Oxidative stress in autoimmune rheumatic diseases

Nanomedicines targeting activated immune cells and effector cells for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and inflammatory cellular infiltration. Functional cells in the RA microenvironment (RAM) are composed of activated immune cells and effector cells. Activated immune cells, including macrophages, neutrophils, and T cells, can induce RA. Effector cells, including synoviocytes, osteoclasts, and chondrocytes, receiving inflammatory stimuli, exacerbate RA. These functional cells, often associated with the upregulation of surface-specific receptor proteins and significant homing effects, can secrete pro-inflammatory factors and interfere with each other, thereby jointly promoting the progression of RA. Recently, some nanomedicines have alleviated RA by targeting and modulating functional cells with ligand modifications, while other nanoparticles whose surfaces are camouflaged by membranes or extracellular vesicles (EVs) of these functional cells target and attack the lesion site for RA treatment. When ligand-modified nanomaterials target specific functional cells to treat RA, the functional cells are subjected to attack, much like the intended targets. When functional cell membranes or EVs are modified onto nanomaterials to deliver drugs for RA treatment, functional cells become the attackers, similar to arrows. This study summarized how diversified functional cells serve as targets or arrows by engineered nanoparticles to treat RA. Moreover, the key challenges in preparing nanomaterials and their stability, long-term efficacy, safety, and future clinical patient compliance have been discussed here.

Machine learning-based identification of novel hub genes associated with oxidative stress in lupus nephritis: implications for diagnosis and therapeutic targets

BACKGROUND

Lupus nephritis (LN) is a complication of SLE characterised by immune dysfunction and oxidative stress (OS). Limited options exist for LN. We aimed to identify LN-related OS, highlighting the need for non-invasive diagnostic and therapeutic approaches.

METHODS

LN-differentially expressed genes (DEGs) were extracted from Gene Expression Omnibus datasets (GSE32591, GSE112943 and GSE104948) and Molecular Signatures Database for OS-associated DEGs (OSEGs). Functional enrichment analysis was performed for OSEGs related to LN. Weighted gene co-expression network analysis identified hub genes related to OS-LN. These hub OSEGs were refined as biomarker candidates via least absolute shrinkage and selection operator. The predictive value was validated using receiver operating characteristic (ROC) curves and nomogram for LN prognosis. We evaluated LN immune cell infiltration using single-sample gene set enrichment analysis and CIBERSORT. Additionally, gene set enrichment analysis explored the functional enrichment of hub OSEGs in LN.

RESULTS

The study identified four hub genes, namely STAT1, PRODH, TXN2 and SETX, associated with OS related to LN. These genes were validated for their diagnostic potential, and their involvement in LN pathogenesis was elucidated through ROC and nomogram. Additionally, alterations in immune cell composition in LN correlated with hub OSEG expression were observed. Immunohistochemical analysis reveals that the hub gene is most correlated with activated B cells and CD8 T cells. Finally, we uncovered that the enriched pathways of OSEGs were mainly involved in the PI3K-Akt pathway and the Janus kinase-signal transducer and activator of transcription pathway.

CONCLUSION

These findings contribute to advancing our understanding of the complex interplay between OS, immune dysregulation and molecular pathways in LN, laying a foundation for the identification of potential diagnostic biomarkers and therapeutic targets.

Association between oxidative balance score and rheumatoid arthritis in female: a cross-sectional study

OBJECTIVE

Although oxidative stress is a recognized factor of inflammation, the correlation between oxidative balance score (OBS), a biomarker indicating the balance of oxidation and antioxidant, and rheumatoid arthritis (RA), an immune system disease that tends to occur in women, remains unexplored. Hence, the aim of this study was to investigate the potential association between OBS and RA in women.

METHODS

Observational surveys were performed by employing information extracted from the National Health and Nutrition Examination Survey (NHANES) for the period 2007-2018. Various statistical techniques were employed to investigate the association between OBS and RA, encompassing multivariable logistic regression analysis, subgroup analyses, smooth curve fitting, and threshold effect analysis.

RESULTS

The study included 8219 female participants, including 597 patients with RA. The results showed that higher Total OBS (TOBS) significantly correlated with lower RA prevalence in the entirely modified model [odd ratio (OR) = 0.968; 95% confidence interval (CI) = 0.952 to 0.984; P = 0.0001]. Dietary OBS (DOBS) and lifestyle OBS (LOBS) also negatively correlated with RA. This association was remarkably consistent across TOBS subgroups by age, race, education level, family poverty-to-income ratio (PIR), hypertension and diabetes. Smooth curve fitting and threshold effect analysis also revealed the linear relationship between OBS and RA.

CONCLUSIONS

Overall, OBS was negatively associated with RA in female. This study suggested that an antioxidant diet and lifestyle may be promising measures to prevent RA in female.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

Silibinin's Effects against Methotrexate-Induced Hepatotoxicity in Adjuvant-Induced Arthritis Rat Model

Methotrexate (MTX) is the first drug of choice to treat several diseases, including rheumatoid arthritis. However, its administration is accompanied by severe side effects, most commonly hepatotoxicity. Hence, alternative therapies with a lower toxicity and fewer side effects are needed. This study aimed to investigate the antioxidant and hepatoprotective effects of silibinin (SIL, natural agent) against MTX-induced hepatotoxicity in an adjuvant-induced arthritis (AIA) rat model. Arthritic rats were treated with SIL (100 mg/kg) and/or methotrexate (2 mg/kg). Non-arthritic rats, arthritic untreated rats, and arthritic rats who received the vehicle were followed in parallel. SIL alleviated the systemic consequences of arthritis by restoring lost weight, decreasing the erythrocyte sedimentation rate, and ameliorating joint damage, which was evident both micro- and macroscopically. Additionally, SIL prevented the histopathological alterations in the liver and significantly reduced the liver damage caused by MTX and AIA, as shown by a decrease in the markers of liver damage (ALT and AST). Furthermore, SIL relieved the oxidative stress induced by AIA and MTX in liver tissue by decreasing the lipid peroxidation (MDA) levels and enhancing the antioxidant defense system (GSH levels; catalase and superoxide dismutase (SOD) activities). In conclusion, our results suggest that SIL is a potent antioxidant and hepatoprotective agent in arthritic rats. It markedly attenuated the progression and severity of the arthritic disease and eased the oxidative stress in liver tissue by improving the pro-oxidant/antioxidant balance.

Association of autoimmune and allergic diseases with senile cataract: a bidirectional two-sample Mendelian randomization study

Background

Many observational studies have been reported that patients with autoimmune or allergic diseases seem to have a higher risk of developing senile cataract, but the views are not consistent. In order to minimize the influence of reverse causality and potential confounding factors, we performed Mendelian Randomization (MR) analysis to investigate the genetic causal associations between autoimmune, allergic diseases and senile cataract.

Methods

Single nucleotide polymorphisms associated with ten common autoimmune and allergic diseases were obtained from the IEU Open genome-wide association studies (GWAS) database. Summary-level GWAS statistics for clinically diagnosed senile cataract were obtained from the FinnGen research project GWAS, which consisted of 59,522 individuals with senile cataracts and 312,864 control individuals. MR analysis was conducted using mainly inverse variance weighted (IVW) method and further sensitivity analysis was performed to test robustness.

Results

As for ten diseases, IVW results confirmed that type 1 diabetes (OR = 1.06; 95% CI = 1.05-1.08; p = 2.24×10-12), rheumatoid arthritis (OR = 1.05; 95% CI = 1.02-1.08; p = 1.83×10-4), hypothyroidism (OR = 2.4; 95% CI = 1.42-4.06; p = 1.12×10-3), systemic lupus erythematosus (OR = 1.02; 95% CI = 1.01-1.03; p = 2.27×10-3), asthma (OR = 1.02; 95% CI = 1.01-1.03; p = 1.2×10-3) and allergic rhinitis (OR = 1.07; 95% CI = 1.02-1.11; p = 2.15×10-3) were correlated with the risk of senile cataract. Celiac disease (OR = 1.04; 95% CI = 1.01-1.08; P = 0.0437) and atopic dermatitis (OR = 1.05; 95% CI = 1.01-1.10; P = 0.0426) exhibited a suggestive connection with senile cataract after Bonferroni correction. These associations are consistent across weighted median and MR Egger methods, with similar causal estimates in direction and magnitude. Sensitivity analysis further proved that these associations were reliable.

Conclusions

The results of the MR analysis showed that there were causal relationships between type 1 diabetes, rheumatoid arthritis, hypothyroidism, systemic lupus erythematosus, asthma, allergic rhinitis and senile cataract. To clarify the possible role of autoimmune and allergy in the pathophysiology of senile cataract, further studies are needed.

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.

Immune-mediated diseases and risk of incident cardiovascular diseases: a prospective cohort study

OBJECTIVES

Disorders of immune system may impact cardiovascular health; however, comprehensive study is lacking. We aimed to analyse the association of total and 20 individual immune-mediated diseases (IMDs) with risk of incident cardiovascular disease (CVD).

METHODS

In this prospective cohort study, 414 495 participants (55.6% women; mean age 55.9 years) from UK Biobank with baseline assessment at 2006-10 were included. Among them, 21 784 participants had prevalent IMDs. Information on IMDs at baseline and incidence of CVDs during follow-up were recorded. Cox proportional hazard models were used to estimate the association between IMDs and CVDs risk.

RESULTS

During the median follow-up of 12.1 years, there were 6506 cases of CVDs in participants with IMDs (29.9%) and 77 699 cases in those without IMDs (19.8%). After multivariable adjustment, participants with IMDs were significantly associated with an increased risk of total CVD [hazard ratio (HR) 1.57; 95% CI 1.52-1.61]. Among the 20 IMDs, 16 showed significant associations with CVD (all P < 0.0025 after Bonferroni correction), with HR ranging from 1.34 (1.16-1.54) for celiac disease to 2.75 (2.10-3.61) for SLE. Participants with any IMD exposure had a higher risk of all individual CVD events, with HR ranging from 1.34 (1.14-1.58) for cerebral hemorrhage to 1.80 (1.54-2.11) for pericardium diseases. IMD duration <5, 5-10 and >10 years was associated with 55%, 59% and 56% increased risk of total CVD, respectively.

CONCLUSION

Total and individual IMDs were associated with an increased risk of overall CVDs. It is important to consider primary prevention of CVD in patients with IMD and dysregulation of immune system in the cardiovascular health.

Advances in Immunomodulatory MOFs for Biomedical Applications

Given the crucial role of immune system in the occurrence and progression of various diseases such as cancer, wound healing, bone defect, and inflammation-related diseases, immunomodulation is recognized as a potential solution for treatment of these diseases. Immunomodulation includes both immunosuppression in hyperactive immune conditions and immune activation in hypoactive conditions. For these purposes, metal-organic frameworks (MOFs) are investigated to modulate immune responses either by their own bioactivities or by delivering immunomodulatory agents due to their excellent biodegradability and high delivery capacity. This review starts with an overview of the synthesis strategies of immunomodulatory MOFs, followed by a summarization on the latest applications of immunomodulatory MOFs in cancer immunomodulatory, wound healing, inflammatory disease, and bone tissue engineering. A variety of design considerations, in order to optimize immunomodulatory properties and efficacy of MOFs, is also involved. Last, the challenges and perspectives of future research, which are expected to provide researchers with new insight into the design and application of immunomodulatory MOFs, are discussed.

Prevalence of Steatotic Liver Disease Among US Adults with Rheumatoid Arthritis

BACKGROUND

The prevalence of steatotic liver disease (SLD) among patients with rheumatoid arthritis (RA) remains largely unknown.

AIMS

To investigate the prevalence of SLD and liver fibrosis among patients with RA.

METHODS

We utilized data from the United States (US)-based National Health and Nutrition Examination Survey (NHANES) 2017-2020 cycle. After applying established sample weights, we estimated the age-adjusted prevalence of SLD and its subclassifications (CAP ≥ 285 dB/m), high-risk NASH (FAST score) and liver fibrosis (LSM) among participants with self-reported RA. Multivariable logistic regression was performed to identify independent risk factors for metabolic dysfunction associated SLD (MASLD), high-risk NASH and fibrosis, respectively, among participants with RA. We present adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

Age-adjusted prevalence of MASLD among US adults with RA was 34.91% (95% CI: 24.02-47.65%). We also found that the age-adjusted prevalence of high-risk NASH (FAST score > 0.35) and significant fibrosis (LSM > 8.6 kPa) was 12.97% (95% CI: 6.89-23.07%) and 10.35% (95% CI: 5.55-18.48%), respectively. BMI ≥ 30 kg/m2, (aOR 6.23; 95% CI: 1.95-19.88), diabetes (aOR 5.90; 95% CI: 1.94-17.94), and dyslipidemia (aOR 2.83; 95% CI: 1.12-7.11) were independently associated with higher odds of MASLD among participants with RA. Diabetes (aOR 19.34; 95% CI: 4.69-79.70) was also independently associated with high-risk NASH.

CONCLUSIONS

The prevalence of MASLD, high-risk NASH, and liver fibrosis among patients with RA is equal or higher than the general population. Future studies of large cohorts are needed to substantiate the role of systemic inflammation in the pathophysiology of MASLD.

Inflammatory mediators, oxidative stress and genetic disturbance in rheumatoid arthritis rats supported by alfalfa seeds metabolomic constituents via blocking interleukin-1receptor

Rheumatoid arthritis (RA) is an autoimmune disease characterized by aggressive cartilage and bone erosion. This work aimed to evaluate the metabolomic profile of Medicago sativa L. (MS) (alfalfa) seeds and explore its therapeutic impact against RA in rats. Arthritis was induced by complete Freund's adjuvant (CFA) and its severity was assessed by the arthritis index. Treatment with MS seeds butanol fraction and interlukin-1 receptor antagonist (IL-1RA) were evaluated through measuring interlukin-1 receptor (IL-1R) type 1 gene expression, interlukin-1 beta (IL-1β), oxidative stress markers, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), caspase-3 (Cas-3), intracellular adhesion molecule-1 (ICAM-1), DNA fragmentation, and chromosomal damage. Total phenolics/ flavonoids content in the ethyl acetate, butanol fraction and crude extract of MS seeds were estimated. The major identified compounds were Quercetin, Trans-taxifolin, Gallic acid, 7,4'-Dihydroxyflavone, Cinnamic acid, Kudzusaponin SA4, Isorhamnetin 3-O-beta-D-2'',3'',4''-triacetylglucopyranoside, Apigenin, 5,7,4'-Trihydroxy-3'-methoxyflavone, Desmethylxanthohumol, Pantothenic acid, Soyasapogenol E, Malvidin, Helilandin B, Stigmasterol, and Wairol. Treatment with MS seeds butanol fraction and IL-1RA enhanced all the biochemical parameters and the histopathological features of the ankle joint. In conclusion, Trans-taxifolin was isolated for the first time from the genus Medicago. MS butanol fraction seeds extract and IL-1 RA were considered as anti-rheumatic agents.

Coenzyme Q10 supplementation in rheumatic diseases: A systematic review

Coenzyme Q10 (CoQ10) is a potent antioxidant and anti-inflammatory substance used to treat some rheumatic diseases. Our objective was to review the use of CoQ10 in rheumatic diseases. PubMed/Medline, Embase, Scopus, and Web of Science databases were searched for articles on CoQ10 and rheumatic diseases between 1966 and April 2023. Twenty articles were found, including 483 patients. The investigated conditions were Fibromyalgia (FM) with 15 studies, Rheumatoid Arthritis (RA) with 3 studies, and Antiphospholipid Syndrome (APS) with 2 studies. After CoQ10 supplementation, RA patients observed improvements in disease activity index, inflammatory biomarkers (erythrocyte sedimentation rate), cytokine levels, and a decrease in malondialdehyde. In APS, CoQ10 improved endothelial function and decreased prothrombotic and proinflammatory mediators. Regarding FM, in most of the studies, the patients observed improvements in pain, fatigue, sleep, tender points count, mood disorders, and scores on the Fibromyalgia Impact Questionnaire (FIQ). The drug was well tolerated, with reports of minor side effects in two studies. CoQ10 supplementation seems to be efficacious as a complementary treatment for RA and FM. Upcoming studies with larger samples and including other rheumatic diseases are welcome.

Dietary oleacein, a secoiridoid from extra virgin olive oil, prevents collagen-induced arthritis in mice

Olacein (OLA), one of the main secoiridoids derived from extra virgin olive oil (EVOO), has been shown to modulate oxidative and inflammatory responses in various pathological conditions; however, its potential benefit in joint disorders such as rheumatoid arthritis (RA) is unknown. Therefore, this study was designed to evaluate the preventive role of the effects of an OLA-supplemented diet in the murine model of collagen-induced arthritis (CIA), delving into the possible mechanisms and signaling pathways involved. Animals were fed an OLA-enriched preventive diet for 6 weeks prior to CIA induction and until the end of the experimental time course. On day 43 after the first immunization, mice were sacrificed: blood was collected, and paws were histologically and biochemically processed. Dietary OLA prevented collagen-induced rheumatic bone, joint and cartilage conditions. Circulating matrix metalloproteinase (MMP)-3 and proinflammatory cytokine (IL-6, IL-1β, TNF-α, IL-17) levels were significantly decreased in the joint, as well as MMP-9 and cathepsin-K (CatK) expression in secoiridoid-fed animals. In addition, dietary OLA was able to decrease COX-2, mPGES-1 and iNOS protein expressions and, also, PGE2 levels. The mechanisms possibly involved in these protective effects could be related to the activation of the Nrf-2/HO-1 axis and the inhibition of proinflammatory signaling pathways, including JAK-STAT, MAPKs and NF-κB, involved in the production of inflammatory and oxidative mediators. These results support the interest of OLA, as a nutraceutical intervention, in the management of RA.

A turn-on fluorescence strategy for hypochlorous acid detection based on DNAzyme-assisted cyclic signal amplification

Hypochlorous acid (HClO) is a crucial active oxygen component and one of the innate immunity's barrier substances in the body. Abnormal fluctuations in HClO concentration can lead to increased oxidative stress, cellular dysfunction, and the onset of various diseases. Thus, developing convenient, affordable, efficient, and sensitive methods to monitor HClO concentration in healthcare and pathophysiology research is highly significant. In this study, we developed a novel fluorescence strategy for HClO detection based on nucleic acid oxidative cleavage and Pb2+-dependent DNAzyme. By introducing a phosphorothioate site in the hairpin-structured nucleic acid sequence, the nucleic acid probe specifically recognized HClO and underwent oxidative cleavage. Upon cleavage, the enzyme strand is liberated, forming DNAzyme. This DNAzyme then cleaves the substrate strand, liberating the initially quenched fluorescent dyes and generating a turn-on fluorescent signal. The enzyme strand produced by the oxidative cleavage of HClO can be repeatedly utilized, thus realizing the cyclic signal amplification to reduce background noise. We verified the detection mechanism of this strategy through stepwise fluorescence spectroscopy analysis and electrophoresis. Under optimal experimental conditions, the method achieved a detection limit of 5.38 nM and a linear range of 1 nM-800 nM. This method demonstrated exceptional performance in actual biological sample testing and presented an exciting opportunity for expanded utilization in clinical diagnosis and medical research.

Cognitive dysfunction in systemic lupus erythematosus is associated with disease activity and oxidative stress: a comparative study with rheumatoid arthritis for identifying biomarkers

BACKGROUND

The prevalence and pathophysiological mechanisms of cognitive deficits (CD) Systemic Lupus Erythematosus (SLE) and Rheumatoid arthritis (RA) are very heterogeneous and poorly understood. We characterized CD in patients with SLE compared with RA patients and healthy controls. We compared the neuropsychological profile of SLE and RA with patients' oxidative/inflammatory biomarkers for CD.

METHODS

We performed a cross-sectional study, including 50 SLE patients, 29 RA patients, and 32 healthy controls. SLEDAI and DAS28 assessed disease activity. SF-36 questionnaire and a battery of cognitive tests were applied to all participants. Blood samples were collected to determine IL-6, S100ß, myeloperoxidase (MPO), malondialdehyde and reduced glutathione (GSH) alterations.

RESULTS

In the SLE group, higher GSH was associated with the absence of CD (With CD = 69 ± 49, Without CD = 112 ± 81, p = 0.030), while higher IL-6 was associated with the presence of CD in the RA group (With CD = 603 ± 173, Without CD = 431 ± 162, p = 0.032). Regarding specific cognitive domains, in SLE higher MPO was associated with poor performance in reasoning and abstraction (p = 0.039), higher IL-6 was associated with poor performance in inhibitory control and attention (p = 0.031), and higher GSH was associated with better performance in memory(p = 0.021). Higher SLEDAI was associated with poor performance in semantic fluency(p = 0.031), inhibitory control, and attention in the SLE group(p = 0.037). In the RA group, higher DAS-28 was associated with poor performance in executive functions(p = 0.016) and phonemic fluency (p = 0.003).

CONCLUSION

SLE patients' disease activity, inflammatory state, and oxidative stress were associated with CD. In RA patients, CD was associated with disease activity and inflammatory state. These results encourage further studies with larger samples aiming to confirm oxidative stress parameters as biomarkers of CD in SLE patients.

Oxidative modification of carbonic anhydrase by peroxynitrite trigger immune response in mice and rheumatic disease patients

BACKGROUND

Carbonic anhydrases (CA) are metalloenzymes with wide tissue distribution, involved in many important physiological processes, and in some rheumatic diseases, autoantibodies are formed against these enzymes. Recent studies have suggested that oxidative stress triggers anti-CA antibody formation. In this study, we aimed to investigate the effects of modification with oxidative/nitrosative stress end products on CA antigenicity in mice and the relationship between the modified CA autoantibodies and oxidant-antioxidant status in patients with rheumatoid arthritis (RA) and Sjögren's syndrome (SjS).

METHODS

CA I and CA II isoenzymes were isolated from human erythrocytes and modified with 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), and peroxynitrite (PN). Balb-c mice were immunized with these agents to determine the effects of modification on CA antigenicity. The autoantibody titers of modified CA isoenzymes were detected in patients. In addition MDA, 4-HNE, 3-nitrotyrosine (3-NT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured to assess the oxidant-antioxidant status in patients.

RESULTS

Modifications of carbonic anhydrase with oxidative stress end products, HNE, MDA and PN, lead to alterations in the immune response to these enzymes in mice. It was found that HNE and MDA decreased the antigenicity while PN increased. In addition, PN-modified CA autoantibody levels were found to be significantly different in both RA and SjS patients compared to their controls (p<0.05).

CONCLUSIONS

PN modifications can also trigger an immune response against CA isoenzymes in mice, and PN-modified CA I and CA II autoantibody titers were found at a significantly high level in both RA and SjS patients.

Chronic stress predisposes to the aggravation of inflammation in autoimmune diseases with focus on rheumatoid arthritis and psoriasis

The global incidence of autoimmune diseases is on the rise, and many healthcare professionals believe that chronic stress plays a prominent role in both the aggravation and remission of these conditions. It is believed that prolonged exposure to stress is associated with neuroimmune axis malfunction, which eventually dysregulates multiple immunological factors as well as deregulates autoimmune responses that play a central role in various autoimmune diseases, including rheumatoid arthritis and psoriasis. Herein, we performed validation of an 8-week long rat model of chronic unpredictable stress (CUS) which consisted of exposing groups of rats to random stressors daily for 8 weeks. Additionally, we developed a novel rat model combining 8-week long random stressor-induced CUS with CIA-triggered arthritis and IMQ-triggered psoriasis and have successfully used both these models to assess the role of chronic stress in the aggravation of arthritis and psoriasis, respectively. Notably, the 8-week CUS protocol extensively aggravated and prolonged both arthritis and psoriasis condition in the rat model by upregulating the release of different pro-inflammatory cytokines, dysregulation of immune cell responses and oxidative stress system, which were all related to severe inflammation. Further, CUS aggravated macroscopic features and the increase in destruction of joint tissue and epidermal thickness induced by CIA and IMQ, respectively, in rats. In conclusion, this study suggests that exposure to an 8-week long CUS paradigm aggravates the distinctive characteristics of rheumatoid arthritis and psoriasis in rats via amplifying the inflammatory circuits and immune cell responses linked to these autoimmune diseases.

A study on the therapeutic potential of graphene titanate nanocomposite for treating chemically induced arthritis in rats

Nanotechnology holds substantial promise in the innovative therapies for rheumatoid arthritis (RA). The current study was designed to synthesize and characterize a new graphene titanate nanocomposite (GTNc) and explore its anti-arthritic, anti-inflammatory, and antioxidant potencies against Complete Freund's adjuvant (CFA)-induced arthritis in rats, as well as investigate the underlying molecular mechanisms. Our characterization methods included XRD, FT-IR, SEM, EDX, zeta potential, practical size, and XRF to characterize the novel GTNc. Our findings revealed that arthritic rats treated with GTNc exhibited lower levels of RF, CRP, IL-1β, TNF-α, IL-17, and ADAMTS-5, and higher levels of IL-4 and TIMP-3. In arthritic rats, GTNc reduced LPO levels while increasing GSH content and GST antioxidant activity. Additionally, GTNc decreased the expression of the TGF-β mRNA gene in arthritic rats. Histopathological investigation showed that GTNc reduced inflammatory cell infiltration, cartilage degradation, and bone destruction in joint injuries caused by CFA in the arthritic rats. Collectively, the anti-arthritic, anti-inflammatory, and antioxidant properties of GTNc appear promising for future arthritis treatments and bone disability research.

Relationship between bilirubin and systemic lupus erythematosus: A systematic review and meta-analysis

AIMS

Systemic lupus erythematosus (SLE) is an autoimmune disease with a high prevalence worldwide. This study aimed to examine the correlation between serum bilirubin levels and SLE.

METHODS

The Cochrane library, Embase, PubMed, and China National Knowledge Infrastructure (CNKI) databases were examined and assessed until March 2023. RevMan 5.3 software was utilized for the analysis of clinical trails.

RESULTS

Five case-control studies were chosen and incorporated, examining the levels of serum bilirubin in patients with SLE compared to healthy individuals, as well as in active SLE patients versus inactive ones, in different sexes and in SLE patients with or without lupus nephritis (LN). The results of this meta-analysis demonstrated that serum bilirubin in healthy individuals were obviously increased compared to SLE patients (MD = 4.76; 95% CI, 3.15-6.38, p < .00001). Additionally, inactive SLE patients had higher levels of bilirubin than active SLE patients (MD = 3.15; 95% CI, 0.46-5.84, p = .02), and SLE patients without lupus nephritis had higher levels of serum bilirubin than those with lupus nephritis (MD = 4.91;95% CI, 2.87-6.95, p < .00001). Nevertheless, there were no disparities observed among SLE patients of varying sexes (MD = 0.34; 95% CI, -0.01 to 0.69, p = .06).

CONCLUSION

The concentration of serum bilirubin may potentially be used as an indicator for estimating the advancement of SLE and reflecting the presence of kidney complications in individuals with SLE. Furthermore, more high quality studies were needed to identify these findings.

Immunomodulatory roles of metalloproteinases in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, autoimmune pathology characterized by persistent synovial inflammation and gradually advancing bone destruction. Matrix metalloproteinases (MMPs), as a family of zinc-containing enzymes, have been found to play an important role in degradation and remodeling of extracellular matrix (ECM). MMPs participate in processes of cell proliferation, migration, inflammation, and cell metabolism. A growing number of persons have paid attention to their function in inflammatory and immune diseases. In this review, the details of regulation of MMPs expression and its expression in RA are summarized. The role of MMPs in ECM remodeling, angiogenesis, oxidative and nitrosative stress, cell migration and invasion, cytokine and chemokine production, PANoptosis and bone destruction in RA disease are discussed. Additionally, the review summarizes clinical trials targeting MMPs in inflammatory disease and discusses the potential of MMP inhibition in the therapeutic context of RA. MMPs may serve as biomarkers for drug response, pathology stratification, and precision medicine to improve clinical management of rheumatoid arthritis.

Secondary Metabolites for the Reduction of Oxidative Stress

Oxidative stress is a condition that occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them [...].

A Review of the Potential of Nuclear Factor [Erythroid-Derived 2]-like 2 Activation in Autoimmune Diseases

An autoimmune disease is the consequence of the immune system attacking healthy cells, tissues, and organs by mistake instead of protecting them. Inflammation and oxidative stress (OS) are well-recognized processes occurring in association with acute or chronic impairment of cell homeostasis. The transcription factor Nrf2 (nuclear factor [erythroid-derived 2]-like 2) is of major importance as the defense instrument against OS and alters anti-inflammatory activities related to different pathological states. Researchers have described Nrf2 as a significant regulator of innate immunity. Growing indications suggest that the Nrf2 signaling pathway is deregulated in numerous diseases, including autoimmune disorders. The advantageous outcome of the pharmacological activation of Nrf2 is an essential part of Nrf2-based chemoprevention and intervention in other chronic illnesses, such as neurodegeneration, cardiovascular disease, autoimmune diseases, and chronic kidney and liver disease. Nevertheless, a growing number of investigations have indicated that Nrf2 is already elevated in specific cancer and disease steps, suggesting that the pharmacological agents developed to mitigate the potentially destructive or transformative results associated with the protracted activation of Nrf2 should also be evaluated. The activators of Nrf2 have revealed an improvement in the progress of OS-associated diseases, resulting in immunoregulatory and anti-inflammatory activities; by contrast, the depletion of Nrf2 worsens disease progression. These data strengthen the growing attention to the biological properties of Nrf2 and its possible healing power on diseases. The evidence supporting a correlation between Nrf2 signaling and the most common autoimmune diseases is reviewed here. We focus on the aspects related to the possible effect of Nrf2 activation in ameliorating pathologic conditions based on the role of this regulator of antioxidant genes in the control of inflammation and OS, which are processes related to the progression of autoimmune diseases. Finally, the possibility of Nrf2 activation as a new drug development strategy to target pathogenesis is proposed.

The Role of the Oxidative State and Innate Immunity Mediated by TLR7 and TLR9 in Lupus Nephritis

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE) and is considered one of the leading causes of mortality. Multiple immunological pathways are involved in the pathogenesis of SLE, which makes it imperative to deepen our knowledge about this disease's immune-pathological complexity and explore new therapeutic targets. Since an altered redox state contributes to immune system dysregulation, this document briefly addresses the roles of oxidative stress (OS), oxidative DNA damage, antioxidant enzymes, mitochondrial function, and mitophagy in SLE and LN. Although adaptive immunity's participation in the development of autoimmunity is undeniable, increasing data emphasize the importance of innate immunity elements, particularly the Toll-like receptors (TLRs) that recognize nucleic acid ligands, in inflammatory and autoimmune diseases. Here, we discuss the intriguing roles of TLR7 and TLR9 in developing SLE and LN. Also included are the essential characteristics of conventional treatments and some other novel and little-explored alternatives that offer options to improve renal function in LN.

Cold atmospheric pressure plasma: A potential physical therapy for rheumatoid arthritis hyperplastic synovium

The most significant pathological change in rheumatoid arthritis (RA) is synovial hyperplasia within the joint. The production of a series of degrading enzymes and oxidative stress caused by synovial hyperplasia lead to severe bone and cartilage damage in rheumatoid joints. The core effector cell in hyperplastic synovium is fibroblast-like synovium cells, which can invade cartilage, cause inflammation, destroy joints, and show tumor-like anti-apoptosis characteristics. This study focused on the effect of cold atmospheric pressure plasma on proliferative synovium, and the results showed that no synovial hyperplasia, angiogenesis, or inflammatory infiltration was observed after cold atmospheric pressure plasma (CAP) treatment. The molecular and cellular mechanisms also reveal the spontaneous reactive oxygen species (ROS) cascade inducing apoptosis in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) cells. This study proposes a potential physical therapy method for treating proliferative synovium and also provides ideas for the application of CAP in other types of tumor diseases.

Hyaluronic acid-based M1 macrophage targeting and environmental responsive drug releasing nanoparticle for enhanced treatment of rheumatoid arthritis

Herein, hyaluronic acid (HA) and β-cyclodextrin (β-CD) is used to form targeted drug delivery platform HCPC/DEX NPs with previously prepared carbon dots (CDs) as cross-linker, dexamethasone (DEX) is loaded for rheumatoid arthritis (RA) treatment. The drug loading capacity of β-CD and M1 macrophage targeting of HA were utilized for efficient delivery of DEX to the inflammatory joints. Because of the environmental responsive degradation of HA, DEX can be released in 24 h and inhibit the inflammatory response in M1 macrophages. The drug loading of NPs is 4.79 %. Cellular uptake evaluation confirmed that NPs can specifically target to M1 macrophages via HA ligands, the uptake of M1 macrophages is 3.7 times that of normal macrophages. In vivo experiments revealed that NPs can accumulate in RA joints to alleviate inflammation and accelerate cartilage healing, the accumulation can be observed in 24 h. The cartilage thickness increased to 0.45 mm after HCPC/DEX NPs treatment, indicating its good RA therapeutic effect. Importantly, this study was the first to utilize the potential acid and reactive oxygen species responsiveness of HA to release drug and prepare M1 macrophage targeting nanodrug for RA treatment, which provides a safe and effective RA therapeutic strategy.

Influence of genetically predicted autoimmune diseases on NAFLD

Introduction

Non-alcoholic fatty liver disease (NAFLD), the emerging cause of end-stage liver disease, is the most common liver disease. Determining the independent risk factors of NAFLD and patients who need more monitoring is important.

Methods

Two-Sample Mendelian randomization (MR) was performed in the analysis to investigate the causal association of different autoimmune diseases with NAFLD using summary level data. Genome-wide association study (GWAS) of 5 autoimmune diseases including celiac disease (CeD), Crohn's disease (CD), multiple sclerosis (MS), rheumatoid arthritis (RA), and type 1 diabetes (T1D) were selected for Instrument variables (IVs). NAFLD was included as outcome.

Result

After adjusting for confounding factors, genetic predisposition of CeD (OR= 0.973, [0.949,0.997], IVW p-value=0.026), MS (OR= 1.048, [1.012,1.085], IVW p-value= 0.008), RA (OR= 1.036, [1.006,1.066], IVW p-value=0.019), T1D (OR= 1.039, [1.002,1.079], IVW p-value= 0.041) is causally associated with NAFLD. No causal effect was found between CD and NAFLD.

Conclusion

CeD itself may be a protective factor for NAFLD, the results of previous observational studies have been influenced by confounding factors, and the morbidity of NAFLD may be higher in patients with MS, RA, and T1D than in common populations, and monitoring the prevalence of NAFLD in these populations is considerable.

Posttranslational modifications in psoriatic arthritis: A systematic literature review

BACKGROUND AND AIMS

Psoriatic arthritis (PsA) is an inflammatory complex condition. Posttranslational modifications influence almost all aspects of normal cell biology and pathogenesis. The aim of this systematic review was to collect all published evidence regarding posttranslational modifications in PsA, and the main outcome was to evaluate an association between disease outcomes and specific posttranslational modifications in PsA.

METHODS

A systematic electronic search was performed in Medline, PubMed, Cochrane, Virtual Health Library, and Embase databases. A total of 587 articles were identified; 59 were evaluated after removing duplicates and scanning, of which 47 were included. A descriptive analysis was conducted, with results grouped according to the type of posttranslational modification evaluated. The protocol was registered at the PROSPERO database.

RESULTS

Seven posttranslational modifications were identified: citrullination, carbamylation, phosphorylation, glycosylation, acetylation, methylation, and oxidative stress. Anti-citrullinated peptide and anti-carbamylated protein have been evaluated in rheumatoid arthritis. There is now information suggesting that these antibodies may be helpful in improving the diagnosis of PsA and that they may demonstrate a correlation with worse disease progression (erosions, polyarticular involvement, and poor treatment response). Glycosylation was associated with increased inflammation and phosphorylation products related to the expression of SIRT2 and pSTAT3 or the presence of Th17 and cytokine interleukin-22, suggesting a possible therapeutic target.

CONCLUSIONS

Posttranslational modifications often play a key role in modulating protein function in PsA and correlate with disease outcomes. Citrullination, carbamylation, phosphorylation, glycosylation, acetylation, methylation, and oxidative stress were identified as associated with diagnosis and prognosis.

High plasma homocysteine level is associated with increased prevalence of the non-remission state in rheumatoid arthritis: Findings from the KURAMA cohort

OBJECTIVES

We aimed to determine the clinical impact of plasma homocysteine levels on disease activity and clinical remission in patients with rheumatoid arthritis (RA).

METHODS

A cross-sectional study was conducted using KURAMA (Kyoto University Rheumatoid Arthritis Management Alliance) database. We enrolled 291 female patients, who were treated in a treat-to-target manner. We measured plasma total homocysteine using a liquid chromatography-tandem mass spectrometry system and collected clinical data including a 28-joint RA disease activity score-erythrocyte sedimentation rate (DAS28-ESR). Clinical remission of disease activity was defined as a DAS28-ESR < 2.6.

RESULTS

In a univariable analysis, the plasma homocysteine concentration was significantly and positively associated with DAS-28-ESR and was higher in the non-remission group than in the remission group. The cutoff value of the plasma homocysteine level was calculated to be 7.9 nmol/mL by the test of the receiver operating characteristic curve analysis. In a multivariable analysis, after adjusting for clinically relevant variables, the high homocysteine level remained a significant positive association for DAS28-ESR (estimate 0.27, P = .0019) and a positive factor for the presence of RA non-remission (odds ratio 2.39, P = .0071).

CONCLUSIONS

Increased plasma homocysteine levels showed a significant positive association with current disease activity and the non-remission state in female patients with RA under treat-to-target treatment. The findings suggest the potential utility of plasma homocysteine as a disease state marker reflecting conditions that are treatment failure and difficult to remission and may provide clinical evidence on the interplay between homocysteine and inflammatory activation in RA.

Biomarkers of Oxidative Stress in Systemic Lupus Erythematosus Patients with Active Nephritis

Oxidative stress plays an important role in systemic lupus erythematosus (SLE) and especially in lupus nephritis (LN). The aim of this study was to compare redox-related biomarkers between patients with active LN, quiescent SLE (Q-SLE) and healthy controls (HC) and to explore their association with clinical characteristics such as disease activity in patients. We investigated levels of plasma free thiols (R-SH, sulfhydryl groups), levels of soluble receptor for advanced glycation end products (sRAGE) and levels of malondialdehyde (MDA) in SLE patients with active LN (n = 23), patients with quiescent SLE (n = 47) and HC (n = 23). Data of LN patients who previously participated in Dutch lupus nephritis studies and longitudinal samples up to 36 months were analyzed. Thiol levels were lower in active LN at baseline and Q-SLE patients compared to HC. In generalized estimating equation (GEE) modelling, free thiol levels were negatively correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) over time (p < 0.001). sRAGE and MDA were positively correlated with the SLEDAI over time (p = 0.035 and p = 0.016, respectively). These results indicate that oxidative stress levels in LN patients are increased compared to HC and associated with SLE disease activity. Therefore, interventional therapy to restore redox homeostasis may be useful as an adjunctive therapy in the treatment of oxidative damage in SLE.

Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

Introduction

Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults.

Methods

We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population.

Results

Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ESWMD = -0.56, 95% CI: -0.72, -0.39; p < 0.001, and ESSMD = -0.50, 95% CI: -0.66, -0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ESWMD = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ESSMD = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ESWMD: 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ESWMD: 1.48; 95% CI: 0.31, 2.65, p = 0.013; I2 = 51.7%, p = 0.043).

Discussion

Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.

A Systematic Review and Meta-Analysis of the Association between Uric Acid and Allantoin and Rheumatoid Arthritis

Alterations in the circulating concentrations of uric acid and its degradation product, allantoin, might account for the systemic pro-oxidant state and the increased cardiovascular risk in rheumatoid arthritis (RA). We sought to address this issue by conducting a systematic review and meta-analysis of the association between the plasma/serum concentrations of uric acid and allantoin and RA. We searched PubMed, Scopus, and Web of Science from inception to 20 June 2023 for studies comparing plasma/serum concentrations of uric acid and allantoin between RA patients and healthy controls. We assessed the risk of bias with the JBI Critical Appraisal Checklist for analytical studies and the certainty of evidence with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) Working Group system. In the 19 studies selected for analysis, there were non-significant differences in uric acid concentrations between RA patients and controls (standard mean difference, SMD = 0.11, 95% CI -0.07 to 0.30, p = 0.22; I2 = 87.9%, p < 0.001; low certainty of evidence). By contrast, the concentrations of allantoin were significantly higher in RA patients (SMD = 1.10, 95% CI 0.66 to 1.55, p < 0.001; I2 = 55.6%, p = 0.08; extremely low certainty of evidence). In meta-regression, a significant association was observed between the SMD of uric acid concentrations and body mass index, a risk factor for atherosclerosis and cardiovascular disease (t = 3.35, p = 0.007). Our study has shown a significant increase in the concentrations of the oxidative stress biomarker allantoin in patients with RA. Further research is warranted to investigate the interplay between uric acid, allantoin, redox balance, and cardiovascular disease in this group. (PROSPERO registration number: CRD42023441127).

Relationship between Malondialdehyde Serum Levels and Disease Features in a Full Characterized Series of 284 Patients with Systemic Lupus Erythematosus

Malondialdehyde (MDA) is a marker of oxidative stress and antioxidant status. Oxidative stress has been observed to be increased in systemic lupus erythematosus (SLE). Some studies have shown that MDA is upregulated in SLE compared to controls. However, the literature lacks reports regarding the relationship of MDA to disease manifestations. This is relevant since SLE is a multisystemic disease which may affect virtually any organ in the body. In this study, we set out to analyze how MDA serum levels are associated with disease expression in a large series of SLE patients who were fully characterized in clinical and laboratory terms. A total of 284 patients with SLE were recruited. Serum levels of MDA, and the activity (SLEDAI), severity (Katz) and damage index (SLICC-DI) scores, full lipid profile, and carotid subclinical atherosclerosis were assessed. In addition, a full characterization of the complement system was performed in SLE patients' samples. Multivariable linear regression analysis was executed to study the relationship between clinical and laboratory disease characteristics and MDA. A statistically significant negative relationship was found between disease duration and MDA. In contrast, the presence of anti-nucleosome antibodies was positively associated with MDA. Regarding the SLICC-DI areas, both the musculoskeletal domain and the cutaneous domain were significantly related to higher serum MDA values. Furthermore, after adjustment for confounding factors, lower levels of the classical complement pathway, which denotes activation, were associated with higher serum levels of MDA. In conclusion, cumulative musculoskeletal and skin damage in SLE patients is associated with superior serum levels of MDA. In addition, activation of the complement system is also related to higher circulating MDA levels.

Antibodies against multiple post-translationally modified proteins aid in diagnosis of autoimmune hepatitis and associate with complete biochemical response to treatment

Background

(Auto)immune mediated and cholestatic liver disease (AILD) includes autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). Especially AIH is characterized by the presence of autoantibodies and elevated serum immunoglobulins. In rheumatoid arthritis, autoantibodies against post-translational modifications (PTMs) such as citrullination (Cit) and carbamylation (CarP) are used as diagnostic and prognostic markers, respectively. We studied the presence of six anti-PTM antibodies in patients with the three AILDs and non-AILD.

Methods

Antibodies against six PTMs (malondialdehyde-acetaldehyde adducts (MAA), advanced glycation end-products (AGE), CarP, acetylation (AL), Cit, and nitration (NT)) were tested in sera of patients with AILD (n = 106), non-AILD (n = 101) and compared with healthy controls (HC) (n = 100). Levels and positivity were correlated with clinical and biochemical features in a well-defined cohort of untreated AIH patients.

Results

Anti-PTM antibodies were more often detectable in sera from AILD patients compared with HCs (anti-MAA: 67.9% vs. 2.0%, anti-AGE: 36.8% vs. 4.0%, anti-CarP: 47.2% vs. 5.0% and anti-AL: 18.9% vs. 5.0%). In untreated AIH, time to complete biochemical response (CBR) was associated with anti-MAA, anti-AGE, anti-CarP and anti-AL antibodies. Significantly more patients with at least three anti-PTM antibodies attained CBR at 12  months of treatment (13 vs. 3 p = 0.01).

Conclusion

Anti-PTM antibodies are frequently present in AILD. The presence of anti-MAA, anti-AGE and anti-CarP antibodies correlates with the presence of AIH within this cohort. In AIH, harboring at least three anti-PTM antibody responses is positively associated with CBR. Determination of anti-PTM antibodies in liver disease may have diagnostic and prognostic value.

Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases?

Optic nerve disorders encompass a wide spectrum of conditions characterized by the loss of retinal ganglion cells (RGCs) and subsequent degeneration of the optic nerve. The etiology of these disorders can vary significantly, but emerging research highlights the crucial role of oxidative stress, an imbalance in the redox status characterized by an excess of reactive oxygen species (ROS), in driving cell death through apoptosis, autophagy, and inflammation. This review provides an overview of ROS-related processes underlying four extensively studied optic nerve diseases: glaucoma, Leber's hereditary optic neuropathy (LHON), anterior ischemic optic neuropathy (AION), and optic neuritis (ON). Furthermore, we present preclinical findings on antioxidants, with the objective of evaluating the potential therapeutic benefits of targeting oxidative stress in the treatment of optic neuropathies.

Medicinal Chemistry Insights into the Development of Small-Molecule Kelch-Like ECH-Associated Protein 1-Nuclear Factor Erythroid 2-Related Factor 2 (Keap1-Nrf2) Protein-Protein Interaction Inhibitors

Oxidative stress has been implicated in a wide range of pathological conditions. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) exerts a central role in regulating the cellular defense system against oxidative and electrophilic insults. Nonelectrophilic inhibition of the protein-protein interaction (PPI) between Kelch-like ECH-associated protein 1 (Keap1) and Nrf2 has become a promising approach to activate Nrf2. Recently, multiple drug discovery strategies have facilitated the development of small-molecule Keap1-Nrf2 PPI inhibitors with potent activity and favorable drug-like properties. In this Perspective, we summarize the latest progress of small-molecule Keap1-Nrf2 PPI inhibitors from medicinal chemistry insights and discuss future prospects and challenges in this field.

Measurement of superoxide dismutase: clinical usefulness for patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

To investigate the clinical usefulness of serum superoxide dismutase (SOD) measurement in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

In this single-center retrospective study, demographic data, serum SOD levels, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), the Birmingham Vasculitis Activity Score (BVAS), ANCA, organ involvement, and outcomes were analyzed for 152 AAV patients hospitalized in the Second Affiliated Hospital of Chongqing Medical University. Meanwhile, the serum SOD levels of 150 healthy people were collected as the control group.

RESULTS

Compared to the healthy control group, serum SOD levels of the AAV group were significantly lower (P < 0.001). SOD levels of AAV patients were negatively correlated to ESR, CRP, and BVAS (ESR rho = - 0.367, P < 0.001; CRP rho = - 0.590, P < 0.001; BVAS rho = - 0.488, P < 0.001). SOD levels for the MPO-ANCA group were significantly lower than the PR3-ANCA group (P = 0.045). SOD levels for the pulmonary involvement group and the renal involvement group were significantly lower than those for the non-pulmonary involvement group and the non-renal involvement group (P = 0.006; P < 0.001, respectively). SOD levels in the death group were significantly lower than the survival group (P = 0.001).

CONCLUSIONS

In AAV patients, low SOD levels might indicate disease associated oxidative stress. SOD levels in AAV patients were decreased with inflammation, suggesting that SOD levels could potentially be a surrogate marker for disease activity. SOD levels in AAV patients were closely related to ANCA serology, pulmonary involvement, and renal involvement, with low SOD levels an important indicator of a poor prognosis for AAV patients.

Can pyroptosis be a new target in rheumatoid arthritis treatment?

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease of undefined etiology, with persistent synovial inflammation and destruction of articular cartilage and bone. Current clinical drugs for RA mainly include non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease modifying anti-rheumatic drugs (DMARDs) and so on, which can relieve patients' joint symptoms. If we want to have a complete cure for RA, there are still some limitations of these drugs. Therefore, we need to explore new mechanisms of RA to prevent and treat RA radically. Pyroptosis is a newly discovered programmed cell death (PCD) in recent years, which is characterized by the appearance of holes in cell membranes, cell swelling and rupture, and the release of intracellular pro-inflammatory factors into the extracellular space, resulting in a strong inflammatory response. The nature of pyroptosis is pro-inflammatory, and whether it is participating in the development of RA has attracted a wide interest among scholars. This review describes the discovery and mechanism of pyroptosis, the main therapeutic strategies for RA, and the role of pyroptosis in the mechanism of RA development. From the perspective of pyroptosis, the study of new mechanisms of RA may provide a potential target for the treatment of RA and the development of new drugs in the clinics.

Glutathione peroxidase 3 is a novel clinical diagnostic biomarker and potential therapeutic target for neutrophils in rheumatoid arthritis

BACKGROUND

Neutrophils have a critical role in the pathogenesis of rheumatoid arthritis (RA) with immune system dysfunction. However, the molecular mechanisms of this process mediated by neutrophils still remain elusive. The purpose of the present study is to identify hub genes in neutrophils for diagnosis and treatment of RA utilizing publicly available datasets.

METHODS

Gene expression profiles were downloaded from the Gene Expression Omnibus, and batch-corrected and normalized expression data were obtained using the ComBat package. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were used to conduct significantly functional analysis and crucial pathways. The resulting co-expression genes modules and hub genes were generated based on the weighted gene co-expression network analysis and visualization by Cytoscape. Flow cytometry was conducted to detect reactive oxygen species (ROS) levels in neutrophils.

RESULTS

Neutrophils underwent transcriptional changes in synovial fluid (SF) of RA patients, different from peripheral blood of healthy controls or patients with RA. Especially, glycolysis, HIF-1 signaling, NADH metabolism, and oxidative stress were affected. These hub genes were strongly linked with classical glycolysis-related genes (ENO1, GAPDH, and PKM) responsible for ROS production. The antioxidant enzyme glutathione peroxidase 3 (GPX3), a ROS scavenger, was first identified as a hub gene in RA neutrophils. Neutrophils from patients with autoinflammatory and autoimmune diseases had markedly enhanced ROS levels, most notably in RA SF.

CONCLUSION

This research recognized hub genes and explored the characteristics of neutrophils in RA. Our findings suggest that the novel hub gene GPX3 is involved in the neutrophil-driven oxidative stress-mediated pathogenesis of RA. It has the potency to be a target for neutrophil-directed RA therapy.

Rheumatoid Arthritis and Reactive Oxygen Species: A Review

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that causes progressive joint damage and can lead to lifelong disability. Numerous studies support the hypothesis that reactive oxygen species (ROS) are associated with RA pathogenesis. Recent advances have clarified the anti-inflammatory effect of antioxidants and their roles in RA alleviation. In addition, several important signaling pathway components, such as nuclear factor kappa B, activator-protein-1, nuclear factor (erythroid-derived 2)-like 2/kelch-like associated protein, signal transducer and activator of transcription 3, and mitogen-activated protein kinases, including c-Jun N-terminal kinase, have been identified to be associated with RA. In this paper, we outline the ROS generation process and relevant oxidative markers, thereby providing evidence of the association between oxidative stress and RA pathogenesis. Furthermore, we describe various therapeutic targets in several prominent signaling pathways for improving RA disease activity and its hyper oxidative state. Finally, we reviewed natural foods, phytochemicals, chemical compounds with antioxidant properties and the association of microbiota with RA pathogenesis.

Elderberry Extracts: Characterization of the Polyphenolic Chemical Composition, Quality Consistency, Safety, Adulteration, and Attenuation of Oxidative Stress- and Inflammation-Induced Health Disorders

Elderberry is highly reputed for its health-improving effects. Multiple pieces of evidence indicate that the consumption of berries is linked to enhancing human health and preventing or delaying the onset of chronic medical conditions. Compared with other fruit, elderberry is a very rich source of anthocyanins (approximately 80% of the polyphenol content). These polyphenols are the principals that essentially contribute to the high antioxidant and anti-inflammatory capacities and the health benefits of elderberry fruit extract. These health effects include attenuation of cardiovascular, neurodegenerative, and inflammatory disorders, as well as anti-diabetic, anticancer, antiviral, and immuno-stimulatory effects. Sales of elderberry supplements skyrocketed to $320 million over the year 2020, according to an American Botanical Council (ABC) report, which is attributable to the purported immune-enhancing effects of elderberry. In the current review, the chemical composition of the polyphenolic content of the European elderberry (Sambucus nigra) and the American elderberry (Sambucus canadensis), as well as the analytical techniques employed to analyze, characterize, and ascertain the chemical consistency will be addressed. Further, the factors that influence the consistency of the polyphenolic chemical composition, and hence, the consistency of the health benefits of elderberry extracts will be presented. Additionally, adulteration and safety as factors contributing to consistency will be covered. The role of elderberry in enhancing human health alone with the pharmacological basis, the cellular pathways, and the molecular mechanisms underlying the observed health benefits of elderberry fruit extracts will be also reviewed.

Effects of Citrus kawachiensis Peel in Frailty-like Model Mice Induced by Low Protein Nutrition Disorders

"Frailty" caused by a decline in physiological reserve capacity, chronic inflammation, and oxidative stress in the elderly has recently become a major social issue. The present study examined the effects of the peel of Citrus kawachiensis (CK), which exhibits anti-inflammatory, antioxidant, and pro-neurogenesis activities in frailty-like model mice. Male C57BL/6 mice (15 weeks old) were fed an 18% protein diet (CON), a 2.5% protein diet (PM), and PM mixed with 1% dried CK peel powder for approximately 1 month. Mice were euthanized 2 or 8 days after a single intraperitoneal administration of lipopolysaccharide (LPS) and tissues were dissected. Among peripheral tissues, muscle weight, liver weight, and blood glucose levels were significantly higher in the PM-LPS-CK group than in the PM-LPS group. In the behavioral analysis, locomotive activity was significantly lower in the PM-LPS group than in the PM group. The reduction in locomotive activity in the PM-LPS-CK group was significantly smaller than that in the PM-LPS group. The quantification of microglia in the hippocampal stratum lacunosum-moleculare revealed that increases in the PM-LPS group were significantly suppressed by the dried CK peel powder. Furthermore, the quantification of synaptic vesicle membrane proteins in the hippocampal CA3 region showed down-regulated expression in the PM-LPS group, which was significantly ameliorated by the administration of the dried CK peel powder. Collectively, these results suggest that CK inhibits inflammation and oxidative stress induced by PM and LPS in the central nervous system and peripheral tissue. Therefore, C. kawachiensis is highly effective against "frailty".

Sex differences in antioxidant defence and the regulation of redox homeostasis in physiology and pathology

Reactive oxygen species (ROS) is a term that defines a group of unstable compounds derived from exogenous sources or endogenous metabolism. Under physiological conditions, low levels of ROS play a key role in the regulation of signal transduction- or transcription-mediated cellular responses. In contrast, excessive and uncontrolled loading of ROS results in a pathological state known as oxidative stress (OS), a leading contributor to aging and a pivotal factor for the onset and progression of many disorders. Evolution has endowed cells with an antioxidant system involved in stabilizing ROS levels to a specific threshold, preserving ROS-induced signalling function and limiting negative side effects. In mammals, a great deal of evidence indicates that females defence against ROS is more proficient than males, determining a longer lifespan and lower incidence of most chronic diseases. In this review, we will summarize the most recent sex-related differences in the regulation of redox homeostasis. We will highlight the peculiar aspects of the antioxidant defence in sex-biased diseases whose onset or progression is driven by OS, and we will discuss the molecular, genetic, and evolutionary determinants of female proficiency to cope with ROS.

Nanomedicine is more than a supporting role in rheumatoid arthritis therapy

Rheumatoid arthritis(RA) is an autoimmune disorder that affects the joints. Various medications successfully alleviate the symptoms of RA in clinical. Still, few therapy strategies can cure RA, especially when joint destruction begins, and there is currently no effective bone-protective treatment to reverse the articular damage. Furthermore, the RA medications now used in clinical practice accompany various adverse side effects. Nanotechnology can improve the pharmacokinetics of traditional anti-RA drugs and therapeutic precision through targeting modification. Although the clinical application of nanomedicines for RA is in its infancy, preclinical research is rising. Current anti-RA nano-drug studies mainly focus on the following: drug delivery systems, nanomedicines with anti-inflammatory and anti-arthritic properties, biomimetic design with better biocompatibility and therapeutic features, and nanoparticle-dominated energy conversion therapies. These therapies have shown promising therapeutic benefits in animal models, indicating that nanomedicines are a potential solution to the current bottleneck in RA treatment. This review will summarize the present state of anti-RA nano-drug research.

Using mass spectrometry to identify neoantigens in autoimmune diseases: The type 1 diabetes example

In autoimmune diseases, recognition of self-antigens presented by major histocompatibility complex (MHC) molecules elicits unexpected attack of tissue by autoantibodies and/or autoreactive T cells. Post-translational modification (PTM) may alter the MHC-binding motif or TCR contact residues in a peptide antigen, transforming the tolerance to self to autoreactivity. Mass spectrometry-based immunopeptidomics provides a valuable mechanism for identifying MHC ligands that contain PTMs and can thus provide valuable insights into pathogenesis and therapeutics of autoimmune diseases. A plethora of PTMs have been implicated in this process, and this review highlights their formation and identification.

Role of chemokine receptor 2 in rheumatoid arthritis: A research update

Rheumatoid arthritis (RA) is a multisystemic and inflammatory autoimmune disease characterized by joint destruction. The C-C motif chemokine receptor 2 (CCR2) is mainly expressed in monocytes and T cells, initiating their migration to sites of inflammation, ultimately leading to cartilage damage and bone destruction. CCR2 has long been considered a prospective target for treating autoimmune diseases. However, clinical studies on inhibitors or neutralizing antibodies against CCR2 in RA have exhibited limited efficacy. Recent evidence indicates that CCR2 may play different roles in RA. Hence, a comprehensive understanding regarding the role of CCR2 may facilitate the development of targeted drugs and provide novel insights for improving CCL2-mediated inflammatory diseases. This review summarizes the biological characteristics of CCR2, the related signaling pathways, and recent developments in CCR2-targeting therapeutics.

The combined effect of heavy metals and polycyclic aromatic hydrocarbons on arthritis, especially osteoarthritis, in the U.S. adult population

The evaluation of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) impact on arthritis is usually limited to the analysis of the arthritis subtype (rheumatoid arthritis, RA), whereas studies on osteoarthritis (OA) are relatively sparse. Furthermore, the combined effect of HMs and PAHs co-exposure on arthritis also has rarely been analyzed. Herein, we aimed to comprehensively estimate the association between HMs and PAHs (three blood HMs and six urinary PAHs metabolites) co-exposure and arthritis. Using data from the National Health and Nutrition Examination Survey (NHANES), 2003-2016, we included 9735 adults, of whom 2464 had total arthritis, 1371 had OA, and 468 had RA. The logistic regression model was conducted to estimate the single effect of HMs and PAHs on arthritis. Moreover, weighted quantile sum (WQS) regression, quantile-based g computation (qgcomp), and Bayesian kernel machine regression (BKMR) were separately performed to assess the combined effect of HMs and PAHs co-exposure on arthritis. In the single-exposure analyses, cadmium (Cd) and lead (Pb) statistically grew the risk of total arthritis, OA, and RA. Among PAHs, 1-hydroxynaphthalene (1-NAP) and 3-hydroxyfluorene (3-FLU) showed a positive association with total arthritis, OA, and RA. Meanwhile, 2-NAP also was significantly associated with total arthritis. 2-NAP, 2-FLU, and 1-hydroxyphenanthrene (1-PHE) also were significantly associated with RA. Furthermore, the three complementary models consistently demonstrated that co-exposure to high levels of HMs and PAHs was positively associated with total arthritis, OA, and RA risk. The above associations were more obvious in young and medium-aged people. Interestingly, BKMR analyses indicated that 1-NAP might interact with Cd and 3-FLU in total arthritis, while Pb might interact with Cd in OA. Therefore, this study provided novel evidence that co-exposure to HMs and PAHs positively correlated with arthritis, especially OA, and these results were worthy of further prospective studies.

Oxidative Stress Contributes to Inflammatory and Cellular Damage in Systemic Lupus Erythematosus: Cellular Markers and Molecular Mechanism

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with complex pathogenesis, the treatment of which relies exclusively on the use of immunosuppressants. Increased oxidative stress is involved in causing inflammatory and cellular defects in the pathogenesis of SLE. Various inflammatory and cellular markers including oxidative modifications of proteins, lipids, and DNA contribute to immune system dysregulation and trigger an aggressive autoimmune attack through molecular mechanisms like enhanced NETosis, mTOR pathway activation, and imbalanced T-cell differentiation. Accordingly, the detection of inflammatory and cellular markers is important for providing an accurate assessment of the extent of oxidative stress. Oxidative stress also reduces DNA methylation, thus allowing the increased expression of affected genes. As a result, pharmacological approaches targeting oxidative stress yield promising results in treating patients with SLE. The purpose of this review is to examine the involvement of oxidative stress in the pathogenesis and management of SLE.

Iso-seco-tanapartholide induces p62 covalent oligomerization to activate KEAP1-NRF2 redox pathway in rheumatoid arthritis

SQSTM1/p62 sequesters intracellular aberrant proteins and mediates their selective autophagic degradation. p62 oligomerization posttranslational modification enhances its sequestration function and positively regulates the KEAP1-NRF2 redox pathway. However, the regulation of p62 covalent oligomerization has yet been poorly characterized. Here, we identified a natural small-molecule sesquiterpene, Iso-seco-tanapartholide (IST) modified p62 cysteine residues, which induced p62 to form crosslinked oligomers between TBS and TBS or TBS and PB1 domains in a covalently non-disulfide-linked manner. Using LC-MS/MS analysis and complementary approaches, we revealed that Cys residues of p62 were necessary for IST-induced covalent oligomer. This oligomerization promoted p62 recruitment of KEAP1 for degradation by autophagosomes and released NRF2 to the nucleus to activate the expression of downstream genes with anti-oxidant and anti-inflammatory capacities. Accordingly, IST-mediated p62/NRF2 activation conferred protection from oxidative and inflammatory destruction of rheumatoid arthritis in vitro and in vivo. In contrast, p62-knockdown cells displayed a reduced anti-oxidant response and increased pro-inflammatory cytokine secretion in response to TNF-α stimulation. Hence, our findings uncover an unrecognized role of IST in the regulation of p62 oligomerization and provide a new strategy for the treatment of rheumatoid arthritis.

Effect of cerium on the production of reactive oxygen species in the root of Arabidopsis thaliana: An in vitro study

In the current study, the effect of trivalent cerium (Ce³⁺ ) on the production of reactive oxygen species (ROS) was investigated in the root of Arabidopsis thaliana by an in vitro study. The roots of A. thaliana were exposed with 0, 1, and 5 μmol/L Ce³⁺ for 12 h in vitro. It was found that the level of H₂ O₂ , O₂ ^.- , and ·OH was enhanced by 5 μmol/L Ce³⁺ , but reduced by 1 μmol/L Ce³⁺ . The activities of peroxidase (POD), catalase (CAT), and superoxidase dismutase (SOD) were enhanced by 1 μmol/L Ce³⁺ , but reduced by 5 μmol/L Ce³⁺ . Moreover, we used a laser-scanning confocal microscopy to detect the changes of ROS in the root cells of A. thaliana by using a fluorochrome 2',7'-dichlorofluorescein diacetate (H₂ DCF-DA). It showed that the level of ROS was declined in the root cells treated by 1 μmol/L Ce³⁺ , but the oscillation of ROS was found in the root cells treated with 5 μmol/L Ce³⁺ . In addition, REEs affect the uptake of mineral elements, which may be related to the oxidative stress in the cells of roots. In all, the data of our study indicated that the appropriate concentration of Ce³⁺ exhibited an anti-oxidation property and improved the defense system in the root cells of A. thaliana.