Adult-onset Still’s disease (AOSD) is a systemic inflammatory disease characterized by neutrophilia and NLRP3 inflammasome and macrophage activation. We investigated the role of neutrophil extracellular traps (NETs) in the pathogenesis of AOSD, and explored the effect of NETs on activating NLRP3 inflammasome and proinflammatory macrophages. The sera of 73 AOSD patients and 40 healthy controls were used to detect the level of cell-free DNA and NET-DNA complexes. NET formation ex vivo was analyzed using immunofluorescence and flow plates. The activation of NLRP3 inflammasome in THP-1 cells and proinflammatory macrophages stimulated with DNA purified from NETs was measured using RT-PCR, ELISA, Western blotting and flow cytometry. The levels of cell-free DNA and NET-DNA complexes were significantly increased in the circulation of patients with AOSD compared with healthy controls, and freshly isolated neutrophils from patients with AOSD were predisposed to high levels of spontaneous NET release. Interestingly, enhanced NET release was abrogated with NADPH oxidase inhibitors and a mitochondrial scavenger. Furthermore, DNA purified from AOSD NETs activated NLRP3 inflammasomes. NET DNA from AOSD also exerted a potent capacity to accelerate the activation of CD68+CD86+ macrophages and increased the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Finally, the copy number of mitochondrial DNA (mtDNA) in NETs and plasma was significantly increased in AOSD patients, suggesting that mtDNA may be involved in the activation of NLRP3 and inflammatory macrophages. These findings implicate accelerated NET formation in AOSD pathogenesis through activation of NLRP3 and proinflammatory macrophages, and identify a novel link between neutrophils and macrophages by NET formation in AOSD.

InactivatingMEN1mutations are the most common genetic defects present in sporadic and inherited pancreatic neuroendocrine tumours (PNETs). The lack of interventional therapies prompts us to explore the therapeutic approach of targeting β-catenin signalling inMEN1-mutant PNETs. Here we show theMEN1-encoded scaffold protein menin regulates phosphorylation of β-catenin. β-catenin signalling is activated inMEN1-mutant human and mouse PNETs. Conditional knockout of β-catenin suppresses the tumorigenesis and growth ofMen1-deficient PNETs, and significantly prolongs the survival time in mice. Suppression of β-catenin signalling by genetic ablation or a molecular antagonist inhibits the expression of proproliferative genes in menin-null PNETs and potently improves hyperinsulinemia and hypoglycemia in mice. Blockade of β-catenin has no adverse effect on physiological function of pancreatic β-cells. Our data demonstrate that β-catenin signalling is an effective therapeutic target forMEN1-mutant PNETs. Our findings may contribute to individualized and combined medication treatment for PNETs.

Table 1 Baseline information of the AOSD patients at enrolment No. G Age Disease duration (months) Clinical manifestations Previous treatments Treatments before JAKi initiation Treatments after enrolment Follow-up (months) Clinical evaluation CR time with JAKi (months) Present pred dose (mg/day) 1 F 33 12 Polyarthritis, rash CTX, MTX, CsA, NSAIDs iguratimod, thalidomide, Pred 40 mg+tocilizumab Pred 40 mg+JAKi 5 mg two times per day 24 Effective 16 2.5

Previous studies have revealed that several micro-organisms, especially DNA viruses, have been associated with adult-onset Still's disease (AOSD). However, there are no studies on the relationship between the presence of viral infections in AOSD patients with disease occurrence and reactivation. In the present study, we aimed to investigate the presence of antibodies against virus, virus DNA load and nucleic acid sensors in AOSD patients. Anti-viral antibodies were measured by enzyme-linked immunosorbent assay (ELISA) in plasma samples from 100 AOSD patients and 70 healthy controls (HCs). The copy number of cytomegalovirus (CMV) DNA in 100 AOSD patients was detected by PCR. The expression levels of nucleic acid sensors interferon gamma-inducible protein 16 (IFI16) and absent in melanoma 2 (AIM2) in peripheral blood mononuclear cell (PBMC) and skin from AOSD patients and HCs were analyzed by PCR and immunohistochemistry. The levels of antibodies against CMV were significantly higher in AOSD patients compared to HCs. Moreover, the level of anti-CMV IgM antibody was significantly increased in patients with fever, sore throat, arthralgia and rash. CMV DNA was found in plasma of AOSD patients with disease new-onset and relapse. Furthermore, the copy number of CMV DNA significantly increased in patients with fever, sore throat, arthralgia and rash. And the significant associations of the CMV DNA level with the levels of leukocytes, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) were observed. Moreover, we found an upregulation of cytoplasmic DNA-sensing receptor IFI16 and AIM2 in PBMC and skin from AOSD patients. In conclusion, our results showed that CMV infection may play a role in the initiation or amplification of inflammatory responses in AOSD.

The mechanism underlying the increased susceptibility of type 2 diabetes in offspring of maternal malnutrition is poorly determined. Here we tested the hypothesis that functional microRNAs (miRNAs) mediated the maternal low-protein (LP) isocaloric diet induced pancreatic β-cell impairment. We performed miRNA profiling in the islets from offspring of LP and control diet mothers to explore the potential functional miRNAs responsible for β-cell dysfunction. We found that LP offspring exhibited impaired glucose tolerance due to decreased β-cell mass and insulin secretion. Reduction in the β-cell proliferation rate and cell size contributed to the decreased β-cell mass. MiR-15b was up-regulated in the islets of LP offspring. The up-regulated miR-15b inhibited pancreatic β-cell proliferation via targeting cyclin D1 and cyclin D2. Inhibition of miR-15b in LP islet cells restored β-cell proliferation and insulin secretion. Our findings demonstrate that miR-15b is critical for the regulation of pancreatic β-cells in offspring of maternal protein restriction, which may provide a further insight for β-cell exhaustion originated from intrauterine growth restriction.

Interleukin (IL)-37 has been known to play an immunosuppressive role in various inflammatory disorders, but whether it participates in the regulation of pathogenesis of adult-onset Still’s disease (AOSD) has not been investigated. In this study, we examined serum IL-37 levels and their clinical association with AOSD, and we explored the anti-inflammatory effects of IL-37 on peripheral blood mononuclear cells (PBMCs) from patients with AOSD. Blood samples were collected from 62 patients with AOSD and 50 healthy control subjects (HC). The serum IL-37 levels were determined using an enzyme-linked immunosorbent assay (ELISA). The correlations of serum IL-37 levels with disease activity, laboratory values, and inflammatory cytokines in AOSD were analyzed by Spearman’s correlation test. The correlations between serum IL-37 levels and clinical manifestations were analyzed by Mann-Whitney U test. PBMCs from ten patients with AOSD were stimulated with recombinant human IL-37 protein, and expression levels of tumor necrosis factor (TNF)-α, IL-6, IL-10, IL-1β, and IL-18 were determined by qRT-PCR and ELISA. A significantly higher IL-37 protein level was observed in patients with AOSD than in HC. Serum IL-37 levels correlated with systemic score, laboratory values, IL-1β, IL-18, and IL-10 in patients with AOSD. The expression levels of IL-37 were closely related to the patients with AOSD who also had fever, skin rash, lymphadenopathy, splenomegaly, myalgia, and arthralgia. Moreover, the production of proinflammatory cytokines such as IL-6, IL-1β, TNF-α, and IL-18 in PBMCs from patients with AOSD was obviously attenuated after recombinant human IL-37 stimulation. Increased expression of IL-37 and its positive correlation with disease activity suggest its involvement in AOSD pathogenesis. More importantly, IL-37 inhibits the expression of proinflammatory cytokines in PBMCs from patients with AOSD, indicating the potential anti-inflammatory role of IL-37 in AOSD. Thus, IL-37 may be a novel disease activity biomarker and research target in AOSD.