Depletion of DNMT1 in differentiated human cells highlights key classes of sensitive genes and an interplay with polycomb repression

Additional file 3: Figure S2. Changes in methylation levels by genomic element. (A) Protein levels in knockdown lines by western blotting. As a control HCT116 colon cancer cells which are WT or have a homozygous mutation in DNMT1 (KO) are shown: the DNMT1-specific top band is indicated by the arrowhead at right. (B) Median levels of methylation are shown for each genomic element (listed at top). The positions of medians are also indicated at right (arrowheads). The differences between WT and KD medians were used to plot Fig. 1d. (C) Density distribution of methylation at the three main elements involved in gene regulation, shown by cell line. Demethylation seems most marked at gene bodies (Genes), indicated by increased density of probes at low methylation (β) values

Intragenic sequences in the trophectoderm harbour the greatest proportion of methylation errors in day 17 bovine conceptuses generated using assisted reproductive technologies

Abstract Background Assisted reproductive technologies (ART) are widely used to treat fertility issues in humans and for the production of embryos in mammalian livestock. The use of these techniques, however, is not without consequence as they are often associated with inauspicious pre- and postnatal outcomes including premature birth, intrauterine growth restriction and increased incidence of epigenetic disorders in human and large offspring syndrome in cattle. Here, global DNA methylation profiles in the trophectoderm and embryonic discs of in vitro produced (IVP), superovulation-derived (SOV) and unstimulated, synchronised control day 17 bovine conceptuses (herein referred to as AI) were interrogated using the EmbryoGENE DNA Methylation Array (EDMA). Pyrosequencing was used to validate four loci identified as differentially methylated on the array and to assess the differentially methylated regions (DMRs) of six imprinted genes in these conceptuses. The impact of embryo-production induced DNA methylation aberrations was determined using Ingenuity Pathway Analysis, shedding light on the potential functional consequences of these differences. Results Of the total number of differentially methylated loci identified (3140) 77.3 and 22.7% were attributable to SOV and IVP, respectively. Differential methylation was most prominent at intragenic sequences within the trophectoderm of IVP and SOV-derived conceptuses, almost a third (30.8%) of the differentially methylated loci mapped to intragenic regions. Very few differentially methylated loci were detected in embryonic discs (ED); 0.16 and 4.9% of the differentially methylated loci were located in the ED of SOV-derived and IVP conceptuses, respectively. The overall effects of SOV and IVP on the direction of methylation changes were associated with increased methylation; 70.6% of the differentially methylated loci in SOV-derived conceptuses and 57.9% of the loci in IVP-derived conceptuses were more methylated compared to AI-conceptuses. Ontology analysis of probes associated with intragenic sequences suggests enrichment for terms associated with cancer, cell morphology and growth. Conclusion By examining (1) the effects of superovulation and (2) the effects of an in vitro system (oocyte maturation, fertilisation and embryo culture) we have identified that the assisted reproduction process of superovulation alone has the largest impact on the DNA methylome of subsequent embryos

The UHRF1 protein is a key regulator of retrotransposable elements and innate immune response to viral RNA in human cells

While epigenetic mechanisms such as DNA methylation and histone modification are known to be important for gene suppression, relatively little is still understood about the interplay between these systems. The UHRF1 protein can interact with both DNA methylation and repressive chromatin marks, but its primary function in humans has been unclear. To determine what that was, we first established stable UHRF1 knockdowns (KD) in normal, immortalized human fibroblasts using targeting shRNA, since CRISPR knockouts (KO) were lethal. Although these showed a loss of DNA methylation across the whole genome, transcriptional changes were dominated by the activation of genes involved in innate immune signalling, consistent with the presence of viral RNA from retrotransposable elements (REs). We confirmed using mechanistic approaches that 1) REs were demethylated and transcriptionally activated; 2) this was accompanied by activation of interferons and interferon-stimulated genes and 3) the pathway was conserved across other adult cell types. Restoring UHRF1 in either transient or stable KD systems could abrogate RE reactivation and the interferon response. Notably, UHRF1 itself could also re-impose RE suppression independent of DNA methylation, but not if the protein contained point mutations affecting histone 3 with trimethylated lysine 9 (H3K9me3) binding. Our results therefore show for the first time that UHRF1 can act as a key regulator of retrotransposon silencing independent of DNA methylation

A randomized controlled trial of folic acid intervention in pregnancy highlights a putative methylation-regulated control element at ZFP57

Table S1. Pyrosequencing and transcriptional primer sets used in this study. Pyroassay primers are given as bisulfite converted sequence. The same primers were used for both RT-PCR and RT-qPCR. (DOCX 15 kb

Genomic, Proteomic and Phenotypic Biomarkers of COVID-19 Severity::Protocol for a Retrospective Observational Study

Background:Background - Health organisations and countries around the world have found it difficult to control the spread of the coronavirus disease 2019. To minimise the impact on the NHS and improve patient care, there is a drive for rapid tests capable of detecting individuals who are at high risk of contracting severe COVID-19. Early work focused on single omic approaches, highlighting a limited amount of information.Objective:Objective - The Covid Response Study (COVRES, NCT05548829) aims to carry out an integrated multi-omic analysis of factors contributing to host susceptibility to SARS-CoV-2 among a patient cohort of 1000 people from the geographically isolated island of Ireland.Methods:Methods - The protocol below describes the study to be carried out in Northern Ireland (NI-COVRES) by Ulster University, the Republic of Ireland component will be described separately. All participants (n=519) were recruited from the Western Health and Social Care Trust, Northern Ireland, forty patients are also being followed up at 1, 3, 6 and 12 months to assess the longitudinal impact of infection on symptoms, general health, and immune response, this is ongoing. Data will be sourced from whole blood, saliva samples, and clinical data from the Northern Ireland Electronic Care Record, general health questionnaire, and the GHQ12 mental health survey. Saliva and blood samples were processed for DNA and RNA prior to whole genomic sequencing, RNA sequencing, DNA methylation, microbiome, 16S, and proteomic analysis. Multi-omics data will be combined with clinical data to produce sensitive and specific prognostic models of severity risk.Results:Results - An initial profile of the cohort has been completed: n=249 hospitalised and n=270 non-hospitalised patients were recruited, 64% were female, the mean age was 45 years. High levels of comorbidity were evident in the hospitalised cohort, with cardiovascular disease and metabolic and respiratory disorders (P<0.001) being the most significant.Conclusions:Conclusion – This study will provide a comprehensive opportunity to study multi-omic mechanisms of COVID-19 severity in re-contactable participants. Clinical Trial: Trial Registration - The trial has been registered as an observational study on clinicaltrials.gov as NCT05548829. An outline of the trial protocol is included; SPIRIT checklist (Supplementary Figure 1)