Role In Pathogenesis Of Rheumatoid Arthritis Research Articles

Mannose-Binding Lectin Gene Variants as Disease Susceptibility Biomarkers in Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a chronic, inflammatory autoimmune disease characterized by progressive destruction of peripheral joints. About 1% of the human population worldwide is suffering from this disease. The pathophysiology of RA is largely being influenced by immune dysregulation. Mannose-binding lectin (MBL), an acute-phase protein, has been reported to play an important role in pathogenesis of RA by the activation of complement pathway. Various studies documented the established the role of MBL in pathogenesis of various autoimmune diseases, including RA. MBL protein is encoded by gene MBL2, mapped on chromosome 10q11.2-q21. Objective: Both MBL serum levels and activity are mainly determined genetically by its variants. So considering the putative clinical role of MBL2, this case-control association study was designed to assess its six functional variants in a northwestern Indian cohort. Methods: Genetic typing of six MBL2 variants was done by amplification refractory mutation system-polymerase chain reaction. Data were analyzed using suitable statistical tools. Results: Significant difference has been observed in genotypic and allelic distribution between cases and controls for rs11003125. Comparison of allelic distribution for rs1800450 showed significantly high prevalence of A allele in cases than controls. Conclusion: These results indicate that MBL2 variants may act as plausible marker for susceptibility toward RA. Keeping this in view, it is pertinent to screen these variants in other population groups of India.

Macrophage polarization in rheumatoid arthritis: signaling pathways, metabolic reprogramming, and crosstalk with synovial fibroblasts.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation and progressive joint destruction. Macrophages are key effector cells that play a central role in RA pathogenesis through their ability to polarize into distinct functional phenotypes. An imbalance favoring pro-inflammatory M1 macrophages over anti-inflammatory M2 macrophages disrupts immune homeostasis and exacerbates joint inflammation. Multiple signaling pathways, including Notch, JAK/STAT, NF-κb, and MAPK, regulate macrophage polarization towards the M1 phenotype in RA. Metabolic reprogramming also contributes to this process, with M1 macrophages prioritizing glycolysis while M2 macrophages utilize oxidative phosphorylation. Redressing this imbalance by modulating macrophage polarization and metabolic state represents a promising therapeutic strategy. Furthermore, complex bidirectional interactions exist between synovial macrophages and fibroblast-like synoviocytes (FLS), forming a self-perpetuating inflammatory loop. Macrophage-derived factors promote aggressive phenotypes in FLS, while FLS-secreted mediators contribute to aberrant macrophage activation. Elucidating the signaling networks governing macrophage polarization, metabolic adaptations, and crosstalk with FLS is crucial to developing targeted therapies that can restore immune homeostasis and mitigate joint pathology in RA.

Dual drug nanoparticle synergistically induced apoptosis, suppressed inflammation, and protected autophagic response in rheumatoid arthritis fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a chronic immune-mediated joint inflammatory disorder associated with aberrant activation of fibroblast-like synoviocytes (FLS). Recently, FLS gained importance due to its crucial role in RA pathogenesis, and thus, targeting FLS is suggested as an attractive treatment strategy for RA. FLS-targeted approaches may be combined with disease-modifying antirheumatic drugs (DMARDs) and natural phytochemicals to improve efficacy in RA control and negate immunosuppression. In this study, we assessed the therapeutic effectiveness of DD NP HG in primary RA-FLS cells isolated from the synovial tissue of FCA-induced RA rats. We observed that DD NP HG had good biosafety for healthy FLS cells and, at higher concentrations, a mild inhibitory effect on RA-FLS. The combination therapy (DD NP HG) of MTX NP and PEITC NE in RA-FLS showed a higher rate of apoptosis with significantly reduced LPS-induced expression of pro-inflammatory cytokines (TNF-α, IL-17A, and IL-6) in arthritic FLS. Further, the gene expression studies showed that DD NP HG significantly down-regulated the mRNA expression of IL-1β, RANKL, NFATc1, DKK1, Bcl-xl, Mcl-1, Atg12, and ULK1, and up-regulated the mRNA expression of OPG, PUMA, NOXA and SQSTM1 in LPS-stimulated RA-FLS cells. Collectively, our results demonstrated that DD NP HG significantly inhibited the RA-FLS proliferation via inducing apoptosis, down-regulating pro-inflammatory cytokines, and further enhancing the expression of genes associated with bone destruction in RA pathogenesis. A nanotechnology approach is a promising strategy for the co-delivery of dual drugs to regulate the RA-FLS function and achieve synergistic treatment of RA.

Neutrophilic Activity Biomarkers (Plasma Neutrophil Extracellular Traps and Calprotectin) in Established Patients with Rheumatoid Arthritis Receiving Biological or JAK Inhibitors: A Clinical and Ultrasonographic Study.

This study assesses the accuracy of neutrophil activation markers, including neutrophil extracellular traps (NETs) and calprotectin, as biomarkers of disease activity in patients with established rheumatoid arthritis (RA). We also analyse the relationship between NETs and various types of therapies as well as their association with autoimmunity. Observational cross-sectional study of patients with RA receiving treatment with biological disease-modifying antirheumatic drugs or Janus kinase inhibitors (JAK-inhibitors) for at least 3months. Plasma calprotectin levels were measured using an enzyme-linked immunosorbent assay test kit and NETs by measuring their remnants in plasma (neutrophil elastase-DNA and histone-DNA complexes). We also assessed clinical disease activity, joint ultrasound findings and autoantibody status [reumatoid factor (RF), anti-citrullinated peptide/protein antibodies (ACPAs) and anti-carbamylated protein (anti-CarP)]. Associations between neutrophilic biomarkers and clinical or ultrasound scores were sought using correlation analysis. The discriminatory capacity of both neutrophilic biomarkers to detect ultrasound synovitis was analysed through receiver-operating characteristic (ROC) curves. One hundred fourteen patients were included. Two control groups were included to compare NET levels. The active control group consisted of 15 patients. The second control group consisted of 30 healthy subjects. Plasma NET levels did not correlate with clinical disease status, regardless of the clinic index analysed or the biological therapy administered. No significant correlation was observed between NET remnants and ultrasound synovitis. There was no correlation between plasma NET and autoantibodies. In contrast, plasma calprotectin positively correlated with clinical parameters (swollen joint count [SJC] rho = 0.49; P < 0.001, Clinical Disease Activity Index [CDAI] rho = 0.30; P < 0.001) and ultrasound parameters (rho > 0.50; P < 0.001). Notably, this correlation was stronger than that observed with acute phase reactants. While NET formation induced by neutrophils may play a role in RA pathogenesis, our study raises questions about the utility of NET remnants in peripheral circulation as a biomarker for inflammatory activity. In contrast, this study strongly supports the usefulness of calprotectin as a biomarker of inflammatory activity in patients with RA.

Association of Interleukin 23 Receptor Polymorphisms with Predisposition to Rheumatoid Arthritis: An Updated Meta and Trial Sequential Analysis.

The etiology of Rheumatoid Arthritis (RA) development remained unclear, and several factors, such as environmental, genetic, and immune system dysfunction, have been attributed to the susceptibility. Interleukin 23 (IL23) induces expansion of the Th17 cells through the IL-23 receptor (IL-23R) and believes in playing a major role in RA pathogenesis. Various genetic mutants in the IL23R gene (rs10489629, rs1343151, rs2201841, rs7517847, rs1004819, rs10889677, rs11209026, rs7530511) have been associated with the susceptibility RA, but results are contradictories. We performed a meta-analysis to establish the association of IL23R polymorphisms with susceptibility RA. For the meta-analysis, a detailed search of databases like Google Scholar, PubMed, Scopus, Web of Science, and Science Direct was conducted, and data were extracted from the included reports. The meta-analysis was performed by the Comprehensive Meta-Analysis v3 software. A significant association of IL-23R rs11209026 (AA vs. GG: Odds ratio = 2.250, p-value = 0.01; AA vs. GG+GA: Odds ratio = 2.271, p-value = 0.01), rs1343151 (A vs. G: Odds ratio = 1.091, p-value = 0.001; AA vs. GG: Odds ratio = 1.209, p-value = 0.001; GA vs. GG: Odds ratio = 1.116, p-value = 0.004; AA+GA vs. GG: Odds ratio = 1.135, p-value = 0.000; AA vs. GG+GA: Odds ratio = 1.144, p-value = 0.012) and rs10889677 (CA vs. CC: Odds ratio = 1.375, p-value = 0.041) polymorphisms were observed with increased susceptibility for the development of RA. In contrast, IL-23R rs10489629 (G vs. A: odds ratio = 0.901, p-value = 0.047, GG vs. AA: Odds ratio = 0.763, p-value = 0.022, GG vs. AA+AG: Odds ratio = 0.852, p-value = 0.00) and IL23R rs2201841 (CC vs. TT+TC: Odds ratio = 0.826, p-value = 0.026) variants were linked with protection against the development of RA. In addition, the trial sequential analysis revealed the inclusion of a sufficient number of studies in the present meta-analysis, and no further additional studies are required. IL-23R variants are associated with genetic susceptibility or resistance against the development of RA.

Estimation of Interleukin 32 and Interleukin 37 Serum Levels in Iraqi Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune condition characterized by persistent inflammation in synovial joints. Interleukine-32 (IL32) is known to have significant pro-inflammatory effects in RA, and IL37 is an anti-inflammatory cytokine that reduces the immune response and inflammation. This study aimed to investigate serum levels of IL32 and IL73 in RA patients. The sample included 50 patients (46 females and four males) with RA and 40 healthy controls. The enzyme-linked immunosorbent assay (ELISA) detected serum levels of IL32 and IL37. The disease parameters' activity was measured by the clinical disease activity index, and the Erythrocyte sedimentation rate was measured by the Westergren method. Moreover, C-Reactive protein, Rheumatoid factor, and Anti-Cyclic Citrullinated Peptide antibodies were measured using the ELISA. The results showed elevated serum levels of IL32 and IL37 in patients with RA (P<0.05). The mean duration of RA in most patients was <12 years, and the level of disease activity among the cases group was mainly moderate (70%). There was no significant difference between the mean levels of IL32 and IL37 in patients with RA. This study showed that although IL32 and IL37 played an essential role in RA pathogenesis, there was no significant correlation between serum levels of IL32 and IL37 and disease duration or activity.

Polymorphisms in DNA Repair Genes and Association with Rheumatoid Arthritis in a Pilot Study on a Central European Population.

Rheumatoid arthritis (RA) is a chronic, multifactorial autoimmune disease characterized by chronic arthritis, a tendency to develop joint deformities, and involvement of extra-articular tissues. The risk of malignant neoplasms among patients with RA is the subject of ongoing research due to the autoimmune pathogenesis that underlies RA, the common etiology of rheumatic disease and malignancies, and the use of immunomodulatory therapy, which can alter immune system function and thus increase the risk of malignant neoplasms. This risk can also be increased by impaired DNA repair efficiency in individuals with RA, as reported in our recent study. Impaired DNA repair may reflect the variability in the genes that encode DNA repair proteins. The aim of our study was to evaluate the genetic variation in RA within the genes of the DNA damage repair system through base excision repair (BER), nucleotide excision repair (NER), and the double strand break repair system by homologous recombination (HR) and non-homologous end joining (NHEJ). We genotyped a total of 28 polymorphisms in 19 genes encoding DNA repair-related proteins in 100 age- and sex-matched RA patients and healthy subjects from Central Europe (Poland). Polymorphism genotypes were determined using the Taq-man SNP Genotyping Assay. We found an association between the RA occurrence and rs25487/XRCC1, rs7180135/RAD51, rs1801321/RAD51, rs963917/RAD51B, rs963918/RAD51B, rs2735383/NBS1, rs132774/XRCC6, rs207906/XRCC5, and rs861539/XRCC3 polymorphisms. Our results suggest that polymorphisms of DNA damage repair genes may play a role in RA pathogenesis and may be considered as potential markers of RA.

Investigating the correlation of the NF-κB and FoxP3 gene expression with the plasma levels of pro- and anti-inflammatory cytokines in rheumatoid arthritis patients.

Rheumatoid arthritis (RA) is a chronic inflammatory systemic autoimmune disease. Cytokines regulate a wide range of inflammatory processes involved in RA pathogenesis. Anti-inflammatory cytokines (i.e., TGF-β and lL-10) and pro-inflammatory cytokines, like IL-6, were found to be potentially implicated in RA pathogenesis. Besides, NF-κB and FoxP3 are critical transcription factors regulating the inflammatory events occurring in RA patients. This study intends to assess the plasma levels of IL-6, IL-10, and TGF-β1 cytokines, as well as the expression of NF-κB and FoxP3 genes in RA patients, compared to the healthy controls. Peripheral blood was collected from 50 RA patients (25 new case and 25 under-treatment) and 25 age- and gender-matched healthy subjects. The disease activity was determined using the DAS-28 and ESR criteria. Also, plasma levels of TGF-β1, lL-10, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) technique, and the gene expression of NF-κB and FoxP3 was evaluated using the real-time PCR method. Our results showed a significant up-regulation of Rel-A and NF-κB1, and also a down-regulation of FoxP3 gene expression in under-treatment RA patients compared to the controls (P=0.031, P=0.014, and P=0.011, respectively). Moreover, there was a significant reduction of Rel-A and FoxP3 in the under-treatment RA patients compared to new case RA patients (P=0.005 and P=0.015, respectively). Also, plasma levels of TGF-β1 were significantly increased in both the new case and under-treatment RA patients relative to controls (P<0.001). In conclusion, classical NF-κB (P65/P50) and FoxP3 may have significant pro- and anti-inflammatory roles in RA pathogenesis, respectively. Key Point •NF-κB (P65/P50) has a contribution to the early phase of RA.

The Effect of Oral Administration of Silymarin on Serum Levels of Tumor Necrosis Factor-α and Interleukin-1ß in Patients with Rheumatoid Arthritis.

Rheumatoid Arthritis (RA) is a systemic chronic autoimmune disease. Several inflammatory agents play key roles in RA pathogenesis, among which tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) are of great importance. Silymarin is a potent anti-oxidant extracted from Silybummarianum L. seeds. To study the effect of silymarin on serum levels of TNF-α and IL-1β in patients with RA. Patients with stable RA received 140 mg of silymarin, 3 times a day, for 3 months. Serum samples were collected before and after the treatment. Both TNF-α and IL-1β serum levels were measured by ELISA. 42 patients (14.3% male, and 85.7% female, with a mean age of 47.59±12.8 years old) completed the treatment course. There was no significant difference in the overall mean concentration of either TNF-α (p=0.14) or IL-1β (p=0.27) in all 42 patients after the treatment with silymarin. The addition of silymarin to the treatment regimen of patients with stable RA has no significant effect on the serum levels of TNF-α and IL-1β, however, this study needs further evaluation with a larger sample size.

Interleukin 23 receptor gene polymorphisms and their role in the inflammatory status of rheumatoid arthritis patients in an Iranian population.

Several investigations have disclosed the involvement of the interleukin (IL)-23/IL-17 pathway in rheumatoid arthritis (RA) pathogenesis. Here we investigated the association of single nucleotide polymorphisms (SNPs) in the IL23 receptor (IL23R) gene with RA risk. In addition, the role of these SNPs with the inflammatory state of the patients were determined. In this case-control study, 200 RA cases and 200 healthy subjects were recruited. Using allelic discrimination real-time polymerase chain reaction, both IL23R rs10489629 and rs1004819 SNPs were genotyped. The messenger RNA (mRNA) expression levels of IL-23R, IL-23, and IL-17A were determined in peripheral blood mononuclear cells (PBMCs). The serum levels of IL-23 and IL-17A were also determined. The A allele (odds ratio [OR]=1.52, 95% CI: 1.15-2.01; P= .0030), AA genotype (OR=2.41, 95% CI: 1.33-4.35; P= .0035), and AG genotype (OR=2.55, 95% CI: 1.56-4.16, P= .0002) of rs1004819 SNP was significantly associated with increased RA risk. The mRNA expression of IL-17A (fold change=2.55, P= .00027), IL-23 (fold change=1.62, P= .0081), and IL-23R (fold change=1.59, P= .0077) was significantly upregulated in the PBMCs from RA patients compared to that of healthy controls. Serum levels of IL-17A (P= .00019) and IL-23 (P= .00055) was significantly higher in the RA patients compared to the controls. No significant association was detected between patient data and SNPs. The IL-23/IL-27 pathway plays a role in RA pathogenesis, but IL23R gene rs1004819 SNP might not be regulating this pathway in RA disease.

Increased TIGIT+PD‑1+CXCR5‑CD4+Tcells are associated with disease activity in rheumatoid arthritis.

It is well established that increased programmed cell death protein 1 (PD-1)+C-X-C chemokine receptor type 5 (CXCR5)- CD4+T cells are found in patients with rheumatoid arthritis (RA). T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) is a co-inhibitory receptor that is expressed on T cells. However, the expression patterns and immunomodulatory roles of TIGIT on PD1+CXCR5-CD4+T cells in RA are poorly understood. Patients with RA were recruited and their clinical characteristics were recorded. The expression level of TIGIT on PD-1+CXCR5-CD4+T cells was examined using flow cytometry. Subsequently, the correlation between various parameters of TIGIT+PD-1+CXCR5-CD4+T cells [percentage of the cells, mean fluorescence intensity (MFI) of PD-1 and TIGIT in the cells] in patients with RA and clinical data, including autoantibodies, inflammatory indicators and RA activity, were analyzed. In addition, the risk factors of RA were assessed using univariate and multivariate regression analyses. The percentages of TIGIT+CXCR5-CD4+T, PD-1+CXCR5-CD4+T, TIGIT+PD-1+CXCR5-CD4+T, TIGIT-PD-1+CXCR5-CD4+T cells, the MFI of PD-1 in these cells and the MFI of TIGIT in TIGIT+PD-1+CXCR5-CD4+T cells were revealed to be significantly increased in patients with RA compared with those in healthy individuals. The parameters of TIGIT+PD-1+CXCR5-CD4+T cells (percentage and/or MFI of PD-1) in patients with RA were found to be associated with the levels of anti-cyclic citrullinated peptide antibodies, rheumatoid factor and inflammatory markers, such as lymphocyte count, lymphocyte percentage, neutrophil percentage, lymphocyte-to-monocyte ratio, neutrophil-to-lymphocyte ratio, systemic immune inflammation index, derived neutrophil-to-lymphocyte ratio, erythrocyte sedimentation rate and C-reactive protein. In addition, the MFI of PD-1 in TIGIT+PD-1+CXCR5-CD4+T cells was associated with a disease activity score of 28 and the patient visual analogue scale. Multivariate logistic regression analysis demonstrated that the percentage of TIGIT+PD-1+CXCR5-CD4+T cells and the MFI of PD-1 in TIGIT+PD-1+CXCR5-CD4+T cells were risk factors for RA. The present study suggests that the increase in TIGIT+PD-1+CXCR5-CD4+T cells is associated with the production of autoantibodies and RA activity and may serve a role in RA pathogenesis.

Nesfatin-1 exerts protective effects on acidosis-stimulated chondrocytes and rats with adjuvant-induced arthritis by inhibiting ASIC1a expression

AbstractNesfatin-1, a newly identified energy-regulating peptide, has been reported to possess antioxidant, anti-inflammatory, and antiapoptotic properties; however, to date, its effect on rheumatoid arthritis (RA) has not been previously explored in detail. We previously showed that activation of acid-sensing ion channel 1a (ASIC1a) by acidosis plays an important role in RA pathogenesis. Therefore, in this study, we evaluated the effects of nesfatin-1 on acidosis-stimulated chondrocyte injury in vitro and in vivo and examined the involvement of ASIC1a and the mechanism underlying the effects of nesfatin-1 on RA. Acid-stimulated articular chondrocytes were used to examine one of the several possible mechanisms underlying RA pathogenesis in vitro. The mRNA expression profile of acid-induced chondrocytes treated or not treated with nesfatin-1 was investigated by RNA sequencing. The effects of nesfatin-1 on oxidative stress, inflammation, and apoptosis in acid-induced chondrocytes were measured. The mechanistic effect of nesfatin-1 on ASIC1a expression and intracellular Ca2+ in acid-stimulated chondrocytes was studied. Rats with adjuvant-induced arthritis (AA) were used for in vivo analysis of RA pathophysiology. Cartilage degradation and ASIC1a expression in chondrocytes were detected in rats with AA after intraarticular nesfatin-1 injection. The in vitro experiments showed that nesfatin-1 decreased acidosis-induced cytotoxicity and elevation of intracellular Ca2+ levels in chondrocytes. Moreover, it attenuated acid-induced oxidative stress, inflammation, and apoptosis in chondrocytes. Nesfatin-1 decreased ASIC1a protein levels in acid-stimulated chondrocytes via the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and nuclear factor kappa-B (NF-κB) signaling pathways. In vivo analysis showed that nesfatin-1 ameliorated cartilage degradation and decreased ASIC1a expression in the chondrocytes of rats with AA. Collectively, nesfatin-1 suppressed acidosis-induced oxidative stress, inflammation, and apoptosis in acid-stimulated chondrocytes and alleviated arthritis symptoms in rats with AA, and its mechanism may be related to its ability to decrease ASIC1a protein levels via the MAPK/ERK and NF-κB pathways.

A novel mechanism for macrophage pyroptosis in rheumatoid arthritis induced by Pol β deficiency

Rheumatoid arthritis (RA) is a chronic and inflammatory autoimmune disease. Macrophage pyroptosis, a proinflammatory form of cell death, is critically important in RA; however, the detailed mechanism underlying pyroptosis induction is not yet well understood. Here, we report that DNA polymerase β (Pol β), a key enzyme in base excision repair, plays a pivotal role in RA pathogenesis. Our data shows that Pol β expression is significantly decreased in peripheral blood mononuclear cells (PBMCs) from active RA patients and collagen-induced arthritis (CIA) mice, and Pol β deficiency increases the incidence of RA, macrophage infiltration, and bone destruction in CIA mouse models. In vitro, experiments showed that Pol β deficiency exacerbated macrophage pyroptosis induced by LPS plus ATP, while overexpression of Pol β inhibited macrophage pyroptosis. Further characterization revealed that Pol β knockout resulted in DNA damage accumulation and cytosolic dsDNA leakage, which activated the cGAS-STING-NF-κB signaling pathway and upregulated the expression of NLRP3, IL-1 β, and IL-18. In conclusion, our findings clarify the influence of Pol β on the development of RA and provide a detailed explanation for the STING-NF-κB pathway to induce macrophage pyroptosis.

8-Shogaol inhibits rheumatoid arthritis through targeting TAK1

Rheumatoid arthritis (RA) is a chronic immune-mediated disorder, mainly characterized by synovial inflammation and joint damage. If insufficiently treated, RA can lead to irreversible joint destruction and decreased life expectancy. While better understanding of the pathologies and the development of new antirheumatic drugs have improved the outcome of individuals with RA, many patients still cannot achieve remission and experience progressive disability. Fibroblast-like synoviocytes (FLS) have gained attention due to its pivotal role in RA pathogenesis and thus targeting FLS has been suggested as an attractive therapeutic strategy. To identify candidate molecules with strong inhibitory activity against FLS inflammation, we tested the effect of 315 natural extracts against IL-17-mediated IL-6 production. Zingiber officinale was found as the top hit and further analysis on the active compound responsible led to the discovery of 8-shogaol as a potent molecule against synovitis. 8-Shogaol displayed significant inhibitory effects against TNF-α-, IL-1β-, and IL-17-mediated inflammation and migration in RA patient-derived FLS (RA-FLS) and 3D synovial culture system. 8-Shogaol selectively and directly inhibited TAK1 activity and subsequently suppressed IKK, Akt, and MAPK signaling pathways. Moreover, treatment with 8-shogaol reduced paw thickness and improved walking performance in the adjuvant-induced arthritic (AIA) rat model. 8-Shogaol also reversed pathologies of joint structure in AIA rats and decreased inflammatory biomarkers in the joints. Collectively, we report a novel natural compound that inhibits RA through reversing pathologies of the inflamed synovium via targeting TAK1.

The Role of Different Circulating T Follicular Helper Cell Markers in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic incurable inflammatory autoimmune disease. T follicular helper (Tfh) cells expressing different markers play critical roles in the development of RA. However, their specific mechanisms of action and association with RA clinical parameters are not clear. We therefore performed a cohort study to investigate the effects of different Tfh cell markers on RA pathogenesis. We retrospectively reviewed clinical data from 30 patients diagnosed with RA and 30 healthy controls (HCs) who visited our hospital. Based on X-ray findings, the patients were divided into a joint bone erosion group (n = 17) and a non-erosive joint bone group (n = 13). Using flow cytometry, we determined the frequencies of five peripheral blood CD4+ Tfh cell types characterized by different markers, and examined these cell types for correlations with clinical parameters. RA patients exhibited higher frequencies of CD4+CXCR5+, CD4+CXCR5+ICOS+, CD4+CXCR5+OX40+, and CD4+CXCR5+CD40L+ Tfh cells than HCs. CD4+CXCR5+, CD4+CXCR5+CD40L+, and CD4+CXCR5+OX40+ Tfh cell frequencies positively correlated with disease activity score-28 with erythrocyte sedimentation rate (DAS28-ESR), while those of CD4+CXCR5+ and CD4+CXCR5+CD40L+ Tfh cells were related to rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies. In RA patients without joint bone erosion, CD4+CXCR5+CD40L+ Tfh cell frequencies were positively correlated with both RF and DAS28-ESR. Serum anti-CCP antibody levels and CD4+CXCR5+ICOS+ Tfh cell frequencies were also positively correlated. Circulating CD4+CXCR5+CD40L+ Tfh cells appear to play critical roles in RA pathogenesis, and restricting CD4+CXCR5+CD40L+ Tfh cells may be a therapeutic strategy for controlling RA.

Microbiome Resilience and Health Implications for People in Half-Year Travel.

Travel entail change in geography and diet, both of which are known as determinant factors in shaping the human gut microbiome. Additionally, altered gut microbiome modulates immunity, bringing about health implications in humans. To explore the effects of the mid-term travel on the gut microbiome, we generated 16S rRNA gene and metagenomic sequencing data from longitudinal samples collected over six months. We monitored dynamic trajectories of the gut microbiome variation of a Chinese volunteer team (VT) in their whole journey to Trinidad and Tobago (TAT). We found gut microbiome resilience that VT’s gut microbial compositions gradually transformed to the local TAT’s enterotypes during their six-month stay in TAT, and then reverted to their original enterotypes after VT’s return to Beijing in one month. Moreover, we identified driven species in this bi-directional plasticity that could play a role in immunity modulation, as exemplified by Bacteroides dorei that attenuated atherosclerotic lesion formation and effectively suppressed proinflammatory immune response. Another driven species P. copri could play a crucial role in rheumatoid arthritis pathogenesis, a chronic autoimmune disease. Carbohydrate-active enzymes are often implicated in immune and host-pathogen interactions, of which glycoside hydrolases were found decreased but glycosyltransferases and carbohydrate esterases increased during the travel; these functions were then restored after VT’ returning to Beijing. Furthermore, we discovered these microbial changes and restoration were mediated by VT people’s dietary changes. These findings indicate that half-year travel leads to change in enterotype and functional patterns, exerting effects on human health. Microbial intervention by dietary guidance in half-year travel would be conducive to immunity modulation for maintaining health.

Lessons From the Success and Failure of Targeted Drugs for Rheumatoid Arthritis: Perspectives for Effective Basic and Translational Research.

Rheumatoid arthritis (RA) is a representative autoimmune disease that is primarily characterized by persistent inflammation and progressive destruction of synovial joints. RA has a complex and heterogeneous pathophysiology, involving interactions among various immune and joint stromal cells and a diverse network of cytokines and intracellular signaling pathways. With improved understanding of RA, over the past decades, therapeutic strategies have become considerably advanced and now included targeted molecular therapies, such as tumor necrosis factor inhibitors, IL-6 blockers, B-cell depletion agents, as well as inhibitors of T-cell co-stimulation and Janus kinases. However, a considerable proportion of RA patients experience refractory disease and interrupted treatment owing to the associated risk of developing serious infections and cancers. In contrast, although IL-1β, IL-17A, and p38α play significant roles in RA pathogenesis, several drugs targeting these factors have not been approved because of their low efficacy and severe adverse effects. In this review, we provide an overview of the working mechanism, advantages, and limitations of the currently available targeted drugs for RA. Additionally, we suggest potential mechanistic causes for clinically approved and failed drugs. Thus, this review provides perspectives on approaches for basic and translational studies that hold promise for identifying future next-generation therapeutics for RA.

The Role of Serum Chitinase-3-Like 1 Protein (YKL-40) Level and its Correlation with Proinflammatory Cytokine in Patients with Rheumatoid Arthritis

Chitinase-3-like 1 protein (YKL-40) is a glycoprotein primarily produced in the arthritic joint and plays a crucial role in inflammatory processes. The aim of the study is to establish the role of YKL-40 as a biomarker for rheumatoid arthritis (RA) compared to proinflammatory biomarkers and disease activity. The study included 58 patients and 18 control. Diseases activity score (DAS-28) and clinical disease activity index (CDAI) were measured. Serum level of YKL-40, tumor necrosis factor-α (TNF-α), interleukin-1B (IL-1β), erythrocyte sedimentation (ESR), rheumatoid factor (RF), C-reactive protein (CRP), and anti-citrullinated protein antibody (ACPA) were assessed. The results showed that the median serum YKL-40 level which was 5.42 ng/ml, the TNF-a level which was 123.6 ng/ml, and the IL-1B level which was 204.365 pg/dl were significantly higher in patients compared to control 3.28 (1.58–4.99) ng/ml, 56.47 (9.38–77.01) ng/ml and 67.887 (15.493–122.689)pg/dl respectively. There was no correlation between serum YKL-40 and disease activity, while there were significant associations observed with TNF-α (r=0.5,p =0.0001) and IL-1β (r=0.41, p=0.001). YKL-40 indicating good levels of RA prediction at 2.47 ng/ml, sensitivity 87.9%, specificity 58.6%, accuracy 78.1%, PPV 80.9%, and NPV 70.8%. In conclusion, a higher level of serum YKL-40 is found in RA patients. The findings from our study suggest a strong association between YKL-40 and the proinflammatory biomarkers. As a result, these biomarkers together might play a role in RA pathogenesis, and YKL-40 may be used as a potential diagnostic biomarker for RA.

Interleukin – 6 Serum Level and Single Nucleotide Gene -174 G/C promoter Polymorphism in Patients with Rheumatoid Arthritis / Iraq

Objective: To 1) assess IL-6 levels in the serum of patients with rheumatoid arthritis (RA). 2) study IL-6 promoter -174 G>C “single nucleotide polymorphism (SNP)” as an imminent factor for the disease development. 3) find any relation between the level of serum IL-6 cytokine and other parameters such as age, gender, clinical severity of diseases and “disease activity scores (DAS28)”. Materials & methods: This research was carried out through a case – control approach at “Ibn – Senna Teaching Hospital” in Mosul city between November 2020 and July 2021. It included 61 RA patients diagnosed according to “ACR / EULAR 2010 criteria” and 50 healthy individuals. IL-6 serum levels were ascertained by ELISA and genotyping of IL-6 promoter was accomplished by “sequence-specific primer-polymerase chain reaction (SSP-PCR)”. Results: Mean IL-6 level in RA (69.42 ng /l ± 62.99) was elevated in comparison to healthy people (14.66 ng /l ± 23.58), P < 0.001. No age or gender effects on IL-6 concentration were noted. The ideal cut-off of IL-6 for discrimination of RA with best discriminative utility compared to healthy controls was 22.80 ng/l. At this value the IL-6 sensitivity was 91.8%, specificity 82.0% and accuracy rate 73.80%. G/G genotype was the most pervasive genotype in both RA patients and controls (70.5% in RA and 64% in healthy controls). However, it did not seem to be a risk factor for RA development compared to G/C or C/C genotypes “(OR = 1.3438, 95% CI=0.605-2.984,P=0.469)”. The mean IL-6 level in patients with GG genotype was (73.70 ng / l ± 71.09) compared to (58.37 ng /l ± 37.86) in patients with GC genotype. There was no significant difference in the IL-6 level between patients with GG and patients with GC genotypes (P = 0.2375). Although higher IL-6 mean concentration was reported in severe RA, however, no significant difference was found between patients with mild, moderate and severe RA respectively. No correlation of serum levels of IL-6 with genetic promoter polymorphism, clinical severity of diseases or DAS 28 score were reported. Conclusion: The concentration of serum IL-6 was elevated in RA in regard to healthy controls which confirmed its pivotal role in RA pathogenesis. Our data did not support the role of IL-6 promoter -174 G> C polymorphism as a risk factor for RA, nor seem to play a major role in the increase of IL-6 level among our patients with RA.

Interleukin 16 polymorphism and susceptibility of rheumatoid arthritis disease in Egyptian population

Rheumatoid arthritis (RA) is a systemic and multiple-stage disorder characterized by chronic inflammation with extensive synovitis. The genetic and environmental factors are associated with the risk for RA development. In RA, the induced IL-16 may play a role in initiating, sustaining and increasing the inflammatory response and development of synovitis, nevertheless IL-16's actual role in RA pathogenesis must be studied further. This study intended to investigate the association of IL-16 gene polymorphism and RA disease, to determine the genetic role of IL-16 polymorphism and predict the risk of RA development and clinical disease activity. One hundred and Fifty RA patients and 150 apparently healthy control subjects were included in this case-control study. RA disease activity and functional status were evaluated for all RA patients. IL-16 gene polymorphism (SNP rs11556218 T/G) was genotyped using real-time polymerase chain reaction. The difference in IL-16 (rs11556218 T/G) genotype frequencies between RA patients and controls was not statistically significant. However, the G allele was frequently presented in RA patients as compared to controls (p=0.047). Moreover, G allele carriers had two times more risk to develop RA disease than T allele carriers (OR=2.598; 95%CI=1.078-6.825) with dominant genetic association. Alternatively, the G/G genotype was associated with high CDAI, RADAS-5 and HAQ disability index in comparing to other genotypes (T/T-T/G). In conclusion, there was an association between allele G of IL-16 polymorphism (rs11556218 T/G) and risk of RA disease development. In addition, there was an association between genotype G/G and increased clinical disease activity and health disability.