Amelioration of nephritis in receptor for advanced glycation end-products (RAGE)-deficient lupus-prone mice through neutrophil extracellular traps.

The receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor that regulates inflammation, cell migration, and cell fate. Systemic lupus erythematosus (SLE) is a chronic multiorgan autoimmune disease. To understand the function of RAGE in SLE, we generated RAGE-deficient (Ager-/-) lupus-prone mice by backcrossing MRL/MpJ-Faslpr/J (MRL-lpr) mice with Ager-/- C57BL/6 mice. In 18-week-old Ager-/- MRL-lpr, the weights of the spleen and lymph nodes, as well as the frequency of CD3+CD4-CD8- cells, were significantly decreased. Ager-/- MRL-lpr mice had significantly reduced urine albumin/creatinine ratios and markedly improved renal pathological scores. Moreover, neutrophil infiltration and neutrophil extracellular trap formation in the glomerulus were significantly reduced in Ager-/- MRL-lpr. Our study is the first to reveal that RAGE can have a pathologic role in immune cells, particularly neutrophils and T cells, in inflammatory tissues and suggests that the inhibition of RAGE may be a potential therapeutic strategy for SLE.

Deletion of Mir223 Exacerbates Lupus Nephritis by Targeting S1pr1 in Faslpr/lpr Mice.

Objective: The micro RNAs (miRNAs) and their target mRNAs are differentially expressed in various immune-mediated cells. Here, we investigated the role of Mir223 and sphingosine-1-phosphate receptor 1 (S1pr1) in the pathogenesis of systemic lupus erythematosus. Methods: We analyzed miRNA and mRNA profiling data of CD4+ splenic T cells derived from MRL/MpJ-Faslpr /J mice. We performed 3' untranslated region (UTR) luciferase reporter gene assay using human umbilical vein endothelial cells (HUVECs). We generated the B6-Mir223-/-Faslpr/lpr mice and the lupus phenotypes were analyzed. Results: In CD4+ splenic T cells, we identified upregulation of miR-223-3p and downregulation of the possible target, S1pr1 by RNA sequencing of MRL/MpJ-Faslpr /J mice. The transfection with miR-223-3p mimic significantly suppressed a luciferase activity in HUVEC treated with a Lentivirus vector containing 3' UTR of S1pr1. The mRNA levels of S1pr1 were significantly decreased after miR-223-3p overexpression. In B6-Mir223-/-Faslpr/lpr mice, the proportion of CD3+ T cells, CD3+CD4-CD8- cells, B cells, plasma cells, and S1PR1+CD4+ T cells in the spleen was significantly increased compared with that in B6-Mir223+/+Faslpr/lpr mice by flow cytometry. B6-Mir223-/-Faslpr/lpr mice demonstrated the elevation of glomerular and renal vascular scores associated with enhanced intraglomerular infiltration of S1PR1+CD4+ T cells. Conclusion: Unexpectedly, the deletion of Mir223 exacerbated the lupus phenotypes associated with increased population of S1PR1+CD4+ T in spleen and the enhanced infiltration of S1PR1+CD4+ T cells in inflamed kidney tissues, suggesting compensatory role of Mir223 in the pathogenesis of lupus nephritis.

Regulation of Cathepsin E gene expression by the transcription factor Kaiso in MRL/lpr mice derived CD4+ T cells.

Global DNA hypomethylation in CD4+ cells in systemic lupus erythematosus (SLE) was suggested to play a key role in the pathogenesis. To identify new methylation-sensitive genes, we integrated genome-wide DNA methylation and mRNA profiling data in CD4+ cells of MRL/lpr (MRL) and C57BL6/J (B6) mice. We identified Cathepsin E (Ctse), in which 13 methyl-CpGs within 583 bp region of intron 1 were hypomethylated, and Ctse mRNA upregulated in MRL compared with B6 mice. One of methyl-CpGs, mCGCG was 93.3 ± 2.05% methylated in B6 mice, while 80.0 ± 6.2% methylated and mutated to CGGG in MRL mice. Kaiso is known to bind to mCGCG and we hypothesized that it represses expression of Ctse in B6 mice. The binding of Kaiso to mCGCG site in B6 mice was reduced in MRL mice revealed by ChIP-PCR. EL4 cells treated with 5-azaC and/or Trichostatin A showed the suppression of binding of Kaiso to mCGCG motif by ChIP-PCR and the overexpression of Ctse was demonstrated by qPCR. Ctse gene silencing by siRNA in EL4 cells resulted in reduction of IL-10 secretion. The hypomethylation of mCGCG motif, reduced recruitment of Kaiso, and increased expression of Ctse and Il-10 in CD4+ cells may be involved in the pathogenesis of SLE.

Role of Lgals9 Deficiency in Attenuating Nephritis and Arthritis in BALB/c Mice in a Pristane-Induced Lupus Model.

OBJECTIVE: In systemic lupus erythematosus (SLE), an autoimmune disease associated with multiple organ involvement, the development of lupus nephritis determines prognosis, and arthritis impairs quality of life. Galectin 9 (Gal-9, Lgals9) is a ß-galactoside-binding lectin that has been used for clinical application in autoimmune diseases, since recombinant Gal-9, as a ligand for T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), induces apoptosis of activated CD4+TIM-3+ Th1 cells. This study was undertaken to investigate whether deficiency of Lgals9 has beneficial or deleterious effects on lupus in a murine model. METHODS: Gal-9+/+ and Gal-9-/- female BALB/c mice were injected with pristane, and the severity of arthritis, proteinuria, and levels of autoantibody production were assessed at several time points immediately following injection. At 7 months after pristane injection, renal pathologic features, the severity of joint inflammation, and formation of lipogranulomas were evaluated. Subsets of inflammatory cells in the spleen and peritoneal lavage were characterized, and expression levels of cytokines from peritoneal macrophages were analyzed. RESULTS: Lgals9 deficiency protected against the development of immune complex glomerulonephritis, arthritis, and peritoneal lipogranuloma formation in BALB/c mice in this murine model of pristane-induced lupus. The populations of T cell subsets and B cells in the spleen and peritoneum were not altered by Lgals9 deficiency in pristane-injected BALB/c mice. Furthermore, Lgals9 deficiency protected against pristane-induced lupus without altering the Toll-like receptor 7-type I interferon pathway. CONCLUSION: Gal-9 is required for the induction and development of lupus nephritis and arthritis in this murine model of SLE. The results of the current investigation provide a potential new strategy in which antagonism of Gal-9 may be beneficial for the treatment of nephritis and arthritis in patients with SLE through targeting of activated macrophages.

Anti-SS-A/Ro antibody positivity as a risk factor for relapse in patients with polymyositis/dermatomyositis.

OBJECTIVE: The objective of this study is to elucidate predictors of relapse in patients with polymyositis and dermatomyositis (PM/DM). METHODS: Fifty PM/DM patients who achieved disease stabilization at Okayama University Hospital in 2004-2014 were enrolled retrospectively. Candidate predictors such as demographic factors, clinical symptoms, laboratory data, and treatment status were compared. RESULTS: The mean age of enrolled patients was 58 years; 34 were female. The patient groupings were as follows: 21 with PM, 27 with DM, and two with clinically amyopathic DM. During a mean observation period of 685 d, 5 patients (10%) died and 20 (40%) relapsed. The relapsed patients displayed baseline muscle weakness less frequently (85% versus 100%, p = .03) and anti-SS-A/Ro antibody more frequently (65% versus 27%, p = .007). Anti-SS-A/Ro-positive patients exhibited a higher relapse rate than anti-SS-A/Ro-negative patients (log-rank test, p = .03). Anti-SS-A/Ro-positive patients also exhibited higher anti-Jo-1 antibody positivity and lower levels of serum complement. After adjusting anti-Jo-1 antibody positivity, age, sex, CK <500 IU/L, and lung involvement, anti-SS-A/Ro positivity was still an independent risk factor for higher relapse-rate (odds ratio, 5.5; 95% confidence interval, 1.4-25.1). CONCLUSIONS: Anti-SS-A/Ro antibody positivity may be a useful biomarker for prediction of relapse.

Alternative to Rituximab Therapy for a Patient with Ankylosing Spondylitis Who Was Unable to Continue Anti-TNF Therapy.

We herein present a case of a 38-year-old man who had bamboo spine and severe sacroiliitis and who was diagnosed with ankylosing spondylitis (AS). Infliximab (IFX) markedly improved the axial symptom but was discontinued due to the side effect of peripheral neuropathy. Switching from IFX to etanercept worsened the side effect. Rituximab (RTX) administration elicited a good response without side effects. RTX might be a suitable option for AS therapy when TNF inhibitors are difficult to use.

Azathioprine Intolerance in Japanese Patients with Antineutrophil Cytoplasmic Antibody-associated Vasculitis.

Objective To assess the safety of azathioprine (AZA) in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Methods We retrospectively enrolled 67 consecutive AAV patients who had initiated AZA treatment from January 2006 to August 2014 at Okayama University Hospital. We evaluated the development of severe adverse events (AEs), AZA discontinuation due to total AEs (severe AEs included) within 1 year, and AZA-associated risk factors. Results The patients' median age was 70 years old. Forty-nine women and 18 men participated at the initiation of the study. Fifty-eight (87%) patients experienced AEs, and 36 experienced severe AEs (21 hepatic and 11 cytopenic severe AEs). Thirty-one (46%) patients discontinued treatment because of AEs. Abnormal hepatic laboratory test results at the treatment initiation were more frequent in patients with hepatic severe AEs and were associated with treatment discontinuation. The leukocyte and neutrophil counts at the treatment initiation were lower in the patients who discontinued treatment because of cytopenic AEs than in those who continued treatment. Only two patients experienced flare-ups during treatment. Conclusion The AE-associated AZA discontinuation rate in Japanese AAV patients was relatively high. AZA use warrants caution in patients with abnormal hepatic laboratory test results or low leukocyte or neutrophil counts.

Anti-high Mobility Group Box 1 Antibody Ameliorates Albuminuria in MRL/lpr Lupus-Prone Mice.

We evaluated the efficacy of a neutralizing anti-high mobility group box 1 (HMGB1) monoclonal antibody in MRL/lpr lupus-prone mice. The anti-HMGB1 monoclonal antibody (5 mg/kg weight) or class-matched control immunoglobulin G2a (IgG2a) was administered intravenously twice a week for 4-15 weeks. Urine albumin was monitored, and histological evaluation of the kidneys was conducted at 16 weeks. Lymphadenopathies were evaluated by 1-(2'-deoxy-2'-[18F]fluoro-ß-D-arabinofuranosyl)cytosine ([18F]FAC) positron emission tomography/computed tomography (PET/CT) at 12 weeks. Following 4-week treatment, [18F]FAC-PET/CT showed similar accumulation in cervical and axillary lymph nodes at 12 weeks of age. However, anti-HMGB1 monoclonal antibody sufficiently inhibited the increase in albuminuria compared to an isotype control following 15-week treatment. Complement deposition was also improved; however, there were no significant differences in IgG deposition and renal pathological scores between the two groups. Anti-double-stranded DNA (dsDNA) antibody titers and cytokine and chemokine levels were also unaltered. Although there were no significant differences in glomerular macrophage infiltration, neutrophil infiltration was significantly decreased by the anti-HMGB1 monoclonal antibody. Antagonizing HMGB1 treatment suppressed HMGB1 translocation from nuclei in the kidney and suppressed neutrophil extracellular traps. The anti-HMGB1 monoclonal antibody demonstrated therapeutic potential against albuminuria in lupus nephritis by inhibiting neutrophil recruitment and neutrophil extracellular traps.

Downregulation of miR-200a-3p, Targeting CtBP2 Complex, Is Involved in the Hypoproduction of IL-2 in Systemic Lupus Erythematosus-Derived T Cells.

Systemic lupus erythematosus (SLE) damages multiple organs by producing various autoantibodies. In this study, we report that decreased microRNA (miR)-200a-3p causes IL-2 hypoproduction through zinc finger E-box binding homeobox (ZEB)1 and C-terminal binding protein 2 (CtBP2) in a lupus-prone mouse. First, we performed RNA sequencing to identify candidate microRNAs and mRNAs involved in the pathogenesis of SLE. We found that miR-200a-3p was significantly downregulated, whereas its putative targets, ZEB2 and CtBP2, were upregulated in CD4+ T cells from MRL/lpr-Tnfrsf6lpr mice compared with C57BL/6J mice. ZEB1 and ZEB2 comprise the ZEB family and suppress various genes, including IL-2 by recruiting CtBP2. IL-2 plays a critical role in immune tolerance, and insufficient IL-2 production upon stimulation has been recognized in SLE pathogenesis. Therefore, we hypothesized that decreased miR-200a-3p causes IL-2 deficit through the ZEB1-CtBP2 and/or ZEB2-CtBP2 complex in SLE CD4+ T cells. Overexpression of miR-200a-3p induced IL-2 production by downregulating ZEB1, ZEB2, and CtBP2 in EL4 cell lines. We further revealed that miR-200a-3p promotes IL-2 expression by reducing the binding of suppressive ZEB1-CtBP2 and ZEB2-CtBP2 complexes on negative regulatory element A in the IL-2 promoter in EL4 cells. Interestingly, the ZEB1-CtBP2 complex on negative regulatory element A was significantly upregulated after PMA/ionomycin stimulation in lupus CD4+ T cells. Our studies have revealed a new epigenetic pathway in the control of IL-2 production in SLE whereby low levels of miR-200a-3p accumulate the binding of the ZEB1-CtBP2 complex to the IL-2 promoter and suppress IL-2 production.

Prognostic factors of methotrexate-associated lymphoproliferative disorders associated with rheumatoid arthritis and plausible application of biological agents.

OBJECTIVES: To determine prognostic factors of methotrexate-associated lymphoproliferative disorder (MTX-LPD) and evaluate the efficacy and safety of biological therapy in rheumatoid arthritis (RA) complicated with MTX-LPD. METHODS: Thirty RA patients who developed MTX-LPD were investigated in this study. We compared the clinical and laboratory parameters of patients who achieved regression of LPD by MTX withdrawal with those who required chemotherapy and evaluated the clinical course of RA after LPD development. RESULTS: Twenty-three patients (76.7%) achieved regression of LPD by MTX withdrawal. Chemotherapy-free patients had a tendency of shorter RA duration (13.1 vs. 22.0 years, p = 0.108) and higher doses of MTX at LPD diagnosis (8.0 vs. 5.3 mg/w, p = 0.067) than patients who required chemotherapy. A significantly higher positive rate of peripheral blood Epstein-Barr virus (EBV)-DNA was observed in the chemotherapy-free group (9/9 vs. 0/3, p = 0.0002). Of 15 patients that received biological agents after LPD development, 14 patients (93.3%) demonstrated an improved disease activity of RA and persistent remission of LPD, whereas only one patient experienced relapse of LPD during tocilizumab therapy. CONCLUSIONS: Peripheral blood EBV-DNA positivity is a potential prognostic marker of better outcome in MTX-LPD. Biological agents could be an option for the treatment of RA patients with MTX-LPD.