MRI contributes to accurate and early diagnosis of non-radiographic HLA-B27 negative axial spondyloarthritis.

BACKGROUND: Nonradiographic axial spondyloarthropathies (nr-axSpA) are diagnosed by the absence of radiographic sacroiliitis and the presence of bone marrow edema (BME) on magnetic resonance imaging (MRI). According to the classification criteria of the international Assessment of Spondyloarthritis Society (ASAS), structural changes to sacroiliac joints (SIJs) on MRI cannot be used as criteria in the absence of BME. However, less than half the Asian patients with clinically active axSpA show BME. The incidence of human leukocyte antigen (HLA)-B27 is low in Asian populations, which makes it more difficult to identify nr-axSpA. We used MRI to evaluate the structural damage to SIJs in patients with nr-axSpA with and without BME with the aim of identifying the best methodology for accurate diagnosis, especially in populations with less common BME and HLA-B27. METHODS: One hundred three patients with inflammatory back pain were included in this prospective study. No patient's radiograph met the definition of positive modified New York criteria. BME and structural damage to SIJ including sclerosis and erosion were assessed independently on coronal and axial short-tau inversion recovery and T1-weighted spin echo MRI scans by two well-trained musculoskeletal radiologists using the Spondyloarthritis Research Consortium of Canada (SPARCC) score. Demographics of patients were collected. Disease characteristics and structural damage were analyzed in patients with and without BME on SIJ MRI. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of structural damage. RESULTS: All individuals in the cohort had at least one abnormal finding on SIJ MRI, including BME or structural damage; 36 of 103 patients had BME. We identified a significant positive correlation between SPARCC scores and severe erosion assessed by focal joint space widening (fJSW) (p = 0.001) in these 36 patients. Fifty-eight of the 103 enrolled patients fulfilled the ASAS criteria for nr-axSpA in the either absence or presence of BME. Of these 58 patients, 57 and 19 had erosions or fJSW, respectively, and the presence of BME was significantly correlated with fJSW (phi score of 0.319 and p = 0.015). We demonstrated a significant positive correlation between fJSW and either the presence or the severity of BME in patients with nr-axSpA who met the ASAS definition. There was a positive correlation between BME and fJSW across the whole study cohort (phi score of 0.389; p < 0.001). The area under the ROC curve (AUC) for fJSW on SIJ MRI was 0.736, p < 0.001. In both HLA-B27-positive and -negative groups, BME was more common in the presence of fJSW (phi scores of 0.370 and 0.377, p = 0.018 and 0.003, respectively) and SPARCC scores were higher in patients with fJSW (p < 0.001 and p = 0.005). We also identified a positive correlation between fJSW and BME in patients with nr-axSpA and normal serum levels of C-reactive protein (phi score of 0.362 and p = 0.001). CONCLUSION: Structural damage detected on SIJ MRI, sclerosis, erosions and fJSW may be present in patients without detectable inflammation on SIJ MRI. However, fJSW is significantly correlated with the severity of inflammation seen on SIJ MRI, which contributes to the accurate diagnosis of nr-axSpA, and it could be used as an alternative diagnostic test for nr-axSpA in the general population, especially for those who do not carry the HLA-B27 gene, Asian patients without BME, or patients with normal serum inflammatory biomarkers.

Thymoma-Related Paraneoplastic Syndrome Mimicking Reactive Arthritis.

Background and Objectives: Thymomas are associated with a high frequency of paraneoplastic manifestations. Paraneoplastic syndrome (PNS) with thymoma presents a challenge to clinicians because of the need to decipher the association between the presenting symptoms and the underlying tumor. The condition most commonly noted in patients with PNS with thymoma is myasthenia gravis. Other common autoimmune diseases that may present as PNS include systemic lupus erythematosus, pure red cell aplasia, and Good syndrome. Seventy-six percent of patients with PNS-associated thymoma experience resolution of PNS after curing thymoma. Materials and Methods: A 37-year-old man with a two-month fever accompanied by polyarthritis accidently found thymoma after contrast computed tomography scans of his chest. He accepted Video assisted thoracoscopic surgery with resection of thymoma. Results: Fever and polyarthritis resolved after operation but recurred in five days due to cytomegalovirus viremia, which might be predisposed by previous antibiotics treatment before the diagnosis of thymoma. Conclusion: Patients with a thymoma also have a high frequency of PNS, and the most frequent condition found in patients with PNS-associated thymoma is myasthenia gravis. Fever with polyarthritis has been rarely reported as a symptom of PNS-associated thymoma. Here we reported an unusual case of PNS mimicking reactive arthritis with thymoma, as diagnosed based on the patient's clinical progression, imaging examination, and laboratory tests. The patient died of his comorbidities, and his death may have been related to long-term antibiotic use and consequent intestinal dysbiosis. This challenging case may help to inform clinicians of the need for detailed work-up of fever with unknown origin in the presence of chronic polyarthritis to prevent the overdiagnosis of inflammatory arthritis or rheumatic disease and avoid further comorbidities. Detailed work-up should include the patient's history of infections, inflammation, and malignant or nonmalignant tumors.

Application of classification criteria of Sjogren syndrome in patients with sicca symptoms: Real-world experience at a medical center.

BACKGROUND: Patients who have symptoms of sicca, such as dry eyes and mouth, may have Sjögren's syndrome (SS). However, the conservative culture makes patients hesitate to undergo an invasive biopsy, which contributes to the difficulty of confirming a diagnosis. We aimed to identify the characteristics of patients with sicca symptoms to develop a better predictive value for each item included in the three different diagnostic criteria for SS and clarify the best diagnostic tools for the local population. METHODS: This is a single-center retrospective case-control study from January 2016 to December 2017. Patients who underwent sialoscintigraphy because of clinical symptoms of xerostomia and xerophthalmia at one medical center were reviewed via the patients' electronic medical records. RESULTS: Of 515 patients enrolled, the severity of results for sialoscintigraphy and Schirmer's test was correlated with a diagnosis of SS and generated receiver operator characteristic curve. The area under curve (AUC) was 0.603 for positive Schirmer's test, 0.687 for positive anti-Ro/La results, 0.893 for a positive salivary gland biopsy. The AUC was 0.626 and 0.602 for Schirmer's test which is redefined as <10 mm/5 minutes in either eye and according to 2016 the American College of Rheumatology/ European League Against Rheumatism criteria, respectively. CONCLUSION: Our results indicate the cut-off point for defining a positive test result in the Schirmer's test is worth modified to <10 mm/5 minutes in either eye.

Deltex1 suppresses T cell function and is a biomarker for diagnosis and disease activity of systemic lupus erythematosus.

OBJECTIVE: Deletion of Deltex1 (DTX1) in mice caused hyperactivation of T cells and lupus-like autoimmune syndromes, however, the association of DTX1 with human autoimmune diseases is totally unknown. This study investigated the role of DTX1 in human T cell functions and its correlation with disease activity in patients with SLE. METHODS: The influence of DTX1 on T cell function was evaluated using human primary cells. DTX1 expression in peripheral blood mononuclear cells (PBMCs) from healthy controls and SLE patients was measured by quantitative real-time PCR and the SLEDAI was used to assess disease activity. RESULTS: After stimulation with anti-CD3 and anti-CD28, silencing of DTX1 expression enhanced IFN-γ secretion by human T cells. The expression of DTX1 in PBMCs was significantly lower in 100 SLE patients than in 50 age- and sex-matched healthy controls (DTX1/glyceraldehyde 3-phosphate dehydrogenase, 0.452 vs 1.269, P < 0.001). The area under the receiver operator characteristics curve of the model was 0.737 (95% CI 0.658, 0.815). Intriguingly, a low DTX1 level in T cells led to high IFN-γ production in SLE patients and had a correlation with severe disease activity. In addition, low DTX1 expression in SLE patients was associated with active LN, lung involvement or hypocomplementaemia. CONCLUSION: Knockdown DTX1 expression in human T cells reduced IFN-γ secretion. DTX1 expression in the PBMCs was significantly lower in SLE patients and had an inverse correlation with disease activity, indicating that the DTX1 level may be a good disease marker of SLE.

The current status and unmet needs in the management of psoriatic arthritis: Viewpoint from physicians in Taiwan.

BACKGROUND/PURPOSE: To analyze the real-world clinical practice for the treatment of psoriatic arthritis (PsA) and to assess physicians' prescription, difficulties in diagnosis, therapeutic strategy, rationales for biologic therapies and unmet needs in Taiwan. METHODS: We conducted a nationwide cross-sectional observational study by face-to-face in depth interviews with 50 rheumatologists and 30 dermatologists who took care of patients with PsA. RESULTS: The major procedures for recognizing PsA included joint, skin and nail examinations, radiographic imaging, and medical history. More dermatologists established the diagnosis when psoriatic patients with arthritis didn't present with rheumatoid factors (p < 0.05). For milder arthritis, physicians tended to prescribe etanercept in combination with conventional disease-modifying antirheumatic drugs (DMARDs). The efficacy, safety, retention rate, and non-parenteral administration are the major concerns of physicians which are also the primary unmet needs in the current management of PsA. CONCLUSION: This survey showed the status quo in Taiwan of the clinical management for PsA including diagnostic difficulties, therapeutic consideration, rationales for biologic DMARDs selection and unmet needs in treatment. It has indicated that interdisciplinary collaboration may further improve the quality for PsA care. These results may help establish new strategy to develop next generation biologics.

The Simultaneous Inhibitory Effect of Niclosamide on RANKL-Induced Osteoclast Formation and Osteoblast Differentiation.

The bone destruction disease including osteoporosis and rheumatoid arthritis are caused by the imbalance between osteoblastogenesis and osteoclastogenesis. Inhibition of the NF-κB pathway was responsible for decreased osteoclastogenesis. Recently many studies indicated that niclosamide, the FDA approved an antihelminth drug, inhibits prostate and breast cancer cells growth by targeting NF-κB signaling pathways. This study evaluated the effects of niclosamide on osteoclast and osteoblast differentiation and function in vitro. In RANKL-induced murine osteoclast precursor cell RAW264.7 and M-CSF/RANKL-stimulated primary murine bone marrow-derived macrophages (BMM), niclosamide dose-dependently inhibited the formation of TRAP-positive multinucleated osteoclasts and resorption pits formation between 0.5uM and 1uM. In addition, niclosamide suppressed the expression of nuclear factor of activated T cells c1 (NFATc1) and osteoclast differentiated-related genes in M-CSF/ RANKL-stimulated BMM by interference with TRAF-6, Erk1/2, JNK and NF-κB activation pathways. However, the cytotoxic effects of niclosamide obviously appeared at the effective concentrations for inhibiting osteoclastogenesis (0.5-1uM) with increase of apoptosis through caspase-3 activation in osteoblast precursor cell line, MC3T3-E1. Niclosamide also inhibited ALP activity, bone mineralization and osteoblast differentiation-related genes expression in MC3T3-E1. Therefore, our findings suggest the new standpoint that niclosamide's effects on bones must be considered before applying it in any therapeutic treatment.

Glucosamine Modulates T Cell Differentiation through Down-regulating N-Linked Glycosylation of CD25.

Glucosamine has immunomodulatory effects on autoimmune diseases. However, the mechanism(s) through which glucosamine modulates different T cell subsets and diseases remain unclear. We demonstrate that glucosamine impedes Th1, Th2, and iTreg but promotes Th17 differentiation through down-regulating N-linked glycosylation of CD25 and subsequently inhibiting its downstream Stat5 signaling in a dose-dependent manner. The effect of glucosamine on T helper cell differentiation was similar to that induced by anti-IL-2 treatment, further supporting an IL-2 signaling-dependent modulation. Interestingly, excess glucose rescued this glucosamine-mediated regulation, suggesting a functional competition between glucose and glucosamine. High-dose glucosamine significantly decreased Glut1 N-glycosylation in Th1-polarized cells. This finding suggests that both down-regulated IL-2 signaling and Glut1-dependent glycolytic metabolism contribute to the inhibition of Th1 differentiation by glucosamine. Finally, glucosamine treatment inhibited Th1 cells in vivo, prolonged the survival of islet grafts in diabetic recipients, and exacerbated the severity of EAE. Taken together, our results indicate that glucosamine interferes with N-glycosylation of CD25, and thereby attenuates IL-2 downstream signaling. These effects suggest that glucosamine may be an important modulator of T cell differentiation and immune homeostasis.

Decreased SMG7 expression associates with lupus-risk variants and elevated antinuclear antibody production.

OBJECTIVES: Following up the systemic lupus erythematosus (SLE) genome-wide association studies (GWAS) identification of NMNAT2 at rs2022013, we fine-mapped its 150 kb flanking regions containing NMNAT2 and SMG7 in a 15 292 case-control multi-ancestry population and tested functions of identified variants. METHODS: We performed genotyping using custom array, imputation by IMPUTE 2.1.2 and allele specific functions using quantitative real-time PCR and luciferase reporter transfections. SLE peripheral blood mononuclear cells (PBMCs) were cultured with small interfering RNAs to measure antinuclear antibody (ANA) and cyto/chemokine levels in supernatants using ELISA. RESULTS: We confirmed association at NMNAT2 in European American (EA) and Amerindian/Hispanic ancestries, and identified independent signal at SMG7 tagged by rs2702178 in EA only (p=2.4×10-8, OR=1.23 (95% CI 1.14 to 1.32)). In complete linkage disequilibrium with rs2702178, rs2275675 in the promoter region robustly associated with SMG7 mRNA levels in multiple expression quantitative trait locus (eQTL) datasets. Its risk allele was dose-dependently associated with decreased SMG7 mRNA levels in PBMCs of 86 patients with SLE and 119 controls (p=1.1×10-3 and 6.8×10-8, respectively) and conferred reduced transcription activity in transfected HEK-293 (human embryonic kidney cell line) and Raji cells (p=0.0035 and 0.0037, respectively). As a critical component in the nonsense-mediated mRNA decay pathway, SMG7 could regulate autoantigens including ribonucleoprotein (RNP) and Smith (Sm). We showed SMG7 mRNA levels in PBMCs correlated inversely with ANA titres of patients with SLE (r=-0.31, p=0.01), and SMG7 knockdown increased levels of ANA IgG and chemokine (C-C motif) ligand 19 in SLE PBMCs (p=2.0×10-5 and 2.0×10-4, respectively). CONCLUSION: We confirmed NMNAT2 and identified independent SMG7 association with SLE. The inverse relationship between levels of the risk allele-associated SMG7 mRNAs and ANA suggested the novel contribution of mRNA surveillance pathway to SLE pathogenesis.

Rituximab therapy in primary Sjögren's syndrome with interstitial lung disease: a retrospective cohort study.

OBJECTIVES: Interstitial lung disease (ILD) is one of the major systemic manifestations of primary Sjögren's syndrome (pSS). The aim of this study was to evaluate the therapeutic effect of rituximab on pSS patients with ILD. METHODS: Pulmonary function test results, including diffusing capacity for carbon monoxide (DLCO) and DLCO/alveolar volume (Va) ratio, and high-resolution computed tomography (HRCT) findings/scores in ten pSS patients with ILD treated with rituximab were retrospectively investigated. Global disease, fatigue, dryness of eyes and mouth, shortness of breath, and cough were assessed by visual analogue scales (VAS, 0-100 mm). RESULTS: At 6 months after rituximab treatment, improvement in pulmonary function was observed (from 49.3±12.6 to 56.9±11.4% for DLCO, p=0.011; from 74.4±15.8 to 85.6±10.3% for DLCO/Va, p=0.021). Similarly, significant improvement of subjective symptoms were also noted after treatment (VAS global disease, from 62.0±11.4 to 26.0±10.8 mm, p<0.001; VAS fatigue, from 38.0±23.0 to 18.0±7.9 mm, p=0.006; VAS dryness of eyes, from 53.0±24.4 to 29.0±13.7 mm, p=0.004; VAS dryness of mouth, from 45.0±14.3 to 28.0±9.2 mm, p=0.001; VAS shortness of breath, from 64.0±16.5 to 31.0±16.0 mm, p<0.001; VAS cough, from 42.0±23.5 to 18.0±10.3 mm, p=0.011). The mean HRCT score decreased after rituximab therapy although to a lesser extent (from 8.7±4.1 to 7.6±4.6, p=0.419). An adverse event was observed in only one patient who had non-fatal pneumonia 4 months after rituximab infusion. CONCLUSIONS: Rituximab was effective in improving clinical symptoms and gas exchange, and in stabilising HRCT score in pSS patients with ILD.

Preferential binding to Elk-1 by SLE-associated IL10 risk allele upregulates IL10 expression.

Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7×10⁻8, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans.

Development of 1-Amino-4-(phenylamino)anthraquinone-2-sulfonate Sodium Derivatives as a New Class of Inhibitors of RANKL-Induced Osteoclastogenesis.

A series of 1-amino-4-(phenylamino)anthraquinone-2-sulfonate sodium derivatives was synthesized and evaluated for osteoclast inhibition using a TRAP-staining assay. Among them, two compounds, LCCY-13 and LCCY-15, dose-dependently suppressed receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation. Moreover, the cytotoxicity assay on RAW264.7 cells suggested that the inhibition of osteoclastic bone resorption by these compounds was not a result of their cytotoxicity. Further, the inhibitory activities of compounds LCCY-13 and LCCY-15 were further confirmed by including specific inhibition of NFATc1 expression levels in nuclei using an immunofluorescent analysis. In addition, LCCY-13 and LCCY-15 also significantly attenuated the bone resorption activity of osteoclasts according to a pit formation assay. Thus, a new class of 1-amino-4-(phenylamino)anthraquinone-2-sulfonate sodium compounds might be considered as an essential lead structure for the further development of anti-resorptive agents.

Targeting tumour necrosis factor receptor 1 assembly reverses Th17-mediated colitis through boosting a Th2 response.

OBJECTIVE: The soluble preligand assembly domain (PLAD) of tumour necrosis factor receptor 1 (TNFR1) interferes with receptor trimerisation to block downstream signalling, and mediates Th17 suppression. We explored the therapeutic potential of recombinant PLAD.Fc protein on a spontaneous experimental colitis. DESIGN: A T-cell-specific BLIMP-1 knockout mouse model with mixed Th1/Th17 responses, resembling human Crohn's disease (CD) was established, and its colitogenic phenotype was characterised. Mice, 9 weeks old, were treated with PLAD.Fc protein at 5 mg/kg of body weight twice per week for 16 weeks, and presence of colitis was monitored by the appearance of diarrhoea, weight loss, and by histological colonic scoring. Activation status, cytokine profiles, and transcription factors in T cells were further analysed. RESULTS: The colitogenic phenotype in BLIMP-1 knockout mice was alleviated when an interleukin (IL)-23 knockdown transgene was introduced, indicating a therapeutic potential by downregulating IL-23-Th17 axis in these knockout mice. In PLAD.Fc-treated group, the mouse body weight remained stable and only mild disease scores were revealed. The percentage of naive CD4 T cells was increased and that of effector/memory CD4 T cells was decreased after PLAD.Fc-treatment. Moreover, the levels of IFN-γ, IL-17, IL-21, IL-22, IL-23R, granulocyte-macrophage colony-stimulating factor (GM-CSF) and TNF-α were diminished. Strikingly, Th2-associated cytokines (IL-4, IL-13 and IL-10) in sera, as well as percentages of Th2 cells, were increased in PLAD.Fc-treated mice. However, PLAD.Fc-mediated suppression of effector phenotypes in Th1/Th17 was abrogated after neutralising IL-10. CONCLUSIONS: The Th2 cytokine milieu induced by PLAD.Fc rebalanced T-helper cell subsets and conferred a protection against colitis in BLIMP-1 knockout mice.

Genetic associations of leptin-related polymorphisms with systemic lupus erythematosus.

Leptin is abnormally elevated in the plasma of patients with systemic lupus erythematosus (SLE), where it is thought to promote and/or sustain pro-inflammatory responses. Whether this association could reflect an increased genetic susceptibility to develop SLE is not known, and studies of genetic associations with leptin-related polymorphisms in SLE patients have been so far inconclusive. Here we genotyped DNA samples from 15,706 SLE patients and healthy matched controls from four different ancestral groups, to correlate polymorphisms of genes of the leptin pathway to risk for SLE. It was found that although several SNPs showed weak associations, those associations did not remain significant after correction for multiple testing. These data do not support associations between defined leptin-related polymorphisms and increased susceptibility to develop SLE.

Identification of IRF8, TMEM39A, and IKZF3-ZPBP2 as susceptibility loci for systemic lupus erythematosus in a large-scale multiracial replication study.

Systemic lupus erythematosus (SLE) is a chronic heterogeneous autoimmune disorder characterized by the loss of tolerance to self-antigens and dysregulated interferon responses. The etiology of SLE is complex, involving both heritable and environmental factors. Candidate-gene studies and genome-wide association (GWA) scans have been successful in identifying new loci that contribute to disease susceptibility; however, much of the heritable risk has yet to be identified. In this study, we sought to replicate 1,580 variants showing suggestive association with SLE in a previously published GWA scan of European Americans; we tested a multiethnic population consisting of 7,998 SLE cases and 7,492 controls of European, African American, Asian, Hispanic, Gullah, and Amerindian ancestry to find association with the disease. Several genes relevant to immunological pathways showed association with SLE. Three loci exceeded the genome-wide significance threshold: interferon regulatory factor 8 (IRF8; rs11644034; p(meta-Euro) = 2.08 × 10(-10)), transmembrane protein 39A (TMEM39A; rs1132200; p(meta-all) = 8.62 × 10(-9)), and 17q21 (rs1453560; p(meta-all) = 3.48 × 10(-10)) between IKAROS family of zinc finger 3 (AIOLOS; IKZF3) and zona pellucida binding protein 2 (ZPBP2). Fine mapping, resequencing, imputation, and haplotype analysis of IRF8 indicated that three independent effects tagged by rs8046526, rs450443, and rs4843869, respectively, were required for risk in individuals of European ancestry. Eleven additional replicated effects (5 × 10(-8) < p(meta-Euro) < 9.99 × 10(-5)) were observed with CFHR1, CADM2, LOC730109/IL12A, LPP, LOC63920, SLU7, ADAMTSL1, C10orf64, OR8D4, FAM19A2, and STXBP6. The results of this study increase the number of confirmed SLE risk loci and identify others warranting further investigation.

Novel inhibitors of RANKL-induced osteoclastogenesis: Design, synthesis, and biological evaluation of 6-(2,4-difluorophenyl)-3-phenyl-2H-benzo[e][1,3]oxazine-2,4(3H)-diones.

A series of novel 6-(2,4-difluorophenyl)-3-phenyl-2H-benzo[e][1,3]oxazine-2,4(3H)-dione derivatives were synthesized and evaluated for their inhibitory effects on osteoclast activities by using TRAP-staining assay. Among the tested compounds, 3d and 3h exhibited more potent osteoclast-inhibitory activities than the lead compound NDMC503 (a ring-fused structure of NDMC101), as reported in our previous study. Both 3d and 3h exhibited two-fold increase in activity compared to NDMC503. In addition, our biological results indicated that 3d and 3h could suppress RANKL-induced osteoclastogenesis-related marker genes, such as NFATc1, c-fos, TRAP, and cathepsin K. Notably, 3d could significantly attenuate the bone-resorbing activity of osteoclasts in the pit formation assay. Thus, this study might provide a new class of lead structures that warrant further development as potential anti-resorptive agents.

Different modulation of Ptpn22 in effector and regulatory T cells leads to attenuation of autoimmune diabetes in transgenic nonobese diabetic mice.

Ptpn22 encodes PEST domain-enriched tyrosine phosphatase (Pep), which negatively regulates TCR proximal signaling and is strongly associated with a variety of autoimmune diseases in humans. The net effect of Pep on the balance of immunity and tolerance is uncertain because of the simultaneous inhibition of TCR-mediated signaling of effector and regulatory T cells (T(regs)). In this study, we generated transgenic NOD mice that overexpressed Pep in T cells. The transgenic mice had a significantly lower incidence of spontaneous autoimmune diabetes, which was accompanied by fewer IFN-γ-producing T cells, and an increased ratio of CD4(+)Foxp3(+) T(regs)to CD4(+)IFN-γ(+) or to CD8(+)IFN-γ(+) T cells, respectively, in pancreatic islets. Transgenic T cells showed markedly decreased TCR-mediated effector cell responses such as proliferation and Th1 differentiation. By contrast, the inhibitory effect of transgenic Pep on TCR signaling did not affect the differentiation of T(regs) or their suppressive activity. Adoptive transfer experiments showed that transgenic splenocytes exhibited attenuated diabetogenic ability. To examine further the pathogenic features of transgenic T cells, we generated Ptpn22/BDC2.5 doubly transgenic mice and found reduced proliferation and Th1 differentiation in CD4(+) T lymphocytes with additional Pep in pancreatic lymph nodes but not in inguinal lymph nodes of NOD/SCID recipients. This finding indicates that transgenic Pep attenuates T cell functions in an islet Ag-driven manner. Taken together, our results demonstrate that Pep overexpression in T cells attenuates autoimmune diabetes in NOD mice by preferentially modulating TCR signaling-mediated functions in diabetogenic T cells but not in T(regs).

T cell-specific BLIMP-1 deficiency exacerbates experimental autoimmune encephalomyelitis in nonobese diabetic mice by increasing Th1 and Th17 cells.

Recently, we demonstrated that B lymphocyte-induced maturation protein 1 (BLIMP-1) has a role in regulating the differentiation and effector function of Th1 and Th17 cells. As these cells play critical roles in the induction and pathogenesis of experimental autoimmune encephalomyelitis (EAE), we investigated the potential role of T cell BLIMP-1 in modulating MOG35-55-induced EAE. We established T cell-specific BLIMP-1 conditional knockout (CKO) NOD mice to dissect the role of BLIMP-1 in EAE using loss-of-function model. Our results indicate that EAE severity is dramatically exacerbated in CKO mice. The numbers of CNS-infiltrating Th1, Th17, IFN-γ(+)IL-17A(+), and IL-21(+)IL-17A(+) CD4(+) T cells are remarkably increased in brain and spinal cord of CKO mice. Moreover, the ratio of Tregs/effectors and IL-10 production of Tregs are significantly downregulated in CNS of CKO mice. We conclude that BLIMP-1 suppresses autoimmune encephalomyelitis via downregulating Th1 and Th17 cells and impairing Treg cells.

Identification of a systemic lupus erythematosus susceptibility locus at 11p13 between PDHX and CD44 in a multiethnic study.

Systemic lupus erythematosus (SLE) is considered to be the prototypic autoimmune disease, with a complex genetic architecture influenced by environmental factors. We sought to replicate a putative association at 11p13 not yet exceeding genome-wide significance (p < 5 × 10(-8)) identified in a genome-wide association study (GWAS). Our GWA scan identified two intergenic SNPs located between PDHX and CD44 showing suggestive evidence of association with SLE in cases of European descent (rs2732552, p = 0.004, odds ratio [OR] = 0.78; rs387619, p = 0.003, OR = 0.78). The replication cohort consisted of >15,000 subjects, including 3562 SLE cases and 3491 controls of European ancestry, 1527 cases and 1811 controls of African American (AA) descent, and 1265 cases and 1260 controls of Asian origin. We observed robust association at both rs2732552 (p = 9.03 × 10(-8), OR = 0.83) and rs387619 (p = 7.7 × 10(-7), OR = 0.83) in the European samples with p(meta) = 1.82 × 10(-9) for rs2732552. The AA and Asian SLE cases also demonstrated association at rs2732552 (p = 5 × 10(-3), OR = 0.81 and p = 4.3 × 10(-4), OR = 0.80, respectively). A meta-analysis of rs2732552 for all racial and ethnic groups studied produced p(meta) = 2.36 × 10(-13). This locus contains multiple regulatory sites that could potentially affect expression and functions of CD44, a cell-surface glycoprotein influencing immunologic, inflammatory, and oncologic phenotypes, or PDHX, a subunit of the pyruvate dehydrogenase complex.

TACE-dependent amphiregulin release is induced by IL-1ß and promotes cell invasion in fibroblast-like synoviocytes in rheumatoid arthritis.

OBJECTIVES: The aims of this study were to investigate the expression of amphiregulin (AREG) and TNF-α-converting enzyme (TACE) in fibroblast-like synoviocytes from humans with RA (FLS-RA) when stimulated with proinflammatory cytokines and to explore whether AREG plays a role in RA. METHODS: The effects of cytokines on the expression of AREG and TACE in FLS-RA were measured by quantitative RT-PCR and western blotting. Blockade of IL-1ß-mediated pathways was used to verify the involvement of intracellular signal pathways in the induction of AREG and TACE. TAPI-1 and TACE short hairpin RNA (shRNA) infection were used to identify the role of TACE in IL-1ß-induced AREG secretion and shedding. AREG-induced production of MMP-1 and cadherin-11 in FLS-RA were measured by ELISA or western blotting. The effect of AREG on FLS-RA invasion was examined using a Transwell invasion assay. RESULTS: IL-1ß, but not other tested cytokines, increased the expressions of AREG mRNA and protein in a dose-responsive and time-dependent manner in FLS-RA. IL-1ß induced AREG expression via p38 MAPK, NF-κB, JNK and ERK1/2 signalling pathways and induced TACE expression via PI3K, p38MAPK and NF-κB signalling pathways in FLS-RA. TACE mediated AREG secretion and shedding. EGFR (ErbB1) and Her-2 (ErbB2) were expressed in FLS-RA, and AREG increased MMP-1 and cadherin-11 expression in FLS-RA. AREG promoted the FLS-RA invasion ability. CONCLUSION: AREG and TACE expression were up-regulated by IL-1ß and their activations on FLS-RA lead to the matrix degradation by inducing MMP-1 and cadherin-11 production. TACE activity is necessary for IL-1ß-induced AREG release. Our results demonstrate that IL-1ß-induced AREG release may be involved in the pathogenesis of RA.