Integrated Analysis of Microbiome and Metabolome Reveals Disease-Specific Profiles in Inflammatory Bowel Diseases and Intestinal Behçet's Disease.

The gut microbial and metabolic characteristics of intestinal Behçet's disease (BD), a condition sharing many clinical similarities with ulcerative colitis (UC) and Crohn's disease (CD), are largely unexplored. This study investigated the gut microbial and metabolic characteristics of intestinal BD as well as potential biomarkers, comparing them with those in UC, CD, and healthy controls. Colon tissue and stool samples from 100 patients (35 UC, 30 CD, and 35 intestinal BD) and 41 healthy volunteers were analyzed using 16S ribosomal RNA sequencing to assess microbial diversity, taxonomic composition, and functional profiling. Plasma metabolomic analyses were performed using gas chromatography and ultra-performance liquid chromatography-mass spectrometry. Results indicated reduced microbial diversity in CD but not in intestinal BD, with intestinal BD showing fewer changes compared to controls yet distinct taxonomic features from UC, CD, and controls. Common alterations across all diseases included a reduction in beneficial bacteria producing short-chain fatty acids. Intestinal BD-specific changes featured a decreased abundance of Bacteroides fragilis. Metabolomic profiles in intestinal BD were similar to those in CD but distinct from those in UC, displaying significant changes in energy metabolism and genetic information processing. This integrative analysis revealed both shared and unique profiles in intestinal BD compared with UC, CD, and controls, advancing our understanding of the distinctive features of these diseases.

PLK1-activating IFI16-STING-TBK1 pathway induces apoptosis of intestinal epithelial cells in patients with intestinal Behçet's syndrome.

Inflammatory signals from immunological cells may cause damage to intestinal epithelial cells (IECs), resulting in intestinal inflammation and tissue impairment. Interferon-γ-inducible protein 16 (IFI16) was reported to be involved in the pathogenesis of Behçet's syndrome (BS). This study aimed to investigate how inflammatory cytokines released by immunological cells and IFI16 participate in the pathogenesis of intestinal BS. RNA sequencing and real-time quantitative PCR (qPCR) showed that the positive regulation of tumor necrosis factor-α (TNF-α) production in peripheral blood mononuclear cells (PBMCs) of intestinal BS patients may be related to the upregulation of polo like kinase 1 (PLK1) in PBMCs (P = 0.012). The plasma TNF-α protein level in intestinal BS was significantly higher than in healthy controls (HCs; P = 0.009). PBMCs of intestinal BS patients and HCs were co-cultured with human normal IECs (NCM460) to explore the interaction between immunological cells and IECs. Using IFI16 knockdown, PBMC-NCM460 co-culture, TNF-α neutralizing monoclonal antibody (mAb), stimulator of interferon genes (STING) agonist 2'3'-cGAMP, and the PLK1 inhibitor SBE 13 HCL, we found that PLK1 promotes the secretion of TNF-α from PBMCs of intestinal BS patients, which causes overexpression of IFI16 and induces apoptosis of IECs via the STING-TBK1 pathway. The expressions of IFI16, TNF-α, cleaved caspase 3, phosphorylated STING (pSTING) and phosphorylated tank binding kinase 1 (pTBK1) in the intestinal ulcer tissue of BS patients were significantly higher than that of HCs (all P < 0.05). PLK1 in PBMCs of intestinal BS patients increased TNF-α secretion, inducing IEC apoptosis via activation of the IFI16-STING-TBK1 pathway. PLK1 and the IFI16-STING-TBK1 pathway may be new therapeutic targets for intestinal BS.

B Cells Specific CpG Induces High IL-10 and IL-6 Expression In Vitro in Neuro-Behçet's Disease.

Remitting-RelapsingMultiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuroinflammatory disorders leading to neurological damage. Herein, we investigated in these patients the IL-10-producing cells during the early stages of these disorders. Cellular and molecular investigations were carried out on treatment naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that CSF-B cells from NBD patients, but not RRMS, are the major source of intrathecal IL-10 as compared to T-CD4 cells. Moreover, we showed a lower expression of TGF-ß and IL35, in the CSF cells of NBD patients as compared to the control group. Specific in vitro CpG stimulation of peripheral blood B cells from NBD patients resulted in a concomitant early mRNA expression of IL6 and IL10 but was limited to IL10 for RRMS patients. Furthermore, mRNA expression of IL-6 and IL-10 receptors was assessed and intriguingly IL6ST receptor subunit was significantly lower in NBD CSF, but not RRMS while IL10RB was increased in both. Deciphering the role of increased IL-10-producing B cells and IL10RB despite relapsing disease as well as the discordant expression of IL6 and IL6ST may pave the way for a better understanding of the pathophysiology of these neuro-inflammatory disorders.

Expression of miRNAs derived from plasma exosomes in patients with intestinal Behçet's syndrome.

OBJECTIVES: MicroRNAs (miRNAs) derived from plasma exosomes are potential diagnostic biomarkers. However, little is known about the expression of miRNAs derived from plasma exosomes in patients with intestinal Behçet's syndrome (BS). This study aimed to explore the difference of miRNAs derived from plasma exosomes between intestinal BS patients and healthy people, and further identify potential biomarkers that predict the disease activity of intestinal BS. METHODS: A total of 43 intestinal BS patients and 23 healthy volunteers were enrolled, among whom 23 were active intestinal BS and 20 were stable intestinal BS. The miRNAs expression profiles of plasma exosomes in 3 active intestinal BS patients and 3 healthy volunteers were determined using next-generation high throughput sequencing. Additionally, significantly differentially expressed miRNAs were further analysed by quantitative real-time polymerase chain reaction (qRT-PCR) in a validation cohort of 60 subjects. RESULTS: From the sequencing analysis, 15 miRNAs were identified to be differently expressed (p<0.05). Of these, 13 miRNAs were up-regulated, and 2 were down-regulated in intestinal BS patients compared with healthy volunteers. Furthermore, qRT-PCR analysis confirmed that miR-141-3p was down-regulated and miR-122-5p, miR-150-3p, miR-183-5p, miR-224-5p and miR-342-5p were up-regulated in intestinal BS patients' plasma exosomes. Additionally, the level of miR-141-3p was negatively correlated with disease activity indicators of intestinal BS, while miR-122-5p, miR-150-3p, miR-183-5p, miR-224-5p and miR-342-5p was positively correlated with disease activity indicators of intestinal BS. CONCLUSIONS: Circulating miR-141-3p, miR-122-5p, miR-150-3p, miR-183-5p, miR-224-5p and miR-342-5p derived from plasma exosomes may serve as biomarkers of disease activity in intestinal BS.

Molecular dynamics simulations provide molecular insights into the role of HLA-B51 in Behçet's disease pathogenesis.

Behçet's disease is an inflammatory disorder of unknown etiology. Genetic tendency has an important role in its pathogenesis, and HLA-B51, a class I MHC antigen, has been recognized as the strongest susceptibility factor for Behçet's disease. Despite the confirmation of the association of HLA-B51 with Behçet's disease in different populations, its pathogenic mechanisms remain elusive. HLA-B51 differs in only two amino acids from HLA-B52, other split antigen of HLA-B5, which is not associated with Behçet's disease. These two amino acids are located in the B pocket of the antigen-binding groove, which occupies the second amino acids of the bound peptides. To understand the nature of the HLA-peptide interactions, differences in structure and dynamics of two HLA alleles were investigated by molecular dynamics simulations using YAYDGKDYI, LPRSTVINI, and IPYQDLPHL peptides. For HLA-B51, all bound peptides fluctuated to larger extent than HLA-B52. Free energy profiles of unbinding process for YAYDGKDYI by steered molecular dynamics simulations showed that unbinding from HLA-B52 results in greater free energy differences than HLA-B51. These results suggest the possibility of an instability of HLA-B51 associated with the repertoire of peptides, and this finding may provide significant insight to its pathogenic role in Behçet's disease.

BehÒ«et's Disease, and the Role of TNF-α and TNF-α Blockers.

In this both narrative and systematic review, we explore the role of TNF-α in the immunopathogenesis of Behçet's disease (BD) and the effect of treatment with TNF-α blockers. BD is an auto-inflammatory disease, characterized by recurrent painful oral ulcerations. The pathogenesis of BD is not yet elucidated; it is assumed that TNF-α may play a key role. In the narrative review, we report an increased production of TNF-α, which may be stimulated via TLR-signaling, or triggered by increased levels of IL-1ß and IFN-γ. The abundance of TNF-α is found in both serum and in sites of inflammation. This increased presence of TNF-α stimulates T-cell development toward pro-inflammatory subsets, such as Th17 and Th22 cells. Treatment directed against the surplus of TNF-α is investigated in the systematic review, performed according to the PRISMA guideline. We searched the Pubmed and Cochrane database, including comparative studies only. After including 11 studies, we report a beneficial effect of treatment with TNF-α blockers on the various manifestations of BD. In conclusion, the pivotal role of TNF-α in the immunopathogenesis of BD is reflected in both the evidence of their pro-inflammatory effects in BD and in the evidence of the positive effect of treatment on the course of disease in BD.

Identification of an Unconventional Subpeptidome Bound to the Behçet's Disease-associated HLA-B*51:01 that is Regulated by Endoplasmic Reticulum Aminopeptidase 1 (ERAP1).

Human leukocyte antigen (HLA) B*51:01 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly genetically associated with Behçet's disease (BD). Previous studies have defined two subgroups of HLA-B*51 peptidome containing proline (Pro) or alanine (Ala) at position 2 (P2). Little is known about the unconventional non-Pro/Ala2 HLA-B*51-bound peptides. We aimed to study the features of this novel subpeptidome, and investigate its regulation by ERAP1. CRISPR-Cas9 was used to generate an HLA-ABC-triple knockout HeLa cell line (HeLa.ABC-KO), which was subsequently transduced to express HLA-B*51:01 (HeLa.ABC-KO.B51). ERAP1 was silenced using lentiviral shRNA. Peptides bound to HLA-B*51:01 were eluted and analyzed by mass spectrometry. The characteristics of non-Pro/Ala2, Pro2, and Ala2 peptides and their alteration by ERAP1 silencing were investigated. Effects of ERAP1 silencing on cell surface expression of HLA-B*51:01 were studied using flow cytometry. More than 20% of peptides eluted from HLA-B*51:01 lacked Pro or Ala at P2. This unconventional group of HLA-B*51:01-bound peptides was relatively enriched for 8-mers (with relatively fewer 9-mers) compared with the Pro2 and Ala2 subpeptidomes and had similar N-terminal and C-terminal residue usages to Ala2 peptides (with the exception of the less abundant leucine at position Ω). Knockdown of ERAP1 increased the percentage of non-Pro/Ala2 from 20% to ∼40%, increased the percentage of longer (10-mer and 11-mer) peptides eluted from HLA-B*51:01 complexes, and abrogated the predominance of leucine at P1. Interestingly knockdown of ERAP1 altered the length and N-terminal residue usage of non-Ala2&Pro2 and Ala2 but not the Pro2 peptides. Finally, ERAP1 silencing regulated the expression levels of cell surface HLA-B*51 in a cell-type-dependent manner. In conclusion, we have used a novel methodology to identify an unconventional but surprisingly abundant non-Pro/Ala2 HLA-B*51:01 subpeptidome. It is increased by knockdown of ERAP1, a gene affecting the risk of developing BD. This has implications for theories of disease pathogenesis.

The expression and methylation status of vitamin D receptor gene in Behcet's disease.

INTRODUCTION: Vitamin D has important roles as a natural immune modulator via regulating the expression of genes which have been implicated in the pathophysiology of autoimmune diseases. Vitamin D function and its deficiency have been linked to a wide range of metabolic disorders including disorders of calcium metabolism, malignant, cardiovascular, infectious, neuromuscular, and inflammatory diseases. Environmental factors, genetic factors, and epigenetic changes contribute to Behcet's disease (BD) development. The aim of our study was to analyze the expression level and methylation status of the vitamin D receptor (VDR) gene promoter in the peripheral blood mononuclear cells (PBMCs) of patients with BD. METHODS: In a case-control study, 48 Iranian Azeri patients with BD and 60 age-, sex- and ethnically-matched healthy controls were included. Venous blood samples were collected and PBMCs were isolated by Ficoll protocol. The DNA and RNA were subsequently extracted. Promoter methylation levels were evaluated by MeDIP-quantitative polymerase chain reaction (qPCR). The expression of VDR was evaluated by real-time PCR. RESULTS: The results of quantitative real-time PCR analysis showed that the level of VDR expression in patients with BD was significantly lower than the control group (P = .013). There was no significant difference in the level of DNA methylation in the BD and control groups (P > .05). As the results show, the expression level of VDR gene was significantly different between female and male in the patient group (P = .001). VDR gene expression was significantly higher in subjects with phlebitis. No correlation was observed between VDR gene expression rate and BD activity. CONCLUSION: VDR gene expression decreased in patients with BD. However, there is no suggestion evidence that the expression level of VDR is regulated by a unique DNA methylation mechanism. No correlation exists between VDR gene expression and BD activity.

Lymphocyte proliferation induced by high-affinity peptides for HLA-B*51:01 in Behçet's uveitis.

Several proteins have been proposed as candidate auto-antigens in the pathogenesis of Behçet's disease (BD). In this study, we aimed to confirm the cellular responses to candidate peptide autoantigens with high affinity for the HLA-B*51:01 molecule using computerized binding predictions and molecular dynamics simulations. We identified two new candidate peptides (HSP65PD, derived from heat shock protein-65, and B51PD, derived from HLA-B*51:01) with high-affinity to the HLA-B*51:01 binding pocket using the Immune Epitope Database for Major Histocompatibility Complex-I Binding Prediction and molecular dynamics simulations. The peptide-induced proliferation of lymphocytes from patients with BD, sarcoidosis, Vogt-Koyanagi-Harada disease (VKH) with panuveitis, systemic scleroderma (SSc) without uveitis, and healthy controls (HC) was investigated using the bromodeoxyuridine assay. The proliferative response of leukocytes to HSP65PD was significantly higher in BD (SI 1.92 ± 0.65) than that in sarcoidosis (SI 1.38 ± 0.46), VKH (SI 1.40 ± 0.33), SSc (SI 1.32 ± 0.31), and HC (SI 1.27 ± 0.28) (P = 0.0004, P = 0.0007, P < 0.0001, P < 0.0001, respectively, Mann-Whitney's U-test). The proliferative response of leukocytes to B51PD was also higher in BD than that in sarcoidosis, VKH, SSc without uveitis, and HC, whereas no significant differences were observed among the five groups in response to a control peptide derived from topoisomerase 1. A significantly higher response to HPS65PD and B51PD was observed in the HLA-B*51:01-positive patients with BD than in the HLA-B*51:01-negative patients. In conclusion, two peptides that had high affinity to HLA-B*51:01 in computerized binding prediction showed significantly higher response in HLA-B*51:01-positive patients with BD, indicating the usefulness of computerized simulations for identifying autoreactive peptides to HLAs.

Haploinsufficiency of A20 caused by a novel nonsense variant or entire deletion of TNFAIP3 is clinically distinct from Behçet's disease.

BACKGROUND: Haploinsufficiency of A20 (HA20) is caused by loss-of-function TNFAIP3 variants. Phenotypic and genetic features of HA20 remain uncertain; therefore, the clinical distinction between HA20 and Behçet's disease (BD) requires clarification. METHODS: We have collected 12 Japanese BD-like families. Probands of these families were analyzed by whole exome sequencing (WES) and subsequent Sanger sequencing. Clinical features were compared between 54 HA20 patients (including previously reported and new cases) and 520 Japanese BD patients. RESULTS: We identified c.1434C>A:p.(Cys478*) in one family and a 236 kb deletion at 6q23.3 containing TNFAIP3 in another family. Four HA20 patients in the two families presented with childhood-onset recurrent oral and genital ulcers and were initially diagnosed and treated as BD. Consistent with the clinical features of HA20, recurrent, refractory fever attacks (three of four patients), and digestive ulcers (two of the four patients) were observed. A comparison of clinical features between HA20 patients and cohorts of BD patients revealed several critical features specific to HA20. These were early-onset, familial occurrence, recurrent fever attacks, gastrointestinal involvement, and infrequent ocular involvement. CONCLUSIONS: We identified a novel nonsense variant and deletion of the entire TNFAIP3 gene in two unrelated Japanese HA20 families. Genetic screening of TNFAIP3 should be considered for familial BD-like patients with early-onset recurrent fevers.

Redundancy and Complementarity between ERAP1 and ERAP2 Revealed by their Effects on the Behcet's Disease-associated HLA-B*51 Peptidome.

The endoplasmic reticulum aminopeptidases ERAP1 and ERAP2 trim peptides to be loaded onto HLA molecules, including the main risk factor for Behçet's disease HLA-B*51. ERAP1 is also a risk factor among HLA-B*51-positive individuals, whereas no association is known with ERAP2. This study addressed the mutual relationships between both enzymes in the processing of an HLA-bound peptidome, interrogating their differential association with Behçet's disease. CRISPR/Cas9 was used to generate knock outs of ERAP1, ERAP2 or both from transfectant 721.221-HLA-B*51:01 cells. The surface expression of HLA-B*51 was reduced in all cases. The effects of depleting each or both enzymes on the B*51:01 peptidome were analyzed by quantitative label-free mass spectrometry. Substantial quantitative alterations of peptide length, subpeptidome balance, N-terminal residue usage, affinity and presentation of noncanonical ligands were observed. These effects were often different in the presence or absence of the other enzyme, revealing their mutual dependence. In the absence of ERAP1, ERAP2 showed similar and significant processing of B*51:01 ligands, indicating functional redundancy. The high overlap between the peptidomes of wildtype and double KO cells indicates that a large majority of B*51:01 ligands are present in the ER even in the absence of ERAP1/ERAP2. These results indicate that both enzymes have distinct, but complementary and partially redundant effects on the B*51:01 peptidome, leading to its optimization and maximal surface expression. The distinct effects of both enzymes on the HLA-B*51 peptidome provide a basis for their differential association with Behçet's disease and suggest a pathogenetic role of the B*51:01 peptidome.

Aqueous humor IL-8, IL-10, and VEGF levels in Fuchs' uveitis syndrome and Behçet's uveitis.

PURPOSE: This study investigated the levels of interleukin (IL)-8, IL-10, and vascular endothelial growth factor (VEGF) in the aqueous humor (AqH) of patients with Behçet's uveitis (BU) and Fuchs' uveitis syndrome (FUS) during an inactive period and compared these levels with those in the AqH of noninflammatory healthy control subjects. METHODS: This prospective and case-control study included 33 patients (16 patients with BU and 17 patients with FUS) and 35 control subjects. IL-8, IL-10, and VEGF levels in the AqH were quantified by performing sandwich enzyme-linked immunosorbent assay. Kruskal-Wallis test was used to compare the cytokine levels in the different groups, and statistical significance was set at p < 0.05. RESULTS: IL-8 levels were significantly higher in the AqH of patients with BU and FUS than in the AqH of control subjects (p < 0.001 and p < 0.001, respectively). IL-10 levels were significantly lower in the AqH of patients with BU than in the AqH of patients with FUS and of control subjects (p = 0.001 and p < 0.001, respectively). Although VEGF levels were higher in the AqH of patients with FUS than in the AqH of patients with BU and of control subjects, the difference was significant only between patients with FUS and control subjects (p < 0.001). CONCLUSIONS: We observed a significant decrease in IL-10 levels in the AqH of patients with BU and a significant increase in VEGF levels in the AqH of patients with FUS compared to controls. IL-8 and VEGF levels showed no significant difference among uveitis patients.

The molecular and clinical evidence of vitamin D signaling as a modulator of the immune system: Role in Behçet's disease.

Various tissues and cell types are the targets of vitamin D. However, the major targets of vitamin D in the immune system are monocytes/macrophages, dendritic cells (DCs), as well as B and T cells. Vitamin D plays an important role in the immune system modulation via regulating the expression of genes that generate pro-inflammatory mediators and inhibiting the proliferation of pro-inflammatory cells, both of which have been implicated in the pathophysiology of the inflammatory diseases. Recent studies have revealed the important relations between vitamin D and Behçet's disease (BD). Vitamin D function and its deficiency have been linked to a wide range of metabolic disorders including malignant, cardiovascular, infectious, neuromuscular, and autoimmune diseases. Here, we provide a brief analysis of the recent literature regarding immune-regulatory effects as well as clinical evidence of vitamin D influence on the molecular level in BD.

Role of Serum miR-181b, Proinflammatory Cytokine, and Adhesion Molecules in Behçet's Disease.

Behçet's disease (BD) is a chronic multi-systemic inflammatory disease of uncertain pathogenesis and with no definitive diagnostic test. The aims of this study were to investigate serum levels of miR-181b in BD patients and to correlate this candidate biomarker with disease activity, cytokines, and adhesion molecules to identify new markers that can be used as a diagnostic tool for BD. Blood samples were collected from 96 participants who were classified according to their BD current activity form into 3 groups: healthy control, active BD, and inactive BD patients. MiR-181b was estimated by real-time polymerase chain reaction. However, high sensitive C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), E-selectin, and vascular cell adhesion molecule 1 (VCAM-1) levels were determined by enzyme-linked immunosorbent assay. Serum levels of miR-181b, hs-CRP, TNF-α, IL-6, E-selectin, and VCAM-1 were significantly higher in patients than in controls, but no significant difference was observed between the active and inactive BD groups. IL-6 was positively correlated with adhesion molecules, E-selectin, and VCAM-1. MiR-181b was positively correlated with hs-CRP, TNF-α, IL-6, and VCAM-1 in all subjects. In conclusion, miR-181b could play an important role in BD pathophysiology. MiR-181b could be utilized as potential biomarker for diagnosis and therapeutic targeting of BD. However, further studies with larger patient number are required to support these findings.

[Efficacy and safety of metformin for Behcet's disease and its effect on Treg/Th17 balance: a single-blinded, before-after study].

OBJECTIVE: Behcet's disease (BD) is an autoimmune disorder that causes most commonly mouth and genital ulcerations and erythema nodules of the skin and currently has limited options of therapeutic medicines. Metformin is recently reported to suppress immune reaction, and we hypothesized that metformin could be an option for treatment of BD. METHODS: Thirty patients with BD were enrolled in this perspective single-blinded, before-after study. We recorded the changes in the mucocutaneous activity index for BD (MAIBD), relapse frequency, C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) after metformin treatment to assess the changes in the disease activity. We also analyzed the changes in the protein and mRNA expression levels of Foxp3, interleukin-35 (IL-35), transforming growth factor-ß (TGF-ß), Ror-γt, IL-17, and tumor necrosis factor-α (TNF-α) in these patients using ELISA and qRT-PCR. RESULTS: Of the 30 patients enrolled, 26 completed the trial. After the treatment, favorable responses were achieved in 88.46% (23/26) of the patients, and partial remission was obtained in 11.54% (4/26) of them. During the treatment, 8 patients complained of gastrointestinal side effects, for which 4 chose to withdraw from the study in the first week. Our results showed that metformin treatment decreased MAIBD and relapse frequency in the patients, and significantly lowered the clinical inflammatory indexes including CRP and ESR. The results of ELISA and qRT-PCR revealed that metformin treatment obviously increased Foxp3 and TGF-ß expressions at both the protein and mRNA levels and significantly decreased the levels of ROR-γt, IL-17 and TNF-α as well as IL-35 level in these patients. CONCLUSIONS: Metformin treatment relieves the clinical symptoms, reduces the inflammatory reaction indexes and regulates the Treg/Th17 axis in patients with BD, suggesting the potential of metformin as a candidate medicine for treatment of BD.

Faecal but not serum calprotectin levels look promising in predicting active disease in Behçet's syndrome patients with gastrointestinal involvement.

OBJECTIVES: The faecal calprotectin (FC) test is widely used as a non-invasive method for identifying intestinal inflammation. A recent study suggested FC may help to diagnose gastrointestinal involvement of Behçet's syndrome (GIBS). We aimed to determine whether FC helps to distinguish active from inactive intestinal involvement in GIBS. METHODS: We tried to contact 70 GIBS patients registered in our tertiary multidisciplinary clinic. We prospectively collected faecal specimens and serum from 39 GIBS patients who gave informed consent assessing calprotectin and CRP levels followed by a colonoscopy. We included 47 Crohn's disease (CD) patients as controls. Active disease was defined as having ulcer/s on colonoscopy. We filled the Disease Activity Index for Intestinal Behçet's Disease (DAIBD) and Crohn's Disease Activity Index (CDAI). The cut-off for positive FC was defined as ≥150 µg/g. RESULTS: Ulcers were detected in 12/39 GIBS patients. Sensitivity and specificity of the FC test for active disease was 91.7 (95%CI:61.5-99.8) and 74.1% (95%CI:53.7-88.9). Median FC and CRP levels and DAIBD scores were higher among patients with ulcers, whereas serum calprotectin and CDAI scores were not. A negative FC test was the only significant predictor of remission (OR:37.04, 95%CI:2.4-561.6; p=0.009) on multivariate analysis. Among CD patients, 16/25 active patients and 3/22 patients in endoscopic remission had a positive FC test (OR:11, 95%CI:11-49). CONCLUSIONS: FC, but not serum calprotectin seems to be a useful non-invasive tool for assessing disease activity in GIBS. Whether the presence of oral ulcers can cause false positive results remains to be studied.

Determination of mir-155 and mir-146a expression rates and its association with expression level of TNF-α and CTLA4 genes in patients with Behcet's disease.

INTRODUCTION: MicroRNAs (miRNAs) are involved in the pathogenesis of inflammatory diseases. MiR-146 and miR-155 emerged as key regulators of the immune response. This study designed to analyze the miR-146a and miR-155 expression in patients with Behcet's disease (BD) and investigated their association with the expression of tumor necrosis factor-alpha (TNF-α) and cytotoxic T lymphocyte associated antigen-4 (CTLA-4) genes. METHODOLOGY: In a case-control study, 47 Iranian Azeri BD patients and 61 age- and sex matched healthy controls recruited to the study. Peripheral blood mononuclear cells (PBMCs) were isolated from EDTA blood tubes by Ficoll density-gradient centrifugation. Genomic DNA samples of BD and healthy controls were extracted using the rapid genomic DNA extraction method from the peripheral blood collected in tubes containing EDTA. Total RNA was extracted from the PBMCs according to the TRIzol protocol. MiR-146a, miR-155, TNF-α and CTLA-4 expression were studied using real-time PCR. RESULTS: MiR-155 and TNF-α expression was significantly increased, whilst CTLA-4 expression was significantly decreased in the PBMCs of BD patients. There was no significant difference in the miR-146a expression rate between BD patients and controls. A positive correlation between miR-155 and TNF-α expression and negative correlation between miR-155 and CTLA-4 expression were observed. No significant association was observed between the expression of miR-155, miR-146a, TNF-α and CTLA-4 genes with BD activity. MiR-155 and miR-146a expression rate were significantly higher in patients with uveitis and phlebitis, respectively. DISCUSSION AND CONCLUSION: The expression of miR-155 increased in BD and associated with upregulation of TNF-α and downregulation of CTLA-4 genes.

New Insights into Behçet's Syndrome Metabolic Reprogramming: Citrate Pathway Dysregulation.

To date, a major research effort on Behçet's syndrome (BS) has been concentrated on immunological aspects. Little is known about the metabolic reprogramming in BS. Citrate is an intermediary metabolite synthesized in mitochondria, and when transported into the cytosol by the mitochondrial citrate carrier-SLC25A1-encoded protein-it is cleaved into acetyl-CoA and oxaloacetate by ATP citrate lyase (ACLY). In induced macrophages, mitochondrial citrate is necessary for the production of inflammatory mediators. The aim of our study was to evaluate SLC25A1 and ACLY expression levels in BS patients. Following a power analysis undertaken on few random samples, the number of enrolled patients was set. Thirty-nine consecutive BS patients fulfilling ISG criteria, and 21 healthy controls suitable for age and sex were recruited. BS patients were divided into two groups according to the presence (active) or absence (inactive) of clinical manifestations. Real-time PCR experiments were performed on PBMCs to quantify SLC25A1 and ACLY mRNA levels. Data processing through the Kruskal-Wallis test and Dunn's multiple comparison test as post hoc showed higher SLC25A1 and ACLY mRNA levels in BS patients compared to those in healthy controls. Therefore, SLC25A1 and ACLY upregulation suggests that metabolic reprogramming in BS involves the citrate pathway dysregulation.

GWAS-identified CCR1 and IL10 loci contribute to M1 macrophage-predominant inflammation in Behçet's disease.

BACKGROUND: Low C-C chemokine receptor 1 (CCR1) and interleukin (IL)-10 expression is associated with risk of Behçet's disease (BD). The objective of the present study was to clarify the pathological roles of CCR1 and IL10 loci identified by previous BD genome-wide association studies (GWASs). METHODS: M1 and M2 macrophages (Mφ) were differentiated with granulocyte-macrophage colony-stimulating factor or macrophage colony-stimulating factor (M-CSF) from peripheral monocytes of healthy control subjects (HC) and patients with BD. Expression of CD68 and CD163 was evaluated to test for Mφ polarization. CCR1 and IL-10 messenger RNA (mRNA) and protein expression was compared according to CCR1 and IL10 single-nucleotide polymorphism (SNP) genotypes. The migratory ability of M1 and M2 Mφ toward CCR1 ligand macrophage inflammatory protein (MIP)-1α was compared. The ratio of M1 and M2 Mφ in skin lesions of BD and systemic sclerosis (SSc), which was reported to be M2 Mφ-dominant, was compared. To examine the plasticity of polarized Mφ, the differentiated cells were cultured with either the same or the other culture condition. RESULTS: Preferential expression of CD163, CCR1, and IL-10 was found in M2 Mφ compared with M1 Mφ. M2 Mφ migrated more sensitively to low concentrations of MIP-1α than M1 Mφ did. BD-derived M1 Mφ showed higher CCR1 surface expression than HC-derived M1 Mφ did. IL10 and CCR1 mRNA expression differences were observed by GWAS-identified SNP genotypes in polarized Mφ. BD skin lesions showed M1 Mφ predominance compared with SSc skin lesions. A plasticity assay revealed that M-CSF restored IL-10 synthesis and reduced IL-6 production by M1 Mφ. CONCLUSIONS: The present study reveals that GWAS-identified SNPs contribute to M1 Mφ-predominant inflammation in BD. Our data also suggest that the skewed Mφ polarization is correctable by immunological intervention.

Curcumin reduces the expression of interleukin 1ß and the production of interleukin 6 and tumor necrosis factor alpha by M1 macrophages from patients with Behcet's disease.

OBJECTIVE: Behcet's disease (BD) is an auto-inflammatory disorder. Curcumin as a bio-active agent has anti-inflammatory properties. Effects of curcumin on the pathogenesis of BD are still not clear. In this study, we investigated the effect of curcumin on the inflammatory cytokines expression and production in M1 macrophages from BD patients compared with healthy controls. METHODS: Monocytes were collected from 10 healthy controls and 20 active BD patients, differentiated to macrophages by macrophage-colony stimulating factor for 7 d. Macrophages were then treated with interferon gamma, lipopolysaccharide, and curcumin (10 or 30 µg/ml) for 24 h. Analysis of tumor necrosis factor-alpha (TNFα), interleukin 1ß (IL-1ß), and IL-6 mRNA expression and protein production was performed using SYBR Green qPCR and ELISA method. RESULTS: Treatment with 30 µg/ml curcumin significantly down-regulated mRNA expression of IL-1ß (p < .05) and protein production of IL-6 (p < .05) in M1 macrophages from BD patients but not in M1 macrophage from controls. Treatment with 30 µg/ml curcumin also significantly diminishes the protein production of TNFα in BD patients (p < .01) and healthy controls (p < .05) M1 macrophages. CONCLUSIONS: We demonstrated that curcumin can inhibit the expression and production of inflammatory cytokines in M1 macrophages from BD patients. Our results suggest that curcumin can modulate inflammatory signaling more specifically in macrophages from BD patients than healthy macrophages.