The p53 status in rheumatoid arthritis with focus on fibroblast-like synoviocytes

Iron metabolism in rheumatic diseases

Iron is a crucial element for living organism in terms of oxygen transport, hematopoiesis, enzymatic activity, mitochondrial respiratory chain function and also immune system function. The human being has evolved a mechanism to regulate body iron. In some rheumatic diseases such as rheumatoid arthritis (RA), systemic lupus erythematous (SLE), systemic sclerosis (SSc), ankylosing spondylitis (AS), and gout, this balanced iron regulation is impaired. Altered iron homeostasis can contribute to disease progression through ROS production, fibrosis, inflammation, abnormal bone homeostasis, NETosis and cell senescence. In this review, we have focused on the iron metabolism in rheumatic disease and its role in disease progression.

Chinese herbal extracts mediated programmed cell death in cancer and inflammation therapy

Programmed cell death is a common phenomenon in the development of organisms. It is an active and orderly mode of cell death determined by genes. Programmed cell death is usually classified into 3 different types according to the cell morphological changes, stimulus, and biochemical pathways involved, namely, apoptosis, programmed necrosis, and autophagy. Chinese herbal extracts, mainly obtained from traditional Chinese medicine and their primary plants through the physicochemical extraction and separation process, are concentrated with 1 or more effective ingredients from the herbal materials. Recently, studies focused on the influence of traditional Chinese medicine on programmed cell death are increasing, involving the protection of the nervous system and cardio-cerebrovascular system, the prevention of gastrointestinal and immune function damage, the treatment against tumors, and so on. This review mainly focuses on the effects of Chinese herbal extracts on various types of programmed cell death. In addition, the therapeutic approaches and prospects of CHEs are also discussed. Although there are promising clinical applications of Chinese herbal extracts, some challenges are still waiting to be overcome by further research for the wider use of Chinese herbal extracts in clinical practice.

RMRP variants inhibit the cell cycle checkpoints pathway in cartilage‑hair hypoplasia

Cartilage‑hair hypoplasia (CHH) is an autosomal recessive form of metaphyseal chondrodysplasia caused by RNA component of mitochondrial RNA processing endoribonuclease (RMRP) gene variants; however, its molecular etiology remains unclear. Whole‑exome sequencing was performed to detect possible pathogenic variants in a patient with a typical short stature and sparse hair. A co‑segregation analysis was also conducted and variants in the family members of the patient were confirmed by Sanger sequencing. A novel compound heterozygous variant in RMRP (NR_003051.4: n.‑21_‑2dup and n.197C>T) was identified in the affected patient. Data from 2 years and 4 months of follow‑up showed a positive effect of growth hormone (GH) therapy on height. Subsequently, two gene expression profiles associated with CHH were obtained from the EMBL‑EBI ENA and ArrayExpress databases. Differentially expressed genes between patients with CHH and healthy controls were selected using R software and were subjected to core analysis using ingenuity pathway analysis (IPA) software. IPA core analysis showed that the 'cell cycle checkpoints' was the most prominent canonical pathway, and the top enriched diseases and functions included various types of cancer, immunological diseases, development disorders and respiratory diseases. The integrative analysis displayed that RMRP can regulate the aberrant expression of downstream targets mainly via the transcription factor TP53, which results in the inhibition of 'cell cycle checkpoints'; eventually, functions associated with the CHH phenotype, such as 'growth failure or short stature' are activated. In conclusion, novel disease‑causing genetic variants of RMRP expand the genetic etiology of CHH, which must be clinically differentiated from achondroplasia. The findings of the present study provide new insights into the mechanisms underlying CHH.

Refining synovial inflammation assessment: A modified General Synovitis Score for active rheumatoid arthritis

The General Synovitis Score (GSS) is a well-established method for scoring synovial inflammation. Despite its widespread use, the GSS does not fully capture the inflammatory manifestations characteristic of the synovium in rheumatoid arthritis (RA). To address this limitation, the modified GSS (mGSS) was developed. The present study compared the correlation of the mGSS and the GSS with clinical disease activity. The aim was to provide a more precise histopathological scoring system based on hematoxylin and eosin (H&E) staining for assessing synovial inflammation in patients with active RA. In this cross-sectional study, synovial tissues were obtained from 60 patients with RA using a novel synovial biopsy device. Sections from synovial tissues were stained with H&E, and were assessed using the GSS and the mGSS. Neovascularization was observed in 56 patients (93.3%) and was significantly correlated with disease activity score in 28 joints-C-reactive protein (DAS28-CRP) (ρ=0.49; P<0.001), erythrocyte sedimentation rate (ESR) (ρ=0.44; P<0.001) and CRP (ρ=0.51; P<0.001). In addition, patients with severe neovascularization had significantly higher DAS28-CRP, ESR and CRP levels than those with mild-to-moderate neovascularization (P<0.05). Synoviocyte detachment, which occurred in nine patients (15.0%), was associated with higher DAS28-CRP, ESR and CRP levels than in the patients with synoviocyte proliferation (P<0.05). Furthermore, the mGSS was more strongly correlated with DAS28-CRP (ρ=0.62; P<0.001) than the GSS (ρ=0.37; P=0.003). These findings indicated that neovascularization and synoviocyte detachment, which are critical yet often overlooked aspects in the traditional GSS, are important in RA. Incorporating these elements into the mGSS may enhance the assessment of disease activity, providing a more precise and accurate evaluation of the synovial histopathology in patients with RA.

Programmed Cell Death in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, progressive, systemic autoimmune disease characterised by synovial inflammation, synovial pannus formation and subsequent destruction of articular cartilage and bone. Programmed cell death (PCD), encompassing apoptosis, autophagy, pyroptosis, necroptosis, and ferroptosis, plays a pivotal role in the pathogenesis of RA. An imbalance in PCD causes a variety of immune cells to release large amounts of inflammatory factors and mediators that exacerbate not only chronic synovial inflammation, but also bone and joint damage. The purpose of this article is to review the relevant studies between PCD and RA, with the aim of providing further insights and considerations for a deeper understanding of the pathogenesis of RA and to guide clinical management.

Exploring Anticitrullinated Antibodies (ACPAs) and Serum-Derived Exosomes Cargoes

BACKGROUND

Autoantibodies such as rheumatoid factor (RF) and anticitrullinated protein autoantibodies (ACPAs) are useful tools for rheumatoid arthritis (RA). The presence of ACPAs against citrullinated proteins (CPs), especially citrullinated fibrinogen (cFBG), seems to be a useful serological marker for diagnosing RA. RA patients' sera were found to be enriched in exosomes that can transmit many proteins. Exosomes have been found to express citrullinated protein such as cFBG.

OBJECTIVE

We conducted this study in two stages. In the first phase, we aimed to evaluate the association between autoantibodies and risk factors. In the next step, ACPA-positive serum samples from the first phase were subjected to exosomal studies to explore the presence of cFBG, which is a frequent target for ACPAs.

METHODS

We investigated the autoantibodies in one hundred and sixteen Saudi RA patients and correlated with host-related risk factors. Exosomes were extracted from patients' sera and examined for the presence of cFBG using monoclonal antibodies.

RESULTS

The study reported a high female-to-male ratio of 8:1, and seropositive RA (SPRA) was more frequent among included RA patients. The frequency and the levels of ACPAs were similar in both genders. Autoantibodies incidences have a direct correlations with patient age, while the average titers decreased as the age increased. Further, the highest incidence and levels of autoantibodies were reported in patients with RA duration between 5 and 10 years. Smoking and family history have no impact on autoantibody, except for ACPAs titers among smokers' RA. Our analysis of serum exosomes revealed that about 50% of SPRA patients expressed cFBG.

CONCLUSIONS

The female-to-male ratio is 8:1, which is higher than the global ratio. We can conclude that patients' age and disease duration contribute to the autoantibodies, particularly RF and anti-MCV, whereas smoking and family history had no effects on autoantibodies. We detected cFBG in all exosomes from SPRA patients; thus, we suggest that the precise mechanism of exosomes in RA pathogenesis can be investigated to develop effective treatment strategies.

Inhibition of ASIC1a reduces ferroptosis in rheumatoid arthritis articular chondrocytes via the p53/NRF2/SLC7A11 pathway

The activation of acid-sensing ion channel 1a (ASIC1a) in response to extracellular acidification leads to an increase in extracellular calcium influx, thereby exacerbating the degeneration of articular chondrocytes in rheumatoid arthritis (RA). It has been suggested that the inhibition of extracellular calcium influx could potentially impede chondrocyte ferroptosis. The cystine transporter, solute carrier family 7 member 11 (SLC7A11), is recognized as a key regulator of ferroptosis. Recent studies suggest that the tumor suppressor gene p53 facilitates the induction of ferroptosis by suppressing the upregulation of SLC7A11. This process is mediated by the nuclear factor erythroid 2-related factor 2 (NRF2), a key transcription factor integral to the maintenance of cellular redox homeostasis and the regulation of inflammatory responses. This study aims to investigate the role of ASIC1a in the ferroptosis of RA chondrocytes and to determine the involvement of the p53/NRF2/SLC7A11 pathway in its underlying mechanism. In vitro experiments revealed that acidosis induces ferroptosis and reduces the expression of NRF2 and SLC7A11 in chondrocytes. Moreover, acidification significantly increased p53 protein levels in chondrocytes. Pifithrin-α (PFN-α), a p53 inhibitor, mitigated acidosis-induced ferroptosis and restored the diminished expression of NRF2 and SLC7A11. Furthermore, PcTx-1, an ASIC1a inhibitor, inhibited acidification-induced ferroptosis, enhanced the protein levels of SLC7A11 and NRF2, and reduced p53 expression. In vivo experiments demonstrated that the ASIC1a-specific inhibitor PcTx-1 ameliorated histopathological characteristics of ankle joints in collagen-induced arthritis (CIA) mice, decreased p53 expression, and enhanced NRF2 and SLC7A11 expression in chondrocytes. These findings suggest that ASIC1a inhibition may mitigate acidification-induced ferroptosis in articular chondrocytes in RA, potentially via the p53/NRF2/SLC7A11 pathway.

Targeting IL-17 and its receptors: A feasible way for natural herbal medicines to modulate fibroblast-like synoviocytes in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by processive synovial hyperplasia and abnormal proliferation of fibroblast-like synoviocytes (FLSs), and can eventually lead to progressive joint destruction. Increasing evidence has demonstrated that cytokines play pivotal roles in the pathogenesis of RA. In particular, the production of interleukin (IL)-17 by T helper 17 (Th17) cells is closely associated with the development of RA, and inhibition of IL-17/IL-17R could regulate the production of inflammatory factors by FLSs, which may be a feasible way to reduce inflammation and bone destruction in RA. Currently, accumulating evidence suggests that the utilization of natural herbal medicines is advantageous in the management of RA. In our present paper, a comprehensive reference search was conducted of the classic Materia Medica books, literature, online databases, academic search engines, and MS. or Ph. D theses. In conclusion, natural herbal medicines with antirheumatic activities that modulate FLSs by targeting IL-17/IL-17R were summarized. Furthermore, we also discuss the limitations and potential research directions for the future development of natural herbal medicines as candidate drugs for RA management in the clinic.

Analysis and identification of ferroptosis-related diagnostic markers in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune, inflammatory joint disease. There is growing evidence that ferroptosis is involved in the pathogenesis of RA. This study aimed to search for diagnostic markers of ferroptosis in RA and to analyse the potential mechanisms and clinical value.

MATERIALS AND METHODS

RA-associated datasets were used from the publicly available GEO database. Three methods of machine learning were applied to screen biomarkers. The diagnostic efficacy of the results was also verified by receiver operating characteristic (ROC) curve, external dataset, qRT-PCR and Western blot. Enrichment analysis was performed in this process, while protein-protein interaction (PPI) analysis and immune infiltration correlation analysis were performed using biomarkers, and competing endogenous RNA (ceRNA) networks were constructed to search for prospective therapeutic targets.

RESULTS

MMP13 and GABARAPL1 can be used as ferroptosis diagnostic genes in RA. The ROC curve and PPI result demonstrated that MMP13 and GABARAPL1 had an excellent diagnostic value. The results of signature genes in the external dataset, qRT-PCR and Western blot further confirm our findings. The enrichment analysis showed that p53, MAPK and NOD-like receptor signalling pathways may be involved in the process of ferroptosis in RA. In addition, two ferroptosis diagnostic genes in RA participate in the occurrence of ferroptosis in RA via oxidative stress, metabolism and immune response. Immune infiltration analysis showed that RA extensively infiltrated B cells, T cells, macrophages and other immune cells. Persistent immune activation may be an essential reason for the progression of ferroptosis in RA. We also obtained five potential therapeutic agents for RA and some long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) regulating ferroptosis diagnostic genes.

CONCLUSIONS

Our study suggests that MMP13 and GABARAPL1, which are closely linked with oxidative stress and immunological modulation, can be used as ferroptosis-related potential diagnostic markers in RA and provide new clues regarding the diagnostic and therapeutic targets of ferroptosis in RA.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Identification of critical genes and metabolic pathways in rheumatoid arthritis and osteoporosis toward drug repurposing

BACKGROUND

Rheumatoid arthritis (RA) and osteoporosis (OP) are considered to be complex diseases. In recent studies, a positive association between RA and OP has been reported triggering growing research interest. This study aims to investigate the drugs related to critical genes in RA and OP, using bioinformatics approaches, toward drug repurposing.

METHOD

RA and OP genes were identified. The RA-OP PPI network was constructed and analyzed using the STRING and Cytoscape, respectively. Hub genes and modules were extracted and enriched Gene Ontology, through the WebGestalt and g:Profiler. The identification of the drugs related to critical genes using the DGIDB, and extracted the miRNAs using miRWalk and miRNet.

RESULTS

By network clustering, five significant modules were obtained that have important roles in the immune system. IL6, TNF, IL1B, STAT3, TGFB1, TP53, HIF1A, CCL2, IL10, and MMP9 were found as the top 10 hub genes in the RA-OP network. Hub genes were shown to have implications in inflammatory response, significant functions in cytokine receptor binding, and localized mostly in extracellular space. By investigating the drugs related to hub genes, 16 drugs were identified as repurposing candidate drugs. The 10 drugs included Hydroxychloroquine, Infliximab, Adalimumab, Etanercept, Certolizumab, Cyclosporine, Diacerein, Gevokizumab, Canakinumab, and Olokizumab proposed for OP. Also, six drugs including Pirfenidone, Pentoxifylline, Vadimezan, Rilonacept, Metelimumab, and Siltuximab have important roles in inflammatory control and were proposed for both RA and OP.

CONCLUSIONS

The results of the present study can provide novel insights into the pathogenesis and treatment of RA and OP.

Low-Dose Radiotherapy Attenuates Experimental Autoimmune Arthritis by Inducing Apoptosis of Lymphocytes and Fibroblast-Like Synoviocytes

Low-dose radiotherapy (LDRT) has been explored as a treatment option for various inflammatory diseases; however, its application in the context of rheumatoid arthritis (RA) is lacking. This study aimed to elucidate the mechanism underlying LDRT-based treatment for RA and standardize it. LDRT reduced the total numbers of immune cells, but increased the apoptotic CD4+ T and B220+ B cells, in the draining lymph nodes of collagen induced arthritis and K/BxN models. In addition, it significantly reduced the severity of various pathological manifestations, including bone destruction, cartilage erosion, and swelling of hind limb ankle. Post-LDRT, the proportion of apoptotic CD4+ T and CD19+ B cells increased significantly in the PBMCs derived from human patients with RA. LDRT showed a similar effect in fibroblast-like synoviocytes as well. In conclusion, we report that LDRT induces apoptosis in immune cells and fibro-blast-like synoviocytes, contributing to attenuation of arthritis.

P53 Alleviates the Progression of Periodontitis by Reducing M1-type Macrophage Differentiation

Our objective is to explore the effect of P53 on the progression of periodontitis by regulating macrophages differentiation both in vitro and in vivo. Eighteen normal and periodontitis gingival tissues were collected for detecting P53 expression and macrophages infiltration by immunofluorescence, real-time PCR (qPCR) and western-blot. The differentiation and the inflammatory cytokines (TNF-α and IL-6) expression of THP-1, RAW264.7 and bone marrow derived macrophage (BMDM) cells, treating with Pifithrin-α (P53 inhibitor) or Nutlin-3a (P53 activator) under lipopolysaccharide (LPS) stimulation, were observed by flow cytometry, qPCR and ELISA. The severity of periodontitis, inflammatory cytokines expression and macrophages infiltration were measured in experimental periodontitis wild-type mice and p53 gene conditional knocked-out (p53-CKO) mice, which were established by ligation and LPS injection. A higher number of P53-positive macrophages was found infiltrated in periodontitis tissues. In vitro experiments showed that compared with Nutlin-3a, the proportion of M1-type macrophages and the expression of TNF-α and IL-6 were higher in Pifithrin-α treated cells under LPS stimulation. In vivo experimental periodontitis mice, the Pifithrin-α intraperitoneal injection group showed greater alveolar bone loss, higher levels of TNF-α and IL-6 secretion and more M1-type macrophages infiltration, while the Nutlin-3a intraperitoneal injection group were observed mild symptoms compared with mice in the periodontitis group. P53-CKO mice exhibited more severe periodontitis and more M1-type macrophages infiltrated in local tissues compared with wild-type mice. The activation of p53 gene could alleviate periodontitis by reducing M1-type macrophage polarization. P53 may serve as keeper in the progression of periodontitis, providing new insights into periodontitis treatment.

Study on the mechanism of action of Saposhnikovia divaricata and its key phytochemical on rheumatoid arthritis based on network pharmacology and bioinformatics

ETHNOPHARMACOLOGICAL RELEVANCE

Saposhnikovia divaricata (Turcz.) Schischk (SD; called "fangfeng" in China) has been widely used in the clinical treatment of rheumatoid arthritis (RA) and has shown well therapeutic effects, but the specific mechanisms of action of its bioactive phytochemicals remain unclear.

AIM OF THE STUDY

This study aimed to investigate the molecular biological mechanism of SD in treating RA through a pharmacology-based strategy. The SD-specific core ingredient Prangenidin was screened for further in-depth study.

MATERIALS AND METHODS

The bioactive phytochemicals of SD and potential targets for the treatment of RA were screened by network pharmacology, and phytochemicals-related parameters such as pharmacology, and toxicology were evaluated. The protein interaction network was established to screen the core targets, and the correlation between the core targets and RA was further validated by bioinformatics strategy. Finally, molecular docking of core components and corresponding targets was performed. The in vitro experiments were performed to elucidate the regulation of Prangenidin on MH7A cells and on the PI3K/AKT pathway, and the in vivo therapeutic effect of Prangenidin was validated in collagen-induced arthritis (CIA) mice.

RESULTS

A total of 18 bioactive phytochemicals and 66 potential target genes intersecting with the screened RA disease target genes were identified from SD. Finally, core ingredients such as wogonin, beta-sitosterol, 5-O-Methylvisamminol, and prangenidin and core targets such as PTGS2, RELA, and AKT1 were obtained. The underlying mechanism of SD in treating RA might be achieved by regulating pathways such as PI3K/AKT, IL-17 pathway, apoptosis, and multiple biological processes to exert anti-inflammatory and immunomodulatory effects. Molecular docking confirmed that all core ingredients and key targets had great docking activity. Prangenidin inhibited viability, migration, and invasion, and induced apoptosis in MH7A cells. Prangenidin also reduced the production of IL-1β, IL-6, IL-8, MMP-1, and MMP-3. Molecular analysis showed that Prangenidin exerts its regulatory effect on MH7A cells by inhibiting PI3K/AKT pathway. Treatment with Prangenidin ameliorated synovial inflammation in the joints of mice with CIA.

CONCLUSION

Our findings provide insights into the therapeutic effects of SD on RA, successfully predicting the effective ingredients and potential targets, which could suggest a novel theoretical basis for further exploration of its molecular mechanisms. It also revealed that Prangenidin inhibited viability, migration, invasion, cytokine, and MMPs expression, and induced apoptosis in RA FLSs via the PI3K/AKT pathway.

Mutant p53R211* ameliorates inflammatory arthritis in AIA rats via inhibition of TBK1-IRF3 innate immune response

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune inflammation disease characterized by imbalance of immune homeostasis. p53 mutants are commonly described as the guardian of cancer cells by conferring them drug-resistance and immune evasion. Importantly, p53 mutations have also been identified in RA patients, and this prompts the investigation of its role in RA pathogenesis.

METHODS

The cytotoxicity of disease-modifying anti-rheumatic drugs (DMARDs) against p53 wild-type (WT)/mutant-transfected RA fibroblast-like synoviocytes (RAFLSs) was evaluated by MTT assay. Adeno-associated virus (AAV) was employed to establish p53 WT/R211* adjuvant-induced arthritis (AIA) rat model. The arthritic condition of rats was assessed by various parameters such as micro-CT analysis. Knee joint samples were isolated for total RNA sequencing analysis. The expressions of cytokines and immune-related genes were examined by qPCR, ELISA assay and immunofluorescence. The mechanistic pathway was determined by immunoprecipitation and Western blotting in vitro and in vivo.

RESULTS

Among p53 mutants, p53R213* exhibited remarkable DMARD-resistance in RAFLSs. However, AAV-induced p53R211* overexpression ameliorated inflammatory arthritis in AIA rats without Methotrexate (MTX)-resistance, and our results discovered the immunomodulatory effect of p53R211* via suppression of T-cell activation and T helper 17 cell (Th17) infiltration in rat joint, and finally downregulated expressions of pro-inflammatory cytokines. Total RNA sequencing analysis identified the correlation of p53R211* with immune-related pathways. Further mechanistic studies revealed that p53R213*/R211* instead of wild-type p53 interacted with TANK-binding kinase 1 (TBK1) and suppressed the innate immune TBK1-Interferon regulatory factor 3 (IRF3)-Stimulator of interferon genes (STING) cascade.

CONCLUSIONS

This study unravels the role of p53R213* mutant in RA pathogenesis, and identifies TBK1 as a potential anti-inflammatory target.

Ferroptosis as an emerging target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology. Due to the rise in the incidence rate of RA and the limitations of existing therapies, the search for new treatment strategies for RA has become a global focus. Ferroptosis is a novel programmed cell death characterized by iron-dependent lipid peroxidation, with distinct differences from apoptosis, autophagy, and necrosis. Under the conditions of iron accumulation and the glutathione peroxidase 4 (GPX4) activity loss, the lethal accumulation of lipid peroxide is the direct cause of ferroptosis. Ferroptosis mediates inflammation, oxidative stress, and lipid oxidative damage processes, and also participates in the occurrence and pathological progression of inflammatory joint diseases including RA. This review provides insight into the role and mechanism of ferroptosis in RA and discusses the potential and challenges of ferroptosis as a new therapeutic strategy for RA, with an effort to provide new targets for RA prevention and treatment.

Obese Asthma Phenotype Is Associated with hsa-miR-26a-1-3p and hsa-miR-376a-3p Modulating the IGF Axis

Clarifying inflammatory processes and categorising asthma into phenotypes and endotypes improves asthma management. Obesity worsens severe asthma and reduces quality of life, although its specific molecular impact remains unclear. We previously demonstrated that hsa-miR-26a-1-3p and hsa-miR-376a-3p, biomarkers related to an inflammatory profile, discriminate eosinophilic from non-eosinophilic asthmatics. We aimed to study hsa-miR-26a-1-3p, hsa-miR-376a-3p, and their target genes in asthmatic subjects with or without obesity to find biomarkers and comprehend obese asthma mechanisms. Lung tissue samples were obtained from asthmatic patients (n = 16) and healthy subjects (n = 20). We measured miRNA expression using RT-qPCR and protein levels (IGF axis) by ELISA in confirmation samples from eosinophilic (n = 38) and non-eosinophilic (n = 39) obese (n = 26) and non-obese (n = 51) asthma patients. Asthmatic lungs showed higher hsa-miR-26a-1-3p and hsa-miR-376a-3p expression than healthy lungs. A study of seven genes regulated by these miRNAs revealed differential expression of IGFBP3 between asthma patients and healthy individuals. In obese asthma patients, we found higher hsa-miR-26a-1-3p and IGF-1R values and lower values for hsa-miR-376a-3p and IGFBP-3. Hsa-miR-26a-1-3p and IGFBP-3 were directly and inversely correlated with body mass index, respectively. Hsa-miR-26a-1-3p and hsa-miR-376a-3p could be used as biomarkers to phenotype patients with eosinophilic and non-eosinophilic asthma in relation to comorbid obesity.

Altered expression of apoptosis-related genes in rheumatoid arthritis peripheral blood mononuclear cell and related miRNA regulation

AIM

Impaired apoptosis and proliferation resulted in autoreactive lymphocyte development and inflammation in Rheumatoid arthritis (RA). TP53, BAX, FOXO1, and RB1 are related genes in cell survival, proliferation, and inflammation which could be important in RA development and disease severity. Here we investigated their expression in peripheral blood mononuclear cells (PBMCs) from RA patients in comparison to healthy controls.

METHODS

Fifty healthy controls and 50 RA patients were selected. The quantitative real-time polymerase chain reaction was used to assess the gene expression level in PBMCs.

RESULTS

The mRNA expression of TP53 (FC = 0.65, p = .000), BAX (FC = 0.76, p = .008), FOXO1 (FC = 0.59, p = .000) and RB1 (FC = 0.50, p = .000) were significantly reduced in RA PBMCs. TP53 expression was negatively correlated with miR-16-5p (p = .032) and FOXO1 expression was negatively correlated with miR-335-5p (p = .005) and miR-34a-5p (p = .014). A positive correlation was seen between TP53 expression and its downstream gene, BAX (p = .001). FOXO1 expression was also negatively correlated with disease activity, DAS28 (p = .021).

CONCLUSION

All selected genes have downregulated expression in RA PBMCs which could be correlated with RA pathogenesis by regulating apoptosis, cell survival, inflammatory mediator production, and proliferation. Due to the correlation of miR-16-5p, miR-34a-5p, and miR-335-5p with TP53 and FOXO1 expression in RA PBMCs, they could be used as future therapeutic targets.

p53/p21 Inhibits Osteoarthritis Progression by Regulating Chondrocyte Pyroptosis

This study aimed to explore the role of p53/p21 in osteoarthritis (OA). OA animal model was established by the anterior cruciate ligamentotomy (ACLT). 24 rats were randomly divided into control, OA, OA+p53 inhibitor and OA+pyroptosis inducer groups (n = 6). In the knee joint tissue, microstructural changes were analysed by Micro-CT. Histopathological changes were stained by HE and safranin-fast green. NLRP3 and Caspase-1 were detected by immunohistochemistry. The chondrocytes C-28I2 were divided into control, LPS+ ATP and p53 inhibitor groups. The cell viability, apoptosis, and LDH release were measured by MTT assay, TUNEL staining and LDH kit. The expression of p53/p21 and pyroptosis pathways were examined by western blot. The p53 inhibitor reduced the relative volume of trabecular bone (BV/TV) and trabecular bone thickness (Tb.Th), while increased trabecular separation (Tb.Sp). Moreover, the p53 inhibitor improved histopathological changes in the knee joint, attenuated cartilage damage, and reduced the expression of p53/p21 and pyroptosis pathways-related proteins. In vitro assay showed that the p53 inhibitor increased C-28I2 cell activity, reduced LDH release and apoptosis and reduced p53/p21 and pyroptosis pathways-related proteins. Totally, p53 inhibitors improved the cartilage tissue and chondrocyte damage, inhibited cell pyroptosis and the progression of OA.

Detecting potential mechanism of vitamin D in treating rheumatoid arthritis based on network pharmacology and molecular docking

Aim: Vitamin D plays a vital role in Rheumatoid arthritis (RA). However, the mechanism of vitamin D and rheumatism is still unclear. Therefore, a strategy based on network pharmacology and molecular docking was used to explore the mechanism of vitamin D and RA.

Methods: The targets of RA were obtained from the GeneCards database and Therapeutic Targets Database, and the targets of vitamin D were obtained from the Drugbank database and STITCH database. Next, overlapping genes were identified by Venny, and further Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and molecular docking analyses were performed.

Results: A total of 1,139 targets of RA and 201 targets of vitamin D were obtained. A total of 76 overlapping genes were identified by Venny. The enrichment analysis showed that cell proliferation, immune response, and apoptotic process were the critical biological processes of vitamin D in treating RA. Antifolate resistance, osteoclast differentiation, and the nuclear factor-kappa B (NF-κB) signalling pathway are fundamental mechanisms of vitamin D in treating RA. According to further molecular docking, ALB, TNF, CASP3, and TP53 may be important punctuation points or diagnostic markers for future RA treatment.

Conclusion: By analysing overlapping genes of diseases and drugs, this study confirmed that ALB, TNF, CASP3, and TP53 may be essential markers or diagnostic markers for future RA treatment.

ATF6α contributes to rheumatoid arthritis by inducing inflammatory cytokine production and apoptosis resistance

Objective

The contribution of activating transcription factor 6α (ATF6α) in rheumatoid arthritis (RA) pathogenesis, especially on fibroblast-like synoviocytes (FLSs), has been suggested by its sensitivity to inflammatory stimulus. However, the exact role and therapeutic potential of ATF6α in RA remains to be fully elucidated.

Methods

ATF6α expression was determined in joint tissues and FLS, and gain-of-function and loss-of-function analyses were applied to evaluate the biological roles of ATF6α in RA FLSs. A murine collagen-induced arthritis (CIA) model, combining both gene deletion of ATF6α and treatment with the ATF6α inhibitor Ceapin-A7, was employed. Joint inflammation, tissue destruction, circulating levels of inflammatory cytokines were assessed in CIA mice. Transcriptome sequencing analysis (RNASeq), molecular biology, and biochemical approaches were performed to identify target genes of ATF6α.

Results

ATF6α expression was significantly increased in synovium of RA patients and in synovium of mice subjected to CIA. ATF6α silencing or inhibition repressed RA FLSs viability and cytokine production but induced the apoptosis. CIA-model mice with ATF6α deficiency displayed decreased arthritic progression, leading to profound reductions in clinical and proinflammatory markers in the joints. Pharmacological treatment of mice with Ceapin-A7 reduced arthritis severity in CIA models. RNA-sequencing of wild-type and knockdown of ATF6α in RA FLSs revealed a transcriptional program that promotes inflammation and suppresses apoptosis, and subsequent experiments identified Baculoviral IAP Repeat Containing 3 (BIRC3) as the direct target for ATF6α.

Conclusion

This study highlights the pathogenic role of ATF6α-BIRC3 axis in RA and identifies a novel pathway for new therapies against RA.

Bacterial Compositional Shifts of Gut Microbiomes in Patients with Rheumatoid Arthritis in Association with Disease Activity

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disabling autoimmune disorder. Little is known regarding the association between the gut microbiome and etiopathogenesis of RA. We aimed to dissect the differences in gut microbiomes associated with RA in comparison to healthy individuals and, in addition, to identify the shifts in the bacterial community in association with disease activity; Methods: In order to identify compositional shifts in gut microbiomes of RA patients, V3-V4 hypervariable regions of 16S rRNA were sequenced using Illumina MiSeq. In total, sixty stool samples were collected from 45 patients with RA besides 15 matched healthy subjects; Results: Notably, RA microbiomes were significantly associated with diverse bacterial communities compared with healthy individuals. Likewise, a direct association between bacterial diversity and disease activity was detected in RA patients (Kruskal Wallis; p = 0.00047). In general, genus-level analysis revealed a positive coexistence between RA and Megasphaera, Adlercreutzia, Ruminococcus, Bacteroides, Collinsella, and Acidaminococcus. Furthermore, Spearman correlation analysis significantly stratified the most dominant genera into distinct clusters that were mainly based on disease activity (r ≥ 0.6; p ≤ 0.05). The predictive metabolic profile of bacterial communities associated with RA could support the potential impact of gut microbiomes in either the development or recovery of RA; Conclusions: The overall shifts in bacterial composition at different disease statuses could confirm the cross-linking of certain genera either to causation or progression of RA.

Stromal p53 Regulates Breast Cancer Development, the Immune Landscape, and Survival in an Oncogene-Specific Manner

Coevolution of tumor cells and adjacent stromal elements is a key feature during tumor progression; however, the precise regulatory mechanisms during this process remain unknown. Here, we show stromal p53 loss enhances oncogenic KrasG12D, but not ErbB2, driven tumorigenesis in murine mammary epithelia. Stroma-specific p53 deletion increases both epithelial and fibroblast proliferation in mammary glands bearing the KrasG12D oncogene in epithelia, while concurrently increasing DNA damage and/or DNA replication stress and decreasing apoptosis in the tumor cells proper. Normal epithelia was not affected by stromal p53 deletion. Tumors with p53-null stroma had a significant decrease in total, cytotoxic, and regulatory T cells; however, there was a significant increase in myeloid-derived suppressor cells, total macrophages, and M2-polarized tumor-associated macrophages, with no impact on angiogenesis or connective tissue deposition. Stroma-specific p53 deletion reprogrammed gene expression in both fibroblasts and adjacent epithelium, with p53 targets and chemokine receptors/chemokine signaling pathways in fibroblasts and DNA replication, DNA damage repair, and apoptosis in epithelia being the most significantly impacted biological processes. A gene cluster in p53-deficient mouse fibroblasts was negatively associated with patient survival when compared with two independent datasets. In summary, stroma-specific p53 loss promotes mammary tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival.

IMPLICATIONS

Expression of the p53 tumor suppressor in breast cancer tumor stroma regulates tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival.

Cuproptosis and cuproptosis-related genes in rheumatoid arthritis: Implication, prospects, and perspectives

Rheumatoid arthritis (RA) is an autoimmune disease that severely affects patients' physical and mental health, leading to chronic synovitis and destruction of bone joints. Although various available clinical treatment options exist, patients respond with varying efficacies due to multiple factors, and there is an urgent need to discover new treatment options to improve clinical outcomes. Cuproptosis is a newly characterized form of cell death. Copper causes cuproptosis by binding to lipid-acylated components of the tricarboxylic acid cycle, leading to protein aggregation, loss of iron-sulfur cluster proteins, and eventually proteotoxic stress. Targeting copper cytotoxicity and cuproptosis are considered potential options for treating oncological diseases. The synovial hypoxic environment and the presence of excessive glycolysis in multiple cells appear to act as inhibitors of cuproptosis, which can lead to excessive survival and proliferation of multiple immune cells, such as fibroblast-like synoviocytes, effector T cells, and macrophages, further mediating inflammation and bone destruction in RA. Therefore, in this study, we attempted to elaborate and summarize the linkage of cuproptosis and key genes regulating cuproptosis to the pathological mechanisms of RA and their effects on a variety of immune cells. This study aimed to provide a theoretical basis and support for translating preclinical and experimental results of RA to clinical protocols.

Ferroptosis in inflammatory arthritis: A promising future

Ferroptosis is a kind of regulatory cell death (RCD) caused by iron accumulation and lipid peroxidation, which is characterized by mitochondrial morphological changes and has a complex regulatory network. Ferroptosis has been gradually emphasized in the pathogenesis of inflammatory arthritis. In this review, we summarized the relevant research on ferroptosis in various inflammatory arthritis including rheumatoid arthritis (RA), osteoarthritis, gout arthritis, and ankylosing spondylitis, and focused on the relationship between RA and ferroptosis. In patients with RA and animal models of RA, there was evidence of iron overload and lipid peroxidation, as well as mitochondrial dysfunction that may be associated with ferroptosis. Ferroptosis inducers have shown good application prospects in tumor therapy, and some anti-rheumatic drugs such as methotrexate and sulfasalazine have been shown to have ferroptosis modulating effects. These phenomena suggest that the role of ferroptosis in the pathogenesis of inflammatory arthritis will be worth further study. The development of therapeutic strategies targeting ferroptosis for patients with inflammatory arthritis may be a promising future.

Trp53 controls chondrogenesis and endochondral ossification by negative regulation of TAZ activity and stability via β-TrCP-mediated ubiquitination

Transformation-related protein 53 (Trp53) is a critical regulator of cell fate determination by controlling cell proliferation and differentiation. Ablation of Trp53 signaling in osteoblast lineages significantly promotes osteogenesis, bone formation, and bone remodeling. However, how Trp53 regulates chondrogenesis and endochondral bone formation is undefined. In this study, we found that Trp53 expression gradually decreased in tibia growth plates during embryonic development in vivo and during chondrogenesis in vitro. By deleting Trp53 in chondrocyte lineage using Col2-Cre transgenic line, we found that loss of Trp53 in chondrocytes significantly increased growth plate growth and bone formation by increasing chondrocyte proliferation, matrix production and maturation, and bone dynamic formation rate. Mechanistically, our data revealed loss of Trp53 significantly promoted TAZ transcriptional activity through inhibition of TAZ phosphorylation and nuclear translocation, whereas its activity was pronouncedly inhibited after forced expression of Trp53. Furthermore, Co-IP data demonstrated that Trp53 associated with TAZ. Moreover, Trp53 decreased the stability of TAZ protein and promoted its degradation through β-TrCP-mediated ubiquitination. Ablation of TAZ in Col2-Cre;Trp53^f/f mice rescued the phenotypes of enhanced chondrogenesis and bone formation caused by Trp53 deletion. Collectively, this study revealed that Trp53 modulates chondrogenesis and endochondral ossification through negative regulation of TAZ activity and stability, suggesting that targeting Trp53 signaling may be a potential strategy for fracture healing, heterotopic ossification, arthritis, and other bone diseases.

MiR-155-5p modulates inflammatory phenotype of activated oral lichen-planus-associated-fibroblasts by targeting SOCS1

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease. Cytokines are closely associated with OLP development. In addition to immune cells, fibroblasts have been reported to induce regional inflammation. MicroRNA(miR)-155-5p is reportedly increased significantly in OLP and is known to regulate inflammation. This study aimed to investigate the role of miR-155-5p in fibroblasts of OLP lesions.

METHODS AND RESULTS

Normal mucosal fibroblasts (NFs) and OLP associated-fibroblasts (OLP AFs) were isolated from the oral mucosa of 15 healthy controls and 30 OLP patients. We detected the expression of miR-155-5p and fibroblast activation protein alpha (FAP-α) using quantitative RT-PCR and analyzed their correlation. Interleukin (IL)-6 and IL-8 levels were determined using ELISA. Expression of suppressor of cytokine signaling (SOCS) 1 was analyzed by western blotting. A dual-luciferase reporter assay was performed to investigate the interaction between miR-155-5p and SOCS1. MiR-155-5p and FAP-α were significantly increased and positively correlated in OLP AFs. Overexpression of miR-155-5p in OLP AFs augmented IL-6 and IL-8 release and decreased SOCS1 expression, whereas knockdown of miR-155-5p in OLP AFs decreased IL-6 and IL-8 release. The expression of SOCS1 was downregulated in OLP AFs, and SOCS1 silencing augmented IL-6 and IL-8 production in OLP AFs. Furthermore, miR-155-5p inhibited SOCS1 expression by directly targeting its 3'-UTR in OLP AFs.

CONCLUSIONS

MiR-155-5p regulates the secretion of IL-6 and IL-8 by downregulating the expression of SOCS1 in activated OLP AFs. Our results provide novel insights into the pathogenesis of OLP and identify a potential new target for OLP therapy.

Sonic Hedgehog Promotes Proliferation and Migration of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via Rho/ROCK Signaling

Objective. To explore the underlying mechanism of the sonic hedgehog (Shh) signaling pathway in promoting cell proliferation and migration in fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). Method. FLS were collected from 8 patients with RA and 3 patients with osteoarthritis (OA). The expression of smoothened (Smo, the Shh pathway activator) was quantified by real-time PCR and western blot. FLS were incubated with cyclopamine (a Smo antagonist), purmorphamine (a Smo agonist), Y27632 (a Rho/ROCK signaling inhibitor), or a combination of purmorphamine and Y27632, respectively. Cell proliferation was examined using cell counting kit-8 and cell cycle assays while cell migration was measured with Transwell and wound healing assays. Results. The expression of Smo was higher in FLS from RA patients than from OA patients ( $p<0.05$ ). RA-FLS treated with purmorphamine showed significantly activated proliferation (119.69 vs. 100.0) and migration (252.38 vs. 178.57) compared to untreated cells (both $p<0.001$ ). RA-FLS incubated with cyclopamine or a combination of purmorphamine and Y27632 exhibited significant suppression of proliferation (81.55 vs. 100.0 and 85.84 vs. 100.0) and migration (100 vs. 178.57 and 109.52 vs. 185) ability (all $p<0.001$ ). Conclusion. Our results demonstrated that Shh promoted cell growth and migration of FLS in RA patients through the Rho/ROCK signaling pathway.

The Role of Reactive Oxygen Species in the Rheumatoid Arthritis-Associated Synovial Microenvironment

Rheumatoid arthritis (RA) is an inflammatory disease that begins with a loss of tolerance to modified self-antigens and immune system abnormalities, eventually leading to synovitis and bone and cartilage degradation. Reactive oxygen species (ROS) are commonly used as destructive or modifying agents of cellular components or they act as signaling molecules in the immune system. During the development of RA, a hypoxic and inflammatory situation in the synovium maintains ROS generation, which can be sustained by increased DNA damage and malfunctioning mitochondria in a feedback loop. Oxidative stress caused by abundant ROS production has also been shown to be associated with synovitis in RA. The goal of this review is to examine the functions of ROS and related molecular mechanisms in diverse cells in the synovial microenvironment of RA. The strategies relying on regulating ROS to treat RA are also reviewed.

RNA Editing-Associated Post-Transcriptional Gene Regulation in Rheumatoid Arthritis

Background:

Rheumatoid arthritis (RA) is an autoimmune disease characterised by systemic inflammation of joints. The observed complexity of RA pathogenesis and studies that have been carried out so far indicate that RA pathogenesis is regulated at multiple levels. Given the role of RNA editing in autoimmune disease, we hypothesised that RNA editing could contribute to RA pathogenesis by regulating gene expression through post-transcriptional mechanisms.

Methods:

We identified RNA editing events in synovial tissues from early and established RA compared with normal subjects from an available transcriptome data set using REDItools. To investigate the potential effect of these RNA editing events on gene expression, we carried out an analysis of differential exon usage in the vicinity of the differentially edited sites using DEXSeq. We then used STRING to identify putative interactions between differentially edited genes identified from REDItools analysis. We also investigated the possible effects of these RNA editing events on miRNA-target mRNA interactions as predicted by miRanda.

Results:

Our analysis revealed that there is extensive RNA editing in RA, with 304 and 273 differentially edited events in early RA and established RA, respectively. Of these, 25 sites were within 11 genes in early RA, and 34 sites were within 7 genes in established RA. DEXSeq analysis revealed that RNA editing correlated with differential exon usage in 4 differentially edited genes that have previously also been associated with RA in some measure: ATM, ZEB1, ANXA4, and TIMP3. DEXSeq analysis also revealed enrichment of some non-functional isoforms of these genes, perhaps at the expense of their full-length counterparts. Network analysis using STRING showed that several edited genes were part of the p53 protein-protein interaction network. We also identified several putative miRNA binding sites in the differentially edited genes that were lost upon editing.

Conclusions:

Our results suggested that the expression of genes involved in DNA repair and cell cycle, including ATM and ZEB1 which are well-known functional regulators of the DNA damage response pathway, could be regulated by RNA editing in RA synovia. This may contribute to an impaired DNA damage response in synovial tissues.

Mechanism of HSP90 Inhibitor in the Treatment of DSS-induced Colitis in Mice by Inhibiting MAPK Pathway and Synergistic Effect of Compound Sophorae Decoction

BACKGROUND

The mechanism of Heat Shock Protein 90 (HSP90) in Ulcerative Colitis (UC) has been studied, and mitogenic-activated protein kinases (MAPK) also contribute to the pathogenesis of UC. However, the effect of the HSP90/MAPK pathway in UC is still unclear. Therefore, the mainstay of this research is to explore the mechanism of action of this pathway in UC. Compound sophorae decoction (CSD), as a Chinese herbal decoction, can synergistically affect the above process.

OBJECTIVE

This study aimed to uncover the synergistic effects of HSP90 inhibitors regulating the MAPK pathway for treating DSS-induced colitis in mice and the synergistic effects of CSD.

METHODS

This experiment used oral administration of standard diets containing 3% dextran sodium sulfate (DSS) to establish an experimental colitis model in mice. The model was treated with HSP90 inhibitor, CSD, or dexamethasone. Mouse feces, mobility, body weight, colon length, and colon histopathology scores were recorded daily to assess the degree of colitis inflammation. Expression levels of HSP90 and MAPK pathway-related genes and proteins were evaluated by Western blot and qPCR. The evaluation of intestinal mucosal permeability was measured by enzyme-linked immunosorbent assay (ELISA), which could detect the protein level of D-Amino Acid Oxidase (DAO) and D-lactic acid (D-LA). The same went for downstream molecules AFT-2, p53, and apoptosis-related proteins BAX, BCL-2, Caspase3, and survivin in the MAPK pathway. Immunohistochemical measured p-38, p-JNK, and p-ERK expressions. JAM-A and claudin-1 connexin were tested by immunofluorescence staining. The TUNEL method was for measuring the apoptosis rate of colonic epithelial cells. CBA kit determined the level of inflammatory factors of colons.

RESULTS

HSP90 inhibitor can improve the degree of pathological damage in the colon of mice treated with DSS, increase the mice's weight and the length of the colon, and significantly reduce the disease activity index (DAI) score. Intraperitoneal injection of HSP90 inhibitor can reduce the expression of MAPK pathway markers P38, JNK, ERK, and their phosphorylation and decrease the content of AFT-2 and p53, which is downstream of the MAPK pathway. In addition, treatment of the HSP90 inhibitor up-regulated the expression of anti-apoptotic proteins BCL-2 and survivin, as well as down-regulated apoptotic protein caspase3, BAX in the colon of mice with colitis. Lower levels of inflammatory factors such as IL-6, MCP-1, IFN-γ, TNF, IL-12p70, and increased IL-10 were observed after HSP90 inhibitor therapy. Furthermore, the combination treatment of CSD can enhance the effect of the single HSP90 inhibitor treatment and play a synergistic effect.

CONCLUSION

These data suggest that an HSP90 inhibitor is available to treat UC by inhibiting the MAPK signaling pathway. This axis can restore the intestinal mucosa barrier's function by reducing intestinal mucosa's permeability and inhibiting apoptosis of intestinal epithelial cells. The specific mechanism is that HSP90 inhibitor can reduce the pathological damage and inflammation levels of colitis mice, and reduce the apoptosis rate of colonic epithelial cells and the mucosal permeability, thereby restoring the mucosal barrier function. During this process, CSD works synergistically to improve the therapeutic effect of the HSP90 inhibitor.

Silencing CoREST inhibits the viability and migration of fibroblast‑like synoviocytes in TNF‑α‑induced rheumatoid arthritis

Fibroblast-like synoviocytes (FLSs) have functions in the pathogenesis of rheumatoid arthritis (RA) through the onset of synovitis, the growth of pannus and the destruction of cartilage and bone. The significant increase in the proliferation, migration and invasion of FLSs induces the onset and advancement of RA. To date, the exact function of corepressor element-1 silencing transcription factor (CoREST) in RA remains unclear, but its expression has been determined in RA synovial tissues. In this study, the effects of CoREST were investigated in a TNF-α-induced FLS activation model. Following the silencing of CoREST expression with small interfering (si)RNA, the viability and migration of FLSs were evaluated. Furthermore, the possible molecular mechanisms were explored by detecting the expression of key factors, including matrix metalloproteinases (MMPs), lysine-specific histone demethylase 1 (LSD1) and associated cytokines, via reverse transcription-quantitative PCR and western blotting. CoREST expression increased not only in the RA synovial tissues, but also in the TNF-α-induced FLS activation model. Following the silencing of CoREST in the FLSs treated with TNF-α, cell viability was inhibited, and the migratory capacity of FLSs was suppressed, which was accompanied by the reduced expression of MMP-3 and MMP-9. The expression of LSD1 was also downregulated. There was a notable decrease in the synthesis of interferon-γ and interleukin (IL)-17, while IL-10 expression was increased. The knockdown of CoREST inhibited the viability and migration of FLSs stimulated with TNF-α. Thus, the suppression of CoREST may have crucial roles in the occurrence and development of RA.