110 research outputs found

    The epigenetic pioneer EGR2 initiates DNA demethylation in differentiating monocytes at both stable and transient binding sites

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    The differentiation of human blood monocytes (MO), the post-mitotic precursors of macrophages (MAC) and dendritic cells (moDC), is accompanied by the active turnover of DNA methylation, but the extent, consequences and mechanisms of DNA methylation changes remain unclear. Here, we profile and compare epigenetic landscapes during IL-4/GM-CSF-driven MO differentiation across the genome and detect several thousand regions that are actively demethylated during culture, both with or without accompanying changes in chromatin accessibility or transcription factor (TF) binding. We further identify TF that are globally associated with DNA demethylation processes. While interferon regulatory factor 4 (IRF4) is found to control hallmark dendritic cell functions with less impact on DNA methylation, early growth response 2 (EGR2) proves essential for MO differentiation as well as DNA methylation turnover at its binding sites. We also show that ERG2 interacts with the 5mC hydroxylase TET2, and its consensus binding sequences show a characteristic DNA methylation footprint at demethylated sites with or without detectable protein binding. Our findings reveal an essential role for EGR2 as epigenetic pioneer in human MO and suggest that active DNA demethylation can be initiated by the TET2-recruiting TF both at stable and transient binding sites.info:eu-repo/semantics/publishedVersio

    Applying Voting Methods in User Research

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    In usability practice, it is often necessary to find a ‘best’ solution that is most suitable for most users. A common way to do this is to present multiple alternatives to a group of users and let them express their preferences. However, integrating many subjective ratings into one generally valid rating is non-trivial. For such data, voting methods from the field of computational social choice might prove useful. In order to investigate their suitability, we conducted an experiment where participants had to complete a pointing task using four different mouse acceleration values and rank the perceived performance of each option via Likert-type items and also by ranking them. For generating an overall ranking, we calculated arithmetic mean and median as well as Borda count and Schulze method for each of the response sets. All methods resulted in nearly the same overall ranking of options which suggests that they might be equally useful for generating consensus on a ‘best’ option

    Diagnostic challenges in a child with early onset desmoplastic medulloblastoma and homozygous variants in MSH2 and MSH6

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    International audienceConstitutional mismatch repair deficiency (CMMRD) is an autosomal recessively inherited childhood cancer susceptibility syndrome caused by biallelic germline mutations in one of the mismatch repair (MMR

    SVA retrotransposon insertion-associated deletion represents a novel mutational mechanism underlying large genomic copy number changes with non-recurrent breakpoints

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    Background: Genomic disorders are caused by copy number changes that may exhibit recurrent breakpoints processed by nonallelic homologous recombination. However, region-specific disease-associated copy number changes have also been observed which exhibit non-recurrent breakpoints. The mechanisms underlying these non-recurrent copy number changes have not yet been fully elucidated. Results: We analyze large NF1 deletions with non-recurrent breakpoints as a model to investigate the full spectrum of causative mechanisms, and observe that they are mediated by various DNA double strand break repair mechanisms, as well as aberrant replication. Further, two of the 17 NF1 deletions with non-recurrent breakpoints, identified in unrelated patients, occur in association with the concomitant insertion of SINE/variable number of tandem repeats/Alu (SVA) retrotransposons at the deletion breakpoints. The respective breakpoints are refractory to analysis by standard breakpoint-spanning PCRs and are only identified by means of optimized PCR protocols designed to amplify across GC-rich sequences. The SVA elements are integrated within SUZ12P intron 8 in both patients, and were mediated by target-primed reverse transcription of SVA mRNA intermediates derived from retrotranspositionally active source elements. Both SVA insertions occurred during early postzygotic development and are uniquely associated with large deletions of 1 Mb and 867 kb, respectively, at the insertion sites. Conclusions: Since active SVA elements are abundant in the human genome and the retrotranspositional activity of many SVA source elements is high, SVA insertion-associated large genomic deletions encompassing many hundreds of kilobases could constitute a novel and as yet under-appreciated mechanism underlying large-scale copy number changes in the human genome

    A cancer stem cell-like phenotype is associated with miR-10b expression in aggressive squamous cell carcinomas

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    Background Cutaneous squamous cell carcinomas (cSCC) are the primary cause of premature deaths in patients suffering from the rare skin-fragility disorder recessive dystrophic epidermolysis bullosa (RDEB), which is in marked contrast to the rarely metastasizing nature of these carcinomas in the general population. This remarkable difference is attributed to the frequent development of chronic wounds caused by impaired skin integrity. However, the specific molecular and cellular changes to malignancy, and whether there are common players in different types of aggressive cSCCs, remain relatively undefined. Methods MiRNA expression profiling was performed across various cell types isolated from skin and cSCCs. Microarray results were confirmed by qPCR and by an optimized in situ hybridization protocol. Functional impact of overexpression or knock-out of a dysregulated miRNA was assessed in migration and 3D-spheroid assays. Sample-matched transcriptome data was generated to support the identification of disease relevant miRNA targets. Results Several miRNAs were identified as dysregulated in cSCCs compared to control skin. These included the metastasis-linked miR-10b, which was significantly upregulated in primary cell cultures and in archival biopsies. At the functional level, overexpression of miR-10b conferred the stem cell-characteristic of 3D-spheroid formation capacity to keratinocytes. Analysis of miR-10b downstream effects identified a novel putative target of miR-10b, the actin- and tubulin cytoskeleton-associated protein DIAPH2. Conclusion The discovery that miR-10b mediates an aspect of cancer stemness – that of enhanced tumor cell adhesion, known to facilitate metastatic colonization – provides an important avenue for future development of novel therapies targeting this metastasis-linked miRNA

    SVA retrotransposon insertion-associated deletion represents a novel mutational mechanism underlying large genomic copy number changes with non-recurrent breakpoints

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    Background: Genomic disorders are caused by copy number changes that may exhibit recurrent breakpoints processed by nonallelic homologous recombination. However, region-specific disease-associated copy number changes have also been observed which exhibit non-recurrent breakpoints. The mechanisms underlying these non-recurrent copy number changes have not yet been fully elucidated. Results: We analyze large NF1 deletions with non-recurrent breakpoints as a model to investigate the full spectrum of causative mechanisms, and observe that the

    Gegenbilder - literarisch/filmisch/fotografisch

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    Gegenbilder in Literatur, Film und Fotografie. Die moderne Welt ist voller Bilder. Auch die wissenschaftliche BeschĂ€ftigung mit ihnen erfĂ€hrt Konjunktur. Dennoch fĂ€llt es eminent schwer, allgemeingĂŒltig zu definieren, was ein Bild ausmacht. Zu verschieden scheint das, was dem Menschen als „Bild“ entgegentritt: Das kann ein Foto, ein GemĂ€lde oder ein Film sein, aber auch ein Gedanke, eine sprachliche Metapher, ein literarisches Motiv. Im Zentrum dieses Sammelbands stehen literatur- und medienwissenschaftliche BeitrĂ€ge, die unter dem Leitbegriff „Gegenbilder“ ihren Fokus auf AusprĂ€gungen des WiderstĂ€ndigen innerhalb einer polymorphen Bildlichkeit richten. Untersucht werden dabei die Inszenierungen von Gegenbildern auf der Figurenebene sowie die Rolle von Bildern bei der Darstellung von sozialer Zugehörigkeit, der Herstellung nationaler IdentitĂ€t und der Konstruktion kollektiver GedĂ€chtnisorte. Welche traditionellen Motive, Topoi und Figurenmodelle transportieren Literatur, Film und Fotografie, gegen welche kĂ€mpfen sie an? Tragen konventionelle Beschreibungsmuster das Potential zum Widerstand gegen das Etablierte bereits in sich? Diesen und weiteren Fragen widmen sich die Autoren aus interdisziplinĂ€rer Perspektive und mit einem zeitgemĂ€ĂŸen VerstĂ€ndnis von Literatur- und Kulturwissenschaft, das Geschriebenes sowie visuell prĂ€sente Bilder als gleichrangige Lesetexte auffasst und ebenso die Grenzen zwischen Hoch- und PopulĂ€rkultur ĂŒberwindet

    Androgen and glucocorticoid levels reflect seasonally occurring social challenges in male redfronted lemurs (Eulemur fulvus rufus)

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    Intense reproductive competition and social instability are assumed to increase concentrations of glucocorticoids and androgens in vertebrates, as a means of coping with these challenges. In seasonally breeding redfronted lemurs (Eulemur fulvus rufus), the mating and the birth season and the associated increased male competition are predicted to pose such reproductive challenges. In this paper, we investigate seasonal variation in hormone excretion in male redfronted lemurs, and examine whether this variation is associated with social or ecological factors. Although dominance status has been shown to affect individual stress levels across many taxa, we predicted no rank-related differences in glucocorticoids for redfronted lemurs because relatively equal costs are associated with both high and low rank positions (based on patterns of rank acquisition/maintenance and threats toward subordinates). Over a 14-month period, we collected behavioral data (1843 focal hours) and 617 fecal samples from 13 redfronted lemur males in Kirindy Forest/Madagascar. We found no general rank-related pattern of testosterone or glucocorticoid excretion in this species. Both hormones were excreted at significantly higher levels during the mating and the birth season, despite social stability during both periods. The elevated mating season levels may be explained by increased within-group reproductive competition during this time and are in line with previous studies of other seasonally reproducing primates. For the birth season increase, we propose that the predictable risk of infanticide in this highly seasonal species affects male gonadal and adrenal endocrine activity. We evaluate alternative social and ecological factors influencing the production of both hormone classes and conclude based on our preliminary investigations that none of them can account for the observed pattern

    Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

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