Role of reactive oxygen species and mitochondrial damage in rheumatoid arthritis and targeted drugs

Fangji Huangqi Decoction alleviates rheumatoid arthritis through regulating HIF-1α mediated the angiogenesis and the balance between autophagy and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Fangji Huangqi Decoction (FHD) is frequently prescribed for the clinical treatment of wind-cold and wind-dampness pathogenic superficial deficiency syndrome. It also has a notable curative effect on rheumatoid arthritis (RA).

AIM OF THE STUDY

The study aimed to explore the possible mechanism of FHD against RA and provided a theoretical basis for alternative therapies for RA.

MATERIALS AND METHODS

We used UPLC-Q-TOF-MS to analysis the ingredients and absorbed blood components of FHD. At the same time, the collagen-induced arthritis (CIA) rat model was established to estimate the therapeutic effects on FHD by considering body weight, arthritis score, paw swelling, autonomous movement ability, and synovial microvessel counts. Subsequently, immunofluorescence, immunohistochemistry, and Western blot were employed to detect the anti-angiogenic capacity of FHD in vivo, as well as the levels of apoptosis and autophagy in the synovial tissue. In addition, flow cytometry and Western blot were used to assess the effects of FHD on apoptosis and autophagy in MH7A cells. The effects of FHD on the proliferation and migration of MH7A cells were measured by CCK8 assay, cell migration and, invasion experiments. Finally, a tube formation assay was performed to evaluate the angiogenic capacity of FHD in co-cultures of MH7A cells and HUVEC cells.

RESULTS

Through testing of FHD's original formula, a total of 26 active ingredients have been identified, with 17 of them being absorbed into the bloodstream. FHD significantly improved the pathological symptoms and synovial hyperplasia of CIA rats. FHD could suppress the expression of HIF-1α, promote apoptosis in CIA rat synovial tissue, and suppress autophagy and angiogenesis. In vitro experiments showed that serum containing FHD inhibited the proliferation, migration, and invasion of MH7A cells, and also suppressed the expression of autophagy-related proteins while promoting apoptosis. FHD markedly repressed the expression of HIF-1α protein in TNF-α-stimulated MH7A cells and inhibited the tube formation capacity induced by MH7A cells in HUVEC cells.

CONCLUSIONS

The study had proven that FHD played an excellent anti-RA role, which may be attributed to its potential mechanism of regulating the balance between autophagy and apoptosis in RA FLS by suppressing the HIF-1α, thus contributing to its anti-angiogenic activities.

IFNγ causes mitochondrial dysfunction and oxidative stress in myositis

Idiopathic inflammatory myopathies (IIMs) are severe autoimmune diseases with poorly understood pathogenesis and unmet medical needs. Here, we examine the role of interferon γ (IFNγ) using NOD female mice deficient in the inducible T cell co-stimulator (Icos), which have previously been shown to develop spontaneous IFNγ-driven myositis mimicking human disease. Using muscle proteomic and spatial transcriptomic analyses we reveal profound myofiber metabolic dysregulation in these mice. In addition, we report muscle mitochondrial abnormalities and oxidative stress in diseased mice. Supporting a pathogenic role for oxidative stress, treatment with a reactive oxygen species (ROS) buffer compound alleviated myositis, preserved muscle mitochondrial ultrastructure and respiration, and reduced inflammation. Mitochondrial anomalies and oxidative stress were diminished following anti-IFNγ treatment. Further transcriptomic analysis in IIMs patients and human myoblast in vitro studies supported the link between IFNγ and mitochondrial dysfunction observed in mice. These results suggest that mitochondrial dysfunction, ROS and inflammation are interconnected in a self-maintenance loop, opening perspectives for mitochondria therapy and/or ROS targeting drugs in myositis.

Viral Mimicking Polyplexes as Hierarchical Unpacking Vectors for Rheumatoid Arthritis Treatment

Nano-delivery systems hold great promise for the treatment of rheumatoid arthritis (RA). Current research efforts are primarily focused on enhancing their targeting capabilities and efficacy. Here, this study proposes a novel viral-mimicking ternary polyplexes system for the controlled delivery of the anti-inflammatory drug Cyclosporin A (CsA) to effectively treat RA. The ternary polyplexes consist of a nanogel core loaded with CsA and a hyaluronic acid shell, which facilitates CD44-mediated targeting. By mimicking the Trojan Horse strategy employed by viruses, these polyplexes undergo a stepwise process of deshielding and disintegration within the inflamed joints. This process leads to the release of CsA within the cells and the scavenging of pathogenic factors. This study demonstrates that these viral-mimicking ternary polyplexes exhibit rapid targeting, high accumulation, and prolonged persistence in the joints of RA mice. As a result, they effectively reduce inflammation and alleviate symptoms. These results highlight the potential of viral-mimicking ternary polyplexes as a promising therapeutic approach for the targeted and programmed delivery of drugs to treat not only RA but also other autoimmune diseases.

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.

A dual dynamically cross-linked hydrogel promotes rheumatoid arthritis repair through ROS initiative regulation and microenvironment modulation-independent triptolide release

High oxidative stress and inflammatory cell infiltration are major causes of the persistent bone erosion and difficult tissue regeneration in rheumatoid arthritis (RA). Triptolide (TPL) has become a highly anticipated anti-rheumatic drug due to its excellent immunomodulatory and anti-inflammatory effects. However, the sudden drug accumulation caused by the binding of "stimulus-response" and "drug release" in a general smart delivery system is difficult to meet the shortcoming of extreme toxicity and the demand for long-term administration of TPL. Herein, we developed a dual dynamically cross-linked hydrogel (SPT@TPL), which demonstrated sensitive RA microenvironment regulation and microenvironment modulation-independent TPL release for 30 days. The abundant borate ester/tea polyphenol units in SPT@TPL possessed the capability to respond and regulate high reactive oxygen species (ROS) levels on-demand. Meanwhile, based on its dense dual crosslinked structure as well as the spontaneous healing behavior of numerous intermolecular hydrogen bonds formed after the breakage of borate ester, TPL could remain stable and slowly release under high ROS environments of RA, which dramatically reduced the risk of TPL exerting toxicity while maximized its long-term efficacy. Through the dual effects of ROS regulation and TPL sustained-release, SPT@TPL alleviated oxidative stress and reprogrammed macrophages into M2 phenotype, showing marked inhibition of inflammation and optimal regeneration of articular cartilage in RA rat model. In conclusion, this hydrogel platform with both microenvironment initiative regulation and TPL long-term sustained release provides a potential scheme for rheumatoid arthritis.

Biomimetic Integrated Nanozyme for Flare and Recurrence of Gouty Arthritis

Flare and multiple recurrences pose significant challenges in gouty arthritis. Traditional treatments provide temporary relief from inflammation but fail to promptly alleviate patient pain or effectively prevent subsequent recurrences. It should also be noted that both anti-inflammation and metabolism of uric acid are necessary for gouty arthritis, calling for therapeutic systems to achieve these two goals simultaneously. In this study, we propose a biomimetic integrated nanozyme, HMPB-Pt@MM, comprising platinum nanozyme and hollow Prussian blue. It demonstrates anti-inflammatory properties by eliminating reactive oxygen species and reducing infiltration of inflammatory macrophages. Additionally, it rapidly targets inflamed ankles through the camouflage of macrophage membranes. Furthermore, HMPB-Pt@MM exhibits urate oxidase-like capabilities, continuously metabolizing locally elevated uric acid concentrations, ultimately inhibiting multiple recurrences of gouty arthritis. In summary, HMPB-Pt@MM integrates ROS clearance with uric acid metabolism, offering a promising platform for the treatment of gouty arthritis.

Precise modulation and use of reactive oxygen species for immunotherapy

Reactive oxygen species (ROS) play an important role in regulating the immune system by affecting pathogens, cancer cells, and immune cells. Recent advances in biomaterials have leveraged this mechanism to precisely modulate ROS levels in target tissues for improving the effectiveness of immunotherapies in infectious diseases, cancer, and autoimmune diseases. Moreover, ROS-responsive biomaterials can trigger the release of immunotherapeutics and provide tunable release kinetics, which can further boost their efficacy. This review will discuss the latest biomaterial-based approaches for both precise modulation of ROS levels and using ROS as a stimulus to control the release kinetics of immunotherapeutics. Finally, we will discuss the existing challenges and potential solutions for clinical translation of ROS-modulating and ROS-responsive approaches for immunotherapy, and provide an outlook for future research.

Associations between periodontitis and serum anti-malondialdehyde-acetaldehyde antibody concentrations in rheumatoid arthritis: A case-control study

BACKGROUND

Malondialdehyde-acetaldehyde (MAA) adducts lead to generation of anti-MAA autoantibodies and have been independently identified in inflamed periodontal and rheumatoid arthritis (RA) tissues. This study evaluates serum samples from RA cases and osteoarthritis (OA) controls to quantify associations between periodontal clinical measures, alveolar bone loss (ABL), and anti-Porphyromonas gingivalis, anti-Prevotella intermedia, and anti-Fusobacterium nucleatum antibody concentrations with anti-MAA antibody concentrations.

METHODS

Participants (n = 284 RA cases, n = 330 OA controls) underwent periodontal clinical assessments and ABL measurements. Serum immunoglobulin (Ig) A, IgG, and IgM anti-MAA and serum IgG antibacterial antibody concentrations were quantified by enzyme-linked immunosorbent assay (ELISA). Analyses utilized simple linear regression and multivariable adjusted models.

RESULTS

No significant associations of periodontal clinical measures with serum anti-MAA were found. Moderate (p = 0.038 and p = 0.036, respectively) and high ABL (p = 0.012 and p = 0.014, respectively) in RA cases (but not in OA) were positively associated with IgG and IgM anti-MAA. Anti-P. gingivalis and anti-P. intermedia antibody concentrations were positively associated with IgA (p = 0.001 for both), IgG (p = 0.007 and p = 0.034, respectively), and IgM anti-MAA antibody concentrations (p < 0.001 and p = 0.020, respectively), while anti-F. nucleatum was positively associated with IgG anti-MAA (p = 0.042), findings that were similar across groups.

CONCLUSIONS

A positive association was demonstrated between ABL and serum IgG and IgM anti-MAA antibody concentrations that was unique to RA and not observed in OA. Serum anti-P. gingivalis, anti-P. intermedia, and anti-F. nucleatum antibody concentrations displayed significant associations with anti-MAA antibody in both groups. These findings suggest MAA may play a role in the interrelationship between the periodontium and RA.

Redox mechanisms in autoimmune thyroid eye disease

Thyroid eye disease (TED) is an autoimmune condition affecting the orbit and the eye with its adnexa, often occurring as an extrathyroidal complication of Graves' disease (GD). Orbital inflammatory infiltration and the stimulation of orbital fibroblasts, triggering de novo adipogenesis, an overproduction of hyaluronan, myofibroblast differentiation, and eventual tissue fibrosis are hallmarks of the disease. Notably, several redox signaling pathways have been shown to intensify inflammation and to promote adipogenesis, myofibroblast differentiation, and fibrogenesis by upregulating potent cytokines, such as interleukin (IL)-1β, IL-6, and transforming growth factor (TGF)-β. While existing treatment options can manage symptoms and potentially halt disease progression, they come with drawbacks such as relapses, side effects, and chronic adverse effects on the optic nerve. Currently, several studies shed light on the pathogenetic contributions of emerging factors within immunological cascades and chronic oxidative stress. This review article provides an overview on the latest advancements in understanding the pathophysiology of TED, with a special focus of the interplay between oxidative stress, immunological mechanisms and environmental factors. Furthermore, cutting-edge therapeutic approaches targeting redox mechanisms will be presented and discussed.

Mechanisms of vascular invasion after cartilage injury and potential engineering cartilage treatment strategies

Articular cartilage injury is one of the most common diseases in orthopedic clinics. Following an articular cartilage injury, an inability to resist vascular invasion can result in cartilage calcification by newly formed blood vessels. This process ultimately leads to the loss of joint function, significantly impacting the patient's quality of life. As a result, developing anti-angiogenic methods to repair damaged cartilage has become a popular research topic. Despite this, tissue engineering, as an anti-angiogenic strategy in cartilage injury repair, has not yet been adequately investigated. This exhaustive literature review mainly focused on the process and mechanism of vascular invasion in articular cartilage injury repair and summarized the major regulatory factors and signaling pathways affecting angiogenesis in the process of cartilage injury. We aimed to discuss several potential methods for engineering cartilage repair with anti-angiogenic strategies. Three anti-angiogenic tissue engineering methods were identified, including administering angiogenesis inhibitors, applying scaffolds to manage angiogenesis, and utilizing in vitro bioreactors to enhance the therapeutic properties of cultured chondrocytes. The advantages and disadvantages of each strategy were also analyzed. By exploring these anti-angiogenic tissue engineering methods, we hope to provide guidance for researchers in related fields for future research and development in cartilage repair.

Ingenious Synergy of a Pathology-Specific Biomimetic Multifunctional Nanoplatform for Targeted Therapy in Rheumatoid Arthritis

Based on the pathological characteristics of rheumatoid arthritis, including the overproduction of reactive oxygen species (ROS), inflammatory responses, and osteoclast differentiation, a biomimetic multifunctional nanomedicine (M-M@I) is designed. Iguratimod (IGU) is loaded, which inhibits inflammatory responses and osteoclast differentiation, into mesoporous polydopamine (MPDA), which scavenges ROS. Subsequently, the nanoparticles are coated with a cell membrane of macrophages to achieve actively targeted delivery of the nanoparticles to inflamed joints. It is shown that the M-M@I nanoparticles are taken up well by lipopolysaccharide-induced RAW 264.7 macrophages or bone marrow-derived macrophages (BMDMs). In vitro, the M-M@I nanoparticles effectively scavenge ROS, downregulate genes related to inflammation promotion and osteoclast differentiation, and reduce the proinflammatory cytokines and osteoclast-related enzymes. They also reduce the polarization of macrophages to a pro-inflammatory M1 phenotype and inhibit differentiation into osteoclasts. In mice with collagen-induced arthritis, the M-M@I nanoparticles accumulate at arthritic sites and circulate longer, significantly mitigating arthritis symptoms and bone destruction. These results suggest that the pathology-specific biomimetic multifunctional nanoparticles are effective against rheumatoid arthritis, and they validate the approach of developing multifunctional therapies that target various pathological processes simultaneously.

Molecular mechanism of Xiaohuoluo wan for rheumatoid arthritis by integrating in vitro and in vivo chemomics and network pharmacology

The cause of rheumatoid arthritis (RA) is unclear. Xiaohuoluo wan (XHLW) is a classical Chinese medicine that is particularly effective in the treatment of RA. Given the chemical composition of XHLW at the overall level has been little studied and the molecular mechanism for the treatment of RA is not clear, we searched for the potential active compounds of XHLW and explored their anti-inflammatory mechanism in the treatment of RA by flexibly integrating the high-resolution ultra-performance liquid chromatography-mass spectrometry (UPLC-MS)-based in vitro and in vivo chemomics, network pharmacology, and other means. The results of the study identified that the active compounds of XHLW, such as alkaloids, nucleosides, and fatty acids, may play an anti-inflammatory role by regulating key targets such as IL-2, STAT1, JAK3, and MAPK8, inducing immune response through IL-17 signaling pathway, T-cell receptor, FoxO, tumor necrosis factor (TNF), and so forth, inhibiting the release of inflammatory factors and resisting oxidative stress and other pathways to treat RA. The results of this study provide referable data for the screening of active compounds and the exploration of molecular mechanisms of XHLW in the treatment of RA.

Cardamonin decreases inflammatory mediator expression in IL-1β-stimulated human periodontal ligament cells

BACKGROUND

Cardamonin is classified as a natural chalcone, and has been reported to possess various bioactive effects. However, there have been limited attempts to utilize cardamonin in the treatment of periodontitis. This study aimed to investigate whether cardamonin has anti-inflammatory effects on human periodontal ligament cells (HPDLCs), which are a component cell of periodontal tissue. Specifically, the study seeks to determine whether cardamonin affects the expression of inflammatory mediators, such as cytokines and adhesion molecules, induced by interleukin-1β (IL-1β) in HPDLCs, as well as the signaling pathways activated by IL-1β.

METHODS

Cytokine and chemokine levels in supernatants of HPDLCs were measured by ELISA. Western blot analysis was used to measure protein expression and signal transduction pathway activation in HPDLCs.

RESULTS

We found that IL-1β-induced CC chemokine ligand (CCL)2, CCL5, CCL20, CXC-chemokine ligand (CXCL)10, and interleukin (IL)-6 production and intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expression in HPDLCs were suppressed by cardamonin treatment. We also found that cardamonin suppressed IL-1β-activated nuclear factor (NF)-κB pathway, and the phosphorylation of signal transducer and activator of transcription (STAT)3. Furthermore, cardamonin treatment enhanced the expression of the antioxidant enzymes, heme oxygenase (HO)-1 and NAD(P)H dehydrogenase [quinone] 1 (NQO1), in HPDLCs.

CONCLUSION

In this study, we found that cardamonin could suppress the production of inflammatory mediators in HPDLCs as well as the activation of several signaling pathways induced by IL-1β treatment.

Study of the DNA damage and cell death in human peripheral blood mononuclear and HepG2/C3A cells exposed to the synthetic 3-(3-hydroxyphenyl)-7-hydroxycoumarin

Hydroxycoumarins are an important source of biologically active compounds. Previous studies have shown that the number and position of the hydroxyl substituents in the scaffold play an important role for the observed biological activity. In the present study, 3-(3-hydroxyphenyl)-7-hydroxycoumarin was synthesized, and potential cytogenotoxic effects determined in human HepG2/C3A cells displaying phase 1 and phase 2 enzymes (metabolizing cell ability) and compared to human peripheral blood mononuclear cells (PBMC) without xenobiotics metabolizing capacity. Cell viability was determined with concentrations between 0.01 and 10 µg/ml of 3-(3-hydroxyphenyl)-7-hydroxycoumarin using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and trypan blue tests. Genotoxicity was determined utilizing the comet assay, and the clastogenic/aneugenic potential employing the micronucleus (MN) test. The results of the in vitro cytotoxicity assays showed a significant decrease in cell viability of PBMC following exposure to 10 µg/ml concentration of the studied compound after 48 and 72 hr. Comet assay observations noted significant DNA damage in PBMC after 4 hr treatment. No marked cytogenotoxic effects were found in HepG2/C3A cells. No chromosomal mutations were observed in both cell lines. It is important to note that 3-(3-hydroxyphenyl)-7-hydroxycoumarin may exert beneficial pharmacological actions at the low micromolar range and with half-life less than 24 hr. Therefore, the results obtained encourage the continuation of studies on this new molecule for medicinal purposes, but its potential toxicity at higher concentrations and longer exposure times needs to be investigated in further studies.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.

Exploring the effect of LncRNA DANCR to regulate the Keap1-Nrf2/ARE pathway on oxidative stress in rheumatoid arthritis

INTRODUCTION

Aberrant expression of long noncoding RNAs (LncRNAs) can regulate oxidative stress in rheumatoid arthritis (RA). This study focused on investigating the effects of LncRNA differentiation antagonizing nonprotein coding RNA (DANCR) regulation of Keap1-Nrf2/ARE pathway on inflammation and oxidative stress in RA.

METHODS

The levels of LncRNA DANCR/miR-486-3p/Keap1 in peripheral blood of 30 RA groups and 30 normal subjects were examined, and the association of LncRNA DANCR with inflammatory indicators of RA was investigated. We stimulated fibroblast-like synoviocytes (FLS) from RA patients with tumor necrosis factor α and subsequently performed in vitro cellular assays to construct overexpression plasmids and small interfering RNAs of LncRNA DANCR to investigate the relationship between LncRNA DANCR and FLSs viability and migration in RA, as well as the effects on cellular oxidative stress factors and Keap1-Nrf2/ARE pathway; molecular biology analysis was used to predict microRNAs that can bind LncRNA DANCR, and luciferase verified the binding sites of LncRNA DANCR with Keap1 and miR-486-3p; to further refine the gene and protein expression results, we used reverse transcription-quantitative polymerase chain reaction and immunoblotting assays.

RESULTS

In both groups of peripheral blood mononuclear cells, the expression levels of LncRNA DANCR and Keap1 messenger RNA were higher in the RA group than in the normal control group, and the opposite was true for miR-486-3p; LncRNA DANCR was positively correlated with total antioxidant capacity (TAOC), IL6, IL17, malondialdehyde (MDA), but not with IL11, rheumatoid factor, cyclic citrullinated peptide, superoxide dismutase (SOD), with 28-joint disease activity score, reactive oxygen species, C-reactive protein, and erythrocyte sedimentation rate were negatively correlated; overexpression of LncRNA DANCR stimulated the Keap1-Nrf2/ARE pathway, decreased the expression of IL10, SOD, TAOC, and increased the expression levels of MDA, IL11, IL-17, PD-L1, and silencing of LncRNA DANCR was the opposite, but knockdown of miR-486-3p or overexpression of keap1 reversed the expression of the above-mentioned inflammatory and oxidative factors. In addition, pcDNA-DANCR clearly showed stronger cell invasion and migration ability and exacerbated its inflammatory response, which may be related to the regulatory role of miR-486-3p and Keap1-Nrf2/ARE signaling pathway, and we verified their targeting relationship using dual luciferase, showing that DANCR could regulate Keap1-Nrf2/ARE through miR-486-3p modulates the Keap1-Nrf2/ARE pathway and affects inflammatory and oxidative responses in RA patients.

CONCLUSION

The low-expressed LncRNA DANCR may regulate the Keap1-Nrf2/ARE pathway and suppress the inflammatory and oxidative responses in RA patients.

A comprehensive review of Tripterygium wilfordii hook. f. in the treatment of rheumatic and autoimmune diseases: Bioactive compounds, mechanisms of action, and future directions

Rheumatic and autoimmune diseases are a group of immune system-related disorders wherein the immune system mistakenly attacks and damages the body's tissues and organs. This excessive immune response leads to inflammation, tissue damage, and functional impairment. Therapeutic approaches typically involve medications that regulate immune responses, reduce inflammation, alleviate symptoms, and target specific damaged organs. Tripterygium wilfordii Hook. f., a traditional Chinese medicinal plant, has been widely studied in recent years for its application in the treatment of autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. Numerous studies have shown that preparations of Tripterygium wilfordii have anti-inflammatory, immunomodulatory, and immunosuppressive effects, which effectively improve the symptoms and quality of life of patients with autoimmune diseases, whereas the active metabolites of T. wilfordii have been demonstrated to inhibit immune cell activation, regulate the production of inflammatory factors, and modulate the immune system. However, although these effects contribute to reductions in inflammatory responses and the suppression of autoimmune reactions, as well as minimize tissue and organ damage, the underlying mechanisms of action require further investigation. Moreover, despite the efficacy of T. wilfordii in the treatment of autoimmune diseases, its toxicity and side effects, including its potential hepatotoxicity and nephrotoxicity, warrant a thorough assessment. Furthermore, to maximize the therapeutic benefits of this plant in the treatment of autoimmune diseases and enable more patients to utilize these benefits, efforts should be made to strengthen the regulation and standardized use of T. wilfordii.

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.

Cross-reactivity and sequence similarity between microbial transglutaminase and human tissue antigens

Microbial transglutaminase (mTG) is a bacterial survival factor, frequently used as a food additive to glue processed nutrients. As a result, new immunogenic epitopes are generated that might drive autoimmunity. Presently, its contribution to autoimmunity through epitope similarity and cross-reactivity was investigated. Emboss Matcher was used to perform sequence alignment between mTG and various antigens implicated in many autoimmune diseases. Monoclonal and polyclonal antibodies made specifically against mTG were applied to 77 different human tissue antigens using ELISA. Six antigens were detected to share significant homology with mTG immunogenic sequences, representing major targets of common autoimmune conditions. Polyclonal antibody to mTG reacted significantly with 17 out of 77 tissue antigens. This reaction was most pronounced with mitochondrial M2, ANA, and extractable nuclear antigens. The results indicate that sequence similarity and cross-reactivity between mTG and various tissue antigens are possible, supporting the relationship between mTG and the development of autoimmune disorders 150W.

LncRNA HOTAIR regulates the PI3K/AKT pathway via the miR-126-3p/PIK3R2 axis to participate in synovial angiogenesis in rheumatoid arthritis

BACKGROUND

The abnormal expression of long noncoding RNA (LncRNA) HOTAIR has been associated with synovial angiogenesis in rheumatoid arthritis (RA). The aim of this study is to investigate whether LncRNA HOTAIR plays a role in synovial angiogenesis in RA by regulating the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway through the miR-126-3p/PIK3R2 axis.

METHODS

In this study, we conducted in vitro experiments by designing overexpression plasmids and small interfering RNAs targeting LncRNA HOTAIR and then transfected them into rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). We then co-cultured the RA-FLS with human umbilical vein endothelial cells (HUVEC) to establish a RA-FLS-induced HUVEC model. We investigated the effects of LncRNA HOTAIR on the proliferation, migration, lumen forming ability of HUVEC, as well as the expression of synovial endothelial cell markers, angiogenic factors, and the PI3K/AKT pathway. To validate the interactions between LncRNA HOTAIR, miR-126-3p, and PIK3R2, we used bioinformatics and luciferase reporter experiments. We also employed real-time fluorescence quantitative, Western blotanalysis, and immunofluorescence techniques to analyze the target genes and proteins.

RESULTS

The expression of LncRNA HOTAIR was upregulated in HUVEC induced by RA-FLS. The overexpression of LncRNA HOTAIR significantly increased the expression of vascular endothelial growth factor, basic fibroblast growth factor, CD34, and CD105 in HUVEC, promoting their proliferation, migration, and lumen formation. At the same time, the overexpression of LncRNA HOTAIR inhibited the expression of miR-126-3p, promoted the expression of PIK3R2, activated the PI3K/AKT pathway, and promoted the expression of PI3K, AKT and phosphorylated-AKT, while the silence of LncRNA HOTAIR reversed these expressions. Bioinformatics and double luciferase reporter gene experiments confirmed the targeting relationship among LncRNA HOTAIR, miR-126-3p, and PIK3R2. Finally, the rescue experiments showed that PI3K agonists could reverse the inhibitory effect of silent LncRNA HOTAIR on HUVEC.

CONCLUSION

LncRNA HOTAIR has the potential to activate the PI3K/AKT pathway, likely through the regulatory axis involving miR-126-3p/PIK3R2, consequently contributing to synovial angiogenesis in RA.

Exploring Natural Products as Radioprotective Agents for Cancer Therapy: Mechanisms, Challenges, and Opportunities

Radiotherapy is an important cancer treatment. However, in addition to killing tumor cells, radiotherapy causes damage to the surrounding cells and is toxic to normal tissues. Therefore, an effective radioprotective agent that prevents the deleterious effects of ionizing radiation is required. Numerous synthetic substances have been shown to have clear radioprotective effects. However, most of these have not been translated for use in clinical applications due to their high toxicity and side effects. Many medicinal plants have been shown to exhibit various biological activities, including antioxidant, anti-inflammatory, and anticancer activities. In recent years, new agents obtained from natural products have been investigated by radioprotection researchers, due to their abundance of sources, high efficiency, and low toxicity. In this review, we summarize the mechanisms underlying the radioprotective effects of natural products, including ROS scavenging, promotion of DNA damage repair, anti-inflammatory effects, and the inhibition of cell death signaling pathways. In addition, we systematically review natural products with radioprotective properties, including polyphenols, polysaccharides, alkaloids, and saponins. Specifically, we discuss the polyphenols apigenin, genistein, epigallocatechin gallate, quercetin, resveratrol, and curcumin; the polysaccharides astragalus, schisandra, and Hohenbuehelia serotina; the saponins ginsenosides and acanthopanax senticosus; and the alkaloids matrine, ligustrazine, and β-carboline. However, further optimization through structural modification, improved extraction and purification methods, and clinical trials are needed before clinical translation. With a deeper understanding of the radioprotective mechanisms involved and the development of high-throughput screening methods, natural products could become promising novel radioprotective agents.

Potential therapeutic targets beyond cytokines and Janus kinases for autoimmune arthritis

Synovial inflammation and destruction of articular cartilage and bone are hallmarks of autoimmune arthritis. Although current efforts to inhibit proinflammatory cytokines (biologics) or block Janus kinases (JAK) appear to be promising in many patients with autoimmune arthritis, adequate disease control is still lacking in a significant proportion of autoimmune arthritis patients. The possible adverse events from taking biologics and JAK inhibitors, such as infection, remain a major concern. Recent advances showing the effects of a loss of balance between regulatory T cells and T helper-17 cells as well as how the imbalance between osteoblastic and osteoclastic activities of bone cells exaggerates joint inflammation, bony destruction and systemic osteoporosis highlight an interesting area to explore in the search for better therapeutics. The recognition of the heterogenicity of synovial fibroblasts in osteoclastogenesis and their crosstalk with immune and bone cells provides an opportunity for identifying novel therapeutic targets for autoimmune arthritis. In this commentary, we comprehensively review the current knowledge regarding the interactions among heterogenic synovial fibroblasts, bone cells and immune cells and how they contribute to the immunopathogenesis of autoimmune arthritis, as well as the search for novel therapeutic targets not targeted by current biologics and JAK inhibitors.

Danthron, an Anthraquinone Isolated from a Marine Fungus, Is a New Inhibitor of Angiogenesis Exhibiting Interesting Antitumor and Antioxidant Properties

The role played by a sustained angiogenesis in cancer and other diseases stimulates the interest in the search for new antiangiogenic drugs. In this manuscript, we provide evidence that 1,8- dihydroxy-9,10-anthraquinone (danthron), isolated from the fermentation broth of the marine fungus Chromolaenicola sp. (HL-114-33-R04), is a new inhibitor of angiogenesis. The results obtained with the in vivo CAM assay indicate that danthron is a potent antiangiogenic compound. In vitro studies with human umbilical endothelial cells (HUVEC) reveal that this anthraquinone inhibits certain key functions of activated endothelial cells, including proliferation, proteolytic and invasive capabilities and tube formation. In vitro studies with human breast carcinoma MDA-MB231 and fibrosarcoma HT1080 cell lines suggest a moderate antitumor and antimetastatic activity of this compound. Antioxidant properties of danthron are evidenced by the observation that it reduces the intracellular reactive oxygen species production and increases the amount of intracellular sulfhydryl groups in endothelial and tumor cells. These results support a putative role of danthron as a new antiangiogenic drug with potential application in the treatment and angioprevention of cancer and other angiogenesis-dependent diseases.

Bioinformatics analysis based on crucial genes of endothelial cells in rheumatoid

Objectives: Synovial neovascularization is an early and remarkable event that promotes the development of rheumatoid arthritis (RA) synovial hyperplasia. This study aimed to find potential diagnostic markers and molecular therapeutic targets for RA at the mRNA molecular level. Method: We download the expression profile dataset GSE46687 from the gene expression ontology (GEO) microarray, and used R software to screen out the differentially expressed genes between the normal group and the disease group. Then we performed functional enrichment analysis, used the STRING database to construct a protein-protein interaction (PPI) network, and identify candidate crucial genes, infiltration of the immune cells and targeted molecular drug. Results: Rheumatoid arthritis datasets included 113 differentially expressed genes (DEGs) including 104 upregulated and 9 downregulated DEGs. The enrichment analysis of genes shows that the differential genes are mainly enriched in condensed chromosomes, ribosomal subunits, and oxidative phosphorylation. Through PPI network analysis, seven crucial genes were identified: RPS13, RPL34, RPS29, RPL35, SEC61G, RPL39L, and RPL37A. Finally, we find the potential compound drug for RA. Conclusion: Through this method, the pathogenesis of RA endothelial cells was further explained. It provided new therapeutic targets, but the relationship between these genes and RA needs further research to be validated in the future.