8 research outputs found

    Stable methylation at promoters distinguishes epiblast stem cells from embryonic stem cells and the in vivo epiblasts

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    Embryonic Stem Cells (ESCs) and Epiblast Stem Cells (EpiSCs) are the in vitro representatives of naĂŻve and primed pluripotency, respectively. It is currently unclear how their epigenomes underpin the phenotypic and molecular characteristics of these distinct pluripotent states. Here, we performed a genome-wide comparison of DNA methylation between ESCs and EpiSCs by MethylCap-Seq. We observe that promoters are preferential targets for methylation in EpiSC compared to ESCs, in particular high CpG island promoters. This is in line with upregulation of the de novo methyltransferases Dnmt3a1 and Dnmt3b in EpiSC, and downregulation of the demethylases Tet1 and Tet2. Remarkably, the observed DNA methylation signature is specific to EpiSCs and differs from that of their in vivo counterpart, the postimplantation epiblast. Using a subset of promoters that are differentially methylated, we show that DNA methylation is established within a few days during in vitro outgrowth of the epiblast, and also occurs when ESCs are converted to EpiSCs in vitro. Once established, this methylation is stable, as ES-like cells obtained by in vitro reversion of EpiSCs display an epigenetic memory that only extensive passaging and sub-cloning are able to almost completely erase

    Implementing guidelines on the prevention of opportunistic infections in inflammatory bowel disease

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    Introduction: Opportunistic infections are a key safety concern in the management of patients with inflammatory bowel disease (IBD). Despite the existence of international guidelines, many gastroenterologists have not adopted routine screening and vaccination. The aim of this study was to modify clinical behaviour by use of a simple screening tool. Methods: A screening and vaccination proforma for hepatitis B, varicella, Influenza, Pneumococcus, human papillomavirus, tuberculosis, hepatitis C and HIV was provided to each participating gastroenterologist. Gastroenterologists were surveyed for awareness of vaccine recommendations and current practice prior to and following the introduction of the proforma. Rates of immunity and the proportion of patients receiving the recommended screening and vaccinations were documented. Results: 30 gastroenterologists at 8 different IBD centres took part in the assessment. A total of 919 patients were included (55% female, 65% Crohn's, 33% ulcerative colitis, 2% indeterminate IBD). Introduction of the proforma increased self-reported gastroenterologist screening from 47% to 97% pre- and post-intervention respectively, p

    Macrophage: A Key Therapeutic Target in Atherosclerosis?

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