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Viral infections seriously affect the health of organisms including humans. Now, more and more researchers believe that microRNAs (miRNAs), one of the members of the non-coding RNA family, play significant roles in cell biological function, disease occurrence, and immunotherapy. However, the roles of miRNAs in virus infection (entry and replication) and cellular immune response remain poorly understood, especially in low vertebrate fish. In this study, based on the established virus-cell infection model, Singapore grouper iridovirus (SGIV)-infected cells were used to explore the roles of miR-124 of Epinephelus coioides , an economically mariculture fish in southern China and Southeast Asia, in viral infection and host immune responses. The expression level of E. coioides miR-124 was significantly upregulated after SGIV infection; miR-124 cannot significantly affect the entry of SGIV, but the upregulated miR-124 could significantly promote the SGIV-induced cytopathic effects (CPEs), the viral titer, and the expressions of viral genes. The target genes of miR-124 were JNK3/p38α mitogen-activated protein kinase (MAPK). Overexpression of miR-124 could dramatically inhibit the activation of NF-κB/activating protein-1 (AP-1), the transcription of proinflammatory factors, caspase-9/3, and the cell apoptosis. And opposite results happen when the expression of miR-124 was inhibited. The results suggest that E. coioides miR-124 could promote viral replication and negatively regulate host immune response by targeting JNK3/p38α MAPK, which furthers our understanding of virus and host immune interactions. [ABSTRACT FROM AUTHOR]

Periodontitis is a chronic inflammatory disease induced by bacteria. Exposure of the host to periodontal pathogens and their virulence factors induces a state of hyporesponsiveness to subsequent stimulations, which is termed endotoxin tolerance. The role and mechanism of lipopolysaccharide (LPS)–tolerized monocytes in inflammatory responses in neutrophils are currently unclear. Here, conditioned supernatants were collected from THP-1 cells treated with or without repeated 1 μg/ml Porphyromonas gingivalis (P.gingivalis) LPS. The chemotactic response of freshly isolated neutrophils recruited by supernatants was determined by a transwell migration assay, which demonstrated a reduced migration of neutrophils stimulated with supernatants from tolerized THP-1 cells in comparison to non-tolerized THP-1 cells. In addition, there was a marked increase in reactive oxygen species (ROS) generation and a significant decrease in Caspase 3 activities in neutrophils treated with supernatants from THP-1 cells that were treated repeatedly with P.gingivalis LPS in comparison to single treatment. A cytokine antibody array was then used to assess cytokine expression patterns in THP-1 cells. In tolerized THP-1 cells, 43 cytokine (43/170) expression levels were decreased, including chemokine ligand 23 (CCL23) and IFN-γ, while 11 cytokine (11/170) expression levels were increased, such as death receptor 6 (DR6). Furthermore, there was decreased production of IFN-γ and epithelial neutrophil activating peptide-78 (ENA-78) in THP-1 cells after stimulation with repeated P. gingivalis LPS in comparison to single challenge, which was confirmed by ELISA. Therefore, P.gingivalis LPS- tolerized THP-1 cells were able to depress neutrophil chemotaxis and apoptosis, and contribute to respiratory burst, which might be related to the changes in cytokine expression patterns in THP-1 cells. [ABSTRACT FROM AUTHOR]

Abstract: Multipotent stem cells have the potential to establish a new field of promising regenerative medicine to treat tissue damage, genetic disorders, and degenerative diseases. However, limited resource of stem cells has turned to be an evitable obstacle in clinical applications. We utilized a simple in vitro epigenetic reprogramming approach to convert skin fibroblasts into multipotent cells. After transient reprogramming, stem cell markers, including Oct4 and Nanog, became activated in the treated cells. The reprogrammed cells were multipotent as demonstrated by their ability to differentiate into a variety of cells and to form teratomas. Genomic imprinting of insulin-like growth factor II (Igf2) and H19 was not affected by this short period of cell reprogramming. This study may provide an alternative strategy to efficiently generate patient-specific stem cells for basic and clinical research, solving major hurdles of virally-induced pluripotent stem (iPS) cells that entail the potential risks of mutation, gene instability, and malignancy. [Copyright &y& Elsevier]

Abstract: Objectives: The effects of hypercholesterolemia (HC) on the myocardium and the underlying mechanisms are unclear. We tested the hypothesis that diet-induced HC-induced myocardial fibrosis by regulating the transforming growth factor (TGF)-β pathway and apoptosis through increased oxidative stress, and that these would be functionally consequential. Methods: Three groups of pigs (n =6 each) were studied after 12 weeks of normal or 2% HC diet, or HC+antioxidant supplementation. Cardiac function was evaluated by electron beam computed tomography, while fibrogenic mechanisms and apoptosis were evaluated in myocardial tissue. Results: HC-induced myocardial fibrosis was accompanied by increased ratio of interstitial collagen I/III (1.4±0.3 versus 0.5±0.1 in normal, p <0.05), expression of TGF-β1 and its downstream smad mediators, as well as myocyte apoptosis. These alterations were also associated with a decrease in diastolic filling rate compared to normal (134.0±10.6ml/s versus 70.3±14.3ml/s, p <0.05), but were attenuated in HC animals chronically supplemented with antioxidants. Conclusions: Myocardial injury elicited by experimental HC includes redox-sensitive increases in TGF-β1 expression and apoptosis, which are associated with diastolic dysfunction. These observations underscore a role of increased oxidative stress in modulating myocardial tissue remodeling and dysfunction in vivo in HC. [Copyright &y& Elsevier]

This study aimed to investigate whether interferon regulatory factor 9 (IRF9) is involved in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury and to explore the underlying molecular mechanisms of this process. Cell death plays a major role in myocardial I/R injury. We recently determined the importance of IRF9 in coordinating molecular events in response to hypertrophic stress in cardiomyocytes. However, the roles of IRF9 in lethal myocardial injury remain to be elucidated. The involvement of IRF9 was assessed via functional assays in a mouse myocardial I/R injury model by genetic knockout and cardiomyocyte-specific transgenic overexpression of IRF9, and its effects on cardiomyocyte apoptosis and inflammation were further studied in vivo and in vitro. IRF9 was upregulated in human ischemic heart tissue and mouse hearts after I/R injury. Ablation of IRF9 protected the heart against I/R-induced cardiomyocyte death, development of inflammation, and loss of heart function. In contrast, cardiomyocyte-specific transgenic overexpression of IRF9 aggravated myocardial reperfusion injury and inflammation. IRF9 negatively regulated the Sirt1-p53 axis under I/R conditions in vivo and in vitro. Downregulation of Sirt1 expression and its downstream apoptosis-related signaling cascade, which results from I/R, was ameliorated by loss of IRF9 and exacerbated by overexpression of IRF9. Cardiomyocyte-specific deletion of Sirt1 abolished the protective effect of IRF9 knockout against I/R injury, which further indicated that IRF9 mediated myocardial reperfusion injury by modulating the Sirt1-p53 axis. Thus, IRF9 may be a novel therapeutic target for the prevention of I/R injury resulting from revascularization therapy after acute myocardial infarction (MI). [ABSTRACT FROM AUTHOR]

The aberrant appearance of DNA in the cytoplasm triggers the activation of cGAS-cGAMP-STING signaling and induces the production of type I interferons, which play critical roles in activating both innate and adaptive immune responses. Recently, numerous studies have shown that the activation of STING and the stimulation of type I IFN production are critical for the anticancer immune response. However, emerging evidence suggests that STING also regulates anticancer immunity in a type I IFN-independent manner. For instance, STING has been shown to induce cell death and facilitate the release of cancer cell antigens. Moreover, STING activation has been demonstrated to enhance cancer antigen presentation, contribute to the priming and activation of T cells, facilitate the trafficking and infiltration of T cells into tumors and promote the recognition and killing of cancer cells by T cells. In this review, we focus on STING and the cancer immune response, with particular attention to the roles of STING activation in the cancer-immunity cycle. Additionally, the negative effects of STING activation on the cancer immune response and non-immune roles of STING in cancer have also been discussed. [ABSTRACT FROM AUTHOR]