86 research outputs found

    What does regional studies study? From subnational to supra-national regional spaces or Grossraum of sovereign governance

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    This article makes a case for expanding the scope of current versions of “regional studies” to include greater emphasis upon transnational regions as of equal if not greater importance compared with an exclusive focus upon sub-national regions. The latter more restrictive approach is typically predicated on the continued centrality of state borders against which the dominant notion of regions as subnational entities is constituted and reiterated. Drawing upon a case study of the African Union our study provides a framework, a critically revised Grossraum theory, for addressing the emergence of a new pluralistic and multipolar world order characterised by supra-national regions and regional organizations. Traditional Schmittian notions of Grossraum are shown to be in need of substantial revision before they are able to adequately accommodate and explain the empirical details of our case study

    Genome-Wide Profiling of MicroRNAs in Adipose Mesenchymal Stem Cell Differentiation and Mouse Models of Obesity

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    In recent years, there has been accumulating evidence that microRNAs are key regulator molecules of gene expression. The cellular processes that are regulated by microRNAs include e.g. cell proliferation, programmed cell death and cell differentiation. Adipocyte differentiation is a highly regulated cellular process for which several important regulating factors have been discovered, but still not all are known to fully understand the underlying mechanisms. In the present study, we analyzed the expression of 597 microRNAs during the differentiation of mouse mesenchymal stem cells into terminally differentiated adipocytes by real-time RT-PCR. In total, 66 miRNAs were differentially expressed in mesenchymal stem cell-derived adipocytes compared to the undifferentiated progenitor cells. To further study the regulation of these 66 miRNAs in white adipose tissue in vivo and their dependence on PPARγ activity, mouse models of genetically or diet induced obesity as well as a mouse line expressing a dominant negative PPARγ mutant were employed

    Targeting Epigenetic Regulation of miR-34a for Treatment of Pancreatic Cancer by Inhibition of Pancreatic Cancer Stem Cells

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    MicroRNA-34a (miR-34a) is a transcriptional target of p53 and is down-regulated in pancreatic cancer. This study aimed to investigate the functional significance of miR-34a in pancreatic cancer progression through its epigenetic restoration with chromatin modulators, demethylating agent 5-Aza-2'-deoxycytidine (5-Aza-dC) and HDAC inhibitor Vorinostat (SAHA).Re-expression of miR-34a in human pancreatic cancer stem cells (CSCs) and in human pancreatic cancer cell lines upon treatment with 5-Aza-dC and SAHA strongly inhibited the cell proliferation, cell cycle progression, self-renewal, epithelial to mesenchymal transition (EMT) and invasion. In pancreatic CSCs, modulation of miR-34a induced apoptosis by activating caspase-3/7. Treatment of pancreatic CSCs with the chromatin-modulating agents resulted in the inhibition of Bcl-2, CDK6 and SIRT1, which are the putative targets of miR-34a. MiR-34a upregulation by these agents also induced acetylated p53, p21(WAF1), p27(KIP1) and PUMA in pancreatic CSCs. Inhibition of miR-34a by antagomiR abrogates the effects of 5-Aza-dC and SAHA, suggesting that 5-Aza-dC and SAHA regulate stem cell characteristics through miR-34a. In CSCs, SAHA inhibited Notch pathway, suggesting its suppression may contribute to inhibition of the self-renewal capacity and induction of apoptosis. Interestingly, treatment of pancreatic CSCs with SAHA resulted in the inhibition of EMT with the transcriptional up-regulation of E-Cadherin and down-regulation of N-Cadherin. Expression of EMT inducers (Zeb-1, Snail and Slug) was inhibited in CSCs upon treatment with SAHA. 5-Aza-dC and SAHA also retard in vitro migration and invasion of CSCs.The present study thus demonstrates the role of miR-34a as a critical regulator of pancreatic cancer progression by the regulating CSC characteristics. The restoration of its expression by 5-Aza-dC and SAHA in CSCs will not only provide mechanistic insight and therapeutic targets for pancreatic cancer but also promising reagents to boost patient response to existing chemotherapies or as a standalone cancer drug by eliminating the CSC characteristics

    Cryptic species in a well-known habitat: applying taxonomics to the amphipod genus Epimeria (Crustacea, Peracarida)

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    Taxonomy plays a central role in biological sciences. It provides a communication system for scientists as it aims to enable correct identification of the studied organisms. As a consequence, species descriptions should seek to include as much available information as possible at species level to follow an integrative concept of ‘taxonomics’. Here, we describe the cryptic species Epimeria frankei sp. nov. from the North Sea, and also redescribe its sister species, Epimeria cornigera. The morphological information obtained is substantiated by DNA barcodes and complete nuclear 18S rRNA gene sequences. In addition, we provide, for the first time, full mitochondrial genome data as part of a metazoan species description for a holotype, as well as the neotype. This study represents the first successful implementation of the recently proposed concept of taxonomics, using data from highthroughput technologies for integrative taxonomic studies, allowing the highest level of confidence for both biodiversity and ecological research

    Regulation of microRNA biogenesis and turnover by animals and their viruses

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    Item does not contain fulltextMicroRNAs (miRNAs) are a ubiquitous component of gene regulatory networks that modulate the precise amounts of proteins expressed in a cell. Despite their small size, miRNA genes contain various recognition elements that enable specificity in when, where and to what extent they are expressed. The importance of precise control of miRNA expression is underscored by functional studies in model organisms and by the association between miRNA mis-expression and disease. In the last decade, identification of the pathways by which miRNAs are produced, matured and turned-over has revealed many aspects of their biogenesis that are subject to regulation. Studies in viral systems have revealed a range of mechanisms by which viruses target these pathways through viral proteins or non-coding RNAs in order to regulate cellular gene expression. In parallel, a field of study has evolved around the activation and suppression of antiviral RNA interference (RNAi) by viruses. Virus encoded suppressors of RNAi can impact miRNA biogenesis in cases where miRNA and small interfering RNA pathways converge. Here we review the literature on the mechanisms by which miRNA biogenesis and turnover are regulated in animals and the diverse strategies that viruses use to subvert or inhibit these processes

    FcγRIIb differentially regulates pre-immune and germinal center B cell tolerance in mouse and human.

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    Several tolerance “checkpoints” exist throughout B cell development to control autoreactive B cells and prevent the generation of pathogenic autoantibodies. FcγRIIb is an Fc receptor that inhibits B cell activation and, if defective, is associated with autoimmune disease. Its impact on specific B cell tolerance checkpoints is unknown. Here we show that reduced expression of FcγRIIb leads to increased deletion and anergy of autoreactive immature B cells, but despite this autoreactive B cells expand in the germinal center and serum autoantibodies are produced, even in response to exogenous non-self antigen. Thus, we show FcγRIIb has opposing effects on pre- and post-immune tolerance checkpoints, and suggest B cell tolerance requires the control of “bystander” germinal center B cells with low or no affinity for the immunization antigen.This work was funded by the Wellcome Trust (Programme Grant Number 083650/Z/07/Z to KGCS) and supported by the NIHR Cambridge Biomedical Research Centre. ME was funded by the Wellcome Trust (Programme Grant Number 083650/Z/07/Z), by a Junior Team Leader starting grant from the Laboratory of Excellence in Research on Medication and Innovative Therapeutics (LabEx LERMIT) supported by a grant from ANR (ANR-10-LABX-33) under the program “Investissements d'Avenir” (ANR-11-IDEX-0003-01) and by an ANR @RAction starting grant (ANR-14-ACHN- 0008). KGCS is an NIHR Senior Clinical Investigator and a Distinguished Innovator of the Lupus Research Institute

    Advances in Aircraft Icing Forecast.

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    Shape and intensity of icing in clouds depend on meteorological parameters and such given by the icing structures. Usually not all of these parameters are known. As a first step towards an universal icing forecast method we developed a model which estimates the icing hazard of the rotor blade of a helicopter penetrating a low stratus layer. The most important meteorological parameters liquid water content and mean volume diameter were calculated by empirical formulas, considering the results of it in-situ observations in low stratus by DLR research aircraft Do 28. The icing profile is approximated by a cylindrical rod. A sufficient ice accretion calculation can be done by use of the Lozowski model
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