytes. Additionally, ZNF667-AS1 overexpression reduced the generation of CD4 + IL-17+ cells. In mechanism, ZNF667-AS1 acted a sponge for miR-523-3p. MiR-523-3p overexpression reversed the ZNF667-AS1-mediated regulation of cell proliferation and inflammation. Furthermore, miR-523-3p overexpression abolished the inhibitory effects of ZNF667-AS1 on the JAK/STAT signalling activation.

CONCLUSION

ZNF667-AS1 exerts protective effects during RA development by sponging miR-523-3p and inactivating the JAK/STAT signalling.

Promising Therapeutic Targets for Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic poly-articular chronic autoimmune joint disease that mainly damages the hands and feet, which affects 0.5% to 1.0% of the population worldwide. With the sustained development of disease-modifying antirheumatic drugs (DMARDs), significant success has been achieved for preventing and relieving disease activity in RA patients. Unfortunately, some patients still show limited response to DMARDs, which puts forward new requirements for special targets and novel therapies. Understanding the pathogenetic roles of the various molecules in RA could facilitate discovery of potential therapeutic targets and approaches. In this review, both existing and emerging targets, including the proteins, small molecular metabolites, and epigenetic regulators related to RA, are discussed, with a focus on the mechanisms that result in inflammation and the development of new drugs for blocking the various modulators in RA.