Insight into the fracture energy dissipation mechanism in elastomer composites via sacrificial bonds and fillers.

Most tough elastomer composites are reinforced by introducing sacrificial structures and fillers. Understanding the contribution of fillers and sacrificial bonds in elastomer composites to the energy dissipation is critical for the design of high-toughness materials. However, the energy dissipation mechanism in elastomer composites remains elusive. In this study, using a tearing test and time-temperature superposition, we investigate the effect of fillers and sacrificial bonds on the energy dissipation of elastomer composites consisting of poly(lipoic acid)/silver-coated Al fillers. We found that the fillers and sacrificial bonds mutually enhance both the intrinsic fracture energy and the bulk energy dissipation, and moreover the sacrificial bonds play a more important role in enhancing fracture toughness than the fillers. It is unreasonable to rely solely on the loss factor for bulk energy dissipation. The addition of sacrificial bonds results in a chain segment experiencing greater binding force compared to the addition of fillers. This suggests that the chain segment consumes more energy during its movement. By calculating the length of the Kuhn chain segment and the Kuhn number, it is evident that the addition of sacrificial bonds results in a greater binding force for the chain segment than the addition of fillers, and this enhanced binding force increases the energy consumption during the motion of the chain segment.

Can Adhesion Energy Optimize Interface Thermal Resistance at a Soft/Hard Material Interface?

Thermal resistance at a soft/hard material interface plays an undisputed role in the development of electronic packaging, sensors, and medicine. Adhesion energy and phonon spectra match are two crucial parameters in determining the interfacial thermal resistance (ITR), but it is difficult to simultaneously achieve these two parameters in one system to reduce the ITR at the soft/hard material interface. Here, we report a design of an elastomer composite consisting of a polyurethane-thioctic acid copolymer and microscale spherical aluminum, which exhibits both high phonon spectra match and high adhesion energy (>1000 J/m2) with hard materials, thus leading to a low ITR of 0.03 mm2·K/W. We further develop a quantitative physically based model connecting the adhesion energy and ITR, revealing the key role the adhesion energy plays. This work serves to engineer the ITR at the soft/hard material interface from the aspect of adhesion energy, which will prompt a paradigm shift in the development of interface science.

[Traditional Chinese medicine therapy for rheumatoid arthritis: a review].

Rheumatoid arthritis(RA) is an autoimmune disease that seriously affects the physical and mental health of patients, but its pathogenesis is still unclear. At present, clinical treatment drugs include conventional synthetic disease modifing anti-rheumatic drugs(csDMARDs), nonsteroid anti-inflammtory drugs(NSAIDs), hormones, small molecule targeted drugs, biological agents, etc. These drugs can relieve the clinical symptoms of most patients with RA to a certain extent, but there are still many limitations, such as drug adverse reactions and individual differences in drug efficacy. Therefore, the research on drug treatment targets and the development of low-toxicity drugs helps further improve the precise prevention, diagnosis, and treatment of RA. There is an urgent need for efficient and low-toxic treatments to delay the clinical progress of RA. As a treasure of Chinese culture, traditional Chinese medicine(TCM) is widely used as an alternative therapy in the treatment of various diseases, and has a significant clinical efficacy. TCM therapy(including monomer traditional Chinese medicine, classical compounds, and non-drug therapies) has a significant curative effect on RA. Based on the literature research in recent years, this paper reviewed the clinical and mechanism research of TCM therapy in the treatment of RA, and provided more in-depth thinking for the wide application of TCM therapy in clinical practice.

Identification of DNA methylation-regulated differentially expressed genes in RA by integrated analysis of DNA methylation and RNA-Seq data.

OBJECTIVE: To identify novel DNA methylation-regulated differentially expressed genes (MeDEGs) in RA by integrated analysis of DNA methylation and RNA-Seq data. METHODS: The transcription and DNA methylation profiles of 9 RA and 15 OA synovial tissue were generated by RNA-Seq and Illumina 850K DNA methylation BeadChip. Gene set enrichment analysis (GSEA) and Weighted gene co-expression network analysis (WGCNA) were used to analyze methylation-regulated expressed genes by R software. The differentially expressed genes (DEGs), differentially methylated probes (DMPs), differentially methylated genes (DMGs) were analyzed by DESeq and ChAMP R package. The functional correlation of MeDEGs was analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The protein-protein interaction (PPI) network of MeDEGs was constructed by STRING and Reactome FI Cytoscape Plugin. Correlation analysis between methylation level and mRNA expression was conducted with R software. RESULTS: A total of 17,736 genes, 25,578 methylated genes and 755,852 methylation probes were detected. A total of 16,421 methylation-regulated expressed genes were obtained. The GSEA showed that these genes are associated with activation of immune response, adaptive immune response, Inflammatory response in C5 (ontology gene sets). For KEGG analysis, these genes are associated with rheumatoid arthritis, NF-kappa B signaling pathway, T cell receptor signaling pathway. The WGCNA showed that the turquoise module exhibited the strongest correlation with RA (R = 0.78, P = 1.27 × 10- 05), 660 genes were screened in the turquoise module. A total of 707 MeDEGs were obtained. GO analysis showed that MeDEGs were enriched in signal transduction, cell adhesion for BP, enriched in plasma membrane, integral component of membrane for CC, and enriched in identical protein binding, calcium ion binding for MF. The KEGG pathway analysis showed that the MeDEGs were enriched in calcium signaling pathway, T cell receptor signaling pathway, NF-kappa B signaling pathway, Rheumatoid arthritis. The PPI network containing 706 nodes and 882 edges, and the enrichment p value < 1.0 × 10- 16. With Cytoscape, based on the range of more than 10 genes, a total of 8 modules were screened out. Spearman correlation analysis showed RGS1(cg10718027), RGS1(cg02586212), RGS1(cg10861751) were significantly correlated with RA. CONCLUSIONS: RGS1 can be used as novel methylated biomarkers for RA.

Enhanced type I interferon signature induces neutrophil extracellular traps enriched in mitochondrial DNA in adult-onset Still's disease.

Adult-onset Still's disease (AOSD) is a rare but clinically well-known auto-inflammatory disorder. Cytokine storm, the hallmark of AOSD, is mediated by neutrophil hyperactivation and enhanced neutrophil extracellular trap (NET) formation. Type I interferons (IFNs), having a primary role in the initiation of proinflammation responses, can induce subsequent inflammatory cytokine production. However, the role of type I IFNs in AOSD is unclear. Indeed, high levels of IFN-α and IFN-ß expression are presented by AOSD patients. In this investigation, hierarchical unsupervised clustering was performed on IFN-α and IFN-ß data to identify a cluster of AOSD patients who had a serious condition. Neutrophils from treatment-naïve active AOSD patients showed very strong enrichment in their IFN-α response, as shown by RNA-seq and confirmed by the IFN score. Whether IFN-α stimulates NET formation was also tested. IFN-α had the ability to form NETs that contained oxidized mitochondrial DNA (ox-mtDNA). Moreover, the JAK inhibitor could be used to dampen type I IFN-induced NET formation and eventually control ox-mtDNA release. Our results demonstrated the important roles of type I IFNs in the pathogenesis of AOSD through their promotion of NET formation, as characterized by the enhanced level of ox-mtDNA. The findings open up new avenues of research into therapeutic approaches for AOSD.

Absent in melanoma 2 (AIM2) in rheumatoid arthritis: novel molecular insights and implications.

Absent in melanoma 2 (AIM2), a member of the Pyrin and HIN domain protein family, is a cytoplasmic receptor that recognizes double-stranded DNA. AIM2 exhibits limited expression under physiological conditions but is widely expressed in many human diseases, including autoimmune diseases, and plays an essential role in the immune response. Rheumatoid arthritis (RA) is an autoimmune disease that poses a severe threat to physical and mental health, and is caused by several genetic and metabolic factors. Multiple immune cells interact to form a complex inflammatory network that mediates inflammatory responses and bone destruction. Abnormal AIM2 expression in multiple immune cell populations (T cells, B cells, fibroblast-like synoviocytes, monocytes, and macrophages) may regulate multiple functional responses in RA through mechanisms such as pyroptosis, PANoptosis, and regulation of other molecules. In this review, we describe and summarize the functional regulation and impact of AIM2 expression in immune cells to improve our understanding of the complex pathological mechanisms. These insights may provide potential directions for the development of new clinical diagnostic strategies for RA.

MicroRNA-106b overexpression suppresses synovial inflammation and alleviates synovial damage in patients with rheumatoid arthritis.

OBJECTIVES: To explore the effect of miR-106b on synovial inflammation and damage in rheumatoid arthritis (RA) patients and further to investigate its possible mechanism. METHODS: Quantitative real-time polymerase chain reaction, immunofluorescence, in situ hybridization, and immunohistochemistry assay were used to verify the levels of miR-106b and cytokines. Pearson's correlation analysis was conducted to examine bivariate relationship between miR-106b and cytokines or receptor activator of nuclear factor-κ B ligand (RANKL). Following the isolation of fibroblast-like synoviocytes (FLS), the cultured cells were separately transfected with or without miR-106b mimic. Thereafter, cell proliferation, invasion and migration were measured by Cell Counting Kit-8 assay and Transwell assay, respectively. Furthermore, concentration and expression of cytokines were separately detected by enzyme-linked immunosorbent assay and Western blot. RESULTS: Compared with osteoarthritis, RA patients had a lower level of miR-106b and higher levels of RANKL, tumour necrosis factor-a (TNF-a), and interleukin-6 (IL-6). The relative transcription of miR-106b level was negatively correlated to TNF-a, IL-6, and RNKAL levels in both patients (all P < 0.05). Furthermore, miR-106b overexpression suppressed cell proliferation, migration, and invasion capacity of RA-FLS. CONCLUSIONS: miR-106b overexpression suppresses synovial inflammation and alleviates synovial damage; thus, it may be served as a potential therapeutic target for RA patients.

[Network Meta-analysis of efficacy and safety of Chinese patent medicines in treatment of ankylosing spondylitis].

To evaluate the efficacy and safety of Chinese patent medicines in the treatment of ankylosing spondylitis(AS) by frequency network Meta-analysis. Randomized controlled trials(RCTs)of Chinese patent medicines for AS were retrieved from CNKI, Wanfang, VIP, CBM, PubMed, EMbase and Cochrane Library databases from the time of database establishment to January 2021. The quality of the included RCTs was evaluated according to the Cochrane bias risk standard, and the data was analyzed by RevMan 5.3 and Stata/MP 15.1. A total of 12 kinds of Chinese patent medicines in 55 RCTs were included. According to Meta-analysis, in term of the effectiveness, the top three optimal medication regimens were Biqi Capsules, Yishen Juanbi Pills and Yaobitong Capsules combined with western medicine. The top three interventions to reduce the erythrocyte sedimentation rate(ESR)were Yishen Juanbi Pills, Xianling Gubao Capsules and Fufang Xuanju Capsules combined with western medicine. The top three interventions to reduce the C-reactive protein(CRP)were Biqi Capsules, Xianling Gubao Capsules and Fufang Xuanju Capsules combined with western medicine. In terms of the safety, top three optimal medication regimens were Total Glucosides of Paeony Capsules, Yishen Juanbi Pills, and Wangbi Tablets combined with western medicine. This network Meta-analysis suggests that Chinese patent medicines combined with conventional western medicine can effectively improve the joint pain symptoms of AS patients and reduce the acute inflammatory indicators, with high safety. However, the literature included in this study is generally of low methodological quality, and the conclusion needs to be verified by high-quality research.

Baricitinib in patients with rheumatoid arthritis with inadequate response to methotrexate: results from a phase 3 study.

OBJECTIVES: This study evaluated the efficacy and safety of baricitinib, an oral Janus kinase (JAK)1/JAK2 inhibitor, in patients with moderately to severely active rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX) therapy. METHODS: In this phase 3, double-blind, 52-week, placebo-controlled study, 290 patients with moderately to severely active RA and inadequate response to MTX were randomly assigned 1:1 to placebo or baricitinib 4-mg once daily, stratified by country (China, Brazil, Argentina) and presence of joint erosions. Primary endpoint measures included American College of Rheumatology 20% response (ACR20) at week 12. Secondary endpoints included changes in Health Assessment Questionnaire-Disability Index (HAQ-DI) and Disease Activity Score for 28-joint counts (DAS28)-high-sensitivity C-reactive protein (hsCRP), Simplified Disease Activity Index (SDAI) score ≤3.3, mean duration of morning joint stiffness, severity of morning joint stiffness numeric rating scale (NRS 0-10), worst tiredness NRS, and worst joint pain NRS at week 12. RESULTS: Most patients (approximately 80%) were from China. More patients achieved ACR20 response at week 12 with baricitinib than with placebo (58.6% vs. 28.3%; p<0.001). Statistically significant improvements were also seen in HAQ-DI, DAS28-hsCRP, morning joint stiffness, worst tiredness, and worst joint pain in the baricitinib group compared to placebo at week 12. Through week 24, rates of treatment-emergent adverse events, including infections, were higher for baricitinib compared to placebo, while serious adverse event rates were similar between baricitinib and placebo. CONCLUSIONS: In patients with RA who had an inadequate response to MTX, baricitinib was associated with significant clinical improvements as compared with placebo.

Effects of Soil Amendments on Microbial Activities in a Typical Cd-Contaminated Purple Field Soil, Southwestern China.

In this study, three soil amendments (inorganic, liming, or organic-inorganic materials) were used in a Cd-contaminated purple field soil to investigate their impacts on soil Cd availability, enzyme (urease, catalase, sucrase, and acid phosphatase) activities, microbial biomass (carbon/nitrogen) and type (bacteria, fungi, and actinomycetes) in mustard and corn trials. Results showed that soil amendments generally decreased soil exchangeable Cd, fungi and bacterial populations while increasing the activities of all the four soil enzymes tested, microbial biomass carbon and populations of actinomycetes (p < 0.05). Soil pH and microbial biomass nitrogen did not exhibit any significant response (p > 0.05) whereas stronger effects appeared in soil organic matter and available nutrients (nitrogen, phosphorous and potassium; p < 0.05). However, only soil available phosphorous significantly correlated with soil microbial activity in both mustard and corn trails (p < 0.05). Thus, application of phosphorous-containing amendments should be considered for promoting soil health in the remediation of the Cd-contaminated purple soils.

IgG Galactosylation status combined with MYOM2-rs2294066 precisely predicts anti-TNF response in ankylosing spondylitis.

BACKGROUND: Tumor necrosis factor (TNF) blockers have a high efficacy in treating Ankylosing Spondylitis (AS), yet up to 40% of AS patients show poor or even no response to this treatment. In this paper, we aim to build an approach to predict the response prior to clinical treatment. METHODS: AS patients during the active progression were included and treated with TNF blocker for 3 months. Patients who do not fulfill ASASAS40 were considered as poor responders. The Immunoglobulin G galactosylation (IgG-Gal) ratio representing the quantity of IgG galactosylation was calculated and candidate single nucleotide polymorphisms (SNPs) in patients treated with etanercept was obtained. Machine-learning models and cross-validation were conducted to predict responsiveness. RESULTS: Both IgG-Gal ratio at each time point and differential IgG-Gal ratios between week 0 and weeks 2, 4, 8, 12 showed significant difference between responders and poor-responders. Area under curve (AUC) of the IgG-Gal ratio prediction model was 0.8 after cross-validation, significantly higher than current clinical indexes (C-reactive protein (CRP) = 0.65, erythrocyte sedimentation rate (ESR) = 0.59). The SNP MYOM2-rs2294066 was found to be significantly associated with responsiveness of etanercept treatment. A three-stage approach consisting of baseline IgG-Gal ratio, differential IgG-Gal ratio in 2 weeks, and rs2294066 genotype demonstrated the ability to precisely predict the response of anti-TNF therapy (100% for poor-responders, 98% for responders). CONCLUSIONS: Combination of different omics can more precisely to predict the response of TNF blocker and it is potential to be applied clinically in the future.

HLA class I and II alleles in susceptibility to ankylosing spondylitis.

OBJECTIVE: To examine associations of HLA class I and class II alleles with ankylosing spondylitis (AS) in three cohorts of patients of European, Asian and African ancestry. METHODS: HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1 and HLA-DPB1 alleles were genotyped in 1948 unrelated white and 67 African-American patients with AS from the Prospective Study of Outcomes in Ankylosing Spondylitis cohort, the North American Spondylitis Consortium and Australo-Anglo-American Spondyloarthritis Consortium, 990 white and 245 African-American Controls and HLA-B alleles in 442 Han Chinese patients with AS and 346 controls from Shanghai and Gansu, China. In addition to the case:control analyses, HLA-B*27-negative patients with AS were analysed separately, and logistic regression and 'relative predispositional effects' (RPE) analyses were carried out to control for the major effect of HLA-B*27 on disease susceptibility. RESULTS: Although numerous associations were seen between HLA alleles and AS in whites, among HLA-B*27-negative patients with AS , positive associations were seen with HLA-A*29, B*38, B*49, B*52, DRB1*11 and DPB1*03:01 and negative associations with HLA-B*07, HLA-B*57, HLA-DRB1*15:01, HLA-DQB1*02:01 and HLA-DQB1*06:02. Additional associations with HLA-B*14 and B*40 (B60) were observed via RPE analysis, which excludes the HLA-B*27 alleles. The increased frequency of HLA-B*40:01 and decreased frequency of HLA-B*07 was also seen in Han Chinese and African-Americans with AS. HLA-B*08 was decreased in whites with acute anterior uveitis. CONCLUSIONS: These data, analysing the largest number of patients with AS examined to date in three ethnic groups, confirm that other HLA class I and II alleles other than HLA-B*27 to be operative in AS predisposition.

Efficacy and safety of certolizumab pegol in combination with methotrexate in methotrexate-inadequate responder Chinese patients with active rheumatoid arthritis: 24-week results from a randomised, double-blind, placebo-controlled phase 3 study.

OBJECTIVES: To evaluate the efficacy and safety of certolizumab pegol (CZP) in combination with methotrexate (MTX) in Chinese patients with active rheumatoid arthritis (RA) and an inadequate response to MTX. METHODS: This 24-week, phase 3, double-blind, placebo-controlled study was conducted in 30 centres across China. A total of 430 patients were randomised 3:1 to receive CZP 200 mg every 2 weeks (loading dose: 400 mg CZP at Weeks 0, 2 and 4) plus MTX or placebo (PBO) plus MTX. The primary endpoint was ACR20 response at Week 24, for which the superiority of CZP+MTX over PBO+MTX was evaluated. Additional parameters for clinical efficacy, health outcomes, immunogenicity and safety were assessed. RESULTS: At Week 24, 54.8% of CZP+MTX patients and 23.9% of PBO+MTX patients achieved ACR20 (odds ratio: 3.9, p<0.001). CZP+MTX patients also achieved greater improvements in HAQ-DI, higher ACR50/70 responses and higher DAS28(ESR) remission rate at Week 24. Rapid onset of response to CZP+MTX was observed as early as Week 1 for most of the clinical, functional and patient-reported outcomes. Incidences of treatment-emergent adverse events (TEAEs) were similar between treatment arms. Serious TEAEs were reported by 6.3% of CZP+MTX patients and 2.7% of PBO+MTX patients. No new safety signals were observed. CONCLUSIONS: CZP in combination with MTX showed an acceptable safety profile, a rapid onset of response and sustained effects in reducing the signs and symptoms of RA and improving physical function in Chinese patients with RA and an inadequate response to MTX.

Maintenance of effect of duloxetine in Chinese patients with pain due to osteoarthritis: 13-week open-label extension data.

BACKGROUND: The objectives of this study were to assess the maintenance of effect of duloxetine 60 mg once-daily (QD) in Chinese patients with chronic pain due to osteoarthritis (OA) of the knee or hip and to provide additional long-term safety data. METHODS: This was an open-label, extension phase of a randomized, double-blind, placebo-controlled clinical trial. Eligible patients were outpatients who met the American College of Rheumatology clinical and radiographic criteria for OA with a rating ≥4 on Brief Pain Inventory (BPI) 24-h average pain. After completing the 13-week placebo-controlled phase, patients originally assigned to placebo were titrated to duloxetine 60 mg QD (PLA_DLX), whereas patients originally assigned to duloxetine 60 mg QD remained on the same dose of duloxetine (DLX_DLX) for another 13 weeks. The maintenance effect of duloxetine 60 mg QD during the extension phase was evaluated by a 1-sided 97.5% confidence interval (CI) of the baseline-to-endpoint change in the extension phase for patients who took duloxetine and reported ≥30% reduction in BPI average pain at the end of placebo-controlled phase (placebo-controlled phase duloxetine responders). Other BPI severity and interference items, as well as safety and tolerability, were assessed. RESULTS: Of 342 patients entering the extension phase, 162 (97.6%) DLX_DLX-treated patients and 157 (89.2%) PLA_DLX-treated patients completed this phase. Most patients (76.0%) were female. Mean age was 60.6 years. Mean BPI average pain was 5.5 at baseline of the placebo-controlled phase. Among 113 placebo-controlled phase duloxetine responders, mean change in BPI average pain during the extension phase was - 0.59 (from 2.47 to 1.88); the upper bound of the 1-sided 97.5% CI was - 0.31 and less than the pre-specified non-inferiority margin of a 1.5-point increase (p < 0.001). Significant within-group improvements in all BPI items were observed for both PLA_DLX and DLX_DLX groups during the extension phase (all p < 0.01). No deaths or suicide-related events occurred. Seven (4.0%) PLA_DLX-treated patients and no DLX_DLX-treated patients discontinued due to an adverse event. CONCLUSION: The analgesic effect of duloxetine 60 mg QD among treatment responders was maintained for the entire duration of the extension phase. Duloxetine 60 mg QD was well tolerated during the extension phase. TRIAL REGISTRATION: ClinicalTrials.gov identification number NCT01931475 . Registered 29 August 2013.

Therapeutic effect of ergotope peptides on CIA by down-regulation of inflammatory and Th1/Th17 responses and induction of regulatory T cells.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that results in a chronic and inflammatory disorder. Dynamic balance of helper T cells (Th)1, Th17 and regulatory T cells (Treg) is broken in RA. Since there is no cure for RA at present, it's necessary to find a truly effective and convenient treatment. Several studies intended to induce ergotopic regulation to treat autoimmune diseases. This study was undertaken to find the potential ergotope peptides and investigate its effect in treating the animal model of RA and their underlying regulatory mechanisms. Firstly, we selected the functional ergotope peptides from 25 overlapping peptides derived from interlukin(IL)-2 receptor (IL-2R) α chain, and then used these peptides to treat collagen-induced arthritis (CIA). The study showed ergotope peptides as immunomodulatory factors with great benefits at the clinical and pathologic levels. This effect was associated with the inhibition of type II collagen (CII)-specific proliferation and autoantibody production as well as the induction of anti-ergotypic immune response, the down-regulation of both Th1 and Th17 cells and their related components, and the emergence of Treg cells that had suppressive actions on autoreactive T cells. We also proved that cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and IL-10 are two important mediators which are critical to Treg suppressive function. The inhibition of Th1 and Th17 in established CIA could be attributed to ergotope induced Treg cells. Our findings reveal that ergotope peptides induce regulatory immune responses and restore immune tolerance, suggesting ergotope peptides treatment appears to be a novel approach to the therapy of RA patients and has a good application prospect with cheap, effective, convenient, wide-spectrum features.

The effects of dopamine receptor 2 expression on B cells on bone metabolism and TNF-α levels in rheumatoid arthritis.

BACKGROUND: Dopamine receptor 2 (DR2) expressions on B cells from Rheumatoid arthritis (RA) patients has been found to be negatively correlated with disease activity and can potentially predict the response to treatment. This study aimed to investigate the role of B cell DR2 expression on bone remodeling in RA. METHODS: Patients with RA (n = 14) or osteoarthritis (OA; n = 12), and healthy controls (n = 12) were recruited for this study. Dopamine receptor (DR) 2 expression was assessed using flow cytometry. Pro-inflammatory cytokines, including interleuin(IL)-1ß, IL-6, IL-17, and tumor necrosis factor(TNF)-α, and bone turnovers, including osteocalcin (OC),serum procollagen type I N propeptide (PINP), C-terminal telopeptide of type I collagen (ß-CTX), collagen type I cross-linked telopeptide (ICTP), as well as matrix metalloproteinase-3 (MMP-3) and osteoprotegerin (OPG) were measured by electrochemiluminescence, chemiluminescence, or enzyme-linked immunosorbent assay. DR2 expression on synovial B cells from 4 RA patients and 3 OA patients was detected by immunofluorescence. RESULTS: There were more DR2(+)CD19(+) B cells in synovial tissues from RA patients than in those from OA patients. The frequency of peripheral B cells that expressed DR2 was positively correlated with plasma TNF-α level. Levels of ICTP and MMP-3 were significantly higher, and OPG were lower in RA patients compared to those in the OA group and healthy controls (all P < 0.05). CONCLUSION: The frequency of B cells that expressed DR2 showed a correlation with levels of the pro-inflammatory cytokine TNF-α. DR2(+)CD19(+) B cells in synovial tissues might have a role in bone metabolism and TNF-α production.

Regulatory Effect of Iguratimod on the Balance of Th Subsets and Inhibition of Inflammatory Cytokines in Patients with Rheumatoid Arthritis.

OBJECTIVE: To expand upon the role of iguratimod (T-614) in the treatment of rheumatoid arthritis (RA), we investigated whether the Th1, Th17, follicular helper T cells (Tfh), and regulatory T cells (Treg) imbalance could be reversed by iguratimod and the clinical implications of this reversal. METHODS: In this trial, 74 patients were randomized into iguratimod-treated (group A) and control (broup B) group for a 24-week treatment period. In the subsequent 28 weeks, both groups were given iguratimod. Frequencies of Th1, Th17, Tfh, and Treg were quantified using flow cytometry, and serum cytokines were detected by enzyme-linked immunosorbent assay. mRNA expression of cytokines and transcriptional factor were quantified by RT-PCR. The composite Disease Activity Score, erythrocyte sedimentation rate, and C-reactive protein were assessed at each visit. RESULT: The clinical scores demonstrated effective suppression of disease after treatment with iguratimod. In addition, iguratimod downregulated Th1, Th17-type response and upregulated Treg. Furthermore, the levels of Th1, Th17, and Tfh associated inflammatory cytokines and transcription factors were reduced after treatment with iguratimod, while the levels of Treg associated cytokines and transcription factors were increased.

(5R)-5-Hydroxytriptolide (LLDT-8) inhibits osteoclastogenesis via RANKL/RANK/OPG signaling pathway.

BACKGROUND: The aim of this study was to investigate the regulative activity of (5R)-5-hydroxytriptolide (LLDT-8) on receptor activator of nuclear factor κ-B ligand (RANKL)/receptor activator of nuclear factor κ-B (RANK)/Osteoprotegerin (OPG) system in rheumatoid arthritis (RA) and its anti-osteoclastogenesis mechanism. METHODS: The expression of OPG, RANK and RANKL in CD3(+) T leukomonocytes in both peripheral blood and synovial fluid of RA patients was evaluated by flow cytometry. The levels of interleukin (IL) 1ß, IL-6, IL-10, IL-21 and IL-23 in the supernatants of peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were assayed by ELISA. Tartaric acid phosphatase (TRAP) staining was used to identify the osteoclast-like cells derived from RAW264.7. Western blotting analysis was used to check the downstream molecules of RANKL. RESULTS: LLDT-8 increased the rate of OPG expression in CD3(+) T leukomonocytes in peripheral blood as well as the ratio of OPG/RANKL in both peripheral blood and synovial fluid. LLDT-8 inhibited IL-1ß, IL-6, IL-21 and IL-23 secretion, but promoted the secretion of IL-10 in the supernatants of PBMCs and SFMCs. In addition, LLDT-8 decreased the number of TRAP-positive cells derived from RAW264.7 in the presence of RANKL and M-CSF. Furthermore, LLDT-8 also inhibited the expression of p-IκB, a key regulator of RANKL signaling pathway. CONCLUSIONS: LLDT-8 exerts its anti-osteoclastogenesis effect in RA probably through regulating RANKL/RANK/OPG system and its downstream signaling pathway as well as cytokine productions.

Expression of cannabinoid receptor 2 and its inhibitory effects on synovial fibroblasts in rheumatoid arthritis.

OBJECTIVE: Recent studies have suggested immunomodulatory and anti-inflammatory effects of cannabinoid receptor 2 (CB2R) activation, which shows no psychoactivity. However, it is still unclear whether CB2R is expressed in fibroblast-like synoviocytes (FLS) of RA. In this study we investigated whether CB2R is expressed in FLS of RA, and whether CB2R activation modulates the function of RA-FLS. METHODS: Expression of CB2R in synovial tissue and FLS was studied by immunohistochemistry, western blotting and RT-PCR. mRNA expression levels of CB2R, IL-6 and MMPs were analysed by quantitative real-time RT-PCR. The protein concentrations of IL-6 and MMPs in culture supernatants were determined by ELISA. The protein levels of signal transducing molecules were assayed by western blotting. RESULTS: Both mRNA and protein expression of CB2R were found in synovial tissue and cultured FLS with slightly higher levels in RA patients than in OA patients. In cultured RA-FLS, the expression level of CB2R was up-regulated by stimulation with IL-1ß, TNF-α or lipopolysaccharide. In vitro, HU-308, a selective CB2R agonist, inhibited IL-1ß-induced proliferation of RA-FLS as well as IL-1ß-induced production of MMP-3, MMP-13 and IL-6 in RA-FLS in a dose-dependent manner. HU-308 also suppressed IL-1ß-induced activation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase in FLS. CONCLUSION: In RA-FLS, proinflammatory mediators up-regulate the expression of CB2R, which negatively regulates the production of proinflammatory cytokines and MMPs. These data suggest that CB2R may be a potential therapeutic target of RA.

siRNA therapy in osteoarthritis: targeting cellular pathways for advanced treatment approaches.

Osteoarthritis (OA) is a common joint disorder characterized by the degeneration of cartilage and inflammation, affecting millions worldwide. The disease's complex pathogenesis involves various cell types, such as chondrocytes, synovial cells, osteoblasts, and immune cells, contributing to the intricate interplay of factors leading to tissue degradation and pain. RNA interference (RNAi) therapy, particularly through the use of small interfering RNA (siRNA), emerges as a promising avenue for OA treatment due to its capacity for specific gene silencing. siRNA molecules can modulate post-transcriptional gene expression, targeting key pathways involved in cellular proliferation, apoptosis, senescence, autophagy, biomolecule secretion, inflammation, and bone remodeling. This review delves into the mechanisms by which siRNA targets various cell populations within the OA milieu, offering a comprehensive overview of the potential therapeutic benefits and challenges in clinical application. By summarizing the current advancements in siRNA delivery systems and therapeutic targets, we provide a solid theoretical foundation for the future development of novel siRNA-based strategies for OA diagnosis and treatment, paving the way for innovative and more effective approaches to managing this debilitating disease.