A network including TGFβ/Smad4, Gata2 and p57 regulates proliferation of mouse hematopoietic progenitor cells.

Transforming growth factor-β (TGFβ) is a potent inhibitor of hematopoietic stem and progenitor cell proliferation. However, the precise mechanism for this effect is unknown. Here, we have identified the transcription factor Gata2, previously described as an important regulator of hematopoietic stem cell (HSC) function, as an early and direct target gene for TGFβ-induced Smad signaling in hematopoietic progenitor cells. We also report that Gata2 is involved in mediating a significant part of the TGFβ response in primitive hematopoietic cells. Interestingly, the cell cycle regulator and TGFβ signaling effector molecule p57 was found to be upregulated as a secondary response to TGFβ. We observed Gata2 binding upstream of the p57 genomic locus, and importantly loss of Gata2 abolished TGFβ-stimulated induction of p57 as well as the resulting growth arrest of hematopoietic progenitors. Our results connect key molecules involved in HSC self-renewal and reveal a functionally relevant network regulating proliferation of primitive hematopoietic cells

Use of Repeated Blood Pressure and Cholesterol Measurements to Improve Cardiovascular Disease Risk Prediction: An Individual-Participant-Data Meta-Analysis

The added value of incorporating information from repeated blood pressure and cholesterol measurements to predict cardiovascular disease (CVD) risk has not been rigorously assessed. We used data on 191,445 adults from the Emerging Risk Factors Collaboration (38 cohorts from 17 countries with data encompassing 1962-2014) with more than 1 million measurements of systolic blood pressure, total cholesterol, and high-density lipoprotein cholesterol. Over a median 12 years of follow-up, 21,170 CVD events occurred. Risk prediction models using cumulative mean values of repeated measurements and summary measures from longitudinal modeling of the repeated measurements were compared with models using measurements from a single time point. Risk discrimination (Cindex) and net reclassification were calculated, and changes in C-indices were meta-analyzed across studies. Compared with the single-time-point model, the cumulative means and longitudinal models increased the C-index by 0.0040 (95% confidence interval (CI): 0.0023, 0.0057) and 0.0023 (95% CI: 0.0005, 0.0042), respectively. Reclassification was also improved in both models; compared with the single-time-point model, overall net reclassification improvements were 0.0369 (95% CI: 0.0303, 0.0436) for the cumulative-means model and 0.0177 (95% CI: 0.0110, 0.0243) for the longitudinal model. In conclusion, incorporating repeated measurements of blood pressure and cholesterol into CVD risk prediction models slightly improves risk prediction

The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

GATA-2 mediated regulation of normal hematopoietic stem/progenitor cell function, myelodysplasia and myeloid leukemia

Unremitting blood cell production throughout the lifetime of an organism is reliant on hematopoietic stem cells (HSCs). A rare and relatively quiescent cell type, HSCs are, on entry into cell cycle fated to self-renew, undergo apoptosis or differentiate to progenitors (HPCs) that eventually yield specific classes of blood cells. Disruption of these HSC fate decisions is considered to be fundamental to the development of leukemia. Much effort has therefore been placed on understanding the molecular pathways that regulate HSC fate decisions and how these processes are undermined in leukemia. Transcription factors have emerged as critical regulators in this respect. Here we review the participation of zinc finger transcription factor GATA-2 in regulating normal hematopoietic stem and progenitor cell functionality, myelodysplasia and myeloid leukemia

High Frequency of Large Intragenic Deletions in the Fanconi Anemia Group A Gene

Fanconi anemia (FA) is an autosomal recessive disorder exhibiting chromosomal fragility, bone-marrow failure, congenital abnormalities, and cancer. At least eight complementation groups have been described, with group A accounting for 60%–65% of FA patients. Mutation screening of the group A gene (FANCA) is complicated by its highly interrupted genomic structure and heterogeneous mutation spectrum. Recent reports of several large deletions of FANCA, coupled with modest mutation-detection rates, led us to investigate whether many deletions might occur in the heterozygous state and thus fail to be detected by current screening protocols. We used a two-step screening strategy, in which small mutations were detected by fluorescent chemical cleavage of the FANCA transcript, and heterozygosity for gross deletions was detected by quantitative fluorescent multiplex PCR. We screened 26 cell lines from FA complementation group A for FANCA mutations and detected 33 different mutations, 23 of which were novel. Mutations were observed in all 26 cell lines and included 43 of a possible 52 mutant alleles (83%). Of the mutant alleles, 40% were large intragenic deletions that removed up to 31 exons from the gene, indicating that this may be the most prevalent form of mutation in FANCA. Several common deletion breakpoints were observed, and there was a highly significant correlation between the number of breakpoints detected in a given intron and the number of Alu repeats that it contained, which suggests that Alu-mediated recombination may explain the high prevalence of deletions in FANCA. The dual screening strategy that we describe may be useful for mutation screening in other genetic disorders in which mutation-detection rates are unexpectedly low

Distinct Mechanisms of Inadequate Erythropoiesis Induced by Tumor Necrosis Factor Alpha or Malarial Pigment

<div><p>The role of infection in erythropoietic dysfunction is poorly understood. In children with <i>P</i>. <i>falciparum</i> malaria, the by-product of hemoglobin digestion in infected red cells (hemozoin) is associated with the severity of anemia which is independent of circulating levels of the inflammatory cytokine tumor necrosis alpha (TNF-α). To gain insight into the common and specific effects of TNF-α and hemozoin on erythropoiesis, we studied the gene expression profile of purified primary erythroid cultures exposed to either TNF-α (10ng/ml) or to hemozoin (12.5μg/ml heme units) for 24 hours. Perturbed gene function was assessed using co-annotation of associated gene ontologies and expression of selected genes representative of the profile observed was confirmed by real time PCR (rtPCR). The changes in gene expression induced by each agent were largely distinct; many of the genes significantly modulated by TNF-α were not affected by hemozoin. The genes modulated by TNF-α were significantly enriched for those encoding proteins involved in the control of type 1 interferon signalling and the immune response to viral infection. In contrast, genes induced by hemozoin were significantly enriched for functional roles in regulation of transcription and apoptosis. Further analyses by rtPCR revealed that hemozoin increases expression of transcription factors that form part of the integrated stress response which is accompanied by reduced expression of genes involved in DNA repair. This study confirms that hemozoin induces cellular stress on erythroblasts that is additional to and distinct from responses to inflammatory cytokines and identifies new genes that may be involved in the pathogenesis of severe malarial anemia. More generally the respective transcription profiles highlight the varied mechanisms through which erythropoiesis may be disrupted during infectious disease.</p></div

Representative example of samples used for microarray and rtPCR.

<p>The purity of erythroblast populations treated with either TNF-α or hemozoin was determined by flow cytometry (A). The forward scatter (FSC) and side scatter (SSC) of live cells is shown in red. The proportion of cells (% of total events acquired) expressing lymphoid (CD3) and erythroid markers (CD71^-CD235a⁺ and CD71⁺CD235a⁺) is represented by values to the right of each plot. The average response to treatment of all samples after 24 hours in which viability was assessed (B) or after 6 days when maturation was assessed by comparing the proportion of committed erythroid progenitors (CD235a⁺) that express low levels of CD71 (CD71^lo) (C). Error bars show standard error of the mean of responses from 4 different donors; ND, not determined due to insufficient cell recovery. *p≤0.05 when compared with media alone (two tailed student’s test).</p