Association Between Interleukin 35 Gene Single Nucleotide Polymorphisms and the Uveitis Immune Status in a Chinese Han Population

High interleukin-35 expression is associated with the severity of rheumatic mitral stenosis

Background

Rheumatic mitral stenosis (RMS) is the most common manifestation of rheumatic heart disease, with high morbidity and mortality. Interleukin-35 (IL-35) is a novel anti-inflammatory cytokine associated with many autoimmune diseases. However, the relation between IL-35 expression and RMS remains unknown. We aimed to study IL-35 expression in RMS and its association with disease progression.

Methods

IL-35 concentration was analyzed in blood samples from 40 patients, including 20 moderate, 20 severe RMS, and 20 healthy controls by ELISA. Mitral valve (MV) IL-35 expression was determined by western blot and immunohistochemistry in patients with RMS (22 and 29 cases, respectively) in comparison to control specimens with mitral valve prolapsed (5 cases, respectively).

Results

IL-35 levels were significantly elevated in the blood of the RMS patients compared to those from healthy subjects(p<0.05) and positively correlated with the severity of RMS (r=0.317, p<0.05). The expression of IL-35 and its subunits (p35 and EBI3) was also detected in MV tissues of patients with moderate or severe RMS. The expression of IL-35 and its subunits (p35 and EBI3) had a positive association with the severity of RMS in MV tissues (r=0.528, p<0.01; r=0.561, p<0.001; r=0.456, p<0.01). Co-localization of p35 and EBI3 was seen in MV tissues of RMS patients in a predominantly perivascular pattern.

Conclusion

We show for the first time an increase of IL-35 level in the blood and MV tissues of RMS patients, which is strongly correlated with the severity of RMS. These results suggest that IL-35 plays an important regulatory role in the progression of RMS.

Association of IL-23/IL-17 Pathway-Related Gene Polymorphisms with Idiopathic Scleritis in Chinese Han Population

PURPOSE

To examine the relationship between IL-23/IL-17 pathway gene polymorphisms and scleritis susceptibility in the Chinese Han population.

METHODS

We assessed IL-23/IL-17 pathway-related SNPs in 898 scleritis cases and 1,573 controls, employing stratified analysis to evaluate subtype-specific impacts and a discovery-validation cohort strategy to ensure genetic association reliability.

RESULTS

IL-23 R/rs10789229 TC genotype and C allele, and the IL-21/rs2221903 TT genotype and T allele were more frequent in scleritis patients (Pc = 2.07 × 10-3-2.77 × 10-6, OR = 1.497-2.327, 95% CI = 1.216-3.219), particularly anterior scleritis (Pc = 3.88 × 10-3-2.95 × 10-6, OR = 1.507-2.378, 95% CI = 1.209-3.321). The IL-23 R/rs10789229 TT genotype and T allele, and the IL-21/rs2221903 TC genotype and C allele were found less common among scleritis patients overall (Pc = 2.07 × 10-3-4.18 × 10-6, OR = 0.436-0.668, 95% CI = 0.316-0.822) and in the anterior scleritis subgroups (Pc = 3.88 × 10-3-4.43 × 10-6, OR = 0.427-0.664, 95% CI = 0.306-0.827). The analysis of haplotypes showed a noteworthy surge of IL-23 R CCCG haplotype in both scleritis patients in general (Pc = 1.91 × 10-4) and those with anterior scleritis (Pc = 1.15 × 10-4). Conversely, the frequency of the IL-17A GAA haplotype was significantly lower among scleritis patients overall (Pc = 4.17 × 10-12) and in the anterior or posterior scleritis subgroups (Pc = 7.41 × 10-11; Pc = 0.021). Only the IL-23 R/rs10789229 variant demonstrated consistent replication in the validation cohort.

CONCLUSIONS

The findings suggest that specific polymorphisms of IL-23/IL-17 pathway-related genes could confer risk to the development of scleritis in the Chinese Han population. Patients with varying subtypes of scleritis exhibit somewhat similar genetic profiles.

Abnormal glucose and lipid metabolism promotes disrupted differentiation of T and B cell subsets in Behçet's disease

Introduction

Behçet's disease (BD) is a chronic, systemic inflammatory condition characterized by recurrent immune dysregulation.

Materials & Methods

This study conducted a comprehensive analysis of immune cell subsets, metabolic markers, and their interplay in BD patients. Using multiparametric flow cytometry, we identified elevated Th1 cells, senescent CD8+ T cells, and abnormal B cell activation as hallmarks of the chronic inflammatory state in BD.

Results

Despite immunotherapy, innate immune activation persisted, with increased mature NK cells, γδT1 cells, and conventional dendritic cells (cDCs), alongside reduced plasmacytoid dendritic cells (pDCs). Elevated glucose (GLU) and triacylglycerol (TAG) levels in BD patients correlated with increased Th1 cells, functional CD8+ T cells, and B cell activation. In vitro experiments demonstrated that GLU and TAG promote Th1 differentiation, CD8+ T cell activation, and B cell antibody production, revealing their role as drivers of immune dysregulation.

Conclusion

These findings underscore the intricate relationship between metabolic dysregulation and immune dysfunction in BD, highlighting potential diagnostic and therapeutic targets. Our study provides critical insights into BD pathogenesis, offering a foundation for optimizing disease management and monitoring immune and metabolic markers for improved patient outcomes.

Regulatory B cells in autoimmune diseases: Insights and therapeutic potential

Autoimmune diseases are characterized by the body's immune system attacking its own cells, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). In recent studies, regulatory B cells (Bregs), which play a vital role in maintaining peripheral tolerance and controlling persistent autoimmune diseases (ADs), have shown great potential in treating ADs. This review synthesizes the latest advancements in targeted therapies for ADs, with a particular emphasis on the subgroups, phenotypic markers, and signal pathways associated with Bregs. Following an examination of these elements, the discussion pivots to innovative Breg-based therapeutic approaches for the management of ADs.

Regional variations in serum IL-35 levels and association with systemic lupus erythematosus: a systematic review and meta-analysis

Interleukin (IL)-35 is an anti-inflammatory cytokine that regulates autoimmune diseases, including systemic lupus erythematosus (SLE). However, the association between the cytokine and disease may vary by geographical region. This study performed a meta-analysis to quantitatively assess the correlation between the serum IL-35 levels in SLE patients and sub-group analyses were conducted. Four main electronic databases-Scopus, Embase, Science Direct, PubMed-were searched for relevant studies. After a database search, Endnote software was used to find and remove duplicate studies. Random-effects models were used to estimate standard mean differences in serum/plasma IL-35 levels by Hedges' g with 95% confidence intervals (CIs). Publication bias was assessed with funnel plots, and risk of bias was assessed according to the Newcastle-Ottawa Scale (NOS). Sixteen studies met the eligibility criteria and were included in a qualitative review; data from 15 studies were included in the meta-analysis. Total IL-35 levels (pg/mL) did not differ among patients with active SLE and healthy controls (Hedges's g: 0.22, 95% CI - 0.51, 0.95, p = 0.55). Sub-group analysis revealed that IL-35 levels in patients with active SLE were lower than in healthy controls in Chinese studies (Hedges's g: - 3.11, 95% CI - 5.72, - 0.51), but not in non-Chinese studies (Hedges's g: 1.63, 95% CI - 0.31, 3.57). This regional difference was statistically significant (p < 0.01). The analysis comparing patients with inactive SLE and healthy controls showed a similar trend. This study suggests that serum IL-35 levels are lower in patients with SLE in studies from China, but not other regions. However, standardized protocols with large sample sizes are needed to confirm these findings.

The effects of IL-27 and IL-35 gene variation and expression levels on the susceptibility and clinical manifestations of pulmonary tuberculosis

Inflammatory cytokines have crucial roles in the pathogenesis of tuberculosis (TB), and interleukin (IL)-27 and IL-35 have a pro-inflammatory and anti-inflammatory effect on many diseases, including infectious diseases. Therefore, we evaluated the relationship between IL-27 and IL-35 gene polymorphism, expression levels, and pulmonary TB (PTB) susceptibility. Nine single-nucleotide polymorphisms (SNPs) in the IL-27 gene (rs181206, rs153109, and rs17855750) and the IL-35 gene (rs4740, rs428253, rs9807813, rs2243123, rs2243135, and rs568408) were genotyped by the SNPscan technique in 497 patients with PTB and 501 controls. There was no significant difference regarding the genotype and allele frequencies of the above SNPs in the IL-27 and IL-35 genes between patients with PTB and controls. Haplotype analysis showed that the frequency of the GAC haplotype in the IL-35 gene was significantly decreased in patients with PTB when compared to controls (p = 0.036). Stratified analysis suggested that the frequency of the IL-27 rs17855750 GG genotype was significantly increased in patients with PTB with fever. Moreover, the lower frequency of the IL-35 rs568408 GA genotype was associated with drug-induced liver injury in patients with PTB. The IL-35 rs428253 GC genotype, as well as the rs4740 AA genotype and A allele, showed significant relationships with hypoproteinemia in patients with PTB. When compared with controls, the IL-27 level was significantly increased in patients with PTB. Taken together, IL-35 gene variation might contribute to a protective role on the susceptibility to PTB, and IL-27 and IL-35 gene polymorphisms were associated with several clinical manifestations of patients with PTB.

Risk factors, clinical features and treatment of Behçet's disease uveitis

Behçet's disease is a systemic vasculitis frequently associated with intraocular inflammation. Recent findings identified independent clinical clusters in Behçet's disease, each involving distinct combinations of affected organs. Ocular Behçet's disease, mainly manifested as uveitis, is characterized as an independent cluster with a low likelihood of association with other system involvements, such as intestinal, cardiovascular, or central nervous system. A prevailing theory suggests that the pathogenesis of the disease is multifactorial, where a variety of genetic and infectious agents may interact with each other to cause the disease. Among sporadic cases, the human leukocyte antigen (HLA) genes, including HLA-B51, HLA-A26, HLA-B15, and HLA-B5701, have been found to be a key component conferring genetic susceptibility. Outside the HLA region, a set of susceptibility variants are identified, closely related to interleukin (IL)-23/IL-17 pathway, tumor necrosis factor (TNF) signaling, and pattern recognition receptor systems. Microbial infections, such as Streptococcus sanguinis, Mycobacterium tuberculosis, and Herpes simplex virus (HSV), are linked to play the triggering of disease in immunogenetically predisposed individuals. Clinically, due to the notable relapsing-remitting course of ocular Behçet's disease, the prevention of recurrent attack would be the primary treatment goal. Combination of corticosteroids and immunomodulatory drugs, such as anti-TNF agents, interferon, and conventional immunosuppressants (e.g. cyclosporine, azathioprine), have been the mainstream regimen for the disease. Future research may focus on comparing the effectiveness of immunomodulatory drugs and identifying the most suitable subgroups for a specific drug on the basis of the knowledge of the molecular heterogeneity of the disease.

Apigenin Alleviates Autoimmune Uveitis by Inhibiting Microglia M1 Pro-Inflammatory Polarization

Purpose

Apigenin is a natural small molecule compound widely present in various vegetables and fruits. Recently, Apigenin was reported to inhibit lipopolysaccharide (LPS)-simulated microglial proinflammatory activation. Considering the important role of microglia in retinal disorders, we wonder whether Apigenin could exert a therapeutic effect on experimental autoimmune uveitis (EAU) through reprogramming retinal microglia to a beneficial subtype.

Methods

EAU was induced in C57BL/6J mice by immunization with interphotoreceptor retinoid-binding protein (IRBP)651-670, followed by intraperitoneal administration of Apigenin. Disease severity was assessed based on clinical and pathological scores. In vivo, Western blotting was used to quantify protein levels of classical inflammatory factors, microglial M1/M2 markers and the tight junction protein of the blood-retinal-barrier (BRB). Immunofluorescence was used to determine the Apigenin's efficacy on microglial phenotype. In vitro, Apigenin was added in LPS and IFN-γ stimulated human microglial cell line. Western blotting and Transwell assays were used to analyze the phenotype of microglia.

Results

In vivo, we found that Apigenin significantly reduced the clinical and pathological scores of EAU. The protein levels of inflammatory cytokines were significantly decreased in retina, and BRB disruption was ameliorated after Apigenin treatment. Meanwhile, Apigenin inhibited microglia M1 transition in EAU mice retina. In vitro functional studies showed that Apigenin decreased LPS and IFN-γ-induced microglial inflammatory factor production and M1-activation via the TLR4/MyD88 pathway.

Conclusions

Apigenin can ameliorate retinal inflammation in IRBP induced autoimmune uveitis through inhibiting microglia M1 pro-inflammatory polarization via TLR4/MyD88 pathway.

Photoreceptor Cells Constitutively Express IL-35 and Promote Ocular Immune Privilege

Interleukin-27 is constitutively secreted by microglia in the retina or brain, and upregulation of IL-27 during neuroinflammation suppresses encephalomyelitis and autoimmune uveitis. However, while IL-35 is structurally and functionally similar to IL-27, the intrinsic roles of IL-35 in CNS tissues are unknown. Thus, we generated IL-35/YFP-knock-in reporter mice (p35-KI) and demonstrated that photoreceptor neurons constitutively secrete IL-35, which might protect the retina from persistent low-grade inflammation that can impair photoreceptor functions. Furthermore, the p35-KI mouse, which is hemizygous at the il12a locus, develops more severe uveitis because of reduced IL-35 expression. Interestingly, onset and exacerbation of uveitis in p35-KI mice caused by extravasation of proinflammatory Th1/Th17 lymphocytes into the retina were preceded by a dramatic decrease of IL-35, attributable to massive death of photoreceptor cells. Thus, while inflammation-induced death of photoreceptors and loss of protective effects of IL-35 exacerbated uveitis, our data also suggest that constitutive production of IL-35 in the retina might have housekeeping functions that promote sterilization immunity in the neuroretina and maintain ocular immune privilege.

Interleukin-35 ameliorates cardiovascular disease by suppressing inflammatory responses and regulating immune homeostasis

The immune response is of great significance in the initiation and progression of a diversity of cardiovascular diseases involving pro-and anti-inflammatory cytokines. Interleukin-35 (IL-35), a cytokine of the interleukin-12 family, is a novel anti-inflammation and immunosuppressive cytokine, maintaining inflammatory suppression and regulating immune homeostasis. The role of IL-35 in cardiovascular diseases (CVDs) has aroused enthusiastic attention, a diversity of experimental or clinical evidence has indicated that IL-35 potentially has a pivot role in protecting against cardiovascular diseases, especially atherosclerosis and myocarditis. In this review, we initiate an overview of the relationship between Interleukin-35 and cardiovascular diseases, including atherosclerosis, acute coronary syndrome, pulmonary hypertension, abdominal aortic aneurysm, heart failure, myocardial ischemia-reperfusion, aortic dissection and myocarditis. Although the specific molecular mechanisms entailing the protective effects of IL-35 remain an unsolved issue, targeted therapies with IL-35 might provide a promising and effective solution to prevent and cure cardiovascular diseases.

Genetics in Behcet's Disease: An Update Review

Behcet's disease (BD) is one of the most vision-threatening clinical entities of uveitis. Although the etiopathogenesis of BD remains obscure, accumulating evidence has demonstrated that both genetic and environmental factors may contribute to the development of BD. Genome-wide association studies (GWAS) and candidate association studies have identified several genetic variants strongly associated with BD, including variants in human leukocyte antigen (HLA) -A02, -A03, -A24, -A26, -A31, -B15, -B27, -B35, -B49, -B51, -B57, -B58, -C0704, CIITA, ERAP1, MICA, IL1A-IL1B, IL10, IL12, IL23R, IL-23R/IL-12RB2, IL1RL1-IL18R1, STAT4, TFCP2L1, TRAF5, TNFAIP3, CCR1/CCR3, RIPK2, ADO-ZNF365-EGR2, KLRC4, LACC1, MEFV, IRF8, FUT2, CEBPB-PTPN1, ZMIZ1, RPS6KA4, IL10RA, SIPA1-FIBP-FOSL1, VAMP1, JRKL/CTCN5, IFNGR1 and miRNA-146a. Epigenetic modifications are also reported to play essential roles in the development of BD, including DNA methylation and histone modification. We review here the recent advances in the genetic and epigenetic factors associated with the BD pathogenesis.

Icariin alleviates uveitis by targeting peroxiredoxin 3 to modulate retinal microglia M1/M2 phenotypic polarization

Uveitis causes blindness and critical visual impairment in people of all ages, and retinal microglia participate in uveitis progression. Unfortunately, effective treatment is deficient. Icariin (ICA) is a bioactive monomer derived from Epimedium. However, the role of ICA in uveitis remains elusive. Our study indicated that ICA alleviated intraocular inflammation in vivo. Further results showed the proinflammatory M1 microglia could be transferred to anti-inflammatory M2 microglia by ICA in the retina and HMC3 cells. However, the direct pharmacological target of ICA is unknown, to this end, proteome microarrays and molecular simulations were used to identify the molecular targets of ICA. Data showed that ICA binds to peroxiredoxin-3 (PRDX3), increasing PRDX3 protein expression in both a time- and a concentration-dependent manner and promoting the subsequent elimination of H₂O₂. In addition, GPX4/SLC7A11/ACSL4 pathways were activated accompanied by PRDX3 activation. Functional tests demonstrated that ICA-derived protection is afforded through targeting PRDX3. First, ICA-shifted microglial M1/M2 phenotypic polarization was no longer detected by blocking PRDX3 both in vivo and in vitro. Next, ICA-activated GPX4/SLC7A11/ACSL4 pathways and downregulated H₂O₂ production were also reversed via inhibiting PRDX3 both in vivo and in vitro. Finally, ICA-elicited positive effects on intraocular inflammation were eliminated in PRDX3-deficient retina from experimental autoimmune uveitis (EAU) mice. Taking together, ICA-derived PRDX3 activation has therapeutic potential for uveitis, which might be associated with modulating microglial M1/M2 phenotypic polarization.