The expression of STAT3 inhibited the NF-ΚB signalling pathway and reduced inflammatory responses in mice with viral myocarditis.

BACKGROUND: The aim of this study was to investigate the mechanism of STAT3 in reducing the inflammatory responses in mice with viral myocarditis (VMC). METHODS: Induce and generate viral myocarditis by using coxsackievirus B3 (CVB3) infected cardiomyocyte-specific STAT3 conditional knockout (STAT3cKO) mice and BALB/c mice. Use RT-PCR and western blot techniques to detect the expression of related cytokines in the uninfected wild-type mice group (Control group), myocarditis wild-type mice group (Model group) and STAT3cKO group, as well as the differentiation of spleen T cells in each group. Eukaryotic expression plasmid pcDNA3-STAT3 can reduce the expression of inflammatory factors the in vitro cultured cardiomyocytes of the STAT3cKO group. RESULTS: RT-PCR showed that compared with the Control group, the expression levels of VMC-related genes (NF-κB, TNF­α, IL-1ß and IL-1) and anti-inflammation-related cytokines (IL-10 and TGF-ß) in the Model group went up (*p < 0.05, **p < 0.01, ***p < 0.001); and also compared with the Control group, the rise in the expression levels of the above VMC-related genes in the STAT3cKO group was particularly significant (***p < 0.001, ****p < 0.0001) but there was no significant difference in the expression of IL-10 and TGF-ß. After 4 weeks, a second RT-PCR showed that the expression of inflammation-related genes in the STAT3cKO group continued to be activated (***p < 0.001, ****p < 0.0001). Western blotting was performed to detect the expression of p65, a key protein of the NF-κB signalling pathway. The results showed that the p65 protein content was increased and the IL-10 protein content was decreased in the STAT3cKO group; the results of the T cell differentiation test showed that the T cell differentiation rate increased in the STAT3cKO group (**p < 0.01). Eukaryotic expression plasmid pcDNA3-STAT3 could reduce the expression of NF-κB, TNF-α, IL-1ß and IL-17 (**p < 0.01). CONCLUSION: The expression of STAT3 gene in VMC could to a certain extent inhibit the NF-κB signalling pathway and reduce the inflammatory responses of VMC.

Sphingomyelin synthase 1 enhances BCR signaling to promote lupus-like autoimmune response.

BACKGROUND: Sphingomyelin synthase 1 (SMS1) has been reported to participate in hepatitis and atherosclerosis. However, its role in autoimmune response is not clear. This study investigates the possible involvement of SMS1 in B-cell activation and lupus-like autoimmunity. METHODS: SMS1 knockout lupus-like animal model and SLE patient samples were utilized. B-cell activation and associated signal transduction were detected by flow cytometry, confocal analysis and western blotting. The SMS1 expression in B cells was measured by real-time qPCR. FINDINGS: SMS1 deficiency suppressed B-cell activation in culture, which was restored by exogenous SM supplementation. The BCR-mediated early signal transduction including the colocalization of BCR with F-actin or pY/pBtk, and the phosphorylation of intracellular Fyn and Syk were impaired in SMS1 knockout B cells. Furthermore, SMS1 knockout mice showed reduced production and deposition of autoantibodies, accompanied by less severe kidney pathological changes after pristane induction. SMS1 deficiency also displayed lower autoantibody titers and 24 h urine protein excretion in bm12-induced lupus, which were associated with reduced B-cell activation. Adoptively transferred wide-type B cells partially recovered B-cell activation and autoantibody production in SMS1 deficient bm12-induced lupus mice. Moreover, the SMS1 mRNA level in B cells of SLE patients was increased and positively correlated with the serum anti-dsDNA level, IgG and globulin titers. INTERPRETATION: These data suggest that SMS1 is involved in lupus-like autoimmunity via regulating BCR signal transduction and B cell activation. (Word count for the abstract: 230).

Serum HMGB1 Serves as a Novel Laboratory Indicator Reflecting Disease Activity and Treatment Response in Ankylosing Spondylitis Patients.

Objective. High mobility group box 1 (HMGB1) is a late inflammatory factor participating in the pathogenesis of various autoimmune and inflammatory diseases. In the current study, we analyzed the association between serum levels of HMGB1 and clinical features of AS patients before and during treatment. Methods. Serum HMGB1 was detected in 147 AS patients and 61 healthy controls using ELISA. We evaluated the association between HMGB1 and extra-articular manifestations as well as disease severity indices. Among these AS patients, 41 patients received close follow-up at 1, 3, and 6 months after treatment. This group comprised 25 patients treated with anti-TNF-α biologics and 16 patients receiving oral NSAIDs plus sulfasalazine. Results. The serum HMGB1 of AS patients was significantly higher than in healthy controls and positively correlated with BASDAI, BASFI, ASDAS-ESR, ASDAS-CRP, ESR, and CRP, but not with HLA-B27, anterior uveitis, and recurrent diarrhea. There was no significant difference between patients with radiographic damage of hip joints and those without. We observed that serum HMGB1 paralleled disease activity after treatment. Conclusion. Serum level of HMGB1 is higher in AS patients, and to some extent, HMGB1 can reflect the activity of AS and be used as a laboratory indicator to reflect the therapeutic response.

Elevated Serum Levels of Soluble CD30 in Ankylosing Spondylitis Patients and Its Association with Disease Severity-Related Parameters.

Soluble CD30 (sCD30), a transmembrane glycoprotein that belongs to the tumor necrosis factor receptor (TNFR) superfamily, has been shown to be associated with various pathological conditions. This study was designed to measure the levels of serum sCD30 in patients with ankylosing spondylitis (AS) and to evaluate the relationships between serum sCD30 levels and other disease severity-related indexes, including bath ankylosing spondylitis disease activity index (BASDAI), ankylosing spondylitis disease activity score (ASDAS), and bath ankylosing spondylitis functional index (BASFI). Our results demonstrated significantly elevated sCD30 levels in AS patients compared to healthy controls (HCs) with mean values of 32.0 ± 12.2 and 24.9 ± 8.0 ng/mL, respectively (P(**) = 0.007), suggesting a potential role of sCD30 in the pathogenesis of AS. However, no significant correlations of sCD30 with BASDAI, ASDAS, or BASFI were detected in our study (P > 0.05). Therefore, sCD30 cannot be used as a reliable marker for reflecting disease activity and functional ability of AS patients.

Detection of serum IgG4 levels in patients with IgG4-related disease and other disorders.

OBJECTIVE: Elevated serum IgG4 levels are an important hallmark for diagnosing IgG4-related disease (IgG4-RD), but can also be observed in other diseases. This study aimed to compare two different testing methods for IgG4: ELISA and nephelometric assay. Both assays were used to measure serum IgG4 concentrations, and to assess the prevalence of high serum IgG4 levels in both IgG4-RD and non-IgG4-RD diseases. METHODS: A total of 80 serum samples were tested using the nephelometric assay and ELISA method that we established. Serum IgG4 concentrations were determined by ELISA for 957 patients with distinct diseases, including 12 cases of IgG4-RD and 945 cases of non-IgG4-RD. RESULTS: IgG4 levels from 80 selected serum samples examined by ELISA were in agreement with those detected using the nephelometry assay. Meanwhile, the serum IgG4 concentrations measured by ELISA were also consistent with the clinical diagnoses of patients with IgG4-RD during the course of disease. The Elevated levels of serum IgG4 (>1.35 g/L) were detected in all IgG4-RD (12/12) patients, and the prevalence of high IgG4 serum levels was 3.39% in non-IgG4-RD cases. Among them, the positive rates of serum IgG4 were 2.06% in patients with carcinoma and 6.3% in patients with other non-IgG4 autoimmune diseases. CONCLUSION: Our established ELISA method is a reliable and convenient technique, which could be extensively used in the clinic to measure serum IgG4 levels. High levels of IgG4 were observed in IgG4-RD. However, this phenomenon could also be observed in other diseases, such as carcinomas and other autoimmune diseases. Thus, a diagnosis of IgG4 disease cannot only be dependent on the detection of elevated serum IgG4 levels.

Preliminary study of high mobility group box chromosomal protein 1(HMGB1) in ankylosing spondylitis patients.

OBJECTIVES: To compare the serum levels of high mobility group box chromosomal protein 1 (HMGB1) between patients with AS and healthy controls, and evaluate its association with disease activities and functional abilities; to investigate the cell surface receptors related to HMGB1 in AS patients. METHODS: The HMGB1 serum levels from71 previously untreated AS patients and 40 healthy controls were detected by ELISA method. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Functional Index (BASFI), erythrocytesedimentationrate (ESR), and C-reactive protein (CRP) levels were assessed on these participants. The mRNA expression of HMGB1 and its relevant cell surface receptors RAGE, TLR2, TLR4, and IL-1Racp complex were analysed by RT-PCR. RESULTS: The HMGB1 serum levels from AS patients were significantly higher than those from healthy controls and remarkably positive correlated with BASDAI, ASDAS, BASFI, CRP, and ESR. ASDAS showed more correlated to HMGB1 serum levels than BASDAI. Besides, the expression of TLR2, TLR4, and IL-1Racp from PBMCs revealed significant correlations with the expression of HMGB1. CONCLUSIONS: HMGB1 might be a good laboratory index for the evaluation of disease activities and disease severity in AS patients. Further, extracellular HMGB1 play its inflammatory role mainly via the expression of cell surface receptors TLR2, TLR4 and IL-1RAcP complex.