Iguratimod attenuated fibrosis in systemic sclerosis via targeting early growth response 1 expression.

BACKGROUND: The early growth response 1 (EGR1) is a central transcription factor involved in systemic sclerosis (SSc) pathogenesis. Iguratimod is a synthesized anti-rheumatic disease-modifying drug, which shows drastic inhibition to EGR1 expression in B cells. This study is aiming to investigate the anti-fibrotic effect of iguratimod in SSc. METHODS: EGR1 was detected by immunofluorescence staining real-time PCR or western blot. Iguratimod was applied in EGR1 overexpressed or knockdown human dermal fibroblast, bleomycin pre-treated mice, tight skin 1 mice, and SSc skin xenografts. RNA sequencing was performed in cultured fibroblast and xenografts to identify the iguratimod regulated genes. RESULTS: EGR1 overexpressed predominantly in non-immune cells of SSc patients. Iguratimod reduced EGR1 expression in fibroblasts and neutralized changes of EGR1 response genes regulated by TGFß. The extracellular matrix (ECM) production and activation of fibroblasts were attenuated by iguratimod while EGR1 overexpression reversed this effect of iguratimod. Iguratimod ameliorated the skin fibrosis induced by bleomycin and hypodermal fibrosis in TSK-1 mice. Decreasing in the collagen content as well as the density of EGR1 or TGFß positive fibroblasts of skin xenografts from naïve SSc patients was observed after local treatment of iguratimod. CONCLUSION: Targeting EGR1 expression is a probable underlying mechanism for the anti-fibrotic effect of iguratimod.

Hypoxia-inducible factor-1α regulates the interleukin-6 production by B cells in rheumatoid arthritis.

Objectives: Rheumatoid arthritis (RA) is a disease characterised by bone destruction and systemic inflammation, and interleukin-6 (IL-6) is a therapeutic target for treating it. The study aimed at investigating the sources of IL-6 and the influence of hypoxia-inducible factor-1α (HIF-1α) on IL-6 production by B cells in RA patients. Methods: The phenotype of IL-6-producing cells in the peripheral blood of RA patients was analysed using flow cytometry. Bioinformatics, real-time polymerase chain reaction, Western blot and immunofluorescence staining were used to determine the IL-6 production and HIF-1α levels in B cells. A dual-luciferase reporter assay and chromatin immunoprecipitation were used to investigate the regulatory role of HIF-1α on IL-6 production in human and mouse B cells. Results: Our findings revealed that B cells are major sources of IL-6 in the peripheral blood of RA patients, with the proportion of IL-6-producing B cells significantly correlated with RA disease activity. The CD27-IgD+ naïve B cell subset was identified as the typical IL-6-producing subset in RA patients. Both HIF-1α and IL-6 were co-expressed by B cells in the peripheral blood and synovium of RA patients, and HIF-1α was found to directly bind to the IL6 promoter and enhance its transcription. Conclusion: This study highlights the role of B cells in producing IL-6 and the regulation of this production by HIF-1α in patients with RA. Targeting HIF-1α might provide a new therapeutic strategy for treating RA.

Serosal involvement in adult-onset Still's disease: A multicentre and retrospective study.

OBJECTIVES: This study evaluated the characteristics of serosal involvement in adult-onset Still's disease (AOSD). METHODS: Patients meeting the Yamaguchi classification criteria were classified into AOSD with and without serosal involvement according to their manifestations and sonography/radiography. Clinical data was retrospectively reviewed from 102 patients with AOSD in two centres. RESULTS: Forty-two patients (41.2%) had serosal involvement. The frequencies of pulmonary infiltrate and impaired liver function were significantly higher in patients with serosal involvement (p = .002 and p = .007, respectively), who also had a higher modified systemic score (p = .009). In addition, the percentages of CD3+ T cells (p < .001) and, especially, the CD8+ T cells (p = .004) were significantly increased in the peripheral blood of AOSD patients with serosal involvement. Notably, patients with serosal involvement were more likely to develop macrophage activation syndrome (p = .047) and a chronic pattern (p = .016) during the follow-up. CONCLUSIONS: Patients with serosal involvement demonstrated the more severe disease activity and different immune phenotypes; these patients were more likely to develop macrophage activation syndrome, and they may require more aggressive treatment at an early time to control their systemic inflammation.

HSP90ß chaperoning SMURF1-mediated LATS proteasomal degradation in the regulation of bone formation.

Heat shock protein 90 (HSP90) molecular chaperone is responsible for the stabilization and biological activity of a diverse set of client proteins. We have previously demonstrated that inhibition of HSP90 by 17-Demethoxy-17-allyaminogeldanmycin (17-AAG) not only reverses the glucocorticoid-induced bone loss but also enhances the basal level of bone mass in mice. Here, we investigate the potential mechanism underlying HSP90-associated osteoblast differentiation and bone formation. Knockdown of HSP90ß but not HSP90α or inhibition of HSP90 by 17-AAG or NVP-BEP800 negates the protein levels of large tumor suppressor (LATS), the core kinases of Hippo signaling, resulting in the inactivation of LATS and activation of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), in the enhancement of osteoblastic differentiation. In contrast, genetic ablation of Lats1 in mesenchymal stem cells is sufficient to abolish the HSP90 inhibition-induced osteoblastic differentiation and bone formation. Mechanistically, HSP90ß but not HSP90α chaperones and prevents the SMAD specific E3 ubiquitin protein ligase 1 (SMURF1)-mediated and ubiquitination-dependent LATS protein proteasomal degradation, whereas 17-AAG abolishes these effects of HSP90ß. Thus, these results uncover the HSP90ß chaperoning SMURF1-mediated LATS protein proteasomal degradation and the subsequent YAP/TAZ activation as a hitherto uncharacterized mechanism controlling osteoblastic differentiation and bone formation.

Dynamic changes in serum IL-6, IL-8, and IL-10 predict the outcome of ICU patients with severe COVID-19.

BACKGROUND: Biomarkers to prognosticate the outcomes and guide the treatment of patients with severe coronavirus disease 2019 (COVID-19) are currently required. We aimed to investigate whether the dynamic variation of cytokines was associated with the survival of patients admitted to the intensive care unit (ICU). METHODS: A retrospective study was performed on 40 patients with COVID-19 admitted to the ICU in Wuhan, China. Demographic, clinical, and laboratory variables were collected, and serum cytokines were kinetically assessed. A multivariable-adjusted generalized linear regression model was used to analyze the differences in serum cytokine levels between survivors and non-survivors. RESULTS: Among the 40 patients included, we found a positive correlation between multiple cytokines. Serum levels of interleukin (IL)-6, IL-10, and tumor necrosis factor alpha (TNFα) in non-survivors were consistently elevated compared to those in the survivors. Kinetic variations in IL-6, IL-8, and IL-10 were associated with a fatal outcome in patients with severe COVID-19, independent of sex, age, absolute lymphocyte count, direct bilirubin, hypertension, chronic obstructive pulmonary disease, and cancer as well as the use of glucocorticoids and tocilizumab. CONCLUSIONS: Dynamic changes in serum IL-6, IL-8, and IL-10 levels were associated with survival in patients in the ICU, and could serve as a predictive biomarker to determine the therapeutic options for patients with severe COVID-19.

Low Circulating Monocytes Is in Parallel With Lymphopenia Which Predicts Poor Outcome in Anti-melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis-Associated Interstitial Lung Disease.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM)-associated interstitial lung disease (ILD) may progress rapidly and lead to high mortality within 6 or 12 months. Except for reported prognostic factors, simple but powerful prognostic biomarkers are still in need in practice. In this study, we focused on circulating monocyte and lymphocyte counts and their variation tendency in the early stage of ILD. A total of 351 patients from two inception anti-MDA5 antibody-positive cohorts were included in this study, with various treatment choices. Lymphocyte count remained lower in the first month after admission in the non-survivor patients. Although baseline monocyte count showed no significant differences, average monocyte count in the following 4 weeks was also lower in the non-survivor group. Based on the C-index and analysis by the "survminer" R package in the discovery cohort, we chose 0.24 × 109/L as the cutoff value for Mono W0-2, 0.61 × 109/L as the cutoff value for lymph W0-2, and 0.78 × 109/L as the cutoff value for peripheral blood mononuclear cell (PBMC) W0-2, to predict the 6-month all-cause mortality. The Kaplan-Meier survival curves and adjusted hazard ratio with age, gender, and the number of immunosuppressants used all validated that patients with lower average monocyte count, lower average lymphocyte count, or lower average PBMC count in the first 2 weeks after admission had higher 6-month death risk, no matter in the validation cohort or in the pooled data. Furthermore, flow cytometry figured out that non-classical monocytes in patients with anti-MDA5 antibody-positive DM were significantly lower than healthy controls and patients with DM without anti-MDA5 antibodies. In conclusion, this study elucidated the predictive value of monocyte and lymphocyte counts in the early stage and may help rheumatologists to understand the possible pathogenesis of this challenging disease.

Elevated Serum D-Dimer May Reflect the Presence of Gut Inflammation in Spondyloarthritis.

BACKGROUND: To investigate the association of D-dimer with gut inflammation in spondyloarthritis (SpA). METHODS: Sixty-five patients with SpA and 70 healthy controls were included. Demographic, clinical, and laboratory parameters were collected. The differences of clinical and laboratory parameters were compared between patients with SpA and healthy controls, and between patients with SpA, with and without gut inflammation. The associations of D-dimer with laboratory data were analyzed. The predictive value of D-dimer was obtained by a receiver operator characteristic (ROC) curve analysis. The independent risk factors for gut inflammation in SpA were investigated by binary logistic regression analysis. RESULTS: Patients with SpA had higher D-dimer than healthy controls (P = 0.016). D-dimer was positively correlated with platelet (PLT), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), and negatively correlated with hemoglobin (Hb). Besides, significant differences were observed in D-dimer between SpA patients with and without gut inflammation (P < 0.001). Furthermore, SpA patients with gut inflammation were more likely to have peripheral joint involvement than those without gut inflammation (P < 0.001). The AUC of D-dimer was 0.865 at cut-off value of 0.29 mg/L, with a sensitivity of 82.6%, and a specificity of 81%. Elevated D-dimer (OR = 15.451, 95% CI: 3.030-78.780, P = 0.001) was independently associated with gut inflammation in SpA. CONCLUSION: D-dimer may be a potential biomarker for identifying SpA patients with gut inflammation.