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Epidemiological research suggests that convulsions may have an intrauterine developmental origin related to the application of dexamethasone, an artificially synthesized glucocorticoid. Here, using a rat animal model of prenatal dexamethasone exposure (PDE) we confirm that PDE can cause susceptibility to convulsions in male offspring and explore the epigenetic programming mechanism underlying this effect related to intrauterine type 2 K

Epilepsy (SE) is a common and serious neurological disease. NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome participates in the pathogenesis of SE, while its underlying mechanism is still unclear. Here, we attempted to explore the mechanism of action of NLRP3 inflammasome in SE. SE mouse model was constructed by administration of kainic acid (KA). Astrocytes were treated with KA to mimic SE cell model. MCC950 (NLRP3 inhibitor) and Z-YVAD-FMK (Caspase-1 inhibitor) were used to treat astrocytes to inhibit the activity of NLRP3 and Caspase-1. Nissl staining was performed to examine the morphology of neuron. Western blot, enzyme-linked immunosorbent assay and immunofluorescence staining were performed to assess protein expression. SE mouse model exhibited an increase of neuronal loss, and an up-regulation of Cleaved-Caspase-1, IL-1β and IL-18 in hippocampus. The levels of GFAP+ADK+ cells were significantly increased in SE mice. MCC950 or Z-YVAD-FMK abolished these impacts conferred by KA in SE mice. Moreover, KA treatment enhanced the expression of NLRP3, Cleaved-Caspase-1, IL-1β and IL-18 in astrocytes, which was rescued by knockdown of NLRP3 or Caspase-1. Additionally, CREB, p-CREB, REST were up-regulated, and SP1 was down-regulated in the KA-treated SE mice and KA-treated astrocytes. Inhibition of NLRP3 or Caspase-1 rescued these proteins expression in KA-treated astrocytes. CREB or REST silencing reduced adenosine kinase (ADK) expression, while SP1 knockdown enhanced ADK expression in KA-treated astrocytes. In conclusion, NLRP3 inflammasome activation enhances ADK expression to accelerate SE in mice through regulating CREB/REST/SP1 signaling pathway. Thus, inhibition of NLRP3 inflammasome may be a treatment for SE.

BackgroundmicroRNA-23b (miR-23b) is a multiple functional miRNA. We hypothesize that miR-23b plays a role in the pathogenesis of sepsis. Our study investigated the effect of miR-23b on sepsis-induced immunosuppression.MethodsMice were treated with miR-23b inhibitors by tail vein injection 2 days after cecal ligation puncture (CLP)–induced sepsis. Apoptosis in spleens and apoptotic signals were investigated, and survival was monitored. T-cell immunoreactivities were examined during late sepsis. Nuclear factor κB (NF-κB)–inducing kinase (NIK), tumor necrosis factor (TNF)–receptor associated factor 1 (TRAF1), and X-linked inhibitor of apoptosis protein (XIAP), the putative targets of miR-23b, were identified by a dual-luciferase reporter assay.ResultsmiR-23b expression is upregulated and sustained during sepsis. The activation of the TLR4/TLR9/p38 MAPK/STAT3 signal pathway contributes to the production of miR-23b in CLP-induced sepsis. miR-23b inhibitor decreased the number of spleen cells positive by terminal deoxynucleotidyl transferase dUTP nick-end labeling and improved survival. miR-23b inhibitor restored the immunoreactivity by alleviating the development of T-cell exhaustion and producing smaller amounts of immunosuppressive interleukin 10 and interleukin 4 during late sepsis. We demonstrated that miR-23b mediated immunosuppression during late sepsis by inhibiting the noncanonical NF-κB signal and promoting the proapoptotic signal pathway by targeting NIK, TRAF1, and XIAP.ConclusionsInhibition of miR-23b reduces late-sepsis-induced immunosuppression and improves survival. miR-23b might be a target for immunosuppression.

Depending on the duration and severity, psychological tension and physical stress can enhance or suppress the immune system in both humans and animals. Although it has been established that chronic stress exerts a significant suppressive effect on immune function, the mechanisms by which affects immune responses remain elusive. By employing an in vivo murine system, we revealed that TGF-β1/Smad2/3/Foxp3 axis was remarkably activated following chronic stress. Furthermore, TLR9 and p38 MAPK played a critical role in the activation of TGF-β1/Smad2/3/Foxp3 signaling cascade. Moreover, inhibition of TGF-β1/Smad2/3/Foxp3 or p38 significantly attenuated chronic stress-induced lymphocyte apoptosis and apoptosis-related proteins, as well as the differentiation of T regulatory cells in spleen. Interestingly, disequilibrium of pro-inflammatory and anti-inflammatory cytokines balance caused by chronic stress was also rescued by blocking TGF-β1/Smad2/3/Foxp3 axis. These findings yield insight into a novel mechanism by which chronic stress modulates immune functions and identifies new targets for the development of novel anti-immune suppressant medications.

Cardiovascular dysfunction is a major complication associated with sepsis induced mortality. Cardiac fibrosis plays a critical role in sepsis induced cardiac dysfunction. The mechanisms of the activation of cardiac fibrosis is unclarified. In this study, we found that microRNA-23b (miR-23b) was up-regulated in heart tissue during cecal ligation and puncture (CLP)-induced sepsis and transfection of miR-23b inhibitor improved survival in late sepsis. Inhibition of miR-23b in the myocardium protected against cardiac output and enhanced left ventricular systolic function. miR-23b inhibitor also alleviated cardiac fibrosis in late sepsis. MiR-23b mediates the activation of TGF-β1/Smad2/3 signaling to promote the differentiation of cardiac fibroblasts through suppression of 5'TG3'-interacting factor 1 (TGIF1). MiR-23b also induces AKT/N-Cadherin signaling to contribute to the deposition of extracellular matrix by inhibiting phosphatase and tensin homologue (PTEN). TGIF1 and PTEN were confirmed as the targets of miR-23b in vitro by Dual-Glo Luciferase assay. miR-23b inhibitor blocked the activation of adhesive molecules and restored the imbalance of pro-fibrotic and anti-fibrotic factors. These data provide direct evidence that miR-23b is a critical contributor to the activation of cardiac fibrosis to mediate the development of myocardial dysfunction in late sepsis. Blockade of miR-23b expression may be an effective approach for prevention sepsis-induced cardiac dysfunction.

Physical or psychological chronic stress can suppress the immune system. However, the mechanisms remain to be elucidated. We investigated the effect of hematopoietic stem-progenitor cells (HSPCs) on chronic stress-induced the alterations of immune responses. We demonstrate that HSPCs prevents stress-induced lymphocyte apoptosis. Moreover, we also demonstrate that the protective effect of HSPCs on stress-induced lymphocyte reduction exerts by steroid hormones. Furthermore, we reveal that chronic stress-induced T cell-mediated immune responses contributes to the protective effect of HSPCs. These results indicate that HPSCs might offer a novel therapeutic strategy against the deleterious effects of chronic stress on the immune system.

// Yu Zhou 1, 2 , Yan Song 3, 1 , Zahir Shaikh 1 , Hui Li 1 , Haiju Zhang 1 , Yi Caudle 1 , Shouhua Zheng 4 , Hui Yan 1 , Dan Hu 2 , Charles Stuart 1 and Deling Yin 1 1 Department of Internal Medicine, College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA 2 Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China 3 Department of Vascular Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China 4 Department of Thyroid Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China Correspondence to: Deling Yin, email: yin@etsu.edu Keywords: microRNA-155, late sepsis, cardiac dysfunction, β-arrestin 2, inflammatory Received: February 09, 2017 Accepted: April 19, 2017 Published: May 04, 2017 ABSTRACT Cardiac dysfunction is correlated with detrimental prognosis of sepsis and contributes to a high risk of mortality. After an initial hyperinflammatory reaction, most patients enter a protracted state of immunosuppression (late sepsis) that alters both innate and adaptive immunity. The changes of cardiac function in late sepsis are not yet known. MicroRNA-155 (miR-155) is previously found to play important roles in both regulations of immune activation and cardiac function. In this study, C57BL/6 mice were operated to develop into early and late sepsis phases, and miR-155 mimic was injected through the tail vein 48 h after cecal ligation and puncture (CLP). The effect of miR-155 on CLP-induced cardiac dysfunction was explored in late sepsis. We found that increased expression of miR-155 in the myocardium protected against cardiac dysfunction in late sepsis evidenced by attenuating sepsis-reduced cardiac output and enhancing left ventricular systolic function. We also observed that miR-155 markedly reduced the infiltration of macrophages and neutrophils into the myocardium and attenuated the inflammatory response via suppression of JNK signaling pathway. Moreover, overexpression of β-arrestin 2 (Arrb2) exacerbated the mice mortality and immunosuppression in late sepsis. Furthermore, transfection of miR-155 mimic reduced Arrb2 expression, and then restored immunocompetence and improved survival in late septic mice. We conclude that increased miR-155 expression through systemic administration of miR-155 mimic attenuates cardiac dysfunction and improves late sepsis survival by targeting JNK associated inflammatory signaling and Arrb2 mediated immunosuppression.

Physical or psychological chronic stress induces the expansion of regulatory T cells (Tregs) to contribute to immunosuppression. However, the mechanisms remain to be defined. Recent studies from us and others have shown that hematopoietic stem progenitor cells (HSPCs) significantly modulate the immune system. Since allogeneic hematopoietic stem progenitor cell transplantation contributes to chronic graft-versus-host disease (cGVHD), but attenuation of cGvHD is associated with increased frequency of Treg. We hypothesized that HSPCs prevented the over-expansion of Tregs induced by chronic restraint stress to alleviate immunosuppression. Here we demonstrate that administration of HSPCs prevent Tregs expansion and alleviate the suppressive activity of Tregs following chronic stress. Moreover, we found this protective effect is dependent on IL-12. IL-12/STAT4 signal provides a critical role against the expansion of Tregs in chronic stress. When neutralizing antibody against IL-12 or treatment with selective STAT4 inhibitor was co-administered with HSPCs in chronic stressed mice, the protective effect of HSPCs was abrogated. Additionally, HSPCs treatment promotes IL-12 production by splenocytes in chronic stressed mice. These results suggest that HSPCs can prevent chronic stress-induced Tregs expansion in an IL-12-dependent manner, which might offer a novel strategy against immunosuppression.

Sepsis is characterized with immunosuppression in late phase. microRNA-23b (miR-23b) is a multiple functional miRNA, which has been reported to prevent multiple autoimmune diseases through the regulation of inflammatory cytokine pathways. We hypothesize that miR-23b plays a role in the pathogenesis of sepsis. Our study verified the effect of miR-23b on sepsis induced immunosuppression. We found miR-23b expression was upregulated in early sepsis and sustained in late sepsis. The activation of TLR4/9/p38/STAT3 signal pathway contributes to the production of miR-23b in CLP-induced sepsis. Simultaneous in vivo blockade of miR-23b with inhibitor injection after sepsis initiation decreased TUNEL positive cells in spleen, improved survival via reducing the mortality by 42%. MiR-23b inhibitors restored the T cell immunoreactivity by alleviating the development of T cell exhaustion and producing smaller amounts of immunosuppressive interleukin 10 (IL-10) and IL-4 in late sepsis after LPS stimulation. We also demonstrated that miR-23b triggered apoptosis and T cell exhaustion to mediate immunosuppression in late sepsis by inhibiting the activation of non-canonical NF-κB signal and promoting pro-apoptotic signal pathway via targeting NIK, TRAF1 and XIAP. Circulating miR-23b serum levels might be a potential useful marker to predict survival in patients with critical sepsis. Blocking the expression of miR-23b may be an effective approach for prevention and treatment of sepsis-induced immunosuppression.