Erythroid Kruppel-like factor directly activates the basic Kruppel-like factor gene in erythroid cells

The Sp/Kriippel-like factor (Sp/KIf) family is comprised of around 25 zinc finger transcription factors that recognize CACCC boxes and GC-rich elements. We have investigated basic Kruppel-like factor (Bklf/Klf3) and show that in erythroid tissues its expression is highly dependent on another family member, erythroid Kruppel-like factor (Eklf/Kif1). We observe that Bklf mRNA is significantly reduced in erythroid tissues from Eklf-null murine embryos. We find that Bklf is driven primarily by two promoters, a ubiquitously active GC-rich upstream promoter, la, and an erythroid downstream promoter, 1b. Transcripts from the two promoters encode identical proteins. Interestingly, both the ubiquitous and the erythroid promoter are dependent on Eklf in erythroid cells. Eklf also activates both promoters in transient assays. Experiments utilizing an inducible form of Eklf demonstrate activation of the endogenous Bklf gene in the presence of an inhibitor of protein synthesis. The kinetics of activation are also consistent with Bklf being a direct Eklf target. Chromatin immunoprecipitation assays confirm that Eklf associates with both Bklf promoters. Eklf is typically an activator of transcription, whereas Bklf is noted as a repressor. Our results support the hypothesis that feedback cross-regulation occurs within the Sp/Klf family in vivo

The CACCC-binding protein KLF3/BKLF represses a subset of KLF1/EKLF target genes and is required for proper erythroid maturation in vivo

The CACCC-box binding protein erythroid Kruppel-like factor (EKLF/KLF1) is a master regulator that directs the expression of many important erythroid genes. We have previously shown that EKLF drives transcription of the gene for a second KLF, basic Kruppel-like factor, or KLF3. We have now tested the in vivo role of KLF3 in erythroid cells by examining Klf3 knockout mice. KLF3-deficient adults exhibit a mild compensated anemia, including enlarged spleens, increased red pulp, and a higher percentage of erythroid progenitors, together with elevated reticulocytes and abnormal erythrocytes in the peripheral blood. Impaired erythroid maturation is also observed in the fetal liver. We have found that KLF3 levels rise as erythroid cells mature to become TER119(+). Consistent with this, microarray analysis of both TER119(-) and TER119(+) erythroid populations revealed that KLF3 is most critical at the later stages of erythroid maturation and is indeed primarily a transcriptional repressor. Notably, many of the genes repressed by KLF3 are also known to be activated by EKLF. However, the majority of these are not currently recognized as erythroid-cell-specific genes. These results reveal the molecular and physiological function of KLF3, defining it as a feedback repressor that counters the activity of EKLF at selected target genes to achieve normal erythropoiesis

Rising Tide 2016

Research and scholarship highlights from University of New England community members. This issue highlights student and faculty research and projects within UNE\u27s College of Arts and Sciences, College of Dental Medicine, College of Osteopathic Medicine, College of Pharmacy, Westbrook College of Health Professions, and projects and research from UNE\u27s Centers for Excellence.https://dune.une.edu/risingtide/1005/thumbnail.jp

A global role for KLF1 in erythropoiesis revealed by ChIP-seq in primary erythroid cells

KLF1 regulates a diverse suite of genes to direct erythroid cell differentiation from bipotent progenitors. To determine the local cis-regulatory contexts and transcription factor networks in which KLF1 operates, we performed KLF1 ChIP-seq in the mouse. We found at least 945 sites in the genome of E14.5 fetal liver erythroid cells which are occupied by endogenous KLF1. Many of these recovered sites reside in erythroid gene promoters such as Hbb-bl, but the majority are distant to any known gene. Our data suggests KLF1 directly regulates most aspects of terminal erythroid differentiation including production of alpha- and beta-globin protein chains, heme biosynthesis, coordination of proliferation and anti-apoptotic pathways, and construction of the red cell membrane and cytoskeleton by functioning primarily as a transcriptional activator. Additionally, we suggest new mechanisms for KLF1 cooperation with other transcription factors, in particular the erythroid transcription factor GATA1, to maintain homeostasis in the erythroid compartment

New integrated care models in England associated with small reduction in hospital admissions in longer-term: a difference-in-differences analysis

Closer integration of health and social care services has become a cornerstone policy in many developed countries, but there is still debate over what population and service level is best to target. In England, the 2019 Long Term Plan for the National Health Service included a commitment to spread the integration prototypes piloted under the Vanguard `New Care Models’ programme. The programme, running from 2015-2018, was one of the largest pilots in English history, covering around 9% of the population. It was largely intended to design prototypes aimed at reducing hospital utilisation by moving specialist care out of hospital into the community and by fostering coordination of health, care and rehabilitation services for (i) the whole population (‘population-based sites’), or (ii) care home residents (‘care home sites’). We evaluate and compare the efficacy of the population-based and care home site integrated care models in reducing hospital utilisation. We use area-level monthly counts of emergency admissions and bed-days obtained from administrative data using a quasi-experimental difference-in-differences design. We found that Vanguard sites had higher hospital utilisation than non-participants in the pre-intervention period. In the post-intervention period, there is clear evidence of a substantial increase in emergency admissions among non-Vanguard sites. The Vanguard integrated care programme slowed the rise in emergency admissions, especially in care home sites and in the third and final year. There was no significant reduction in bed-days. In conclusion, integrated care policies should not be relied upon to make large reductions in hospital activity in the short-run, especially for population-based models

Improving children and young people’s mental health services

Across the UK, the number of children and young people experiencing mental health problems is growing. Mental health services are expanding, but not fast enough to meet rising needs, leaving many children and young people with limited or no support. Too little is known about who receives care and crucially, who doesn’t. This briefing presents analysis from the Health Foundation’s Networked Data Lab (NDL) about children and young people’s mental health. The analysis from local teams across England, Scotland and Wales has highlighted three key areas for urgent investigation, to help ensure children and young people get the care they need. These are: rapid increases in mental health prescribing and support provided by GPs the prevalence of mental health problems among adolescent girls and young women stark socioeconomic inequalities across the UK. To inform national policy decisions and local service planning and delivery, the quality of data collection, analysis and the linkage of datasets across services and sectors need to be improved and used more effectively

Geniculo-Cortical Projection Diversity Revealed within the Mouse Visual Thalamus

This is the final version of the article. It was first available from PLOS via http://dx.doi.org/10.1371/journal.pone.0144846All dLGN cell co-ordinates, V1 injection sites, dLGN boundary coordinates, experimental protocols and analysis scripts are available for download from figshare at https://figshare.com/s/36c6d937b1844eec80a1.The mouse dorsal lateral geniculate nucleus (dLGN) is an intermediary between retina and primary visual cortex (V1). Recent investigations are beginning to reveal regional complexity in mouse dLGN. Using local injections of retrograde tracers into V1 of adult and neonatal mice, we examined the developing organisation of geniculate projection columns: the population of dLGN-V1 projection neurons that converge in cortex. Serial sectioning of the dLGN enabled the distribution of labelled projection neurons to be reconstructed and collated within a common standardised space. This enabled us to determine: the organisation of cells within the dLGN-V1 projection columns; their internal organisation (topology); and their order relative to V1 (topography). Here, we report parameters of projection columns that are highly variable in young animals and refined in the adult, exhibiting profiles consistent with shell and core zones of the dLGN. Additionally, such profiles are disrupted in adult animals with reduced correlated spontaneous activity during development. Assessing the variability between groups with partial least squares regression suggests that 4?6 cryptic lamina may exist along the length of the projection column. Our findings further spotlight the diversity of the mouse dLGN?an increasingly important model system for understanding the pre-cortical organisation and processing of visual information. Furthermore, our approach of using standardised spaces and pooling information across many animals will enhance future functional studies of the dLGN.Funding was provided by a Wellcome Trust grant jointly awarded to IDT and SJE (083205, www.wellcome.ac.uk), and by MRC PhD Studentships awarded to MNL and ACH (http://www.mrc.ac.uk/)

Snx3 Regulates Recycling of the Transferrin Receptor and Iron Assimilation

Sorting of endocytic ligands and receptors is critical for diverse cellular processes. The physiological significance of endosomal sorting proteins in vertebrates, however, remains largely unknown. Here we report that sorting nexin 3 (Snx3) facilitates the recycling of transferrin receptor (Tfrc) and thus is required for the proper delivery of iron to erythroid progenitors. Snx3 is highly expressed in vertebrate hematopoietic tissues. Silencing of Snx3 results in anemia and hemoglobin defects in vertebrates due to impaired transferrin (Tf)-mediated iron uptake and its accumulation in early endosomes. This impaired iron assimilation can be complemented with non-Tf iron chelates. We show that Snx3 and Vps35, a component of the retromer, interact with Tfrc to sort it to the recycling endosomes. Our findings uncover a role of Snx3 in regulating Tfrc recycling, iron homeostasis, and erythropoiesis. Thus, the identification of Snx3 provides a genetic tool for exploring erythropoiesis and disorders of iron metabolism.National Institutes of Health (U.S.) (P01 HL032262