Seung-Ye Baek

Ursolic acid ameliorates autoimmune arthritis via suppression of Th17 and B cell differentiation

Aim:Ursolic acid (UA) is a pentacyclic triterpenoid found in most plant species, which has been shown anti-inflammatory and anti-oxidative activities. In this study, we examined the effects of UA on collagen-induced arthritis (CIA) in mice, and to identify the mechanisms underlying the effects.Methods:CIA was induced in mice. Two weeks later, the mice were treated with UA (150 mg/kg, ip, 3 times per week) for 4 weeks. The expression of cytokines and oxidative stress markers in joint tissues was measured with immunohistochemistry. The numbers of CD4+IL-17+, CD4+CD25+Foxp3+ and pSTAT3 cells in spleens were determined using confocal immunostaining or flowcytometric analyses. Serum antibody levels and B cell-associated marker mRNAs were analyzed with ELISAs and qRT-PCR, respectively. CD4+ T cells and CD19+ B cells were purified from mice spleens for in vitro studies.Results:UA treatment significantly reduced the incidence and severity of CIA-induced arthritis, accompanied by decreased expression of proinflammatory cytokines (TNF-α, IL-1β, IL-6, IL-21 and IL-17) and oxidative stress markers (nitrotyrosine and iNOS) in arthritic joints. In CIA mice, UA treatment significantly decreased the number of Th17 cells, while increased the number of Treg cells in the spleens, which was consistent with decreased expression of pSTAT3, along with IL-17 and RORγt in the splenocytes. In addition, UA treatment significantly reduced the serum CII-specific IgG levels in CIA mice. The inhibitory effects of UA on Th17 cells were confirmed in an in vitro model of Th17 differentiation. Furthermore, UA dose-dependently suppressed the expression of B cell-associated markers Bcl-6, Blimp1 and AID mRNAs in purified CD19+ B cells pretreated with IL-21 or LPS in vitro.Conclusion:UA treatment significantly ameliorates CIA in mice via suppression of Th17 and differentiation. By targeting pathogenic Th17 cells and autoantibody production, UA may be useful for the treatment of autoimmune arthritis and other Th17-related diseases.

Anthocyanin Extracted from Black Soybean Seed Coats Prevents Autoimmune Arthritis by Suppressing the Development of Th17 Cells and Synthesis of Proinflammatory Cytokines by Such Cells, via Inhibition of NF-κB

Introduction Oxidative stress plays a role in the pathogenesis of rheumatoid arthritis (RA). Anthocyanin is a plant antioxidant. We investigated the therapeutic effects of anthocyanin extracted from black soybean seed coats (AEBS) in a murine model of collagen-induced arthritis (CIA) and human peripheral blood mononuclear cells (PBMCs) and explored possible mechanisms by which AEBS might exert anti-arthritic effects. Material and Methods CIA was induced in DBA/1J mice. Cytokine levels were measured via enzyme-linked immunosorbent assays. Joints were assessed in terms of arthritis incidence, clinical arthritis scores, and histological features. The extent of oxidative stress in affected joints was determined by measuring the levels of nitrotyrosine and inducible nitric oxide synthase. NF-κB activity was assayed by measuring the ratio of phosphorylated IκB to total IκB via Western blotting. Th17 cells were stained with antibodies against CD4, IL-17, and STAT3. Osteoclast formation was assessed via TRAP staining and measurement of osteoclast-specific mRNA levels. Results In the CIA model, AEBS decreased the incidence of arthritis, histological inflammation, cartilage scores, and oxidative stress. AEBS reduced the levels of proinflammatory cytokines in affected joints of CIA mice and suppressed NF-κB signaling. AEBS decreased Th17 cell numbers in spleen of CIA mice. Additionally, AEBS repressed differentiation of Th17 cells and expression of Th17-associated genes in vitro, in both splenocytes of naïve DBA/1J mice and human PBMCs. In vitro, the numbers of both human and mouse tartrate-resistant acid phosphatase+ (TRAP) multinucleated cells fell, in a dose-dependent manner, upon addition of AEBS. Conclusions The anti-arthritic effects of AEBS were associated with decreases in Th17 cell numbers, and the levels of proinflammatory cytokines synthesized by such cells, mediated via suppression of NF-κB signaling. Additionally, AEBS suppressed osteoclastogenesis and reduced oxidative stress levels.

Digoxin ameliorates autoimmune arthritis via suppression of Th17 differentiation

Digoxin is a cardiac glycoside that is commonly used to treat heart failure. Based on its known anti-inflammatory effect, this study was undertaken to investigate the effect of digoxin on collagen-induced arthritis (CIA) and to delineate the underlying mechanism. Digoxin or vehicle was injected intraperitoneally thrice weekly in mice with CIA, from day 7 or day 35 after immunization to investigate preventive or therapeutic effect, respectively. The incidence and severity of arthritis was evaluated. Digoxin treatment suppressed the incidence of arthritis and joint inflammation in mice with CIA. The expression of IL-17 and other proinflammatory cytokines, including IL-1β, IL-6, TNF-α and IL-21, were markedly reduced in the arthritic joints of digoxin-treated CIA mice. Th17 cells and CD4(+) pSTAT3(+) cells were less frequently observed in the spleen of digoxin-treated CIA mice than controls. The mRNA expression of IL-17 and ROR γt was consistently lower in total splenocytes or draining lymph node cells obtained from digoxin-treated CIA mice. Digoxin also reduced in vitro Th17 differentiation and LPS-stimulated IgG production. The number of osteoclasts in the arthritic joint was lower in digoxin-treated mice, whereas digoxin treatment did not directly suppress in vitro osteoclastogenesis. Our findings suggest that digoxin can regulate Th17 and reciprocally promote Treg cells and suppress joint inflammation and bone erosion in CIA. Digoxin may be a therapeutic option by targeting pathogenic Th17 and immunoglobulin production, for treatment of autoimmune arthritis and other Th17-related diseases.

Halofuginone Ameliorates Autoimmune Arthritis in Mice by Regulating the Balance Between Th17 and Treg Cells and Inhibiting Osteoclastogenesis

The small molecule halofuginone has been shown to inhibit fibrosis, angiogenesis, and tumor progression. This study was undertaken to evaluate the effects of halofuginone in preventing autoimmune arthritis in mice.

Serum Level of Interleukin-33 and Soluble ST2 and Their Association with Disease Activity in Patients with Behcet's Disease

Interleukin (IL)-33 is an important mediator of innate immunity. Behcets disease (BD) is an autoinflammatory disorder characterized by hyperactivity of the innate immune response. We measured serum levels of IL-33 and its receptor soluble ST2 (sST2) in patients with BD to investigate their association with disease activity. Serum levels of both IL-33 and sST2 were higher in patients with BD compared with those in normal controls (IL-33: 594.48±175.04 pg/mL in BD and 224.23±56.64 pg/mL in normal controls [P=0.048], sST2: 99.01±15.92 pg/mL in BD and 23.56±3.25 pg/mL in normal controls [P<0.001]). IL-33 and sST2 expression in skin tissue, as shown by immunohistochemistry, was higher in patients with BD compared with that in the normal controls. Serum sST2 level correlated significantly with the BD currently active form (BDCAF), Iranian BD dynamic activity measure (IBDDAM), erythrocyte sedimentation rate and C-reactive protein. Multiple linear regression showed that serum sST2 was an independent factor associated with IBBDAM (regression coefficient, 0.374; P=0.004), and BDCAF (regression coefficient, 0.236; P=0.047). These results demonstrate that IL-33 and sST2 are highly expressed in patients with BD and that serum sST2 is an independent factor associated with IBDDAM and BDCAF, suggesting a potential role for sST2 as a surrogate marker of disease activity in patients with BD.

Halofuginone ameliorates autoimmune arthritis by regulating the balance between Th17 and regulatory T cells and inhibiting osteoclastogenesis.

The small molecule halofuginone has been shown to inhibit fibrosis, angiogenesis, and tumor progression. This study was undertaken to evaluate the effects of halofuginone in preventing autoimmune arthritis in mice.

Monosodium urate crystal-induced triggering receptor expressed on myeloid cells 1 is associated with acute gouty inflammation

OBJECTIVE Triggering receptor expressed on myeloid cells 1 (TREM-1), which amplifies the inflammation elicited by the Toll-like receptor pathway, was originally implicated in sepsis and bacterial infection. However, it has been suggested that TREM-1 may also play an important role in non-infectious inflammation. The present study was conducted to investigate whether TREM-1 is involved in human acute gouty inflammation. METHODS A total of 37 gout patients were recruited between March 2011 and January 2014 from Seoul St Marys Hospital. The expression of TREM-1 on mononuclear cells was assessed using FACS analysis, immunostaining and real-time RT-PCR. To block the TREM-1 signal, soluble TREM-1 (sTREM-1) or the synthetic blocking peptide LP17 was used. The concentration of sTREM-1 was assessed by ELISA. RESULTS FACS analysis and real-time RT-PCR demonstrated that TREM-1 expression was higher in the SF mononuclear cells of acute gouty arthritis patients than in peripheral blood mononuclear cells (PBMCs). Immunohistochemical staining of tophi tissues revealed TREM-1 expression, with confocal microscopy demonstrating TREM-1 expression on tophi tissue macrophages. We also demonstrated that MSU treatment induced TREM-1 expression on the PBMCs of acute gout patients in vitro. Although blockade of TREM-1 did not directly suppress MSU-induced IL-1β production of PBMCs in vitro, the concentration of soluble TREM-1 was higher in the SF of gout vs OA patients and was positively correlated with serum CRP. CONCLUSION TREM-1 is induced by MSU and is associated with the inflammation of human acute gouty arthritis.

JAK-1 Inhibition Suppresses Interferon-Induced BAFF Production in Human Salivary Gland: Potential Therapeutic Strategy for Primary Sjögren's Syndrome

To examine whether a JAK inhibitor regulates functional responses of human salivary gland epithelial cells (SGECs) and disease parameters in an animal model of Sjögrens syndrome (SS).

THU0264 A Selective JAK1 Inhibitor, Filgotinib Suppresses Lymphocytic Infiltration in Salivary Gland of Non Obese Diabetic Mice via Suppression of Baff Production of Salivary Gland Epithelial Cells

Background Interferon (IFN) signatures are upregulated in patients with primary Sjogrens syndrome (pSS) and interferons are considered to play a pathogenic role in pSS. Therefore, Janus kinase (JAK) which mediates interferon signaling pathway may be a good therapeutic target Objectives We set out to investigate whether a selective JAK1 inhibitor, filgotinib would ameliorate disease-related parameters in non-obese diabetic (NOD) mice, an animal model SS Methods Filgotinib (1.5mg/kg) or vehicle (saline) was intraperitoneally injected three times per week from 8 weeks after birth. Salivary flow rate (SFR) was addressed on 8, 12, 16 and 20 weeks. Histologic analysis was performed on 20 weeks. The effect of filgotinib on the expressions of B cell activating factor (BAFF) and chemokines (CXCL10 [IP-10], CXCL3 [fractalkine], CCL-2 [MCP-1]) in human salivary gland epithelial cell (SGEC) line or primary epithelial cells of patients with pSS was determined in vitro. Results The SFR of NOD mice in both groups decreased over time. Of note, SFRs of filgotinib-treated mice were greater than those of controls. Histologic evaluation of the salivary gland revealed that the lymphocytic infiltration of salivary gland was markedly reduced in the mice treated with filgotinib. Filgotinib suppressed STAT1 phosphorylation in IFN-treated SGECs. In addition, IFN-induced BAFF and chemokine production of SGECs or primary epithelial cells were abrogated by filgotinib treatment. Conclusions Filgotinib suppresses SFR decrease and lymphocytic infiltration of salivary glands of NOD mice by inhibiting inhibiting IFN signaling pathway, thus suppressing BAFF and chemokine production of salivary gland epithelial cells. JAK inhibition may be a novel therapeutic approach for SS. Disclosure of Interest None declared