The two directions of TNF-related apoptosis-inducing ligand in rheumatoid arthritis

E3 ubiquitin ligase gene BIRC3 modulates TNF-induced cell death pathways and promotes aberrant proliferation in rheumatoid arthritis fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by synovitis, degradation of articular cartilage, and bone destruction. Fibroblast-like synoviocytes (FLS) play a central role in RA, producing a significant amount of inflammatory mediators such as tumor necrosis factor(TNF)-α and IL-6, which promote inflammatory responses within the joints. Moreover, FLS exhibit tumor-like behavior, including aggressive proliferation and enhanced anti-apoptotic capabilities, which collectively drive chronic inflammation and joint damage in RA. TNF is a major pro-inflammatory cytokine that mediates a series of signaling pathways through its receptor TNFR1, including NF-κB and MAPK pathways, which are crucial for inflammation and cell survival in RA. The abnormal proliferation and anti-apoptotic characteristics of FLS in RA may result from dysregulation in TNF-mediated cell death pathways such as apoptosis and necroptosis. Ubiquitination is a critical post-translational modification regulating these signaling pathways. E3 ubiquitin ligases, such as cIAP1/2, promote the ubiquitination and degradation of target proteins within the TNF receptor complex, modulating the signaling proteins. The high expression of the BIRC3 gene and its encoded protein, cIAP2, in RA regulates various cellular processes, including apoptosis, inflammatory signaling, immune response, MAPK signaling, and cell proliferation, thereby promoting FLS survival and inflammatory responses. Inhibiting BIRC3 expression can reduce the secretion of inflammatory cytokines by RA-FLS under both basal and inflammatory conditions and inhibit their proliferation. Although BIRC3 inhibitors show potential in RA treatment, their possible side effects must be carefully considered. Further research into the specific mechanisms of BIRC3, including its roles in cell signaling, apoptosis regulation, and immune evasion, is crucial for identifying new therapeutic targets and strategies.

Association of gene polymorphisms and the decreased expression of long non-coding RNA LOC553103 with rheumatoid arthritis

BACKGROUND

Long non-coding RNAs (lncRNAs) are involved in many key bioprocesses, including the occurrence and development of rheumatoid arthritis (RA). We aimed to analyze the association of genetic variants of long non-coding RNA LOC553103 and its peripheral blood mononuclear cells (PBMC) expression with RA.

METHODS

We enrolled 457 RA patients and 551 healthy controls and conducted a case-control study to analyze the relationship between LOC553103 gene rs272879 and the susceptibility of RA by TaqMan single nucleotide polymorphism genotyping. Among them, we sampled 92 cases and 92 controls, respectively, to detect the PBMC level of LOC553103 using quantitative real-time polymerase chain reaction technology. We explored the association between LOC553103 rs272879 and its PBMC expression levels in 71 RA patients. Mann-Whitney, Chi-square, and Spearman correlation analysis were used for statistical analysis and P-value <.05 was considered statistically significant.

RESULTS

The genotype frequency of LOC553103 rs272879 CC was increased, and CG was decreased in RA patients compared to the control group (χ2 = 6.772, P = .034). The LOC553103 expression level in PBMC of RA patients was downregulated compared to healthy control (Z = -4.497, P < .001). Moreover, negative correlations were observed between the PBMC level of LOC553103 and erythrocyte sedimentation rate (rs = -0.262, P = .018), white blood cell count (rs = -0.382, P = .004), platelet (rs = -0.293, P = .030), and disease activity score in 28 joints (rs = -0.271, P = .016) in RA patients.

CONCLUSIONS

This study provides the first evidence supporting an association between LOC553103 gene polymorphisms and susceptibility of RA and a relationship of PBMC level of LOC553103 with clinical manifestations and laboratory indicators of RA patients.

Integrative analysis and validation of necroptosis-related molecular signature for evaluating diagnosis and immune features in Rheumatoid arthritis

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that is characterized by persistent morning stiffness, joint pain, and swelling. However, there is a lack of reliable diagnostic markers and therapeutic targets that are both effective and trustworthy.

METHODS

In this study, gene expression profiles (GSE89408, GSE55235, GSE55457, and GSE77298) were obtained from the Gene Expression Omnibus database. Differentially expressed necroptosis-related genes were attained from intersection of necroptosis-related gene set, differentially expressed genes, and weighted gene co-expression network analysis. The LASSO, random forest, and SVM-RFE machine learning algorithms were utilized to further screen potential diagnostic genes for RA. Immune cell infiltration was analyzed using the CIBERSORT method. The expressions of diagnostic genes were validated through quantitative real-time PCR, western blotting, immunohistochemistry, and immunofluorescence staining in synovial tissues collected from three trauma controls and three RA patients.

RESULTS

Five core necroptosis-related genes (FAS, CYBB, TNFSF10, EIF2AK2, and BIRC2) were identified as potential biomarkers for RA. Two different necroptosis patterns based on these five genes were confirmed to significantly correlated with immune cells (especially macrophages). In vitro experiments showed significantly higher mRNA and protein expression levels of CYBB and EIF2AK2 in RA patients compared to normal controls, consistent with the bioinformatics analysis results.

CONCLUSION

Our study identified a novel necroptosis-related subtype and five diagnostic biomarkers of RA, revealed vital roles in the development and occurrence of RA, and offered potential targets for clinical diagnosis and immunotherapy.

Cross-Tissue Transcriptomic Analysis Leveraging Machine Learning Approaches Identifies New Biomarkers for Rheumatoid Arthritis

There is an urgent need to identify biomarkers for diagnosis and disease activity monitoring in rheumatoid arthritis (RA). We leveraged publicly available microarray gene expression data in the NCBI GEO database for whole blood (N=1,885) and synovial (N=284) tissues from RA patients and healthy controls. We developed a robust machine learning feature selection pipeline with validation on five independent datasets culminating in 13 genes: TNFAIP6, S100A8, TNFSF10, DRAM1, LY96, QPCT, KYNU, ENTPD1, CLIC1, ATP6V0E1, HSP90AB1, NCL and CIRBP which define the RA score and demonstrate its clinical utility: the score tracks the disease activity DAS28 (p = 7e-9), distinguishes osteoarthritis (OA) from RA (OR 0.57, p = 8e-10) and polyJIA from healthy controls (OR 1.15, p = 2e-4) and monitors treatment effect in RA (p = 2e-4). Finally, the immunoblotting analysis of six proteins on an independent cohort confirmed two proteins, TNFAIP6/TSG6 and HSP90AB1/HSP90.

Evaluation of destruction in a collagen-induced arthritis rat model: Bony spur formation

Over the past 40 years, the collagen-induced arthritis (CIA) animal model has been widely used as a model of rheumatoid arthritis (RA). However, no model is able to completely depict the characteristics of cartilage destruction to date. In the later stage of joint cartilage destruction, bony spurs form in RA. This bony spur formation is an important symptom in the pathological development of RA. In the present study, CIA was used to elucidate the pathological process of bony spur formation. Joint damage and spur formation in the animal model was detected by radiology and histology. Radiology identified bony spurs in the knee and foot joints, which worsened as the disease progressed. Furthermore, following observations of histological sections, fusion and damage of the articular cartilage, as well as a higher number of osteoclasts, were identified. Previous results have determined that bony spurs may be involved in another pathological process that occurs during the later stages of RA. Therefore, further studies investigating this symptom are required to improve the understanding of RA and facilitate the development of an appropriate treatment for RA.

Podophyllotoxin Extracted from Juniperus sabina Fruit Inhibits Rat Sperm Maturation and Fertility by Promoting Epididymal Epithelial Cell Apoptosis

This study aimed to investigate the antifertility effect of Juniperus sabina fruit on male rats and its possible mechanism, and hence it might be developed as a potential nonhormonal male contraceptive. Male rats were intragastrically fed for consecutive 8-week and 4-week recovery with the fruit of J. Sabina, and sperm maturation, serum testosterone level, and histopathology were analyzed. Epididymal epithelial cell culture was prepared for detection of podophyllotoxin activities. Furthermore, cell proliferation, transmission electron microscopy, Annexin V/Propidium iodide, TUNEL, RT-PCR, ELISA, and western blotting were examined. The results showed that rat sperm motility and fertility were remarkably declined after feeding the fruit. Moreover, the fruit targeted the epididymis rather than the testis. After 4-week recovery, more than half of the male rats resumed normal fertility. It was found that podophyllotoxin significantly inhibited epididymal epithelial cell proliferation, promoted cell apoptosis, and increased the mRNA and protein levels of TNF-α and the expression levels of cytochrome c, caspase-8, caspase-9, and caspase-3. Our findings suggest that the fruit of J. sabina could inhibit male rat sperm maturation and fertility. The potential mechanism might be related to podophyllotoxin, inducing epididymal epithelial cell apoptosis through TNF-α and caspase signaling pathway.

Redox signaling and oxidative stress: Cross talk with TNF-related apoptosis inducing ligand activity

Redox regulation plays a key role in several physiopathological contexts and free radicals, from nitric oxide and superoxide anion up to other forms of reactive oxygen species (ROS), have been demonstrated to be involved in different biological and regulatory processes. The data reported in the current literature describe a link between ROS, inflammation and programmed cell death that is attracting interest as new pathways to be explored and targeted for therapeutic purposes. In this light, there is also growing attention to the involvement of this link in the activity of the TNF-related apoptosis inducing ligand (TRAIL). TRAIL is a member of the TNF ligands super family able to mediate multiple intracellular signals, with the potential to lead to a range of biological effects in different cell types. In particular, the hallmark of TRAIL is the ability to induce selective apoptosis in transformed cells leaving normal cells almost unaffected and this feature has already opened the door to several clinical studies for cancer treatment. Moreover, TRAIL plays a role in several physiological and pathological processes of both innate and adaptive immune systems and of the cardiovascular context, with a strong clinical potential. Nonetheless, several issues still need to be clarified about the signaling mediated by TRAIL to gain deeper insight into its therapeutic potential. In this light, the aim of this review is to summarize the main preclinical evidences about the interplay between TRAIL and redox signaling, with particular emphasis to the implications in vascular physiopathology and cancer.

Expression of osteoprotegerin and its ligands, RANKL and TRAIL, in rheumatoid arthritis

Osteoprotegerin (OPG), receptor activator of nuclear factor-ΚB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) have been involved in rheumatoid arthritis (RA) pathophysiology. In this study, we assessed messenger RNA (mRNA) expression of these molecules by qPCR in peripheral blood from 26 patients with RA (12 of them with ischemic heart disease –IHD) and 10 healthy controls. Correlation coefficients between OPG, RANKL and TRAIL expression levels in RA patients and their clinical and demographic characteristics were also evaluated. Whereas OPG and OPG/TRAIL ratio expression were significantly increased in RA patients compared to controls (fold change = 1.79, p = 0.013 and 2.07, p = 0.030, respectively), RANKL/OPG ratio was significantly decreased (fold change = 0.50, p = 0.020). No significant differences were found between patients and controls in RANKL and TRAIL expression. Interestingly, TRAIL expression was significantly higher in RA patients with IHD compared to those without IHD (fold change = 1.46, p = 0.033). Moreover, biologic disease-modifying antirheumatic drugs (DMARDs) significantly decreased RANKL expression in RA patients (p = 0.016). Our study supports an important role of OPG and TRAIL in RA. Furthermore, it highlights an effect of biologic DMARDs in the modulation of RANKL.

Clinical perspectives of TRAIL: insights into central nervous system disorders

The TNF-related apoptosis inducing ligand TRAIL is a member of the TNF superfamily that has been firstly studied and evaluated for its anti-cancer activity, and the insights into its biology have already led to the identification of several TRAIL-based anticancer strategies with strong clinical therapeutic potentials. Nonetheless, the TRAIL system is far more complex and it can lead to a wider range of biological effects other than the ability of inducing apoptosis in cancer cells. By virtue of the different receptors and the different signalling pathways involved, TRAIL plays indeed a role in the regulation of different processes of the innate and adaptive immune system and this feature makes it an intriguing molecule under consideration in the development/progression/treatment of several immunological disorders. In this context, central nervous system represents a peculiar anatomic site where, despite its "status" of immune-privileged site, both innate and adaptive inflammatory responses occur and are involved in several pathological conditions. A number of studies have evaluated the role of TRAIL and of TRAIL-related pathways as pro-inflammatory or protective stimuli, depending on the specific pathological condition, confirming a twofold nature of this molecule. In this light, the aim of this review is to summarize the main preclinical evidences of the potential/involvement of TRAIL molecule and TRAIL pathways for the treatment of central nervous system disorders and the key suggestions coming from their assessment in preclinical models as proof of concept for future clinical studies.

Osteoprotegerin and tumor necrosis factor-related apoptosis-inducing ligand as prognostic factors in rheumatoid arthritis: results from the ESPOIR cohort

Introduction

We previously reported that low ratio of osteoprotegerin (OPG) to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was associated with Disease Activity Score in 28 joints (DAS28) remission at 6 months in patients with early rheumatoid arthritis (RA). Here, we aimed to evaluate the value of baseline OPG/TRAIL ratio in predicting clinical and radiological outcomes in patients with early RA in the ESPOIR cohort.

Methods

OPG and TRAIL serum concentrations were assessed in the ESPOIR cohort patients. Patients with definite RA were included in this study. Patients were excluded if they had high erosion score at baseline (>90^th percentile) or received biological therapy during the first 2 years of follow-up. Data were analyzed by univariate analysis and multivariate logistic regression to predict 1-year DAS28 remission and 2-year radiographic disease progression.

Results

On univariate analysis of 399 patients, OPG/TRAIL ratio at baseline was significantly lower in patients with than without remission at 1 year (p = 0.015). On multivariate logistic regression including age, gender, body mass index and DAS28, low OPG/TRAIL ratio was independently associated with remission at 1 year (odds ratio 1.68 [95 % confidence interval 1.01–2.79]). On univariate analysis, high OPG/TRAIL ratio at baseline was associated with rapid progression of erosion at 2 years (p = 0.041), and on multivariate logistic regression including age, anti-citrullinated protein antibody positivity and C-reactive protein level, OPG/TRAIL ratio independently predicted rapid progression of erosion at 2 years.

Conclusions

OPG/TRAIL ratio at baseline was an independent predictor of 1-year remission and 2-year rapid progression of erosion for patients with early rheumatoid arthritis. Thus, OPG/TRAIL ratio could be included in matrix prediction scores to predict rapid radiographic progression. Further confirmation in an independent cohort is warranted.

Tumor necrosis factor-related apoptosis-inducing ligand in vascular inflammation and atherosclerosis: a protector or culprit?

In addition to inducing tumor cell apoptosis, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) shows broad biological functions both in vitro and in vivo. TRAIL gene deletion enhanced atherogenesis in hyperlipidemic mice, supporting that endogenous TRAIL has protective actions in maintaining blood vessel homeostasis and repressing atherosclerosis. The mechanisms of this beneficial effect are not understood. It remains to be determined whether the athero-protective action of TRAIL is via direct impacts on residential vascular cells or indirectly by modulating systemic immune functions. However, in vitro experiments indicate that excessive TRAIL may stimulate endothelial cell apoptosis, smooth muscle proliferation and migration, and inflammatory responses. Moreover, TRAIL can stimulate lipid uptake and foam cell formation in cultured macrophages. Here we provide a critical review on the potential relationships between TRAIL and atherosclerosis. We propose that increased TRAIL production may also have potential detrimental effects on vascular inflammation and atherosclerosis. Further in vivo experiments are warranted to elucidate the effects of exogenous TRAIL on atherogenesis.

Kinesin spindle protein (KSP) inhibitors in combination with chemotherapeutic agents for cancer therapy

A diverse group of proteins, the activities of which are precisely orchestrated during mitosis, have emerged as targets for cancer therapeutics; these include the Aurora kinases (AKs), Polo-like kinases (PLKs), and the kinesin spindle protein (KSP). KSP is essential for the proper separation of spindle poles during mitosis. Agents that target KSP selectively act on cells undergoing cell division, which means that KSP inhibitors are mitosis-specific drugs, and have demonstrated remarkable activities in vitro. However, a significant obstacle to the success of KSP inhibitors is that these compounds, with tremendous efficacy in vitro, have demonstrated little or even no antitumor activity in vivo. Accumulated data suggest that a combination of KSP inhibitors with various cytostatic drugs will result in a more powerful tumor-killing effect than monotherapy. Combination therapies might predominate and represent the next frontier in the discovery research of KSP inhibitors as potential anticancer drugs. Few published studies have reviewed combination therapy using KSP inhibitors. Herein we provide a comprehensive review of the literature on KSP inhibitor monotherapy and therapeutic combinations. The current state and problems are also discussed.

Isolation of xanthone and benzophenone derivatives from Cyclopia genistoides (L.) Vent. (honeybush) and their pro-apoptotic activity on synoviocytes from patients with rheumatoid arthritis

A fast and efficient method for the isolation of the C-glucosidated xanthones mangiferin and isomangiferin from the South-African plant Cyclopia genistoides was developed for the first time. The procedure involved extraction, liquid-liquid partitioning with ethyl acetate and subsequent precipitation of mangiferin and isomangiferin from methanol and acetonitrile-water fractions, respectively. Additionally, two benzophenone derivatives: 3-C-β-glucosides of maclurin and iriflophenone, were isolated from C. genistoides extracts using semi-preparative HPLC. Apart from the above, the isolation procedure also yielded hesperidin and small amounts of luteolin. The structures of the compounds were determined by 1D and 2D NMR experiments and/or LC-DAD-ESI-MS. The selected Cyclopia constituents were screened for pro-apoptotic activity on TNF-α-stimulated synovial cells isolated from rheumatoid arthritis patients. The strongest effect, measured as percent of apoptotic cells, was recorded for isomangiferin (75%), followed by iriflophenone 3-C-β-glucoside (71%), hesperidin (67%) and mangiferin (65%). The results are encouraging for further studies on the use of the above compounds in the treatment of rheumatoid arthritis.