Nuclear factor‐κB in rheumatoid arthritis

NF-κB Signaling Pathway in Rheumatoid Arthritis: Mechanisms and Therapeutic Potential

Rheumatoid arthritis (RA) is an autoimmune chronic inflammatory disease that imposes a heavy economic burden on patients and society. Bone and cartilage destruction is considered an important factor leading to RA, and inflammation, oxidative stress, and mitochondrial dysfunction are closely related to bone erosion and cartilage destruction in RA. Currently, there are limitations in the clinical treatment methods for RA, which urgently necessitates finding new effective treatments for patients. Nuclear transcription factor-κB (NF-κB) is a signaling transcription factor that is widely present in various cells. It plays an important role as a stress source in the cellular environment and regulates gene expression in processes such as immunity, inflammation, cell proliferation, and apoptosis. NF-κB has long been recognized as a pathogenic factor of RA, and its activation can exacerbate RA by promoting inflammation, oxidative stress, mitochondrial dysfunction, and bone destruction. Conversely, inhibiting the activity of the NF-κB pathway effectively inhibits these pathological processes, thereby alleviating RA. Therefore, NF-κB may be a potential therapeutic target for RA. This article describes the physiological structure of NF-κB and its important role in RA through the regulation of oxidative stress, inflammatory response, mitochondrial function, and bone destruction. Meanwhile, we also summarized the impact of NF-κB crosstalk with other signaling pathways on RA and the effect of related drugs or inhibitors targeting NF-κB on RA. The purpose of this article is to provide evidence for the role of NF-κB in RA and to emphasize its significant role in RA by elucidating the mechanisms, so as to provide a theoretical basis for targeting the NF-κB pathway as a treatment for RA.

An orally-administered nanotherapeutics with gold nanospheres supplying for rheumatoid arthritis therapy by re-shaping gut microbial tryptophan metabolism

Dysbiosis of gut microbiota significantly exacerbates the progression of rheumatoid arthritis (RA). Targeting gut microbiota may present a promising therapeutic strategy for RA. Gold nanospheres (GNS), known for excellent biocompatibility, stability and minimal toxicity, have emerged as precise modulators of gut microbiota, reshaping intestinal environments to treat various inflammatory diseases. Our study found that oral administration of 60-nm GNS effectively ameliorated collagen-induced arthritis (CIA) in mice, with a marked reduction in disease severity and synovial inflammation. Specifically, GNS notably enriched the probiotic genus Ligilactobacillus while restoring intestinal barrier function by upregulating tight junction proteins Claudin-1 and ZO-1. Targeted metabolomics analysis revealed GNS substantially increased the production of indole-3-propionic acid (IPA) and indole-3-acetic acid (IAA) in gut, which were shown to activate the aryl hydrocarbon receptor (AhR) pathway. Mechanistic studies demonstrated that the IPA/IAA mixture inhibited PTEN ubiquitination, stabilizing PTEN protein levels and suppressing NF-κB activation in synovial tissues. These changes correlated with reduced synovial hyperplasia and inflammatory infiltration. Our findings established GNS as an effective nanomodulator of the gut-joint axis, providing novel insights into microbiota-targeted therapies for RA and other inflammatory diseases.

Association of UCMA With Cartilage Pathogenesis and Inflammation in Patients With Rheumatoid Arthritis: A Novel Biomarker

BACKGROUND

Rheumatoid arthritis (RA) is a persistent autoimmune disorder that impacts the joints, leading to a reduction in physical function and a decline in overall well-being. UCMA is a vitamin K-dependent protein that plays a role in some human diseases, including osteoarthritis and cardiovascular disorders. Nevertheless, the possible role of UCMA in the pathogenesis of RA remains unclear. Therefore, we aimed to investigate the expression of UCMA in serum samples of patients with RA, its relationship with disease activity and some blood markers.

METHODS

The current study included 98 RA patients and 24 healthy individuals. Serum UCMA, COMP, TNF-α, and IL-6 levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Serum UCMA, COMP, TNF-α, and IL-6 expressions were significantly increased in RA patients compared to healthy controls (p < 0.05). The ROC curve analysis demonstrated that blood UCMA, COMP, TNF-α, and IL-6 levels had the capability to differentiate between patients with RA and healthy controls (p < 0.05). UCMA was positively correlated with certain laboratory indicators, such as COMP, TNF-α, IL-6, CRP, and CCP.

CONCLUSION

Here, we report for the first time that UCMA may reflect cartilage degeneration and inflammatory changes in RA patients. Furthermore, UCMA could be employed as a predictive or diagnostic marker in the clinical practice of RA.

T cell dysregulation in rheumatoid arthritis: Recent advances and natural product interventions

Autoimmune diseases result from chronic and dysregulated activation of the immune system, culminating in pathological self-tissue damage. These disorders are primarily driven by adaptive immune responses, particularly those mediated by T and B lymphocytes, which mistakenly target self-antigens expressed in host tissues. In rheumatoid arthritis (RA), the pathogenesis is closely associated with the emergence of tissue-invasive effector T cells and the functional impairment of regulatory T cells (Tregs), both of which play pivotal roles in disease progression. Therapeutic interventions targeting these dysregulated T cell populations have emerged as a promising strategy for RA management. Although synthetic immunosuppressants remain the mainstay of RA treatment, their long-term application is often hampered by adverse effects, diminished therapeutic efficacy, and poor patient adherence. These limitations highlight the critical need for the development of novel therapeutic approaches. Natural compounds derived from medicinal plants have been widely utilized in the clinical management of RA, with growing evidence supporting their immunomodulatory potential, particularly in restoring T cell-mediated immune tolerance. This review aims to provide a comprehensive overview of recent advances in understanding T cell dysregulation in RA and to elucidate the mechanisms through which natural compounds regulate immune responses. By integrating current findings, this work seeks to offer a theoretical foundation for the optimized use of natural compounds in the treatment of RA, while exploring their potential in advancing precision medicine and personalized therapeutic strategies.

Pharmacological modes of plant-derived compounds for targeting inflammation in rheumatoid arthritis: A comprehensive review on immunomodulatory perspective

BACKGROUND

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune, chronic, inflammatory disease characterized by joint inflammation, synovial swelling, loss of articular structures, swelling, and pain. RA is a major cause of discomfort and disability worldwide, associated with infectious agents, genetic determinants, epigenetic factors, advancing age, obesity, and smoking. Although conventional therapies for RA alleviate the symptoms, but their long-term use is associated with significant side effects. This necessitates the urge to discover complementary and alternative medicine from natural products with minimum side effects.

PURPOSE

In this review, natural product's potential mechanism of action against RA has been documented in the setting of in-vivo, in-vitro and pre-clinical trials, which provides new treatment opportunities for RA patients. The bioefficacy of these natural product's bioactive compounds must be further studied to discover novel natural medications for RA with high selectivity, improved effectiveness, and economic replacement with minimum side effects.

STUDY DESIGN AND METHODS

The current review article was designed systematically in chronological order. Plants and their phytochemicals are discussed in an order concerning their mode of action. All the mechanisms of action are depicted in diagrams which are thoroughly generated by the Chembiodraw to maintain the integrity of the work. Moreover, by incorporating the recent data with simple language which is not incorporated previously, we tried to provide a molecular insight to the readers of every level and ethnicity. Moreover, Google Scholar, PubMed, ResearchGate, and Science Direct databases were used to collect the data.

SOLUTION

Traditionally, various plant extracts and bioactive compounds are effectively used against RA, but their comprehensive pharmacological mechanistic actions are rarely discussed. Therefore, the objective of this study is to systematically review the efficacy and proposed mechanisms of action of different plants and their bioactive compounds including Tripterygium wilfordii Hook F (celastrol and triptolide), Nigella sativa (thymoquinone), Zingiber officinale (shogaols, zingerone), Boswellia serrata (boswellic acids), Curcuma longa (curcumin), and Syzygium aromaticum (eugenol) against rheumatoid arthritis.

CONCLUSION

These plants have strong anti-inflammatory, anti-oxidant, and anti-arthritic effects in different study designs of rheumatoid arthritis with negligible side effects. Phytomedicines could revolutionize pharmacology as they act through alternative pathways hence seeming biocompatible.

Transformable peptide blocks NF-κB/IκBα pathway through targeted coating IκBα against rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by destructive effects. Although current therapies utilizing antibodies against inflammatory cytokines have shown some success, the inhibition of a single inflammatory molecule may not suffice to impede the progression of RA due to the intricate pathogenesis involving multiple molecules. In this study, we have developed an intelligent transformable peptide, namely BP-FFVLK-DSGLDSM (BFD). BFD has the ability to self-assemble into spherical nanoparticles in water or in the blood circulation to facilitate their delivery and distribution. When endocytosed into immune cells, BFD can identify and attach to phosphorylation sites on IκBα and in situ transform into a nanofibrous network coating NF-κB/IκBα complexes, blocking the phosphorylation and degradation of IκBα. As a result, BFD enables decreasing expression of proinflammatory mediators. In the present study, we demonstrate that BFD exhibits notable efficacy in alleviating arthritis-related manifestations, such as joints and tissues swelling, as well as bone and cartilage destruction on the collagen-induced arthritis (CIA) rat model. The investigation of intracellular biodistribution, phosphorylation of IκBα, and cytokine detection in culture medium supernatant, joint tissue, and serum exhibits strong associations with therapeutic outcomes. The utilization of transformable peptide presents a novel approach for the management of inflammatory diseases.

Triptophenolide Improves Rheumatoid Arthritis and Progression by Inducing Macrophage Toxicity

To investigate the role and mechanism of triptophenolide (TRI) in resisting rheumatoid arthritis (RA). Network pharmacology analysis results suggested that TRI was related to multiple inflammation-related signaling proteins, and possessed the stable structural configuration. In animal experiments, TRI suppressed RA in mice, inhibited tissue inflammation, and improved synovial injury. Moreover, TRI can suppress RA via multiple signaling pathways, and inhibiting pyroptosis is one of the feasible treatments for improving RA.

Anti-arthritic effect of spirocyclopiperazinium bromide DXL-A-24 in CFA-induced arthritic rats and its mechanism

This study aimed to investigate the effect of spirocyclopiperazinium bromide DXL-A-24 on complete Freund's adjuvant (CFA)-induced arthritis and its underlying mechanism in rats. A rheumatoid arthritis model was established by the intradermal injection of CFA into the paws of rats. Mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), ankle swelling and paw edema were used to evaluate the effects of DXL-A-24. Bone erosion and bone mineral density (BMD) were observed using micro-computed tomography. Receptor blocking test, western blotting, and enzyme-linked immunosorbent assay were performed to explore the mechanisms. Administration of DXL-A-24 (1, 0.5, 0.25 mg/kg, i.g.) dose-dependently increased the MWT and TWL, while alleviating ankle and paw swelling in CFA rats. The effects were blocked by peripheral α7 nicotinic or M4 muscarinic receptor antagonists. DXL-A-24 improved bone erosion and BMD, as well as downregulated the overexpression of Cav3.2, pJAK2, pSTAT3, pIκBα, pNF-κB p65, c-Fos and TNF-α proteins that were induced by CFA. In conclusion, this study shows, for the first time, that DXL-A-24 improves bone erosion and BMD and exhibits obvious anti-arthritic effects in CFA rats. The mechanism may be related to activating the peripheral α7 nicotinic and M4 muscarinic receptors, reducing Cav3.2 expression, and suppressing JAK2/STAT3 and IκBα/NF-κB p65 inflammatory signaling pathways, ultimately inhibiting inflammation-related proteins TNF-α and c-Fos.

Responsive Multi-Arm PEG-Modified COF Nanocomposites: Dynamic Photothermal, pH/ROS Dual-Responsive, Targeted Carriers for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic immune disease characterized by the infiltration of immune cells and the proliferation of fibroblast-like synoviocytes (FLS) at the joint site, leading to inflammation and joint destruction. However, the available treatment options targeting both inflammatory and proliferative FLS are limited. Herein, this work presents three covalent organic frameworks (COFs) photothermal composite systems modified with multi-armed polyethylene glycols (PEG) for the treatment of RA. These systems exhibit a dual response under low pH and high reactive oxygen species (ROS) conditions at the site of inflammation, with a specific focus on delivering the protein drug ribonuclease A (RNase A). Notably, molecular docking studies reveal the interaction between RNase A and NF-κB p65 protein, and Western blotting confirm its inhibitory effect on NF-κB activity. In vitro and in vivo experiments verify the significant reduction in joint swelling and deformities in adjuvant-induced arthritis (AIA) rats after treatment with RNase A delivered by multi-armed PEG-modified COF ligands, restoring joint morphology to normal. These findings underscore the promising therapeutic potential of COFs for the treatment of RA, highlighting their unique capabilities in addressing both inflammatory and proliferative aspects of the disease and expanding the scope of biomedical applications for COFs.

The Role of MicroRNA in the Pathogenesis of Acute Kidney Injury

Acute kidney injury (AKI) describes a condition associated with elevated serum creatinine levels and decreased glomerular filtration rate. AKI can develop as a result of sepsis, the nephrotoxic properties of several drugs, and ischemia/reperfusion injury. Renal damage can be associated with metabolic acidosis, fluid overload, and ionic disorders. As the molecular background of the pathogenesis of AKI is insufficiently understood, more studies are needed to identify the key signaling pathways and molecules involved in the progression of AKI. Consequently, future treatment methods may be able to restore organ function more rapidly and prevent progression to chronic kidney disease. MicroRNAs (miRNAs) are small molecules that belong to the non-coding RNA family. Recently, numerous studies have demonstrated the altered expression profile of miRNAs in various diseases, including inflammatory and neoplastic conditions. As miRNAs are major regulators of gene expression, their dysregulation is associated with impaired homeostasis and cellular behavior. The aim of this article is to discuss current evidence on the involvement of miRNAs in the pathogenesis of AKI.

Network pharmacology combined with affinity ultrafiltration to elucidate the potential compounds of Shaoyao Gancao Fuzi Decoction for the treatment of rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Shaoyao Gancao Fuzi Decoction (SGFD), has been employed for thousands of years in the treatment of rheumatoid arthritis (RA) with remarkable clinical efficacy. However, the material basis underlying the effectiveness of SGFD still remains unclear.

AIM OF THE REVIEW

This study aims to elucidate the material basis of SGFD through the application of network pharmacology and biological affinity ultrafiltration.

RESULTS

UPLC-Q-TOF-MS/MS was employed to characterize the components in SGFD, the identified 145 chemical components were mainly categorized into alkaloids, flavonoids, triterpenoids, and monoterpenoids according to the structures. Network pharmacology method was utilized to identify potential targets and signaling pathways of SGFD in the RA treatment, and the anti-inflammatory and anti-RA effects of SGFD were validated through in vivo and in vitro experiments. Moreover, as the significant node in the pharmacology network, TNF-α, a classical therapeutic target in RA, was subsequent employed to screen the interacting compounds in SGFD via affinity ultrafiltration screening method, 6 active molecules (i.e.,glycyrrhizic acid, paeoniflorin, formononetin, isoliquiritigenin, benzoyl mesaconitine, and glycyrrhetinic acid) were exhibited significant interactions. Finally, the significant anti-inflammatory and anti-TNF-α effects of these compounds were validated at the cellular level.

CONCLUSIONS

In conclusion, this study comprehensively elucidates the pharmacodynamic material basis of SGFD, offering a practical reference model for the systematic investigation of traditional Chinese medicine formulas.

The impacts of obesity in rheumatoid arthritis and insights into therapeutic purinergic modulation

Rheumatoid Arthritis (RA) is an autoimmune condition responsible for the impairment of synovia and joints, endangering the functionality of individuals and contributing to mortality. Currently, obesity is increasing worldwide, and recent studies have suggested an association between such condition and RA. In this sense, obese individuals present a lower capacity for achieving remission and present more intense symptoms of the disease, demonstrating a link between both disorders. Different studies aim to understand the possible connection between the conditions; however, few is known in this sense. Therefore, knowing that obesity can alter the activity of multiple body systems, this work's objective is to evaluate the main modifications caused by obesity, which can be linked to the pathophysiology of RA, highlighting as relevant topics obesity's negative impact triggering systemic inflammation, intestinal dysbiosis, endocrine disbalances. Furthermore, the relationship between oxidative stress and obesity also deserves to be highlighted, considering the influence of reactive oxygen species (ROS) accumulation in RA exacerbation. Additionally, many of those characteristics influenced by obesity, along with the classic peculiarities of RA pathophysiology, can also be associated with purinergic signaling. Hence, this work suggests possible connections between the purinergic system and RA, proposing potential therapeutic targets against RA to be studied.

Exploring the Mechanism of Topical Application of Clematis Florida in the Treatment of Rheumatoid Arthritis through Network Pharmacology and Experimental Validation

Clematis Florida (CF) is a folk medicinal herb in the southeast of China, which is traditionally used for treating osteoarticular diseases. However, the mechanism of its action remains unclear. The present study used network pharmacology and experimental validation to explore the mechanism of CF in the treatment of rheumatoid arthritis (RA). Liquid chromatography-mass spectrometry (LC-MS/MS) identified 50 main compounds of CF; then, their targets were obtained from TCMSP, ETCM, ITCM, and SwissTargetPrediction databases. RA disease-related targets were obtained from DisGeNET, OMIM, and GeneCards databases, and 99 overlapped targets were obtained using a Venn diagram. The protein-protein interaction network (PPI), the compound-target network (CT), and the compound-potential target genes-signaling pathways network (CPS) were constructed and analyzed. The results showed that the core compounds were screened as oleanolic acid, oleic acid, ferulic acid, caffeic acid, and syringic acid. The core therapeutic targets were predicted via network pharmacology analysis as PTGS2 (COX-2), MAPK1, NF-κB1, TNF, and RELA, which belong to the MAPK signaling pathway and NF-κB signaling pathway. The animal experiments indicated that topical application of CF showed significant anti-inflammatory activity in a mouse model of xylene-induced ear edema and had strong analgesic effect on acetic acid-induced writhing. Furthermore, in the rat model of adjuvant arthritis (AA), topical administration of CF was able to alleviate toe swelling and ameliorate joint damage. The elevated serum content levels of IL-6, COX-2, TNF-α, IL-1β, and RF caused by adjuvant arthritis were reduced by CF treatment. Western blotting tests showed that CF may regulate the ERK and NF-κB pathway. The results provide a new perspective for the topical application of CF for treatment of RA.

Anti-inflammatory properties and characterization of water extracts obtained from Callicarpa kwangtungensis Chun using in vitro and in vivo rat models

Callicarpa kwangtungensis Chun (CK) is a common remedy exhibits anti-inflammatory properties and has been used in Chinese herbal formulations, such as KangGongYan tablets. It is the main component of KangGongYan tablets, which has been used to treat chronic cervicitis caused by damp heat, red and white bands, cervical erosion, and bleeding. However, the anti-inflammatory effects of CK water extract remains unknown. This study assessed the anti-inflammatory effects of CK in vivo and in vitro, characterized its main components in the serum of rats and verified the anti-inflammatory effects of serum containing CK. Nitric oxide (NO), tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) release by RAW264.7 cells was examined by ELISA and Griess reagents. Inflammation-related protein expression in LPS-stimulated RAW264.7 cells was measured by western blotting. Furthermore, rat model of foot swelling induced by λ-carrageenan and a collagen-induced arthritis (CIA) rat model were used to explore the anti-inflammatory effects of CK. The components of CK were characterized by LC-MS, and the effects of CK-containing serum on proinflammatory factors levels and the expression of inflammation-related proteins were examined by ELISA, Griess reagents and Western blotting. CK suppressed IL-6, TNF-α, and NO production, and iNOS protein expression in LPS-stimulated RAW264.7 cells. Mechanistic studies showed that CK inhibited the phosphorylation of ERK, P38 and JNK in the MAPK signaling pathway, promoted the expression of IκBα in the NF-κB signaling pathway, and subsequently inhibited the expression of iNOS, thereby exerting anti-inflammatory effects. Moreover, CK reduced the swelling rates with λ-carrageenan induced foot swelling, and reduced the arthritis score and incidence in the collagen-induced arthritis (CIA) rat model. A total of 68 compounds in CK water extract and 31 components in rat serum after intragastric administration of CK were characterized. Serum pharmacological analysis showed that CK-containing serum suppressed iNOS protein expression and NO, TNF-α, and IL-6 release. CK may be an anti-inflammatory agent with therapeutic potential for acute and chronic inflammatory diseases, especially inflammatory diseases associated with MAPK activation.

Xuetongsu attenuates bone destruction in collagen-induced arthritis mice by inhibiting osteoclast differentiation and promoting osteoclast apoptosis

Tujia ethnomedicine Xuetong (the stems of Kadsura heteroclita) have been widely used in folk for rheumatoid arthritis (RA), which can alleviate rheumatic pain through liquor soaking in folk. In this study, we aimed to evaluate the pharmacological effects and underlying mechanism of Xuetongsu (a key chemical component of Xuetong) on bone destruction. In our previous study, it was found that Xuetong extract can reduce adjuvant arthritic rats paw swelling and inhibit inflammatory factors in serum. Furthermore, Xuetongsu has been demonstrated to inhibit the proliferation of fibroblast-like synoviocytes, but its potential to inhibit bone destruction has not been explored. To address this, we employed the STRING database to predict protein interactions and utilized Autodock software to simulate the binding of Xuetongsu to target proteins. In this study, administration of Xuetongsu significantly alleviated paw swelling and bone destruction in C57BL/6 mice with collagen-induced arthritis (CIA). Mechanistic studies have indicated that Xuetongsu promotes apoptosis of mature osteoclasts in joint tissues by activating Caspase-3 and Bax, while inhibiting Bcl-2. Additionally, Xuetongsu inhibits osteoclast differentiation by suppressing RANKL, RANK, P-NF-κB, and NFATc1, and reduces bone resorption activity by inhibiting MMP-9, CTSK, and TRAP. Importantly, Xuetongsu exhibits good biocompatibility in major organs of mice. In summary, Xuetongsu has the potential to treat bone destruction by promoting apoptosis of mature osteoclasts, inhibiting osteoclast differentiation, and reducing bone resorption. This study reveals the pharmacological effects of Xuetongsu and its mechanism of action, which may contribute to the development of novel approaches for treating RA.

Current situation and trend of non-coding RNA in rheumatoid arthritis: a review and bibliometric analysis

Background

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that affects multiple joints and has adverse effects on various organs throughout the body, often leading to a poor prognosis. Recent studies have shown significant progress in the research of non-coding RNAs (ncRNAs) in RA. Therefore, this study aims to comprehensively assess the current status and research trends of ncRNAs in RA through a bibliometric analysis.

Methods

This study retrieved articles relevant to ncRNAs and RA from the Science Citation Index Expanded Database of the Web of Science Core Collection between January 1st, 2003, and July 31st, 2023. The relevant articles were screened based on the inclusion criteria. VOSviewer and CiteSpace are utilized for bibliometric and visual analysis.

Results

A total of 1697 publications were included in this study, and there was a noticeable increase in annual publications from January 1st, 2003, to July 31st, 2023. China, the United States, and the United Kingdom were the most productive countries in this field, contributing to 43.81%, 13.09%, and 3.87% of the publications. Anhui Medical University and Lu Qianjin were identified as the most influential institution and author. Frontiers In Immunology stood out as the most prolific journal, while Arthritis & Rheumatology was the most co-cited journal. Additionally, the research related to "circular RNA", "oxidative stress", "proliferation", and "migration" have emerged as new hotspots in the field.

Conclusion

In this study, we have summarized the publication characteristics related to ncRNA and RA and identified the most productive countries, institutions, authors, journals, hot topics, and trends.

Cell-based therapies for the treatment of rheumatoid arthritis

Autoimmune diseases, including rheumatoid arthritis that is the most prevalent rheumatic autoimmune disorder, affect autologous connective tissues caused by the breakdown of the self-tolerance mechanisms of the immune system. During the last two decades, cell-based therapy, including stem cells and none-stem cells has been increasingly considered as a therapeutic option in various diseases. This is partly due to the unique properties of stem cells that divide and differentiate from the specialized cells in the damaged tissue. Moreover, stem cells and none-stem cells, impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as rheumatic autoimmune disorders. In the present review, the efficacy of cell-based therapy with four main types of stem cells, including mesenchymal stem cells, hematopoietic stem cells, embryonic stem cells, and human amniotic membrane cells, as well as none-stem cells, including regulatory T cells, chimeric antigen receptor T cells, and tolerogenic dendritic cells will be evaluated. Moreover, other related issues, including safety, changes in immunological parameters, suitable choice of stem cell and none-stem cell origin, conditioning regimen, limitations, and complications will be discussed.

Targeting cyclin-dependent kinases in rheumatoid arthritis and psoriasis - a review of current evidence

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with synovial proliferation and bone erosion, which leads to the structural and functional impairment of the joints. Immune cells, together with synoviocytes, induce a pro-inflammatory environment and novel treatment agents target inflammatory cytokines. Psoriasis is a chronic immune-mediated skin disease, and several cytokines are considered as typical mediators in the progression of the disease, including IL-23, IL-22, and IL-17, among others.

AREA COVERED

In this review, we try to evaluate whether cyclin-dependent kinases (CDK), enzymes that regulate cell cycle and transcription of various genes, could become novel therapeutic targets in RA and psoriasis. We present the main results of in vitro and in vivo studies, as well as scarce clinical reports.

EXPERT OPINION

CDK inhibitors seem promising for treating RA and psoriasis because of their multidirectional effects. CDK inhibitors may affect not only the process of osteoclastogenesis, thereby reducing joint destruction in RA, but also the process of apoptosis of neutrophils and macrophages responsible for the development of inflammation in both RA and psoriasis. However, assessing the efficacy of these drugs in clinical practice requires multi-center, long-term clinical trials evaluating the effectiveness and safety of CDK-blocking therapy in RA and psoriasis.

Targeting transcription factors for therapeutic benefit in rheumatoid arthritis

Rheumatoid arthritis (RA) is a destructive inflammatory autoimmune disease that causes pain and disability. Many of the currently available drugs for treating RA patients are aimed at halting the progression of the disease and alleviating inflammation. Further, some of these treatment options have drawbacks, including disease recurrence and adverse effects due to long-term use. These inefficiencies have created a need for a different approach to treating RA. Recently, the focus has shifted to direct targeting of transcription factors (TFs), as they play a vital role in the pathogenesis of RA, activating key cytokines, chemokines, adhesion molecules, and enzymes. In light of this, synthetic drugs and natural compounds are being explored to target key TFs or their signaling pathways in RA. This review discusses the role of four key TFs in inflammation, namely NF-κB, STATs, AP-1 and IRFs, and their potential for being targeted to treat RA.

Protective and Pain-Killer Effects of AMC3, a Novel N-Formyl Peptide Receptors (FPRs) Modulator, in Experimental Models of Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disorder that causes chronic joint pain, swelling, and movement impairment, resulting from prolonged inflammation-induced cartilage and bone degradation. The pathogenesis of RA, which is still unclear, makes diagnosis and treatment difficult and calls for new therapeutic strategies to cure the disease. Recent research has identified FPRs as a promising druggable target, with AMC3, a novel agonist, showing preclinical efficacy in vitro and in vivo. In vitro, AMC3 (1-30 µM) exhibited significant antioxidant effects in IL-1β (10 ng/mL)-treated chondrocytes for 24 h. AMC3 displayed a protective effect by downregulating the mRNA expression of several pro-inflammatory and pro-algic genes (iNOS, COX-2, and VEGF-A), while upregulating genes essential for structural integrity (MMP-13, ADAMTS-4, and COLIAI). In vivo, AMC3 (10 mg kg^-1) prevented hypersensitivity and restored postural balance in CFA-injected rats after 14 days. AMC3 attenuated joint alterations, reduced joint inflammatory infiltrate, pannus formation, and cartilage erosion. Chronic AMC3 administration reduced transcriptional changes of genes causing excitotoxicity and pain (EAATs and CCL2) and prevented morphological changes in astrocytes, including cell body hypertrophy, processes length, and thickness, caused by CFA in the spinal cord. This study demonstrates the usefulness of AMC3 and establishes the groundwork for further research.

Leocarpinolide B Attenuates Collagen Type II-Induced Arthritis by Inhibiting DNA Binding Activity of NF-κB

Rheumatoid arthritis (RA) is a chronic autoimmune disease triggered by a cascading inflammatory response. Sigesbeckia Herba (SH) has long been utilized as a traditional remedy to alleviate symptoms associated with rheumatism. Our previous study found that leocarpinolide B (LB), a sesquiterpene lactone isolated from the whole plant of SH, possesses potent a anti-inflammatory effect on macrophages. This study was designed to evaluate the therapeutic effects of LB on RA, and further investigate the underlying mechanisms. In collagen type II-induced arthritic mice, LB was demonstrated to decrease the production of autoimmune antibodies in serum and inflammatory cytokines in the joint muscles and recover the decreased regulatory T lymphocytes in spleen. Moreover, LB significantly suppressed the inflammatory infiltration, formation of pannus and bone erosion in the paw joints. In vitro testing showed that LB inhibited the proliferation, migration, invasion, and secretion of inflammatory cytokines in IL-1β-induced human synovial SW982 cells. Network pharmacology and molecular docking suggested NF-κB p65 could be the potential target of LB on RA treatment, subsequent experimental investigation confirmed that LB directly interacted with NF-κB p65 and reduced the DNA binding activity of NF-κB in synovial cells. In conclusion, LB significantly attenuated the collagen type II-induced arthritis, which was at least involved in the inhibition of DNA binding activity of NF-κB through a direct binding to NF-κB p65. These findings suggest that LB could be a valuable lead compound for developing anti-RA drugs.

Complete Freund's Adjuvant Induces a Fibroblast-like Synoviocytes (FLS) Metabolic and Migratory Phenotype in Resident Fibroblasts of the Inoculated Footpad at the Earliest Stage of Adjuvant-Induced Arthritis

The fibroblast-like synoviocytes (FLS) have a crucial role in the pathogenesis of Rheumatoid Arthritis (RA); however, its precise mechanisms remain partially unknown. The involvement of the fibroblast in activating adjuvant-induced arthritis (AA) has not been previously reported. The objective was to describe the participation of footpads' fibroblasts in the critical initial process that drives the AA onset. Wistar rats were injected with Complete Freund's Adjuvant (CFA) or saline solution in the hind paws' footpads and euthanized at 24 or 48 h for genetic and histological analyses. Microarrays revealed the differentially expressed genes between the groups. The CFA dysregulated RA-linked biological processes at both times. Genes of MAPK, Jak-STAT, HIF, PI3K-Akt, TLR, TNF, and NF-κB signaling pathways were altered 24 h before the arrival of immune cells (CD4, CD8, and CD68). Key markers TNF-α, IL-1β, IL-6, NFκB, MEK-1, JAK3, Enolase, and VEGF were immunodetected in fibroblast in CFA-injected footpads at 24 h but not in the control group. Moreover, fibroblasts in the CFA inoculation site overexpressed cadherin-11, which is linked to the migration and invasion ability of RA-FLS. Our study shows that CFA induced a pathological phenotype in the fibroblast of the inoculation site at very early AA stages from 24 h, suggesting a prominent role in arthritis activation processes.

Chymotrypsin attenuates adjuvant-induced arthritis by downregulating TLR4, NF-κB, MMP-1, TNF-α, IL-1β, and IL-6 expression in Sprague-Dawley rats

OBJECTIVE

Rheumatoid arthritis (RA) is mainly characterized by synovial hyperplasia, angiogenesis, inflammatory cells infiltration. Chymotrypsin is a proteolytic enzyme with anti-inflammatory effects. The current project was intended to test the efficacy and mechanism of chymotrypsin in adjuvant-induced arthritis (AIA) rats to provide an experimental basis for the clinical application of chymotrypsin.

METHODS

Sprague-Dawley rats were injected with complete Freund's adjuvant (CFA) in the hind left paw pad to establish an AIA model. Forty rats were randomly divided into five groups (n = 8): blank; CFA model (model); low-dose chymotrypsin (CLD), 0.53 mg/kg; high-dose chymotrypsin (CHD), 1.06 mg/kg; piroxicam, 10 mg/kg. The treatments were performed in the subplantar region of the left hind paw from Day 8 (D8) to Day 28 after adjuvant injection. The body weight, paw diameter, swelling degree of paw, and arthritic score were measured on D0, D7, D14, D21, and D28. All animals were sacrificed on D29. Subsequently, the synovial tissue of the ankle joint of the rats was stained with HE to generate pathological sections for observation of the pathological changes of synovial tissue from the ankle joint. The protein levels of MMP-1, TNF-α, IL-1β, and IL-6 in the rats' serum were determined by ELISA. Western blotting was used to detect the protein expression of TLR4 and NF-κB in the rat ankle tissue. The mRNA expression of TLR4, NF-κB, IL-1β, IL-6, and TNF-α in synovial tissue of the ankle joint was detected by RT-qPCR.

RESULTS

The body weight of the rats in each group showed an increasing trend, and there was no significant difference in weight between the groups. CHD and piroxicam suppressed paw swelling and arthritic scores and decreased synovial hyperplasia, inflammatory cell infiltration, pannus formation, and bone destruction. Furthermore, the overproduction of MMP-1, TNF-α, IL-1β, and IL-6 in serum was remarkably attenuated in the chymotrypsin- and piroxicam-treated rats. The protein levels of TLR4 and NF-κB in the synovial tissue of the chymotrypsin group and the piroxicam group were significantly lower than those in the model group. Likewise, the rats treated with chymotrypsin and piroxicam had a substantial decline in the mRNA expression of TLR4, NF-κB, TNF-α, IL-1β, and IL-6 in synovial tissue.

CONCLUSIONS

Chymotrypsin alleviates the joint damage of AIA rats, probably by reducing the expression of MMP-1, TNF-α, IL-1β, and IL-6 through TLR4/NF-κB signaling pathway.

Traditional Tibetan medicine: therapeutic potential in rheumatoid arthritis

Rheumatoid arthritis (RA) is a severe inflammatory autoimmune disease characterized by the failed spontaneous resolution of inflammation. The induction of immune regulation and resolution of inflammatory pathways are effective in alleviating inflammation in RA. As the oldest medical system in the world, traditional Tibetan medicine (TTM) has a long history of preventing and treating RA. This review provides a comprehensive overview of medicinal plants with anti-RA activity in the TTM system, using classic books of Tibetan medicine, modern research literature, and drug standards. A total of 27 species have been found to be effective in treating RA, including Tinospora sinensis (Lour.) Merr., Terminalia chehula Retz., P. hookeri (C. B. Clarke) Hock.), and Aconitum pendulum Busch. Alkaloids, flavonoids, polyphenols, and terpenoids have turned out to be the major bioactive components for RA treatment. The inhibition of pro-inflammatory cytokine expression by mediating the NF-κB, MAPK, and JAK/STAT pathways is the core mechanism in RA treatment. In conclusion, this review provides key information and research perspectives for further research on the anti-RA effects of TTM.

Aconiti lateralis radix praeparata total alkaloids exert anti-RA effects by regulating NF-κB and JAK/STAT signaling pathways and promoting apoptosis

Aconiti Lateralis Radix Praeparata (“Fuzi” in Chinese) is one of the traditional herbs widely used to intervene rheumatoid arthritis (RA), while Fuzi total alkaloids (FTAs) are the main bioactive components. However, the treatment targets and specific mechanisms of FTAs against RA have not been fully elucidated. The purpose of the present study was to confirm the anti-rheumatism effects of FTAs and reveal its potential molecular mechanisms. In TNF-α-induced MH7A cells model, we found that FTAs showed inhibitory effects on proliferation. While, FTAs significantly decreased the expression levels of IL-1β, IL-6, MMP-1, MMP-3, PGE2, TGF-β, and VEGF. FTAs also enhanced the progress of apoptosis and arrested the cell cycle at G0/G1 phase to prevent excessive cell proliferation. In addition, FTAs inhibited the hyperactivity of NF-κB and JAK/STAT signaling pathways, and regulated the cascade reaction of mitochondrial apoptosis signaling pathway. The results suggested that FTAs exerted anti-inflammatory effects by inhibiting NF-κB and JAK/STAT signaling pathways, promoted apoptosis by stimulating mitochondrial apoptosis signaling pathway, and inhibited cell proliferation by modulating cell cycle progression.

Peimine suppresses collagen-induced arthritis, activated fibroblast-like synoviocytes and TNFα-induced MAPK pathways

BACKGROUND AND PURPOSE

Peimine (PM), a main isosterol alkaloid component isolated from the bulbs of traditional Chinese herb Fritillaria cirrhosa D. Don, has been demonstrated to exhibit multiple pharmacological properties, including anti-inflammation, anti-cancer and pain suppression. However, its effect on rheumatoid arthritis (RA) remains unknown. In the present study, we investigated the effect of PM on collagen-induced arthritis (CIA) rats in vivo and its inhibition on destructive behaviors of arthritic fibroblast-like synoviocytes (FLSs) in vitro.

METHODS

Arthritis was induced in rats by chicken type II collagen. Arthritis score, radiological evaluation, and histopathological assessment were used to evaluate the therapeutic effects of PM on CIA rats. EdU assay, wound healing assay and real-time PCR were used to examine the inhibitory effect of PM on proliferation, migration, and over-expression of pro-inflammatory cytokines in TNFα-induced arthritic FLSs. TRAP staining and scanning electron microscopy were used to analyze the effect of PM on osteoclastogensis and bone resorption. Western blot was used to reveal PM's molecular mechanism of action on RA.

RESULTS

PM significantly suppressed synovitis and bone destruction in CIA rats. In vitro experiments showed that PM treatment significantly inhibited TNFα-induced destructive behaviors of arthritic FLSs, including over-proliferation, migration and over-expression of pro-inflammatory cytokines. Additionally, RANKL-induced osteoclast formation and bone-resorpting function were also inhibited by PM. Further molecular mechanism studies revealed that PM treatment significantly suppressed TNFα-induced activations of MAPKs (ERK, JNK and p38) in arthritic FLSs.

CONCLUSION

Our findings provide strong evidence that PM has the potential to be developed as a therapeutic agent for patients with RA.

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress. Mitochondrial dysfunction can act through modulating innate immunity via redox-sensitive inflammatory pathways or direct activation of the inflammasome. Besides, mitochondria also have a central role in regulating cell death, which is deeply altered in RA. Additionally, multiple evidence suggests that pathological processes in RA can be shaped by epigenetic mechanisms and that in turn, mitochondria are involved in epigenetic regulation. Finally, we will discuss about the involvement of some dietary components in the onset and progression of RA.

Application and pharmacological mechanism of methotrexate in rheumatoid arthritis

Methotrexate (MTX) has been used for the treatment of rheumatoid arthritis (RA) for about forty years and to date MTX remains the part of global standard of treatment for RA. The efficacy of MTX in RA is the result of multiple mechanisms of action. In order to summarize the possible pharmacological mechanisms of MTX in the treatment of RA, this review will elaborate on folate antagonism, promotion of adenosine accumulation, regulation of inflammatory signaling pathways, bone protection and maintenance of immune system function.

NF-κB: A Double-Edged Sword Controlling Inflammation

Inflammation, when properly mounted and precisely calibrated, is a beneficial process that enables the rapid removal of invading pathogens and/or cellular corpses and promotes tissue repair/regeneration to restore homeostasis after injury. Being a paradigm of a rapid response transcription factor, the nuclear factor-kappa B (NF-κB) transcription factor family plays a central role in amplifying inflammation by inducing the expression of inflammatory cytokines and chemokines. Additionally, NF-κB also induces the expression of pro-survival and -proliferative genes responsible for promoting tissue repair and regeneration. Paradoxically, recent studies have suggested that the NF-κB pathway can also exert inhibitory effects on pro-inflammatory cytokine production to temper inflammation. Here, we review our current understanding about the pro- and anti-inflammatory roles of NF-κB and discuss the implication of its dichotomous inflammation-modulating activity in the context of inflammasome activation and tumorigenesis.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 in rheumatoid arthritis: Longitudinal change after treatment and correlation with treatment efficacy of tumor necrosis factor inhibitors

Background

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 (MALT1) correlates with treatment outcomes in inflammatory bowel disease and rheumatoid arthritis (RA). This study aimed to further evaluate the MALT1 longitudinal change and its relationship with tumor necrosis factor inhibitors (TNFi) response in RA patients.

Methods

Seventy‐one RA patients receiving TNFi [etanercept (n = 42) or adalimumab (n = 29)] were enrolled. MALT1 was detected by RT‐qPCR in peripheral blood samples of RA patients before treatment (W0), at week (W)4, W12, and W24 after treatment. RA patients were divided into response/non‐response, remission/non‐remission patients according to their treatment outcome at W24. Meanwhile, MALT1 was also detected by RT‐qPCR in 30 osteoarthritis patients and 30 healthy controls (HCs).

Results

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 was elevated in RA patients compared with HCs (Z=−6.392, p < 0.001) and osteoarthritis patients (Z = −5.020, p < 0.001). In RA patients, MALT1 was positively correlated with C‐reactive protein (r_s = 0.347, p = 0.003), but not other clinical characteristics, treatment history, or current TNFi category. Meanwhile, MALT1 decreased from W0 to W12 in total RA patients (x² = 86.455, p < 0.001), etanercept subgroup (x² = 46.636, p < 0.001), and adalimumab subgroup (x² = 41.291, p < 0.001). Moreover, MALT1 at W24 (p = 0.012) was decreased in response patients compared with non‐response patients; MALT1 at W12 (p = 0.027) and W24 (p = 0.010) were reduced in remission patients than non‐remission patients. In etanercept subgroup, MALT1 at W24 (p = 0.013) was decreased in response patients compared with non‐response patients. In adalimumab subgroup, MALT1 at W24 (p = 0.015) was lower in remission patients than non‐remission patients.

Conclusion

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 reduction after treatment is associated with response and remission to TNFi in RA patients.

New Lanostane-Type Triterpenes with Anti-Inflammatory Activity from the Epidermis of Wolfiporia cocos

A chemical study on the epidermis of cultivated edible mushroom Wolfiporia cocos resulted in the isolation and identification of 46 lanostane triterpenoids, containing 17 new compounds (1-17). An experimental determination of their anti-inflammatory activity showed that poricoic acid GM (39) most strongly inhibited NO production in LPS-induced RAW264.7 murine macrophages with an IC₅₀ value at 9.73 μM. Furthermore, poricoic acid GM induced HO-1 protein expression and inhibited iNOS and COX2 protein expression as well as the release of PGE₂, IL-1β, IL-6, TNF-α, and reactive oxygen species (ROS) in LPS-induced RAW264.7 cells. Mechanistically, poricoic acid GM suppressed the phosphorylation of the IκBα protein, which prevented NF-κB from entering the nucleus to lose transcriptional activity and inhibited the dissociation of Keap1 from Nrf2, thereby activating Nrf2 into the nucleus to regulate antioxidant genes. Furthermore, the MAPK signaling pathway may play a significant role in poricoic acid GM-induced elimination of inflammation. This work further confirms that lanostane triterpenoids are key ingredients responsible for the anti-inflammatory properties of the edible medicinal mushroom W. cocos.

Metabolomics combined with network pharmacology to study the mechanism of Shentong Zhuyu decoction in the treatment of rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Shentong Zhuyu decoction (STZYD) was first recorded in the classic of "Yilin Gaicuo" written by Wang Qingren, and recognized by the Chinese National Administration of Traditional Chinese Medicine as one of the 100 classic formulas. The formula has been widely used in the treatment of rheumatoid arthritis (RA) with significant clinical effects. However, its mechanism of action is not completely clear.

AIM OF THE STUDY

This study aimed to explore the mechanism of STZYD in the treatment of RA by network pharmacology and metabolomics.

MATERIALS AND METHODS

The effects of STZYD anti-RA were investigated by paw swelling, arthritis score, cytokine level, histopathological and micro-CT analysis in adjuvant-induced arthritis (AIA) rats. The chemical constituents of STZYD and absorbed constituents in AIA rat serum were analyzed by UPLC-Q-Exactive MS/MS. Based on the characterized chemical components, the network pharmacology was used to find potential targets and signaling pathways of STZYD in RA treatment. Meanwhile, the predicted pathway was determined by the Western blot (WB). Subsequently, non-targeted metabolomics of serum was performed to analyze metabolic profiles, potential biomarkers, and metabolic pathways of STZYD in the treatment of RA based on LC-MS technology.

RESULTS

STZYD significantly alleviated RA symptoms by improving paw redness and swelling, bone and cartilage damage, synovial hyperplasia, and infiltration of inflammatory cells, and decreased the generation of pro-inflammatory cytokines IL-1β, IL-6, IL-17A and TNF-α in AIA rats. Totally, 59 chemical components of STZYD and 24 serum migrant ingredients were identified. A total of 655 genes of potential bioactive components in STZYD and 1025 related genes of RA were obtained. TNF signaling pathway was considered to one of the main signaling pathways of STZYD anti-RA by KEGG analysis, including a wide range intracellular signaling pathways. NF-κB signaling pathway regulates inflammation and immunity in the TNF signaling pathway. STZYD markedly inhibited the expression of NF-κB signaling pathway. Ten potential biomarkers were found in metabolomics based on LC-MS technology. Alanine, aspartate and glutamate metabolism, arachidonic acid metabolism are the most related pathways of STZYD anti-RA.

CONCLUSION

The study based on serum pharmacochemistry, network pharmacology and metabolomics indicated that STZYD can improve RA through regulating inflammation and immunity related pathways, and provided a new possibility for treatment of RA.

OX40-Fc Fusion Protein Alleviates PD-1-Fc-Aggravated Rheumatoid Arthritis by Inhibiting Inflammatory Response

BACKGROUND

Researches have confirmed that the abnormal signals of OX40 and PD-1 lead to the changes of T cell biological behavior, thus participating the immunopathological process of RA. However, the pathogenesis of RA immunopathological process has not been clarified yet.

METHODS

30 DBA/1 mice were randomly divided into 5 groups (6 mice per group): control group, collagen-induced arthritis (CIA) group, PD-1-Fc/CIA group, OX40-Fc/CIA group, and PD-1-Fc + OX40-Fc/CIA group. The pathological changes in mice joints were observed by H&E staining. The proportion of CD4+ T, CD8+ T, CD28+, and CD19+ cells in peripheral blood mononuclear cells (PBMCs) was detected by flow cytometry. Serum inflammatory factors (CRP, IL-2, IL-4, IL-1β, INF-γ) and bone metabolism-related genes (CTX-I, TRACP-5b, BALP) were detected by ELISA assay. Western blotting was applied to measure the NF-κB signaling pathway-related protein (p-IKKβ, p-IκBα, p50) expression in synovial tissue of mice joint.

RESULTS

Compared with the control group, CIA mice showed significant increases in arthritis score and pathological score. In the CIA group, a marked decrease was identified in the proportion of CD8+ T, CD19+, and CD68+ cells. Additionally, the CIA group was associated with upregulation of secretion of inflammatory factors in serum and expression of bone metabolism-related genes and NF-κB pathway-related proteins. Compared with the CIA group, the same indexes above showed a further aggravation in the PD-1-Fc group while all indexes improved in the OX40-Fc group. Besides, OX40-Fc fusion protein slowed down significantly the further deterioration of CIA mouse pathological process caused by PD-1-Fc fusion protein.

CONCLUSION

OX40-Fc fusion protein alleviates PD-1-Fc-aggravated RA by inhibiting inflammatory response. This research provides biological markers with clinical significance for diagnosis and prognosis of RA, as well as offers theoretical and experimental foundation to the new targets for immune intervention.

Sesquiterpene Lactones from Sigesbeckia glabrescens Possessing Potent Anti-inflammatory Activity by Directly Binding to IKKα/β

Chromatographic fractionation of Sigesbeckia glabrescens led to the identification of 10 new sesquiterpene lactones, named siegesbeckialides I-O (1-7) and glabrescones A-C (8-10), along with 14 known analogues. An anti-inflammatory activity assay showed that siegesbeckialide I (1) most potently inhibited LPS-induced NO production in RAW264.7 murine macrophages. Furthermore, siegesbeckialide I suppressed the protein expression of iNOS and COX2, as well as the release of PGE₂, IL-1β, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells. Mechanistically, siegesbeckialide I directly binds to inhibitors of IKKα/β and suppresses their phosphorylation. This leads to the inhibition of IKKα/β-mediated phosphorylation and degradation of inhibitor α of NF-κB (IκBα), as well as the activation of NF-κB signaling.

Assessment of genetic polymorphisms within nuclear factor-κB signaling pathway genes in rheumatoid arthritis: Evidence for replication and genetic interaction

OBJECTIVE

This study was performed to replicate the associations of genetic polymorphisms within nuclear factor-κB (NF-κB) signaling pathway genes with rheumatoid arthritis (RA), and to further examine genetic interactions in a Chinese population.

METHODS

A total of eleven single-nucleotide polymorphisms (SNPs) were genotyped in 594 RA patients and 604 healthy controls.

RESULTS

Genetic association analysis revealed that NFKBIE rs2233434, TNIP1 rs10036748 and BLK rs13277113 were significantly associated with RA, cyclic citrullinated peptide (CCP)-positive RA and rheumatoid factor (RF)-positive RA, and TNFAIP3 rs2230926 was significantly associated with CCP-positive RA. Significant additive interaction was observed between NFKB1 rs28362491 and IKBKE rs12142086 (RERI = 0.76, 95% CI 0.13-1.38; AP = 0.57, 95% CI 0.11-1.03), NFKBIE rs2233434 and BLK rs13277113 (RERI = 1.41, 95% CI 0.88-1.94; AP = 0.85, 95% CI 0.50-1.20), NFKBIL rs2071592 and TNIP1 rs10036748 (RERI = 0.59, 95% CI 0.17-1.02; AP = 0.46, 95% CI 0.05-0.87), UBE2L3 rs5754217 and TNFSF4 rs2205960 (RERI = 0.50, 95% CI 0.16-0.84; AP = 0.57, 95% CI 0.09-1.05). Significant multiplicative interaction was detected between BLK rs13277113 and UBE2L3 rs5754217 (p = 0.02), BLK rs13277113 and TNFSF4 rs2205960 (p = 0.03).

CONCLUSIONS

Our results lent further support to the role of NF-κB signaling pathway in the pathogenesis of RA from a genetic perspective.

MLL3 Inhibits Apoptosis of Rheumatoid Arthritis Fibroblast-Like Synoviocytes and Promotes Secretion of Inflammatory Factors by Activating CCL2 and the NF-κB Pathway

Rheumatoid arthritis (RA) remains the most common inflammatory arthritis and a major cause of disability. This study investigated the mechanism of MLL3 in fibroblast-like synoviocyte (FLS) apoptosis and inflammatory factor secretion in RA. Expression of MLL3 in synovial tissue of RA patients and patients with bone trauma was detected. FLS was isolated and identified by flow cytometry. Expressions of TNF-α, IL-1β, IL-8, and IL-10 and apoptosis were measured by MTT, flow cytometry, and ELISA. Western blot and qRT-PCR were performed to detect MLL3 and CCL2 expressions, H3K4me3 level, and NF-κB pathway-related proteins in rat joints. MLL3 was highly expressed in the synovial tissue of RA patients, and silencing MLL3 in FLS-RA promoted apoptosis, inhibited pro-inflammatory factors TNF-α, IL-1β, and IL-8 secretion, and promoted anti-inflammatory factor IL-10 secretion. Inhibition of MLL3 suppressed intracellular H3K4me3 and CCL2 expressions. CCL2 activated the NF-κB pathway to promote pro-inflammatory factors TNF-α, IL-1β, and IL-8, inhibit anti-inflammatory factor IL-10, and inhibit apoptosis in FLS-RA. Inhibition of MLL3 expression in RA rats reduced joint redness, swelling, and intra-articular inflammation, but increasing H3K4me3 level reversed the ameliorative effects of sh-MLL3 on RA rats. Collectively, MLL3 activated the NF-κB pathway by increasing H3K4me3 modification in the CCL2 promoter region in FLS-RA, thereby inhibiting apoptosis and promoting pro-inflammatory factors of FLS-RA.