Transcriptional and epigenetic control of early life cell fate decisions

Purpose of review Global epigenetic reprogramming of the parental genomes after fertilization ensures the establishment of genome organization permissive for cell specialization and differentiation during development. In this review, we highlight selected, well-characterized relationships between epigenetic factors and transcriptional cell fate regulators during the initial stages of mouse development. Recent findings Blastomeres of the mouse embryo are characterized by atypical and dynamic histone modification arrangements, noncoding RNAs and DNA methylation profiles. Moreover, asymmetries in epigenomic patterning between embryonic cells arise as early as the first cleavage, with potentially instructive roles during the first lineage allocations in the mouse embryo. Although it is widely appreciated that transcription factors and developmental signaling pathways play a crucial role in cell fate specification at the onset of development, it is increasingly clear that their function is tightly connected to the underlying epigenetic status of the embryonic cells in which they act. Findings on the interplay between genetic, epigenetic and environmental factors during reprogramming and differentiation in the embryo are crucial for understanding the molecular underpinnings of disease processes, particularly tumorigenesis, which is characterized by global epigenetic rewiring and progressive loss of cellular identity

Profiling of pluripotency factors in individual stem cells and early embryos [preprint]

Major cell fate decisions are governed by sequence-specific transcription factors (TFs) that act in small cell populations within developing embryos. To understand how TFs regulate cell fate it is important to identify their genomic binding sites in these populations. However, current methods cannot profile TFs genome-wide at or near the single cell level. Here we adapt the CUT&RUN method to profile chromatin proteins in low cell numbers, mapping TF-DNA interactions in single cells and individual pre-implantation embryos for the first time. Using this method, we demonstrate that the pluripotency TF NANOG is significantly more dependent on the SWI/SNF family ATPase BRG1 for association with its genomic targets in vivo than in cultured cells, a finding that could not have been made using traditional approaches. Ultra-low input CUT&RUN (uliCUT&RUN) enables interrogation of TF binding from low cell numbers, with broad applicability to rare cell populations of importance in development or disease

Regulation of RUVBL1-RUVBL2 AAA-ATPases by the nonsense-mediated mRNA decay factor DHX34, as evidenced by Cryo-EM

Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that degrades aberrant mRNAs and also regulates the expression of a wide range of physiological transcripts. RUVBL1 and RUVBL2 AAA-ATPases form an hetero-hexameric ring that is part of several macromolecular complexes such as INO80, SWR1, and R2TP. Interestingly, RUVBL1-RUVBL2 ATPase activity is required for NMD activation by an unknown mechanism. Here, we show that DHX34, an RNA helicase regulating NMD initiation, directly interacts with RUVBL1-RUVBL2 in vitro and in cells. Cryo-EM reveals that DHX34 induces extensive changes in the N-termini of every RUVBL2 subunit in the complex, stabilizing a conformation that does not bind nucleotide and thereby down-regulates ATP hydrolysis of the complex. Using ATPase-deficient mutants, we find that DHX34 acts exclusively on the RUVBL2 subunits. We propose a model, where DHX34 acts to couple RUVBL1-RUVBL2 ATPase activity to the assembly of factors required to initiate the NMD response.Spanish Ministry of Science and Innovation SAF2017-82632-P Andres Lopez-Perrote Carlos F Rodriguez Marina Serna Oscar Llorca. Autonomous Government of Madrid Y2018/BIO4747 Ana Gonzalez-Corpas Oscar Llorca. Autonomous Government of Madrid P2018/NMT4443 Ana Gonzalez-Corpas Oscar Llorca MRC Core funding Javier F Caceres Spanish Ministry of Science and Innovation BES-2015-071348 Carlos F Rodriguez The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.S

Rlim-Dependent and -Independent Pathways for X Chromosome Inactivation in Female ESCs

During female mouse embryogenesis, two forms of X chromosome inactivation (XCI) ensure dosage compensation from sex chromosomes. Beginning at the four-cell stage, imprinted XCI (iXCI) exclusively silences the paternal X (Xp), and this pattern is maintained in extraembryonic cell types. Epiblast cells, which give rise to the embryo proper, reactivate the Xp (XCR) and undergo a random form of XCI (rXCI) around implantation. Both iXCI and rXCI depend on the long non-coding RNA Xist. The ubiquitin ligase RLIM is required for iXCI in vivo and occupies a central role in current models of rXCI. Here, we demonstrate the existence of Rlim-dependent and Rlim-independent pathways for rXCI in differentiating female ESCs. Upon uncoupling these pathways, we find more efficient Rlim-independent XCI in ESCs cultured under physiological oxygen conditions. Our results revise current models of rXCI and suggest that caution must be taken when comparing XCI studies in ESCs and mice

Deficient spermiogenesis in mice lacking Rlim

The X-linked gene Rlim plays major roles in female mouse development and reproduction, where it is crucial for the maintenance of imprinted X chromosome inactivation in extraembryonic tissues of embryos. However, while females carrying a systemic Rlim knockout (KO) die around implantation, male Rlim KO mice appear healthy and are fertile. Here, we report an important role for Rlim in testis where it is highly expressed in post-meiotic round spermatids as well as in Sertoli cells. Systemic deletion of the Rlim gene results in lower numbers of mature sperm that contains excess cytoplasm, leading to decreased sperm motility and in vitro fertilization rates. Targeting the conditional Rlim cKO specifically to the spermatogenic cell lineage largely recapitulates this phenotype. These results reveal functions of Rlim in male reproduction specifically in round spermatids during spermiogenesis

VENTURA - virtual decision rooms for water neutral planning

The aim of VENTURA is to create and test a prototype digital tool for collaborative early-stage strategic planning for future water management. VENTURA is a 24-month applied research project that started in September 2021 focusing on study areas in Greater Manchester and Enfield, London. The project is funded by the Engineering and Physical Research Council as part of their Digital Economies: Sustainable Digital Societies1 programme. This Briefing Note covers work in Greater Manchester; a separate note has been produced for the Enfield study. VENTURA is an interdisciplinary team of systems thinking and digital geoscience researchers from Imperial College London (ICL), University College London (UCL), and British Geological Survey (BGS). The Greater Manchester study is supported by Greater Manchester Combined Authority (GMCA), United Utilities (UU) and the Environment Agency (EA), and focuses on the Upper Mersey Catchment. This group formed an integrated water management trilateral partnership prior to VENTURA in 20212. Their aim is to influence and deliver sustainable growth in Greater Manchester by improving flood risk resilience, enhancing the environment, driving circular economy approaches, and supporting regeneration

Improved imputation of low-frequency and rare variants using the UK10K haplotype reference panel

Imputing genotypes from reference panels created by whole-genome sequencing (WGS) provides a cost-effective strategy for augmenting the single-nucleotide polymorphism (SNP) content of genome-wide arrays. The UK10K Cohorts project has generated a data set of 3,781 whole genomes sequenced at low depth (average 7x), aiming to exhaustively characterize genetic variation down to 0.1% minor allele frequency in the British population. Here we demonstrate the value of this resource for improving imputation accuracy at rare and low-frequency variants in both a UK and an Italian population. We show that large increases in imputation accuracy can be achieved by re-phasing WGS reference panels after initial genotype calling. We also present a method for combining WGS panels to improve variant coverage and downstream imputation accuracy, which we illustrate by integrating 7,562 WGS haplotypes from the UK10K project with 2,184 haplotypes from the 1000 Genomes Project. Finally, we introduce a novel approximation that maintains speed without sacrificing imputation accuracy for rare variants

European Society of Cardiology: Cardiovascular Disease Statistics 2019

Aims The 2019 report from the European Society of Cardiology (ESC) Atlas provides a contemporary analysis of cardiovascular disease (CVD) statistics across 56 member countries, with particular emphasis on international inequalities in disease burden and healthcare delivery together with estimates of progress towards meeting 2025 World Health Organization (WHO) non-communicable disease targets. Methods and results In this report, contemporary CVD statistics are presented for member countries of the ESC. The statistics are drawn from the ESC Atlas which is a repository of CVD data from a variety of sources including the WHO, the Institute for Health Metrics and Evaluation, and the World Bank. The Atlas also includes novel ESC sponsored data on human and capital infrastructure and cardiovascular healthcare delivery obtained by annual survey of the national societies of ESC member countries. Across ESC member countries, the prevalence of obesity (body mass index ≥30 kg/m2) and diabetes has increased two- to three-fold during the last 30 years making the WHO 2025 target to halt rises in these risk factors unlikely to be achieved. More encouraging have been variable declines in hypertension, smoking, and alcohol consumption but on current trends only the reduction in smoking from 28% to 21% during the last 20 years appears sufficient for the WHO target to be achieved. The median age-standardized prevalence of major risk factors was higher in middle-income compared with high-income ESC member countries for hypertension {23.8% [interquartile range (IQR) 22.5–23.1%] vs. 15.7% (IQR 14.5–21.1%)}, diabetes [7.7% (IQR 7.1–10.1%) vs. 5.6% (IQR 4.8–7.0%)], and among males smoking [43.8% (IQR 37.4–48.0%) vs. 26.0% (IQR 20.9–31.7%)] although among females smoking was less common in middle-income countries [8.7% (IQR 3.0–10.8) vs. 16.7% (IQR 13.9–19.7%)]. There were associated inequalities in disease burden with disability-adjusted life years per 100 000 people due to CVD over three times as high in middle-income [7160 (IQR 5655–8115)] compared with high-income [2235 (IQR 1896–3602)] countries. Cardiovascular disease mortality was also higher in middle-income countries where it accounted for a greater proportion of potential years of life lost compared with high-income countries in both females (43% vs. 28%) and males (39% vs. 28%). Despite the inequalities in disease burden across ESC member countries, survey data from the National Cardiac Societies of the ESC showed that middle-income member countries remain severely under-resourced compared with high-income countries in terms of cardiological person-power and technological infrastructure. Under-resourcing in middle-income countries is associated with a severe procedural deficit compared with high-income countries in terms of coronary intervention, device implantation and cardiac surgical procedures. Conclusion A seemingly inexorable rise in the prevalence of obesity and diabetes currently provides the greatest challenge to achieving further reductions in CVD burden across ESC member countries. Additional challenges are provided by inequalities in disease burden that now require intensification of policy initiatives in order to reduce population risk and prioritize cardiovascular healthcare delivery, particularly in the middle-income countries of the ESC where need is greatest

Whole-genome sequence-based analysis of thyroid function

Tiina Paunio on työryhmän UK10K Consortium jäsen.Normal thyroid function is essential for health, but its genetic architecture remains poorly understood. Here, for the heritable thyroid traits thyrotropin (TSH) and free thyroxine (FT4), we analyse whole-genome sequence data from the UK10K project (N = 2,287). Using additional whole-genome sequence and deeply imputed data sets, we report meta-analysis results for common variants (MAF >= 1%) associated with TSH and FT4 (N = 16,335). For TSH, we identify a novel variant in SYN2 (MAF = 23.5%, P = 6.15 x 10(-9)) and a new independent variant in PDE8B (MAF = 10.4%, P = 5.94 x 10(-14)). For FT4, we report a low-frequency variant near B4GALT6/ SLC25A52 (MAF = 3.2%, P = 1.27 x 10(-9)) tagging a rare TTR variant (MAF = 0.4%, P = 2.14 x 10(-11)). All common variants explain >= 20% of the variance in TSH and FT4. Analysis of rare variants (MAFPeer reviewe

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)