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In order to eliminate viral infections, hundreds of interferon-stimulated genes (ISGs) are induced via type I interferons (IFNs). However, the functions and mechanisms of most ISGs are largely unclear. A tripartite motif (TRIM) protein encoding gene TRIM69 is induced by dengue virus (DENV) infection as an ISG. TRIM69 restricts DENV replication, and its RING domain, which has the E3 ubiquitin ligase activity, is critical for its antiviral activity. An in vivo study further confirmed that TRIM69 contributes to the control of DENV infection in immunocompetent mice. Unlike many other TRIM family members, TRIM69 is not involved in modulation of IFN signaling. Instead, TRIM69 interacts with DENV Nonstructural Protein 3 (NS3) directly and mediates its polyubiquitination and degradation. Finally, Lys104 of NS3 is identified as the target of TRIM69-mediated ubiquitination. Our study demonstrates that TRIM69 restricts DENV replication by specifically ubiquitinating a viral nonstructural protein.

This Review summarizes the past to present achievements in radical-mediated rearrangements, and brings up the prospects that may inspire colleagues to develop more useful synthetic tools based on radical rearrangements.

BackgroundCircular RNAs (circRNAs) are regarded as a novel class of noncoding RNA regulators. Although a number of circRNAs have been identified by bioinformatics analysis of RNA-seq data, tissue and disease-specific circRNAs are still to be uncovered to promote their application in basic research and clinical practice. The purpose of this study was to explore the circRNA profiles in human induced pluripotent stem cells (hiPSCs) and hiPSC-derived cardiomyocytes (hiPSC-CMs), and to identify cardiac or disease-specific circRNAs.MethodshiPSCs were generated from fibroblasts, and then further differentiated to hiPSC-CMs by modulating WNT signaling in RPMI+B27 medium. Following high-throughput RNA sequencing, circRNAs were extracted and quantified by a combined strategy known as CIRCexplorer. Integrative analysis was performed to illuminate the correlation between circRNAs and their parental linear isoforms. Cardiac and disease-specific expression of circRNAs was confirmed by quantitative reverse-transcription PCR.ResultsIn this study, a total of 5602 circRNAs were identified in hiPSCs and hiPSC-CMs. Our data indicated, for the first time, more enriched expression of circRNAs in differentiated cardiomyocytes than in undifferentiated hiPSCs. In addition to the host gene-dependent expression, our integrative analysis also identified a number of circRNAs showing host gene-independent expression in hiPSCs and hiPSC-CMs. CircRNAs including circSLC8A1, circCACNA1D, circSPHKAP and circALPK2 showed cardiac-selective expression during cardiac differentiation and human heart-specific enrichment in fetal tissues. Furthermore, circSLC8A1 abnormally increased in heart tissues from patients suffering from dilated cardiomyopathy.ConclusionsCircRNAs are highly enriched in hiPSC-differentiated CMs, and cardiac-specific circRNAs such as circSLC8A1, circCACNA1D, circSPHKAP and circALPK2 may serve as biomarkers of CMs. Detection of the excessive expression of circSLC8A1 provides a potential approach for pathological status indication of heart disease.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0793-5) contains supplementary material, which is available to authorized users.

BackgroundDengue virus (DENV), the causative agent of human Dengue hemorrhagic fever, is a mosquito-borne virus found in tropical and sub-tropical regions around the world. Vaccines against DENV are currently unavailable. Guanylate-binding protein 1 (GBP1) is one of the Interferon (IFN) stimulated genes (ISGs) and has been shown important for host immune defense against various pathogens. However, the role of GBP1 during DENV infection remains unclarified. In this study, we evaluated the relevance of GBP1 to DENV infection in in vitro model.FindingsQuantitative RT-PCR (qRT-PCR) and Western blot showed that the expression of mouse Gbp1 was dramatically upregulated in DENV-infected RAW264.7 cells. The intracellular DENV loads were significantly higher in Gbp1 silenced cells compared with controls. The expression levels of selective anti-viral cytokines were decreased in Gbp1 siRNA treated cells, while the transcription factor activity of NF-κB was impaired upon GBP1 silencing during infection.ConclusionsOur data suggested that GBP1 plays an antiviral role during DENV infection.

Triple-negative breast cancers (TNBCs) are the most aggressive and hard-to-treat breast tumors with poor prognosis, and exploration for novel therapeutic drugs is impending. Arctigenin (Atn), a bioactive lignan isolated from seeds of Arctium lappa L, has been reported to inhibit many cancer types; however, the effect of Atn on TNBC remains unclear. In this study, we demonstrated that Atn decreased proliferation, and induced apoptosis in TNBC cells. Furthermore, we explored the underlying mechanism of Atn inhibition on TNBC cells. Computational docking and affinity assay showed that Atn bound to the SH2 domain of STAT3. Atn inhibited STAT3 binding to genomic DNA by disrupting hydrogen bond linking between DNA and STAT3. In addition, Atn augmented Taxotere®-induced TNBC cell cytotoxicity. TNBC xenograft tests also confirmed the antitumor effect of Atn in vivo. These characteristics render Atn as a promising candidate drug for further development and for designing new effective STAT3 inhibitors.

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a b s t r a c tIn this paper, some new Banach spaces be introduced. Based on those new Banach spaces and by using the coincidence degree theory, we present two existence results for a coupled system of nonlinear fractional differential equations with three-point boundary conditions at resonance case.