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Sepsis is a multiple organ dysfunction syndrome caused by the host’s immune response to infection, with extremely high incidence and mortality. Immunosuppression is an essential pathophysiological alteration that influences the clinical treatment and prognosis of sepsis. Recent studies have suggested that the programmed cell death 1 signaling pathway is involved in the formation of immunosuppression in sepsis. In this review, we systematically present the mechanisms of immune dysregulation in sepsis and elucidate the expression and regulatory effects of the programmed cell death 1 signaling pathway on immune cells associated with sepsis. We then specify current research developments and prospects for the application of the programmed cell death 1 signaling pathway in immunomodulatory therapy for sepsis. Several open questions and future research are discussed at the end.

Background/Aims: We investigated the correlation between toll-like receptor 4 (TLR4) and β-catenin for disclosing the potential pathogenesis of hepatocellular carcinoma (HCC). Methods: Immunohistochemical toolkit was implemented to measure the expression of TLR4 and β-catenin in 98 cases of HCC tissues and adjacent tissues. After setting up the HepG2.2.15 hepatitis B virus (HBV) related HCC cell line, we divided the cells into the control group, TLR4 siRNA group, β-catenin siRNA group, and pcDNA.3.1 TLR4 + β-catenin siRNA group. Western blot, CCK-8 method, Transwell and flow cytometry were used to detect protein expression, cell proliferation, cell migration and invasion as well as cell apoptosis, respectively. Nude mice tumor model was established to observe the effects of TLR4 and β-catenin on the progression of HBV-related HCC in vivo. Results:The positive rates of TLR4 and β-catenin were higher in HCC tissues compared with normal tissues. Both the TLR4 siRNA group and β-catenin siRNA group exhibited a decreased expression of β-catenin. The proliferation, migration and invasion of tumor cells in the above two groups were suppressed, while the cell apoptosis appeared to be stimulated. As suggested by the results from in vivo and in vitro experiments, the up-regulation of TLR4 could antagonize the corresponding effect of β-catenin siRNA. Conclusions: TLR4 can affect the expression of β-catenin and hence influence the progression of HBV-related HCC.

Abstract Background Docosahexaenoic acid(DHA) inhibits tumor growth and progression in various cancers, including lung cancer. However, the mechanisms involved remain unclear. The aim of this study was to identify the mechanism of DHA in inhibiting progression of non-small cell lung cancer (NSCLC) in vitro. Methods The proliferation of A549 was tested by MTT, and cell apoptosis was analysed using flow cytometer. The migration and invasion were examined respectively by wound healing assay and Transwell invasion assay. The level of ROS (reactive oxygen species, ROS) was checked by DCF (dichlorodihydrofluorescein, DCF) production in cells. The apoptosis associated protein (caspase-3, PARP,Bax,Bcl-2 and survivin) and metastases associated proteins including HEF1, MMP9 and VEGF were detected by Western blot, and the same method was used in the expression of PI3K and Akt. Results DHA inhibited proliferation and induced apoptosis of A549 cells. Moreover, it suppressed the invasion and metastasis of A549 cells, while downregulating the levels of metastasis-associated proteins, including HEF1, matrix metallopeptidase (MMP9), and vascular endothelial growth factor (VEGF), in a dose -dependent manner. In addition, DHA inactivated Akt phosphorylation. All of these responses were associated with the accumulation of intracellular ROS. DHA downregulated the level of antioxidant enzymes such as catalase, while the antioxidant N-acetyl-cysteine (NAC) reversed the effect of DHA, which further validated our findings. Conclusions The present study demonstrates that DHA inhibits the development of non-small lung tumors through an ROS-mediated inactivation of the PI3K/Akt signaling pathway.

Background/Aims: The primary objective of this study was to investigate the role of miR-146a in inducing the inflammatory infiltration of macrophages in polymyositis/dermatomyositis (PM/DM) through targeting TNF receptor associated factor 6 (TRAF6), which may further down-regulate the Interleukin-17 (IL-17)/Intercellular Adhesion Molecule 1 (ICAM-1) pathway. Methods: Biopsies were collected from PM/DM patients and healthy volunteers. PM/DM model establishment and macrophage isolation were performed on Sprague Dawley (SD) rats. Model rats and macrophages were treated with anti-IL-17, anti-ICAM-1, miR-146a mimics, miR-146a inhibitors, and TRAF6 siRNAs. Serum creatine phosphokinase (S-CK) expression was assessed using double antibody sandwich enzyme-linked immunosorbent assay (ELISA) assay, and immunohistochemistry assay was performed to analyze CD163 expression in muscle samples. Furthermore, we used transwell assay to test cell migration; RT-PCR and western blot were carried out to determine the expression of miR-146a, TRAF6, IL-17, and ICAM-1. Results: The S-CK, TRAF6, IL-17 and ICAM-1 levels were higher in PM/DM patients compared with healthy controls and were down-regulated after the conventional treatment. Treatment with miR-146a mimics, anti-IL-17 and anti-ICAM-1 decreased the expression of IL-17 and ICAM-1, whereas miR-146a inhibitors exerted the opposite effects. The effects of miR-146a inhibitors were suppressed by treatment with TRAF6 siRNA. In addition, the luciferase reporter assay validated the targeting relationship between miR-146a and TRAF6. Conclusions: MiR-146a regulates inflammatory macrophage infiltration in PM/DM by targeting TRAF6 and affecting the IL-17/ICAM-1 pathway.

Background: Docosahexaenoic acid(DHA) inhibits tumor growth and progression in various cancers, including lung cancer. However, the mechanisms involved remain unclear. The aim of this study was to identify the mechanism of DHA in inhibiting progression of non-small cell lung cancer (NSCLC) in vitro. Methods: The proliferation of A549 was tested by MTT, and cell apoptosis was analysed using flow cytometer. The migration and invasion were examined respectively by wound healing assay and Transwell invasion assay. The level of ROS (reactive oxygen species, ROS) was checked by DCF (dichlorodihydrofluorescein, DCF) production in cells. The apoptosis associated protein (caspase-3, PARP,Bax,Bcl-2 and survivin) and metastases associated proteins including HEF1, MMP9 and VEGF were detected by Western blot, and the same method was used in the expression of PI3K and Akt. Results: DHA inhibited proliferation and induced apoptosis of A549 cells. Moreover, it suppressed the invasion and metastasis of A549 cells, while downregulating the levels of metastasis-associated proteins, including HEF1, matrix metallopeptidase (MMP9), and vascular endothelial growth factor (VEGF), in a dose -dependent manner. In addition, DHA inactivated Akt phosphorylation. All of these responses were associated with the accumulation of intracellular ROS. DHA downregulated the level of antioxidant enzymes such as catalase, while the antioxidant N-acetyl-cysteine (NAC) reversed the effect of DHA, which further validated our findings. Conclusions: The present study demonstrates that DHA inhibits the development of non-small lung tumors through an ROS-mediated inactivation of the PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]