Molecular signature of neutrophil extracellular trap mediating disease module in idiopathic inflammatory myopathy.

The rarity and heterogeneity of idiopathic inflammatory myopathy (IIM) pose challenges for researching IIM in affected individuals. We analyzed integrated transcriptomic datasets obtained using muscle tissues from patients with five distinct IIM subtypes to investigate the shared and distinctive cellular and molecular characteristics. A transcriptomic dataset of muscle tissues from normal controls (n = 105) and patients with dermatomyositis (n = 89), polymyositis (n = 33), inclusion body myositis (n = 121), immune-mediated necrotizing myositis (n = 75), and anti-synthetase syndrome (n = 18) was used for differential gene-expression analysis, functional-enrichment analysis, gene set-enrichment analysis, disease-module identification, and kernel-based diffusion scoring. Damage-associated molecular pattern-associated pathways and neutrophil-mediated immunity were significantly enriched across different IIM subtypes, although their activities varied. Interferons-signaling pathways were differentially activated across all five IIM subtypes. In particular, neutrophil extracellular trap (NET) formation was significantly activated and correlated with Fcγ R-mediated signaling pathways. NET formation-associated genes were key for establishing disease modules, and FCGRs, C1QA, and SERPINE1 markedly perturbed the disease modules. Integrated transcriptomic analysis of muscle tissues identified NETs as key components of neutrophil-mediated immunity involved in the pathogenesis of IIM subtypes and, thus, has therapeutically targetable value.

De novo molecular subtyping of salivary gland tissue in the context of Sjögren's syndrome heterogeneity.

Understanding the mechanistic features and molecular taxonomy of diseases holds promise for the development of more effective treatments, especially for complex heterogeneous diseases. Here, we analyzed transcriptomic datasets of salivary gland tissues from patients with Sjögren's syndrome (SjS) to identify shared and divergent cellular and molecular signatures. Three molecular subtypes of SjS salivary gland tissue were identified: oxidative phosphorylation (OxPhos)-dominant (C1), weak inflammatory with type I interferon signatures (C2), and B cell receptor (BCR) signaling pathway-dominant (C3). C3 had the highest focus score. Type I helper T cells and B cells were the dominant cell types in C1 and C3 tissues, respectively. Metformin and drugs targeting PI3K, BTK, and JAKs were predicted to be effective treatments for C1 and C3 subtypes, respectively. Three subtypes of SjS salivary gland with distinct molecular signatures were identified. The results could contribute to optimal stratification of patients for more effective treatment approaches.

Integrative analysis of lung molecular signatures reveals key drivers of systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: Interstitial lung disease is a significant comorbidity and the leading cause of mortality in patients with systemic sclerosis. Transcriptomic data of systemic sclerosis-associated interstitial lung disease (SSc-ILD) were analysed to evaluate the salient molecular and cellular signatures in comparison with those in related pulmonary diseases and to identify the key driver genes and target molecules in the disease module. METHODS: A transcriptomic dataset of lung tissues from patients with SSc-ILD (n=52), idiopathic pulmonary fibrosis (IPF) (n=549), non-specific interstitial pneumonia (n=49) and pulmonary arterial hypertension (n=81) and from normal healthy controls (n=331) was subjected to filtration of differentially expressed genes, functional enrichment analysis, network-based key driver analysis and kernel-based diffusion scoring. The association of enriched pathways with clinical parameters was evaluated in patients with SSc-ILD. RESULTS: SSc-ILD shared key pathogenic pathways with other fibrosing pulmonary diseases but was distinguishable in some pathological processes. SSc-ILD showed general similarity with IPF in molecular and cellular signatures but stronger signals for myofibroblasts, which in SSc-ILD were in a senescent and apoptosis-resistant state. The p53 signalling pathway was the most enriched signature in lung tissues and lung fibroblasts of SSc-ILD, and was significantly correlated with carbon monoxide diffusing capacity of lung, cellular senescence and apoptosis. EEF2, EFF2K, PHKG2, VCAM1, PRKACB, ITGA4, CDK1, CDK2, FN1 and HDAC1 were key regulators with high diffusion scores in the disease module. CONCLUSIONS: Integrative transcriptomic analysis of lung tissues revealed key signatures of fibrosis in SSc-ILD. A network-based Bayesian approach provides deep insights into key regulatory genes and molecular targets applicable to treating SSc-ILD.

Pharmacologic Effects of Oxaliplatin Instability in Chloride-Containing Carrier Fluids on the Hyperthermic Intraperitoneal Chemotherapy to Treat Colorectal Cancer In Vitro and In Vivo.

BACKGROUND: Oxaliplatin-based hyperthermic intraperitoneal chemotherapy (HIPEC) involves mixing oxaliplatin with 5% dextrose solution (5DW) to prevent the structural degradation of oxaliplatin in chloride-containing fluids. This study evaluated oxaliplatin degradation in carrier fluids containing different chloride ion concentrations to determine a carrier fluid that is optimal for use in oxaliplatin-based HIPEC. METHODS: Five types of carrier fluids (normal saline, half saline, 5DW, Dianeal PD-2 peritoneal dialysis solution, and non-chloride Dianeal solution) were compared. An in vitro study was performed that monitored an oxaliplatin concentration of 1 ml (2 mg/ml) oxaliplatin mixed in 24 ml of each carrier fluid during 3 days to evaluate the rate of oxaliplatin degradation in each carrier fluid. An in vivo study, which subjected Sprague-Dawley rats to HIPEC for 60 min, also was performed. The efficacy of each carrier fluid for preserving oxaliplatin was evaluated using area under the curve (AUC) ratios between peritoneal fluid and plasma. RESULTS: The degradation rate of oxaliplatin in non-chloride fluids was significantly lower than in chloride-containing fluids. However, the rate was less than 10 to 15% at 30 min. The in vivo study indicated that oxaliplatin concentrations in peritoneal fluids did not differ significantly, whereas those in plasma did differ. The AUC ratios of both normal saline and Dianeal were higher than those of 5DW and non-Cl- Dianeal solutions. CONCLUSIONS: Chloride-containing fluids, such as normal saline or Dianeal, which display high absorption rates of oxaliplatin and acceptable degradation rates, may be more beneficial for use in oxaliplatin-based HIPEC than 5DW.

Exposure Levels and Contributing Factors of Various Arsenic Species and Their Health Effects on Korean Adults.

Arsenic is a human carcinogen. Data on urinary arsenic species analyses of Koreans are limited. This study evaluated the arsenic exposure level, contributing factors, and health effects in Korean adults. Dietary intake information and urine samples were obtained from 2044 participants. Arsenic exposure was assessed based on urinary concentrations of arsenic species, such as inorganic arsenic, As(III) and As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AsB), using high-performance liquid chromatography with inductively coupled plasma mass spectrometry, followed by determination of biomarkers, malondialdehyde and c-peptide. The geometric mean concentrations were 30.9 µg/L for the sum of inorganic arsenic and their metabolites, and 84.7 µg/L for the total sum of arsenic measured. Urinary concentrations of arsenic species were influenced by age, inhabitant area (inland or coastal), and seafood intake, which was positively correlated with inorganic arsenic, DMA, and AsB. Rice intake was positively correlated with inorganic arsenic and its metabolites but not with AsB. Additionally, malondialdehyde and c-peptide levels were significantly associated with urinary concentrations of various arsenic species. Seafood and rice are major sources of organic/inorganic arsenic exposure in Korean adults; however, it is necessary to evaluate whether their overconsumption could have a potentially detrimental effect on human health.

Deep phenotyping of synovial molecular signatures by integrative systems analysis in rheumatoid arthritis.

OBJECTIVE: RA encompasses a complex, heterogeneous and dynamic group of diseases arising from molecular and cellular perturbations of synovial tissues. The aim of this study was to decipher this complexity using an integrative systems approach and provide novel insights for designing stratified treatments. METHODS: An RNA sequencing dataset of synovial tissues from 152 RA patients and 28 normal controls was imported and subjected to filtration of differentially expressed genes, functional enrichment and network analysis, non-negative matrix factorization, and key driver analysis. A naïve Bayes classifier was applied to the independent datasets to investigate the factors associated with treatment outcome. RESULTS: A matrix of 1241 upregulated differentially expressed genes from RA samples was classified into three subtypes (C1-C3) with distinct molecular and cellular signatures. C3 with prominent immune cells and proinflammatory signatures had a stronger association with the presence of ACPA and showed a better therapeutic response than C1 and C2, which were enriched with neutrophil and fibroblast signatures, respectively. C2 was more occupied by synovial fibroblasts of destructive phenotype and carried highly expressed key effector molecules of invasion and osteoclastogenesis. CXCR2, JAK3, FYN and LYN were identified as key driver genes in C1 and C3. HDAC, JUN, NFKB1, TNF and TP53 were key regulators modulating fibroblast aggressiveness in C2. CONCLUSIONS: Deep phenotyping of synovial heterogeneity captured comprehensive and discrete pathophysiological attributes of RA regarding clinical features and treatment response. This result could serve as a template for future studies to design stratified approaches for RA patients.

Clinical phenotype with high risk for initiation of biologic therapy in rheumatoid arthritis: a data-driven cluster analysis.

OBJECTIVES: The clinical manifestations and treatment outcome in patients with rheumatoid arthritis (RA) are heterogeneous. We classified RA patients into subgroups with distinct phenotypes through unsupervised clustering and evaluated the utility of this subclassification for evaluation of clinical outcome. METHODS: A total of 1,103 patients with RA were clustered in an unbiased manner using a k-means clustering method, based on their clinical and phenotypic profiles. Initiation of biological disease-modifying anti-rheumatic drugs (bDMARDs) was evaluated in the segregated clusters to investigate the differential clinical course of each cluster. RESULTS: Patients with RA were classified into four clusters, each with distinct phenotypes. The key features for subclassification were sex, smoking, hypertension, and dyslipidaemia. Cluster 1 consisted of male smokers, who were most likely to initiate bDMARDs by 30 months (p=0.04). Multivariate analysis revealed that overweight, smoking, erythrocyte sedimentation rate, autoantibodies of high titre, and disease activity were the independent predictors of bDMARD initiation at 30 months. Cluster 1 was the highest or the second highest for these independent predictors, suggesting that cluster 1 contained a high-risk group for early initiation of bDMARDs. CONCLUSIONS: The unsupervised clustering of RA patients demonstrated the feasibility of the novel subclassification with respect to predicting clinical outcome. Identifying high-risk patients by a combination of clinical parameters may be useful for the management of RA.

Novel classification of axial spondyloarthritis to predict radiographic progression using machine learning.

OBJECTIVES: Prediction and determination of drug efficacy for radiographic progression is limited by the heterogeneity inherent in axial spondyloarthritis (axSpA). We investigated whether unbiased clustering analysis of phenotypic data can lead to coherent subgroups of axSpA patients with a distinct risk of radiographic progression. METHODS: A group of 412 patients with axSpA was clustered in an unbiased way using a agglomerative hierarchical clustering method, based on their phenotype mapping. We used a generalised linear model, naïve Bayes, Decision Trees, K-Nearest-Neighbors, and Support Vector Machines to construct a consensus classification method. Radiographic progression over 2 years was assessed using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). RESULTS: axSpA patients were classified into three distinct subgroups with distinct clinical characteristics. Sex, smoking, HLA-B27, baseline mSASSS, uveitis, and peripheral arthritis were the key features that were found to stratifying the phenogroups. The three phenogroups showed distinct differences in radiographic progression rate (p<0.05) and the proportion of progressors (p<0.001). Phenogroup 2, consisting of male smokers, had the worst radiographic progression, while phenogroup 3, exclusively suffering from uveitis, showed the least radiographic progression. The axSpA phenogroup classification, including its ability to stratify risk, was successfully replicated in an independent validation group. CONCLUSIONS: Phenotype mapping results in a clinically relevant classification of axSpA that is applicable for risk stratification. Novel coupling between phenotypic features and radiographic progression can provide a glimpse into the mechanisms underlying divergent and shared features of axSpA.

Association of influenza infection with hospitalisation-related systemic lupus erythematosus flares: a time series analysis.

OBJECTIVES: This study aimed to investigate whether the influenza annual outbreak in Korea is related to hospitalisation-related flares in systemic lupus erythematosus (SLE) patients. METHODS: The weekly frequency of hospitalisation-related SLE flares (2012-2015) was collected from the Korean National Health Insurance claim database. The weekly laboratory-confirmed detection rate of influenza infection was obtained from the Korea Centers for Disease Control and Prevention database. A generalised linear model was used to examine the relative risks (RRs) of hospitalisation-related SLE flares associated with influenza infection, after adjusting for time trends and meteorological data. RESULTS: A total of 2,223 hospitalisation-related SLE flares were analysed. An interquartile range (24.5%) increase in influenza infection was associated with a 14.0% increase in hospitalisation-related SLE flares (RR, 1.14; 95% confidence interval [CI]: 1.04-1.25; p=0.006). In addition, influenza infections at lag 0-1 (over 2 weeks including concurrent and 1 previous week) and lag 0-2 (over 3 weeks including concurrent and 2 previous weeks) were associated with increase in hospitalisation-related SLE flares (RR, 1.14; 95% confidence interval [CI]: 1.03-1.26; p=0.014 and RR, 1.13; 95% CI: 1.02-1.26; p=0.023). Significant associations were especially observed in women (RR, 1.15; 95% CI: 1.15-1.16; p=0.006) and immunosuppressant (RR, 1.26; 95% CI: 1.26-1.27; p<0.001) or glucocorticoid recipients (RR, 1.17, 95% CI: 1.16-1.17; p=0.004). CONCLUSIONS: This study shows a significant association between seasonal influenza infection and flares in SLE patients, which suggests influenza can be a novel environmental risk factor for SLE flares.

Integrative analysis of lung molecular signatures reveals key drivers of idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a devastating disease with a high clinical burden. The molecular signatures of IPF were analyzed to distinguish molecular subgroups and identify key driver genes and therapeutic targets. METHODS: Thirteen datasets of lung tissue transcriptomics including 585 IPF patients and 362 normal controls were obtained from the databases and subjected to filtration of differentially expressed genes (DEGs). A functional enrichment analysis, agglomerative hierarchical clustering, network-based key driver analysis, and diffusion scoring were performed, and the association of enriched pathways and clinical parameters was evaluated. RESULTS: A total of 2,967 upregulated DEGs was filtered during the comparison of gene expression profiles of lung tissues between IPF patients and healthy controls. The core molecular network of IPF featured p53 signaling pathway and cellular senescence. IPF patients were classified into two molecular subgroups (C1, C2) via unsupervised clustering. C1 was more enriched in the p53 signaling pathway and ciliated cells and presented a worse prognostic score, while C2 was more enriched for cellular senescence, profibrosing pathways, and alveolar epithelial cells. The p53 signaling pathway was closely correlated with a decline in forced vital capacity and carbon monoxide diffusion capacity and with the activation of cellular senescence. CDK1/2, CKDNA1A, CSNK1A1, HDAC1/2, FN1, VCAM1, and ITGA4 were the key regulators as evidence by high diffusion scores in the disease module. Currently available and investigational drugs showed differential diffusion scores in terms of their target molecules. CONCLUSIONS: An integrative molecular analysis of IPF lungs identified two molecular subgroups with distinct pathobiological characteristics and clinical prognostic scores. Inhibition against CDKs or HDACs showed great promise for controlling lung fibrosis. This approach provided molecular insights to support the prediction of clinical outcomes and the selection of therapeutic targets in IPF patients.

Compendium of skin molecular signatures identifies key pathological features associated with fibrosis in systemic sclerosis.

OBJECTIVES: Treatment of patients with systemic sclerosis (SSc) can be challenging because of clinical heterogeneity. Integration of genome-scale transcriptomic profiling for patients with SSc can provide insights on patient categorisation and novel drug targets. METHODS: A normalised compendium was created from 344 skin samples of 173 patients with SSc, covering an intersection of 17 424 genes from eight data sets. Differentially expressed genes (DEGs) identified by three independent methods were subjected to functional network analysis, where samples were grouped using non-negative matrix factorisation. Finally, we investigated the pathways and biomarkers associated with skin fibrosis using gene-set enrichment analysis. RESULTS: We identified 1089 upregulated DEGs, including 14 known genetic risk factors and five potential drug targets. Pathway-based subgrouping revealed four distinct clusters of patients with SSc with distinct activity signatures for SSc-relevant pathways. The inflammatory subtype was related to significant improvement in skin fibrosis at follow-up. The phosphoinositide-3-kinase-protein kinase B (PI3K-Akt) signalling pathway showed both the closest correlation and temporal pattern to skin fibrosis score. COMP, THBS1, THBS4, FN1, and TNC were leading-edge genes of the PI3K-Akt pathway in skin fibrogenesis. CONCLUSIONS: Construction and analysis of normalised skin transcriptomic compendia can provide useful insights on pathway involvement by SSc subsets and discovering viable biomarkers for a skin fibrosis index. Particularly, the PI3K-Akt pathway and its leading players are promising therapeutic targets.

Pharmacologic Properties of the Carrier Solutions for Hyperthermic Intraperitoneal Chemotherapy: Comparative Analyses Between Water and Lipid Carrier Solutions in the Rat Model.

BACKGROUND: Carrier solutions play an important role in the distribution, plasma absorption, chemical stability, and solubility of anticancer agents during hyperthermic intraperitoneal chemotherapy (HIPEC). In the current study, lipophilic properties of carrier solutions were evaluated to determine whether they improved anticancer drug absorption rates using mitomycin-C (MMC) or oxaliplatin HIPEC as compared to hydrophilic carrier solutions. METHODS: Sprague-Dawley rats were divided into two groups: MMC and oxaliplatin treatment groups. Each group was then further subdivided by carrier solution: Dianeal® PD-2 peritoneal dialysis solution, 5% dextrose solution and 20% lipid solution (Lipision®). HIPEC was performed over 60 min at 41-42 °C using the anticancer drugs MMC (35 mg/m2) or oxaliplatin (460 mg/m2). The plasma area under the curve (AUC; AUCplasma), peritoneal AUC (AUCperitoneum), and peritoneal/plasma AUC ratios were compared among HIPEC carrier solutions. RESULTS: Plasma drug concentrations were significantly different among carrier solutions, varying by time. In contrast, peritoneal drug concentrations did not change with carrier solution. In the MMC group, the peritoneal/plasma AUC ratio of a lipid solution was three times higher than Dianeal® (p < 0.001). In the oxaliplatin group, the peritoneal/plasma AUC ratio was significantly different between carrier solutions (p = 0.046). Although the oxaliplatin AUCperitoneum did not vary (p = 0.941), the AUCplasma of a lipid solution was lower than that of 5% dextrose solution (p = 0.039). CONCLUSIONS: The lipid carrier solution increases the peritoneal/plasma AUC ratio and decreases plasma absorption rates. However, further study is required before clinical uses, considering its pharmacologic properties and possible risks after HIPEC.

Lead, Mercury, and Cadmium Exposure in the Korean General Population.

BACKGROUND: Lead (Pb), mercury (Hg), and cadmium (Cd) are well-known environmental pollutants. They are unnecessary in the biological processes of humans. This study was performed to estimate the representative background exposure levels to the metals by measuring concentrations in whole blood of the Korean general population. METHODS: This population-based cross-sectional study included 4,000 subjects (1,886 males and 2,114 females) 0-83 years of age in 2010 and 2011. Adult subjects (≥ 19 years of age) were collected by sex- and age-stratified probability method, and preschool- and school-aged subjects were recruited by a cluster sampling method. Written consent was provided prior to blood sampling. Pb and Cd blood concentrations were determined by a flameless atomic absorption spectrophotometry, and blood Hg was analyzed by a direct Hg analyzer. RESULTS: The geometric mean, median and 95th percentile of blood Pb was 1.82 µg/dL, 1.83 µg/dL, and 3.78 µg/dL, respectively. The respective values were 2.92 µg/L, 2.87 µg/L, 9.12 µg/L for Hg, and 0.56 µg/L, 0.59 µg/L, 2.20 µg/L for Cd. Blood Pb and Hg were higher in males than in females, but no sex difference was observed, respectively, in subjects 0-4 years of age for Pb and in subjects less than 20 years for Hg. However, blood Cd was higher in females than in males and no sex difference was observed in subjects < 30 years of age. CONCLUSION: This study provides representative data of human exposure to Pb, Hg, and Cd covering whole age groups of the general population in Korea.

Low-Level Environmental Cadmium Exposure Induces Kidney Tubule Damage in the General Population of Korean Adults.

Cadmium (Cd) is the most potent nephrotoxic heavy metal and may affect bone; it also has a long biological half-life in the human body. This study was designed to assess the effect of environmental low-level Cd exposure on kidney function and bone in the general population. The subjects of this cross-sectional study were 1907 healthy Korean adults who had not been exposed to Cd occupationally. We analyzed the concentrations of Cd in the urine, markers of renal tubule damage, such as ß2-microglobulin (ß2-MG) and N-acetyl-ß-D-glucosaminidase (NAG) activity in the urine, calculated the estimated glomerular filtration rate (eGFR) using serum creatinine, and measured bone mineral density (BMD). Also, we analyzed malondialdehyde (MDA) levels in the urine. The geometric mean concentration of Cd in urine was higher in women (1.36 µg/g creatinine) than in men (0.82 µg/g creatinine). Urinary Cd was significantly positively correlated with urinary ß2-MG and NAG activity, whereas it was negatively correlated with eGFR and BMD. The risk of renal tubule damage was significantly associated with urine Cd level, and the association remained significant after controlling for various confounding variables. However, no association was observed between urinary Cd level and glomerular dysfunction or bone damage. The concentration of MDA was increased with urinary Cd level in a dose-dependent manner. These findings suggest that low-level environmental Cd exposure may cause microscopic damage to renal tubules through oxidative stress but might not impair kidney glomeruli or bones.

Association of inflammatory bowel disease with ankylosing spondylitis and rheumatoid arthritis: A nationwide population-based study.

OBJECTIVES: Tantalizing connections between autoimmune rheumatic diseases (ARDs) and inflammatory bowel disease (IBD) have become evident with regard to their genetic and immunologic background. However, the association between these two disease entities remains unclear. The aim of this study is to investigate the association between each ARD and IBD. METHODS: A nationwide population-based cross-sectional study was performed using the Korean National Health Insurance Claims database. The data of patients with IBD and age- and sex-matched controls between 2009 and 2013 were collected from the database. The prevalence of ARDs, including systemic lupus erythematosus (SLE), inflammatory myositis (polymyositis and dermatomyositis), systemic sclerosis (SSc), Sjögren's syndrome (SjS), ankylosing spondylitis (AS), and rheumatoid arthritis (RA), was determined. The associations between each ARD and IBD were analyzed using multivariate logistic regression models. RESULTS: A total of 40,843 IBD patients (28,197 patients with ulcerative colitis and 12,646 with Crohn's disease) and 122,529 controls were enrolled. The nonstratified analysis revealed that patients with IBD had significant risk of being concomitantly affected by AS (odds ratio [OR] 5.140, 95% confidence interval [95% CI] 4.069-6.492) and RA (OR: 3.474, 95% CI: 2.671-4.519) after adjusting for age and sex. No significant association was observed between IBD and other ARDs including SLE, inflammatory myositis, SSc, and SjS. CONCLUSION: IBD is significantly associated with AS and RA in the large-scaled population-based study. This result suggests that etiopathogenesis of IBD might be shared with AS and RA.

JAK2-STAT3 blockade by AG490 suppresses autoimmune arthritis in mice via reciprocal regulation of regulatory T Cells and Th17 cells.

IL-6-mediated STAT3 signaling is essential for Th17 differentiation and plays a central role in the pathogenesis of rheumatoid arthritis. To investigate the molecular mechanism underlying the antirheumatic effects and T cell regulatory effects of STAT3 inhibition, we studied the effects of the JAK 2 inhibitor AG490 on Th17 cell/regulatory T cell (Treg) balance and osteoclastogenesis. AG490 was administered to mice with collagen-induced arthritis (CIA) via i.p. injection, and its in vivo effects were determined. Differential expression of proinflammatory cytokines, including IL-17A, IL-1ß, and IL-6, was analyzed by immunohistochemistry. Levels of phosphorylated STAT3 and STAT5 and differentiation of Th17 cells and Tregs after AG490 treatment in our CIA model were analyzed by immunostaining. In vitro development of Th17 cells and Tregs was analyzed by flow cytometry and real-time PCR. AG490 ameliorated the arthritic phenotype in CIA and increased the proportion of Foxp3(+) Tregs. In contrast, the proportion of IL-17A-producing T cells and levels of inflammatory markers were reduced in AG490-treated mice. Numbers of p-STAT3(+) CD4(+) T cells and p-STAT5(+) CD4(+) T cells were reduced and elevated, respectively, after treatment with AG490. Furthermore, AG490 markedly increased the expression of molecules associated with Treg development (ICOS, programmed cell death protein 1, ICAM-1, and CD103). The development and function of osteoclasts were suppressed by AG490 treatment. Our results suggest that AG490, specifically regulating the JAK2/STAT3 pathway, may be a promising treatment for rheumatoid arthritis.

Oestrogen up-regulates interleukin-21 production by CD4(+) T lymphocytes in patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease in which abnormal immune responses are mediated by tissue-binding autoantibodies and immune complex deposition. Because most SLE patients are women of child-bearing age, oestrogen has been suggested to play an important role in SLE pathogenesis. One proposed role is to induce B-cell activation, culminating in increased autoantibody production. Interleukin-21 (IL-21) has been shown to be crucial in the differentiation of activated B cells into plasma cells. We therefore hypothesized that oestrogen up-regulates IL-21 production and induces subsequent B-cell activation in SLE patients. Peripheral blood was obtained from 22 SLE patients and 16 healthy controls. Expression levels of IL-21 and its receptor in serum, peripheral blood mononuclear cells, and CD4(+) T cells were higher in SLE patients than in healthy controls. Exposure of CD4(+) T cells from SLE patients to 17ß-oestradiol led to a dose- and time-dependent increase in IL-21 expression, which was abolished in the presence of mitogen-activated protein kinase (MAPK) (MAPK kinase, p38, Jun N-terminal kinase) inhibitors. B cells from healthy controls showed increased antibody production when they were co-cultured with oestrogen-treated CD4(+) T cells from SLE patients. Treatment with IL-21 antibody abrogated the increased antibody production of the co-culture systems. This study revealed the association between oestrogen and IL-21 in SLE patients. Oestrogen up-regulates IL-21 expression of CD4(+) T cells via MAPK-dependent pathways in SLE patients, which in turn induces increased antibody production by B cells.