Because autoimmune diseases (AIDs) result from a complex combination of genetic and epigenetic factors, as well as an altered immune response to endogenous or exogenous antigens, systems biology approaches have been widely applied. The use of multi-omics approaches, including blood transcriptomics, genomics, epigenetics, proteomics, and metabolomics, not only allow for the discovery of a number of biomarkers but also will provide new directions for further translational AIDs applications. Systems biology approaches rely on high-throughput techniques with data analysis platforms that leverage the assessment of genes, proteins, metabolites, and network analysis of complex biologic or pathways implicated in specific AID conditions. To facilitate the discovery of validated and qualified biomarkers, better-coordinated multi-omics approaches and standardized translational research, in combination with the skills of biologists, clinicians, engineers, and bioinformaticians, are required.
Autoimmune diseases; Systems biology; Multi-omics; Biomarker; Translational research; Network analysis
The receptor for advanced glycation end-products (RAGE) has been implicated in the pathogenesis of arthritis. We conducted this study to determine the effect of interleukin (IL)-17 on the expression and production of RAGE in fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). The role of nuclear factor-κB (NF-κB) activator 1 (Act1) in IL-17-induced RAGE expression in RA-FLS was also evaluated.
RAGE expression in synovial tissues was assessed by immunohistochemical staining. RAGE mRNA production was determined by real-time polymerase chain reaction. Act-1 short hairpin RNA (shRNA) was produced and treated to evaluate the role of Act-1 on RAGE production.
RAGE, IL-17, and Act-1 expression increased in RA synovium compared to osteoarthritis synovium. RAGE expression and production increased by IL-17 and IL-1β (*P <0.05 vs. untreated cells) treatment but not by tumor necrosis factor (TNF)-α in RA-FLS. The combined stimuli of both IL-17 and IL-1β significantly increased RAGE production compared to a single stimulus with IL-17 or IL-1β alone (P <0.05 vs. 10 ng/ml IL-17). Act-1 shRNA added to the RA-FLS culture supernatant completely suppressed the enhanced production of RAGE induced by IL-17.
RAGE was overexpressed in RA synovial tissues, and RAGE production was stimulated by IL-17 and IL-1β. Act-1 contributed to the stimulatory effect of IL-17 on RAGE production, suggesting a possible inhibitory target for RA treatment.
This study was undertaken to identify the intracellular signaling pathway involved in induction of macrophage migration inhibitory factor (MIF) in human rheumatoid arthritis (RA) synovial fibroblasts.
Human RA synovial fibroblasts were treated with concanavalin A (ConA), various cytokines, and inhibitors of signal transduction molecules. The production of MIF by synovial fibroblasts was measured in culture supernatants by ELISA. The expression of MIF mRNA was determined using reverse transcriptase polymerase chain reaction (RT-PCR) and real-time PCR. Phosphorylation of p38 mitogen-activated protein (MAP) kinase in synovial fibroblasts was confirmed using Western blotting. The expression of MIF and p38 MAP kinase in RA synovium was determined using dual immunohistochemistry.
The production of MIF by RA synovial fibroblasts increased in a dose-dependent manner after ConA stimulation. MIF was also induced by interferon-γ, CD40 ligand, interleukin-15, interleukin-1β, tumor necrosis factor-α, and transforming growth factor-β. The production of MIF by RA synovial fibroblasts was significantly reduced after inhibition of p38 MAP kinase. The expression of MIF and p38 MAP kinase was upregulated in the RA synovium compared with the osteoarthritis synovium.
These results suggest that MIF production was induced through a p38 MAP-kinase-dependent pathway in RA synovial fibroblasts.
Macrophage, migration-inhibitory factors; Arthritis rheumatoid; Synovial fibroblast; p38 mitogen-activated protein kinases
Macrophage activation syndrome (MAS) is one of the serious complications of juvenile rheumatoid arthritis (JRA) and recently, cyclosporine A has been found to be effective in patients with corticosteroid-resistant MAS. A 29-yr-old male was admitted with high fever and jaundice for one month. He was diagnosed as juvenile arthritis 16 yr ago. Physical and laboratory results showed hepatosplenomegaly, high fever, pancytopenia and impaired liver and renal function tests, elevated triglyceride and serum ferritin levels. Bone marrow biopsy showed hyperplasia of histiocytes with active hemophagocytosis. He was diagnosed as MAS associated with juvenile rheumatoid arthritis and managed with high-dose corticosteroids initially, but clinical symptoms and laboratory findings did not improve immediately. Finally, he completely recovered after treatment with cyclosporine A (3 mg/kg/day).
Macrophage activation syndrome; Arthritis, Juvenile Rheumatoid; Cyclosporine
Cryptococcal infection is a rare, yet well recognized complication of systemic lupus erythematosus (SLE). We present a case of mesenteric and retroperitoneal cryptococcal lymphadenitis resulting in the obstruction of the stomach and proximal duodenum in a patient suffering from SLE, while recently she did not receive any immunosuppressive treatment. A 42-yr-old woman was admitted due to high fever and diffuse abdominal pain for three weeks. Abdominal computed tomography (CT) scan showed multiple conglomerated lymphadenopathies in the retroperitoneum and the mesentery resulting in luminal narrowing of the third portion of the duodenum. Cryptococcal lymphadenitis was proven by needle biopsy and she was treated with intravenous liposomal amphotericin B, followed by oral fluconazole. After fourteen-month antifungal therapies, the clinical symptoms and follow-up images improved. This case emphasize that the intrinsic immunological defects of SLE may be directly responsible for the predisposition to fungal infections.
Mesenteric Lymphadenitis; Cryptococcus neoformans; Lupus Erythematosus, Systemic
Inflammatory mediators have been recognized as being important in the pathogenesis of rheumatoid arthritis (RA). Interleukin (IL)-17 is an important regulator of immune and inflammatory responses, including the induction of proinflammatory cytokines and osteoclastic bone resorption. Evidence for the expression and proinflammatory activity of IL-17 has been demonstrated in RA synovium and in animal models of RA. Although some cytokines (IL-15 and IL-23) have been reported to regulate IL-17 production, the intracellular signaling pathways that regulate IL-17 production remain unknown. In the present study, we investigated the role of the phosphoinositide 3-kinase (PI3K)/Akt pathway in the regulation of IL-17 production in RA. Peripheral blood mononuclear cells (PBMC) from patients with RA (n = 24) were separated, then stimulated with various agents including anti-CD3, anti-CD28, phytohemagglutinin (PHA) and several inflammatory cytokines and chemokines. IL-17 levels were determined by sandwich enzyme-linked immunosorbent assay and reverse transcription–polymerase chain reaction. The production of IL-17 was significantly increased in cells treated with anti-CD3 antibody with or without anti-CD28 and PHA (P < 0.05). Among tested cytokines and chemokines, IL-15, monocyte chemoattractant protein-1 and IL-6 upregulated IL-17 production (P < 0.05), whereas tumor necrosis factor-α, IL-1β, IL-18 or transforming growth factor-β did not. IL-17 was also detected in the PBMC of patients with osteoarthritis, but their expression levels were much lower than those of RA PBMC. Anti-CD3 antibody activated the PI3K/Akt pathway; activation of this pathway resulted in a pronounced augmentation of nuclear factor κB (NF-κB) DNA-binding activity. IL-17 production by activated RA PBMC is completely or partly blocked in the presence of the NF-κB inhibitor pyrrolidine dithiocarbamate and the PI3K/Akt inhibitor wortmannin and LY294002, respectively. However, inhibition of activator protein-1 and extracellular signal-regulated kinase 1/2 did not affect IL-17 production. These results suggest that signal transduction pathways dependent on PI3K/Akt and NF-κB are involved in the overproduction of the key inflammatory cytokine IL-17 in RA.
interleukin-17; nuclear factor κB; PI3K/Akt pathway; peripheral blood mononuclear cells; rheumatoid arthritis
Various genetic and environmental factors appear to be involved in systemic lupus erythematosus (SLE). Epstein–Barr virus (EBV) is among the environmental factors that are suspected of predisposing to SLE, based on the characteristics of EBV itself and on sequence homologies between autoantigens and EBV antigens. In addition, higher titers of anti-EBV antibodies and increased EBV seroconversion rates have been observed in SLE patients as compared with healthy control individuals. Serologic responses do not directly reflect EBV status within the body. Clarification of the precise status of EBV infection in SLE patients would help to improve our understanding of the role played by EBV in this disease. In the present study we determined EBV types in SLE patients (n = 66) and normal control individual (n = 63) by direct PCR analysis of mouthwash samples. We also compared EBV load in blood between SLE patients (n = 24) and healthy control individuals (n = 29) using semiquantitative PCR assay. The number of infections and EBV type distribution were similar between adult SLE patients and healthy control individuals (98.5% versus 94%). Interestingly, the EBV burden in peripheral blood mononuclear cells (PBMCs) was over 15-fold greater in SLE patients than in healthy control individuals (mean ± standard deviation: 463 ± 570 EBV genome copies/3 μg PBMC DNA versus 30 ± 29 EBV genome copies/3 μg PBMC DNA; P = 0.001), suggesting that EBV infection is abnormally regulated in SLE. The abnormally increased proportion of EBV-infected B cells in the SLE patients may contribute to enhanced autoantibody production in this disease.
Epstein–Barr virus; Epstein–Barr virus type; systemic lupus erythematosus; virus burden
To investigate the etiologies of urinary bladder involvement in patients with systemic lupus erythematosus (SLE), the clinicoradiologic features of gastrointestinal tract manifestations and clinical outcomes in patients with lupus cystitis accompanied by gastrointestinal manifestations.
We conducted a retrospective chart review on 413 patients with SLE. Patients were selected for review on the basis of tower urinary tract symptoms including urinary frequency, urgency and urinary incontinence. Radiologic studies were analyzed in patients with lupus cystitis.
Ten consecutive patients, complicated with lower urinary tract symptoms, were identified. Underlying etiologies were as follows: lupus cystitis in five, neurogenic dysfunction secondary to transverse myelitis in three, cyclophosphamide-induced cystitis in one and tuberculous cystitis in one patient. All patients with lupus cystitis showed gastrointestinal manifestations, such as abdominal pain, nausea, vomiting and/or diarrhea during the periods of cystitis symptoms. In all patients with lupus cystitis, paralytic ileus was demonstrated on plain abdominal X-ray and ascites, bilateral hydroureteronephrosis and thickened bladder wall were identified on abdominal ultrasound or CT. Abdominal CT revealed bowel wall thickening in four of the five patients. The main sites of thickened bowel on abdominal CT were territory supplied by superior mesenteric artery. Two of five patients with lupus cystitis expired during the follow-up period.
Diverse etiologies may cause lower urinary tract symptoms in patients with SLE. Lupus cystitis is strongly associated with gastrointestinal involvement and abdominal CT can be a useful radiologic tool to investigate the gastrointestinal tract involvement in patients with lupus cystitis.
systemic lupus erythematosus; urinary bladder involvement; gastrointestinal tract involvement
A 13-year-old girl presented with multiple skin abscesses. She was diagnosed as having juvenile dermatomyositis (DM) at the age of 7 years. She had suffered from recurrent skin infections, atypical pruritic dermatitis and pneumonia since the age of 8 years. Bacteriologic and fungal cultures for skin abscesses and oral mucosa were positive S. aureus and C. albicans, respectively. Chemotactic defect in peripheral blood neutrophils was observed. The level of serum IgE was markedly elevated, and anti-S.aureus specific IgE was found. A diagnosis of hyperimmunoglobulin E-recurrent infection syndrome (HIE) was made and she was successfully treated with surgical drainage and antibiotics. To our knowledge, this is the first case report of HIE in a patient with juvenile dermatomyositis.
Juvenile dermatomyositis; hyperimmunoglobulin E-recurrent infection syndrome (HIE)
Behçet’s disease is a chronic multisystemic disorder involving many organs and characterized by recurrent oral and genital ulcers and relapsing iritis. A case of BD with large vein thrombosis involving superior and inferior vena cava is presented. Large vein thrombosis in BD is not commonly developed and most commonly observed in the inferior or superior vena cava. A review of the literature emphasizes the rarity of the combined superior and inferior vena caval occlusion. Existence of extensive large vein occlusion in BD is associated with limited therapy and poor prognosis.
Behçet’s disease; venous thrombosis
To evaluate the patterns of Ro autoantigen recognition in Korean patients with primary Sjogren’s syndrome (SS) and to investigate its clinical significance in SS.
Sera from primary SS (n=51) and systemic lupus erythematosus (SLE) (n=132) were tested by double immunodiffusion test and immunoblotting for reactivity with 60kDa and 52kDa Ro/SS-A proteins. Clinical manifestations were evaluated on the basis of the presence of anti-Ro/SS-A antibodies and anti-60 kDa/52kDa proteins.
The prevalence of anti-Ro/SS-A antibodies in Korean patients with primary SS was 64.7%. In immunoblotting analysis, the incidence of anti-60kDa without anti-52kDa was lower in patients with SS(3.0% vs. 11.6%, p>0.05), whereas anti-52kDa without anti-60kDa was more common in SS patients than in SLE patients(42.5% vs. 4.3%, p<0.001). Patients with anti-Ro/SS-A antibody were significantly associated with the presence of vasculitis, hyperglobulinemia and rheumatoid factor in primary SS (p<0.05).
The patterns of 52kDa and 60kDa Ro autoantigen recognition were quite different in the SLE and primary SS. Anti-52kDa without anti-60kDa antibody may be used as a diagnostic marker for primary SS. Although the presence of anti-Ro/SS-A antibody was closely associated with certain clinical features in SS, these clinical manifestations were not correlated with the presence of antibodies against each 52kDa and 60kDa proteins. Extended studies with a large population are required to determine the clinical correlation of autoantibodies against each peptides or epitopes of Ro/SS-A proteins.
Sjogren syndrome; Systemic lupus erythematosus; anti-Ro antibody; 52kDa and 60kDa Ro proteins
To elucidate the gene frequency of TNFB Ncol polymorphism and its association with HLA class II antigen in patients with systemic lupus erythematosus (SLE) in Korea.
We investigated the gene frequency of the TNFB alleles using DNA obtained from peripheral mononuclear cells in 141 healthy controls and in 58 patients with SLE. The polymorphisms of TNFB gene (735 bp) were studied by Ncol PCR-RELP. A portion of TNFB gene(735 bp) was amplified by PCR and its products were digested with Ncol restriction enzyme. The digested samples of amplified DNA were analyzed by agarose gel electrophoresis. TNFB*1 and TNFB*2 alleles were identified according to polymorphic fragments on Ncol restriction site in the first intron of the TNFB gene. The generic types of HLA-DRBI were also determined by PCR with sequence specific primers (SSP) using genomic DNA from the same subjects.
The genotypic frequency of TNFB*2 homozygote was significantly increased in patients with SLE compared with controls (RR=2.36, P=0.011). The frequency of HLA-DRBI*15 was also significantly increased in patients (RR=2.27, P=0.029). However, the increased frequency of TNFB*2 homozygote was apparently increased in nephritis group (RR=2.79, P=0.035), whereas the significance of TNFB*2 homozygote was weakend in non-nephritis group.
Our results suggest that genetic predisposition of TNFB*2 homozygote is another risk factor in Korean SLE, especially in DR2 negative patients. In addition, TNFB*2 homozygote could have a tendency for the development of nephritis in patients with SLE.
SLE; TNFB Gene; HLA-DR; Lupus nephritis; PCR-RFLP