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Bieker JJ, Philipsen S. Erythroid Krüppel-Like Factor (KLF1): A Surprisingly Versatile Regulator of Erythroid Differentiation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1459:217-242. [PMID: 39017846 DOI: 10.1007/978-3-031-62731-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Erythroid Krüppel-like factor (KLF1), first discovered in 1992, is an erythroid-restricted transcription factor (TF) that is essential for terminal differentiation of erythroid progenitors. At face value, KLF1 is a rather inconspicuous member of the 26-strong SP/KLF TF family. However, 30 years of research have revealed that KLF1 is a jack of all trades in the molecular control of erythropoiesis. Initially described as a one-trick pony required for high-level transcription of the adult HBB gene, we now know that it orchestrates the entire erythroid differentiation program. It does so not only as an activator but also as a repressor. In addition, KLF1 was the first TF shown to be directly involved in enhancer/promoter loop formation. KLF1 variants underlie a wide range of erythroid phenotypes in the human population, varying from very mild conditions such as hereditary persistence of fetal hemoglobin and the In(Lu) blood type in the case of haploinsufficiency, to much more serious non-spherocytic hemolytic anemias in the case of compound heterozygosity, to dominant congenital dyserythropoietic anemia type IV invariably caused by a de novo variant in a highly conserved amino acid in the KLF1 DNA-binding domain. In this chapter, we present an overview of the past and present of KLF1 research and discuss the significance of human KLF1 variants.
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Affiliation(s)
- James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Sjaak Philipsen
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands.
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2
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EKLF/Klf1 regulates erythroid transcription by its pioneering activity and selective control of RNA Pol II pause-release. Cell Rep 2022; 41:111830. [PMID: 36543143 PMCID: PMC9879271 DOI: 10.1016/j.celrep.2022.111830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/06/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022] Open
Abstract
EKLF/Klf1 is a zinc-finger transcription activator essential for erythroid lineage commitment and terminal differentiation. Using ChIP-seq, we investigate EKLF DNA binding and transcription activation mechanisms during mouse embryonic erythropoiesis. We utilize the Nan/+ mouse that expresses the EKLF-E339D (Nan) variant mutated in its conserved zinc-finger region and address the mechanism of hypomorphic and neomorphic changes in downstream gene expression. First, we show that Nan-EKLF limits normal EKLF binding to a subset of its sites. Second, we find that ectopic binding of Nan-EKLF occurs largely at enhancers and activates transcription through pioneering activity. Third, we find that for a subset of ectopic targets, gene activation is achieved in Nan/+ only by Nan-EKLF binding to distal enhancers, leading to RNA polymerase II pause-release. These results have general applicability to understanding how a DNA binding variant factor confers dominant disruptive effects on downstream gene expression even in the presence of its normal counterpart.
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Krüppel-Like Factor 1: A Pivotal Gene Regulator in Erythropoiesis. Cells 2022; 11:cells11193069. [PMID: 36231031 PMCID: PMC9561966 DOI: 10.3390/cells11193069] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Krüppel-like factor 1 (KLF1) plays a crucial role in erythropoiesis. In-depth studies conducted on mice and humans have highlighted its importance in erythroid lineage commitment, terminal erythropoiesis progression and the switching of globin genes from γ to β. The role of KLF1 in haemoglobin switching is exerted by the direct activation of β-globin gene and by the silencing of γ-globin through activation of BCL11A, an important γ-globin gene repressor. The link between KLF1 and γ-globin silencing identifies this transcription factor as a possible therapeutic target for β-hemoglobinopathies. Moreover, several mutations have been identified in the human genes that are responsible for various benign phenotypes and erythroid disorders. The study of the phenotype associated with each mutation has greatly contributed to the current understanding of the complex role of KLF1 in erythropoiesis. This review will focus on some of the principal functions of KLF1 on erythroid cell commitment and differentiation, spanning from primitive to definitive erythropoiesis. The fundamental role of KLF1 in haemoglobin switching will be also highlighted. Finally, an overview of the principal human mutations and relative phenotypes and disorders will be described.
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King R, Gallagher PJ, Khoriaty R. The congenital dyserythropoieitic anemias: genetics and pathophysiology. Curr Opin Hematol 2022; 29:126-136. [PMID: 35441598 PMCID: PMC9021540 DOI: 10.1097/moh.0000000000000697] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW The congenital dyserythropoietic anemias (CDA) are hereditary disorders characterized by ineffective erythropoiesis. This review evaluates newly developed CDA disease models, the latest advances in understanding the pathogenesis of the CDAs, and recently identified CDA genes. RECENT FINDINGS Mice exhibiting features of CDAI were recently generated, demonstrating that Codanin-1 (encoded by Cdan1) is essential for primitive erythropoiesis. Additionally, Codanin-1 was found to physically interact with CDIN1, suggesting that mutations in CDAN1 and CDIN1 result in CDAI via a common mechanism. Recent advances in CDAII (which results from SEC23B mutations) have also been made. SEC23B was found to functionally overlap with its paralogous protein, SEC23A, likely explaining the absence of CDAII in SEC23B-deficient mice. In contrast, mice with erythroid-specific deletion of 3 or 4 of the Sec23 alleles exhibited features of CDAII. Increased SEC23A expression rescued the CDAII erythroid defect, suggesting a novel therapeutic strategy for the disease. Additional recent advances included the identification of new CDA genes, RACGAP1 and VPS4A, in CDAIII and a syndromic CDA type, respectively. SUMMARY Establishing cellular and animal models of CDA is expected to result in improved understanding of the pathogenesis of these disorders, which may ultimately lead to the development of new therapies.
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Affiliation(s)
- Richard King
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, Michigan, USA
| | - Patrick J. Gallagher
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Rami Khoriaty
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, Michigan, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
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5
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Korporaal A, Gillemans N, Heshusius S, Cantú I, van den Akker E, van Dijk TB, von Lindern M, Philipsen S. Hemoglobin switching in mice carrying the Klf1Nan variant. Haematologica 2021; 106:464-473. [PMID: 32467144 PMCID: PMC7849558 DOI: 10.3324/haematol.2019.239830] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 02/23/2020] [Indexed: 12/21/2022] Open
Abstract
Haploinsufficiency for transcription factor KLF1 causes a variety of human erythroid phenotypes, such as the In(Lu) blood type, increased HbA2 levels, and hereditary persistence of fetal hemoglobin. Severe dominant congenital dyserythropoietic anemia IV (OMIM 613673) is associated with the KLF1 p.E325K variant. CDA-IV patients display ineffective erythropoiesis and hemolysis resulting in anemia, accompanied by persistent high levels of embryonic and fetal hemoglobin. The mouse Nan strain carries a variant in the orthologous residue, KLF1 p.E339D. Klf1Nan causes dominant hemolytic anemia with many similarities to CDA-IV. Here we investigated the impact of Klf1Nan on the developmental expression patterns of the endogenous beta-like and alpha-like globins, and the human beta-like globins carried on a HBB locus transgene. We observe that the switch from primitive, yolk sac-derived, erythropoiesis to definitive, fetal liver-derived, erythropoiesis is delayed in Klf1wt/Nan embryos. This is reflected in globin expression patterns measured between E12.5 and E14.5. Cultured Klf1wt/Nan E12.5 fetal liver cells display growth- and differentiation defects. These defects likely contribute to the delayed appearance of definitive erythrocytes in the circulation of Klf1wt/Nan embryos. After E14.5, expression of the embryonic/fetal globin genes is silenced rapidly. In adult Klf1wt/Nan animals, silencing of the embryonic/fetal globin genes is impeded, but only minute amounts are expressed. Thus, in contrast to human KLF1 p.E325K, mouse KLF1 p.E339D does not lead to persistent high levels of embryonic/fetal globins. Our results support the notion that KLF1 affects gene expression in a variant-specific manner, highlighting the necessity to characterize KLF1 variant-specific phenotypes of patients in detail.
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Affiliation(s)
- Anne Korporaal
- Erasmus MC Department of Cell Biology, Rotterdam, The Netherlands
| | - Nynke Gillemans
- Erasmus MC Department of Cell Biology, Rotterdam, The Netherlands
| | - Steven Heshusius
- Department of Hematopoiesis, Sanquin Research, Amsterdam, The Netherlands
| | - Ileana Cantú
- Erasmus MC Department of Cell Biology, Rotterdam, The Netherlands
| | | | | | | | - Sjaak Philipsen
- Erasmus MC Department of Cell Biology, Rotterdam, The Netherlands
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6
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Kulczynska-Figurny K, Bieker JJ, Siatecka M. Severe anemia caused by dominant mutations in Krüppel-like factor 1 (KLF1). MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 786:108336. [PMID: 33339573 DOI: 10.1016/j.mrrev.2020.108336] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/23/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The etiology and severity of anemia, a common blood disorder, are diverse. Dominant mutations in Krüppel-like factor 1 (KLF1/EKLF) underlie the molecular basis for some of them. KLF1 is a zinc finger transcription factor that plays an essential role in red blood cell proliferation and differentiation. Mutations have been identified in the KLF1 gene that cause hematologic diseases. Two of these alter one allele but generate an extreme phenotype: the mouse Nan mutation (E339D) leads to hemolytic neonatal anemia with hereditary spherocytosis, and the human CDA mutation (E325K) causes congenital dyserythropoietic anemia (CDA) type IV. These modify functionally important amino acids in the zinc finger DNA-binding domain at positions involved in direct interactions with regulatory elements of KLF1's target genes. Although the two dominant mutations alter the same evolutionarily conserved glutamic acid residue, the substitutions are not equivalent and lead to divergent consequences for the molecular mechanisms underlying activity of these mutants, particularly in recognition and interaction with their unique binding sites. Consequently, the properties of the protein are transformed such that it acquires novel dominant characteristics whose effects may not be limited to the erythroid compartment. KLF1 mutants cause loss-of-function/haploinsufficiency effects on some KLF1 wild-type target genes, while at the same time gain-of-function effects activate ectopic sites and neomorphic gene expression. Such anomalies not only lead to intrinsic red cell problems, but also to expression of non-erythroid genes that systemically disturb organ development. This review highlights recent molecular, biochemical, and genetic studies of KLF1 mutants, particularly the dramatic consequences that come from just a single amino acid change. The study of these variants provides an important contribution to the overall understanding of the DNA-protein interface of the zinc finger subtype of transcription factors, and the potential clinical consequences of what might appear to be a minor change in sequence.
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Affiliation(s)
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Miroslawa Siatecka
- Department of Genetics, Faculty of Biology, University of Adam Mickiewicz, Poznan, 61-614, Poland.
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7
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A Krüppel-like factor 1 ( KLF1) Mutation Associated with Severe Congenital Dyserythropoietic Anemia Alters Its DNA-Binding Specificity. Mol Cell Biol 2020; 40:MCB.00444-19. [PMID: 31818881 DOI: 10.1128/mcb.00444-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/04/2019] [Indexed: 11/20/2022] Open
Abstract
Krüppel-like factor 1 (KLF1/EKLF) is a transcription factor that globally activates genes involved in erythroid cell development. Various mutations are identified in the human KLF1 gene. The E325K mutation causes congenital dyserythropoietic anemia (CDA) type IV, characterized by severe anemia and non-erythroid-cell-related symptoms. The CDA mutation is in the second zinc finger of KLF1 at a position functionally involved in its interactions with DNA. The molecular parameters of how CDA-KLF1 exerts its biological effects have not been addressed. Here, using an in vitro selection strategy, we determined the preferred DNA-binding site for CDA-KLF1. Binding to the deduced consensus sequence is supported by in vitro gel shifts and by in vivo functional reporter gene studies. Two significant changes compared to wild-type (WT) binding are observed: G is selected as the middle nucleotide, and the 3' portion of the consensus sequence is more degenerate. As a consequence, CDA-KLF1 did not bind the WT consensus sequence. However, activation of ectopic sites is promoted. Continuous activation of WT target genes occurs if they fortuitously contain the novel CDA site nearby. Our findings provide a molecular understanding of how a single mutation in the KLF1 zinc finger exerts effects on erythroid physiology in CDA type IV.
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8
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Ilsley MD, Huang S, Magor GW, Landsberg MJ, Gillinder KR, Perkins AC. Corrupted DNA-binding specificity and ectopic transcription underpin dominant neomorphic mutations in KLF/SP transcription factors. BMC Genomics 2019; 20:417. [PMID: 31126231 PMCID: PMC6534859 DOI: 10.1186/s12864-019-5805-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 05/17/2019] [Indexed: 02/07/2023] Open
Abstract
Background Mutations in the transcription factor, KLF1, are common within certain populations of the world. Heterozygous missense mutations in KLF1 mostly lead to benign phenotypes, but a heterozygous mutation in a DNA-binding residue (E325K in human) results in severe Congenital Dyserythropoietic Anemia type IV (CDA IV); i.e. an autosomal-dominant disorder characterized by neonatal hemolysis. Results To investigate the biochemical and genetic mechanism of CDA IV, we generated murine erythroid cell lines that harbor tamoxifen-inducible (ER™) versions of wild type and mutant KLF1 on a Klf1−/− genetic background. Nuclear translocation of wild type KLF1 results in terminal erythroid differentiation, whereas mutant KLF1 results in hemolysis without differentiation. The E to K variant binds poorly to the canonical 9 bp recognition motif (NGG-GYG-KGG) genome-wide but binds at high affinity to a corrupted motif (NGG-GRG-KGG). We confirmed altered DNA-binding specificity by quantitative in vitro binding assays of recombinant zinc-finger domains. Our results are consistent with previously reported structural data of KLF-DNA interactions. We employed 4sU-RNA-seq to show that a corrupted transcriptome is a direct consequence of aberrant DNA binding. Conclusions Since all KLF/SP family proteins bind DNA in an identical fashion, these results are likely to be generally applicable to mutations in all family members. Importantly, they explain how certain mutations in the DNA-binding domain of transcription factors can generate neomorphic functions that result in autosomal dominant disease. Electronic supplementary material The online version of this article (10.1186/s12864-019-5805-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Melissa D Ilsley
- Mater Research, Translational Research Institute, University of Queensland, Brisbane, QLD, Australia.,School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Stephen Huang
- Mater Research, Translational Research Institute, University of Queensland, Brisbane, QLD, Australia.,School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Graham W Magor
- Mater Research, Translational Research Institute, University of Queensland, Brisbane, QLD, Australia.,Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, Australia
| | - Michael J Landsberg
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Kevin R Gillinder
- Mater Research, Translational Research Institute, University of Queensland, Brisbane, QLD, Australia. .,Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, Australia.
| | - Andrew C Perkins
- Mater Research, Translational Research Institute, University of Queensland, Brisbane, QLD, Australia.,Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, Australia
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9
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Cantú I, van de Werken HJG, Gillemans N, Stadhouders R, Heshusius S, Maas A, Esteghamat F, Ozgur Z, van IJcken WFJ, Grosveld F, von Lindern M, Philipsen S, van Dijk TB. The mouse KLF1 Nan variant impairs nuclear condensation and erythroid maturation. PLoS One 2019; 14:e0208659. [PMID: 30921348 PMCID: PMC6438607 DOI: 10.1371/journal.pone.0208659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/11/2019] [Indexed: 12/13/2022] Open
Abstract
Krüppel-like factor 1 (KLF1) is an essential transcription factor for erythroid development, as demonstrated by Klf1 knockout mice which die around E14 due to severe anemia. In humans, >140 KLF1 variants, causing different erythroid phenotypes, have been described. The KLF1 Nan variant, a single amino acid substitution (p.E339D) in the DNA binding domain, causes hemolytic anemia and is dominant over wildtype KLF1. Here we describe the effects of the KLF1 Nan variant during fetal development. We show that Nan embryos have defects in erythroid maturation. RNA-sequencing of the KLF1 Nan fetal liver cells revealed that Exportin 7 (Xpo7) was among the 782 deregulated genes. This nuclear exportin is implicated in terminal erythroid differentiation; in particular it is involved in nuclear condensation. Indeed, KLF1 Nan fetal liver cells had larger nuclei and reduced chromatin condensation. Knockdown of XPO7 in wildtype erythroid cells caused a similar phenotype. We propose that reduced expression of XPO7 is partially responsible for the erythroid defects observed in KLF1 Nan erythroid cells.
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Affiliation(s)
- Ileana Cantú
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Nynke Gillemans
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Steven Heshusius
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
- Department of Hematopoiesis, Sanquin Research, Amsterdam, The Netherlands
| | - Alex Maas
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Zeliha Ozgur
- Center for Biomics, Erasmus MC, Rotterdam, The Netherlands
| | | | - Frank Grosveld
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Sjaak Philipsen
- Department of Cell Biology, Erasmus MC, Rotterdam, The Netherlands
- * E-mail:
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Varricchio L, Planutis A, Manwani D, Jaffray J, Mitchell WB, Migliaccio AR, Bieker JJ. Genetic disarray follows mutant KLF1-E325K expression in a congenital dyserythropoietic anemia patient. Haematologica 2019; 104:2372-2380. [PMID: 30872368 PMCID: PMC6959163 DOI: 10.3324/haematol.2018.209858] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/12/2019] [Indexed: 12/20/2022] Open
Abstract
Congenital dyserythropoietic anemia type IV is caused by a heterozygous mutation, Glu325Lys (E325K), in the KLF1 transcription factor. Molecular characteristics of this disease have not been clarified, partly due to its rarity. We expanded erythroid cells from a patient's peripheral blood and analyzed its global expression pattern. We find that a large number of erythroid pathways are disrupted, particularly those related to membrane transport, globin regulation, and iron utilization. The altered genetics lead to significant deficits in differentiation. Glu325 is within the KLF1 zinc finger domain at an amino acid critical for site specific DNA binding. The change to Lys is predicted to significantly alter the target site recognition sequence, both by subverting normal recognition and by enabling interaction with novel sites. Consistent with this, we find high level ectopic expression of genes not normally present in the red cell. These altered properties explain patients' clinical and phenotypic features, and elucidate the dominant character of the mutation.
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Affiliation(s)
- Lilian Varricchio
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Antanas Planutis
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Deepa Manwani
- Division of Hematology/Oncology, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Julie Jaffray
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - W Beau Mitchell
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Anna Rita Migliaccio
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Dipartimento di Scienze Biomediche e NeuroMotorie, Alma Mater Studiorum, Università di Bologna, Bologna, Italy
| | - James J Bieker
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA .,Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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11
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Barbarani G, Fugazza C, Strouboulis J, Ronchi AE. The Pleiotropic Effects of GATA1 and KLF1 in Physiological Erythropoiesis and in Dyserythropoietic Disorders. Front Physiol 2019; 10:91. [PMID: 30809156 PMCID: PMC6379452 DOI: 10.3389/fphys.2019.00091] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/25/2019] [Indexed: 01/19/2023] Open
Abstract
In the last few years, the advent of new technological approaches has led to a better knowledge of the ontogeny of erythropoiesis during development and of the journey leading from hematopoietic stem cells (HSCs) to mature red blood cells (RBCs). Our view of a well-defined hierarchical model of hematopoiesis with a near-homogeneous HSC population residing at the apex has been progressively challenged in favor of a landscape where HSCs themselves are highly heterogeneous and lineages separate earlier than previously thought. The coordination of these events is orchestrated by transcription factors (TFs) that work in a combinatorial manner to activate and/or repress their target genes. The development of next generation sequencing (NGS) has facilitated the identification of pathological mutations involving TFs underlying hematological defects. The examples of GATA1 and KLF1 presented in this review suggest that in the next few years the number of TF mutations associated with dyserythropoietic disorders will further increase.
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Affiliation(s)
- Gloria Barbarani
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi Milano-Bicocca, Milan, Italy
| | - Cristina Fugazza
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi Milano-Bicocca, Milan, Italy
| | - John Strouboulis
- School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Antonella E Ronchi
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi Milano-Bicocca, Milan, Italy
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12
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O'Connor T, Bodén M, Bailey TL. CisMapper: predicting regulatory interactions from transcription factor ChIP-seq data. Nucleic Acids Res 2018; 45:e19. [PMID: 28204599 PMCID: PMC5389714 DOI: 10.1093/nar/gkw956] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 09/30/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022] Open
Abstract
Identifying the genomic regions and regulatory factors that control the transcription of genes is an important, unsolved problem. The current method of choice predicts transcription factor (TF) binding sites using chromatin immunoprecipitation followed by sequencing (ChIP-seq), and then links the binding sites to putative target genes solely on the basis of the genomic distance between them. Evidence from chromatin conformation capture experiments shows that this approach is inadequate due to long-distance regulation via chromatin looping. We present CisMapper, which predicts the regulatory targets of a TF using the correlation between a histone mark at the TF's bound sites and the expression of each gene across a panel of tissues. Using both chromatin conformation capture and differential expression data, we show that CisMapper is more accurate at predicting the target genes of a TF than the distance-based approaches currently used, and is particularly advantageous for predicting the long-range regulatory interactions typical of tissue-specific gene expression. CisMapper also predicts which TF binding sites regulate a given gene more accurately than using genomic distance. Unlike distance-based methods, CisMapper can predict which transcription start site of a gene is regulated by a particular binding site of the TF.
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Affiliation(s)
| | - Mikael Bodén
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, Australia
| | - Timothy L Bailey
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0357, USA
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13
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Nébor D, Graber JH, Ciciotte SL, Robledo RF, Papoin J, Hartman E, Gillinder KR, Perkins AC, Bieker JJ, Blanc L, Peters LL. Mutant KLF1 in Adult Anemic Nan Mice Leads to Profound Transcriptome Changes and Disordered Erythropoiesis. Sci Rep 2018; 8:12793. [PMID: 30143664 PMCID: PMC6109071 DOI: 10.1038/s41598-018-30839-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/02/2018] [Indexed: 12/31/2022] Open
Abstract
Anemic Nan mice carry a mutation (E339D) in the second zinc finger of erythroid transcription factor KLF1. Nan-KLF1 fails to bind a subset of normal KLF1 targets and ectopically binds a large set of genes not normally engaged by KLF1, resulting in a corrupted fetal liver transcriptome. Here, we performed RNAseq using flow cytometric-sorted spleen erythroid precursors from adult Nan and WT littermates rendered anemic by phlebotomy to identify global transcriptome changes specific to the Nan Klf1 mutation as opposed to anemia generally. Mutant Nan-KLF1 leads to extensive and progressive transcriptome corruption in adult spleen erythroid precursors such that stress erythropoiesis is severely compromised. Terminal erythroid differentiation is defective in the bone marrow as well. Principle component analysis reveals two major patterns of differential gene expression predicting that defects in basic cellular processes including translation, cell cycle, and DNA repair could contribute to disordered erythropoiesis and anemia in Nan. Significant erythroid precursor stage specific changes were identified in some of these processes in Nan. Remarkably, however, despite expression changes in large numbers of associated genes, most basic cellular processes were intact in Nan indicating that developing red cells display significant physiological resiliency and establish new homeostatic set points in vivo.
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Affiliation(s)
| | - Joel H Graber
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA.,MDI Biological Laboratory, Salisbury Cove, ME, 04672, USA
| | | | | | - Julien Papoin
- Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA
| | - Emily Hartman
- Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA
| | - Kevin R Gillinder
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, 3004, Australia.,The Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - Andrew C Perkins
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, 3004, Australia.,The Alfred Hospital, Melbourne, VIC, 3004, Australia
| | - James J Bieker
- Department of Cell, Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | - Lionel Blanc
- Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA
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14
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Gnanapragasam MN, Crispino JD, Ali AM, Weinberg R, Hoffman R, Raza A, Bieker JJ. Survey and evaluation of mutations in the human KLF1 transcription unit. Sci Rep 2018; 8:6587. [PMID: 29700354 PMCID: PMC5920080 DOI: 10.1038/s41598-018-24962-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/12/2018] [Indexed: 01/03/2023] Open
Abstract
Erythroid Krüppel-like Factor (EKLF/KLF1) is an erythroid-enriched transcription factor that plays a global role in all aspects of erythropoiesis, including cell cycle control and differentiation. We queried whether its mutation might play a role in red cell malignancies by genomic sequencing of the KLF1 transcription unit in cell lines, erythroid neoplasms, dysplastic disorders, and leukemia. In addition, we queried published databases from a number of varied sources. In all cases we only found changes in commonly notated SNPs. Our results suggest that if there are mutations in KLF1 associated with erythroid malignancies, they are exceedingly rare.
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Affiliation(s)
- Merlin Nithya Gnanapragasam
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | - John D Crispino
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Abdullah M Ali
- Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Rona Weinberg
- Cellular Therapy Laboratory, New York Blood Center, New York, NY, 10065, USA
| | - Ronald Hoffman
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | - Azra Raza
- Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Black Familly Stem Cell Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
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15
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16
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Gillinder KR, Ilsley MD, Nébor D, Sachidanandam R, Lajoie M, Magor GW, Tallack MR, Bailey T, Landsberg MJ, Mackay JP, Parker MW, Miles LA, Graber JH, Peters LL, Bieker JJ, Perkins AC. Promiscuous DNA-binding of a mutant zinc finger protein corrupts the transcriptome and diminishes cell viability. Nucleic Acids Res 2017; 45:1130-1143. [PMID: 28180284 PMCID: PMC5388391 DOI: 10.1093/nar/gkw1014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/13/2016] [Accepted: 11/02/2016] [Indexed: 12/27/2022] Open
Abstract
The rules of engagement between zinc finger transcription factors and DNA have been partly defined by in vitro DNA-binding and structural studies, but less is known about how these rules apply in vivo. Here, we demonstrate how a missense mutation in the second zinc finger of Krüppel-like factor-1 (KLF1) leads to degenerate DNA-binding specificity in vivo, resulting in ectopic transcription and anemia in the Nan mouse model. We employed ChIP-seq and 4sU-RNA-seq to identify aberrant DNA-binding events genome wide and ectopic transcriptional consequences of this binding. We confirmed novel sequence specificity of the mutant recombinant zinc finger domain by performing biophysical measurements of in vitro DNA-binding affinity. Together, these results shed new light on the mechanisms by which missense mutations in DNA-binding domains of transcription factors can lead to autosomal dominant diseases.
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Affiliation(s)
- Kevin R Gillinder
- Cancer Genomics Group, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Melissa D Ilsley
- Cancer Genomics Group, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | | | - Ravi Sachidanandam
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY, USA
| | - Mathieu Lajoie
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
| | - Graham W Magor
- Cancer Genomics Group, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Michael R Tallack
- Cancer Genomics Group, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Timothy Bailey
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, NV, USA
| | - Michael J Landsberg
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, The University of Sydney, NSW, Australia
| | - Michael W Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia.,ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Melbourne, VIC, Australia
| | - Luke A Miles
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | | | | | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, USA
| | - Andrew C Perkins
- Cancer Genomics Group, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.,Princess Alexandra Hospital, Brisbane, QLD 4102, Australia
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17
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Planutis A, Xue L, Trainor CD, Dangeti M, Gillinder K, Siatecka M, Nebor D, Peters LL, Perkins AC, Bieker JJ. Neomorphic effects of the neonatal anemia (Nan-Eklf) mutation contribute to deficits throughout development. Development 2017; 144:430-440. [PMID: 28143845 DOI: 10.1242/dev.145656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/18/2016] [Indexed: 12/20/2022]
Abstract
Transcription factor control of cell-specific downstream targets can be significantly altered when the controlling factor is mutated. We show that the semi-dominant neonatal anemia (Nan) mutation in the EKLF/KLF1 transcription factor leads to ectopic expression of proteins that are not normally expressed in the red blood cell, leading to systemic effects that exacerbate the intrinsic anemia in the adult and alter correct development in the early embryo. Even when expressed as a heterozygote, the Nan-EKLF protein accomplishes this by direct binding and aberrant activation of genes encoding secreted factors that exert a negative effect on erythropoiesis and iron use. Our data form the basis for a novel mechanism of physiological deficiency that is relevant to human dyserythropoietic anemia and likely other disease states.
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Affiliation(s)
- Antanas Planutis
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Li Xue
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Cecelia D Trainor
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Mohan Dangeti
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Kevin Gillinder
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia
| | - Miroslawa Siatecka
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Genetics, University of Adam Mickiewicz, Poznan 61-614, Poland
| | | | | | - Andrew C Perkins
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia.,Princess Alexandra Hospital, Brisbane QLD 4102, Queensland, Australia
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA .,Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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18
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Satta S, Paglietti ME, Sollaino MC, Barella S, Moi P, Desogus MF, Demartis FR, Manunza L, Origa R. Changes in HbA2 and HbF in alpha thalassemia carriers with KLF1 mutation. Blood Cells Mol Dis 2017; 64:30-32. [DOI: 10.1016/j.bcmd.2017.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/16/2017] [Accepted: 03/17/2017] [Indexed: 12/29/2022]
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19
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Andolfo I, Russo R, Gambale A, Iolascon A. New insights on hereditary erythrocyte membrane defects. Haematologica 2016; 101:1284-1294. [PMID: 27756835 PMCID: PMC5394881 DOI: 10.3324/haematol.2016.142463] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/16/2016] [Indexed: 01/02/2023] Open
Abstract
After the first proposed model of the red blood cell membrane skeleton 36 years ago, several additional proteins have been discovered during the intervening years, and their relationship with the pathogenesis of the related disorders have been somewhat defined. The knowledge of erythrocyte membrane structure is important because it represents the model for spectrin-based membrane skeletons in all cells and because defects in its structure underlie multiple hemolytic anemias. This review summarizes the main features of erythrocyte membrane disorders, dividing them into structural and altered permeability defects, focusing particularly on the most recent advances. New proteins involved in alterations of the red blood cell membrane permeability were recently described. The mechanoreceptor PIEZO1 is the largest ion channel identified to date, the fundamental regulator of erythrocyte volume homeostasis. Missense, gain-of-function mutations in the PIEZO1 gene have been identified in several families as causative of dehydrated hereditary stomatocytosis or xerocytosis. Similarly, the KCNN4 gene, codifying the so called Gardos channel, has been recently identified as a second causative gene of hereditary xerocytosis. Finally, ABCB6 missense mutations were identified in different pedigrees of familial pseudohyperkalemia. New genomic technologies have improved the quality and reduced the time of diagnosis of these diseases. Moreover, they are essential for the identification of the new causative genes. However, many questions remain to solve, and are currently objects of intensive studies.
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Affiliation(s)
- Immacolata Andolfo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Roberta Russo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Antonella Gambale
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Achille Iolascon
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
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20
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Krüppeling erythropoiesis: an unexpected broad spectrum of human red blood cell disorders due to KLF1 variants. Blood 2016; 127:1856-62. [PMID: 26903544 DOI: 10.1182/blood-2016-01-694331] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/09/2016] [Indexed: 02/06/2023] Open
Abstract
Until recently our approach to analyzing human genetic diseases has been to accurately phenotype patients and sequence the genes known to be associated with those phenotypes; for example, in thalassemia, the globin loci are analyzed. Sequencing has become increasingly accessible, and thus a larger panel of genes can be analyzed and whole exome and/or whole genome sequencing can be used when no variants are found in the candidate genes. By using such approaches in patients with unexplained anemias, we have discovered that a broad range of hitherto unrelated human red cell disorders are caused by variants in KLF1, a master regulator of erythropoiesis, which were previously considered to be extremely rare causes of human genetic disease.
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21
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Rathkolb B, Klempt M, Sabrautzki S, Michel D, Klaften M, Laufs J, Sedlmeier R, Hans W, Fuchs H, Muckenthaler MU, Horsch M, Campagna DR, Fleming M, Hrabé de Angelis M, Wolf E, Aigner B. Screen for alterations of iron related parameters in N-ethyl-N-nitrosourea-treated mice identified mutant lines with increased plasma ferritin levels. Biometals 2015; 28:293-306. [DOI: 10.1007/s10534-015-9824-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/21/2015] [Indexed: 11/28/2022]
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22
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Xue L, Galdass M, Gnanapragasam MN, Manwani D, Bieker JJ. Extrinsic and intrinsic control by EKLF (KLF1) within a specialized erythroid niche. Development 2014; 141:2245-54. [PMID: 24866116 DOI: 10.1242/dev.103960] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The erythroblastic island provides an important nutritional and survival support niche for efficient erythropoietic differentiation. Island integrity is reliant on adhesive interactions between erythroid and macrophage cells. We show that erythroblastic islands can be formed from single progenitor cells present in differentiating embryoid bodies, and that these correspond to erythro-myeloid progenitors (EMPs) that first appear in the yolk sac of the early developing embryo. Erythroid Krüppel-like factor (EKLF; KLF1), a crucial zinc finger transcription factor, is expressed in the EMPs, and plays an extrinsic role in erythroid maturation by being expressed in the supportive macrophage of the erythroblastic island and regulating relevant genes important for island integrity within these cells. Together with its well-established intrinsic contributions to erythropoiesis, EKLF thus plays a coordinating role between two different cell types whose interaction provides the optimal environment to generate a mature red blood cell.
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Affiliation(s)
- Li Xue
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Mariann Galdass
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Merlin Nithya Gnanapragasam
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Deepa Manwani
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
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23
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Abstract
Most heritable anemias are caused by mutations in genes encoding globins, red blood cell (RBC) membrane proteins, or enzymes in the glycolytic and hexose monophosphate shunt pathways. A less common class of genetic anemia is caused by mutations that alter the functions of erythroid transcription factors (TFs). Many TF mutations associated with heritable anemia cause truncations or amino acid substitutions, resulting in the production of functionally altered proteins. Characterization of these mutant proteins has provided insights into mechanisms of gene expression, hematopoietic development, and human disease. Mutations within promoter or enhancer regions that disrupt TF binding to essential erythroid genes also cause anemia and heritable variations in RBC traits, such as fetal hemoglobin content. Defining the latter may have important clinical implications for de-repressing fetal hemoglobin synthesis to treat sickle cell anemia and β thalassemia. Functionally important alterations in genes encoding TFs or their cognate cis elements are likely to occur more frequently than currently appreciated, a hypothesis that will soon be tested through ongoing genome-wide association studies and the rapidly expanding use of global genome sequencing for human diagnostics. Findings obtained through such studies of RBCs and associated diseases are likely generalizable to many human diseases and quantitative traits.
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24
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Kelsey L, Flenniken AM, Qu D, Funnell APW, Pearson R, Zhou YQ, Voronina I, Berberovic Z, Wood G, Newbigging S, Weiss ES, Wong M, Quach I, Yeh SYS, Deshwar AR, Scott IC, McKerlie C, Henkelman M, Backx P, Simpson J, Osborne L, Rossant J, Crossley M, Bruneau B, Adamson SL. ENU-induced mutation in the DNA-binding domain of KLF3 reveals important roles for KLF3 in cardiovascular development and function in mice. PLoS Genet 2013; 9:e1003612. [PMID: 23874215 PMCID: PMC3708807 DOI: 10.1371/journal.pgen.1003612] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 05/22/2013] [Indexed: 12/23/2022] Open
Abstract
KLF3 is a Krüppel family zinc finger transcription factor with widespread tissue expression and no previously known role in heart development. In a screen for dominant mutations affecting cardiovascular function in N-ethyl-N-nitrosourea (ENU) mutagenized mice, we identified a missense mutation in the Klf3 gene that caused aortic valvular stenosis and partially penetrant perinatal lethality in heterozygotes. All homozygotes died as embryos. In the first of three zinc fingers, a point mutation changed a highly conserved histidine at amino acid 275 to arginine (Klf3H275R). This change impaired binding of the mutant protein to KLF3's canonical DNA binding sequence. Heterozygous Klf3H275R mutants that died as neonates had marked biventricular cardiac hypertrophy with diminished cardiac chambers. Adult survivors exhibited hypotension, cardiac hypertrophy with enlarged cardiac chambers, and aortic valvular stenosis. A dominant negative effect on protein function was inferred by the similarity in phenotype between heterozygous Klf3H275R mutants and homozygous Klf3 null mice. However, the existence of divergent traits suggested the involvement of additional interactions. We conclude that KLF3 plays diverse and important roles in cardiovascular development and function in mice, and that amino acid 275 is critical for normal KLF3 protein function. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans. Cardiac defects are among the most common malformations in humans. Most causative genetic mutations remain unknown. To discover new causative genes important in cardiovascular development and function, we examined 1770 mice with randomly mutated genes and found a mutant with aortic valvular stenosis, and increased risk of fetal and neonatal death. Using linkage analysis and sequencing, we identified a protein-altering point mutation in the gene regulatory protein KLF3. Mice that survived into adulthood with one mutant copy of the Klf3 gene had low arterial blood pressure, enlarged hearts, and increased mortality due to heart failure. When both copies of the Klf3 gene was mutant, then embryos had heart defects, and all died before birth. KLF3 had no previously known role in heart development so to confirm these findings, we (1) knocked down klf3 expression in zebrafish embryos and (2) examined mice with a mutation that effectively eliminated the KLF3 protein. In both cases, cardiovascular dysfunction was observed. In conclusion, we have discovered that KLF3 plays diverse and important roles in cardiovascular development and function in mice. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans.
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Affiliation(s)
- Lois Kelsey
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Ann M. Flenniken
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Dawei Qu
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Alister P. W. Funnell
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Richard Pearson
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Yu-Qing Zhou
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Irina Voronina
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Zorana Berberovic
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Geoffrey Wood
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Susan Newbigging
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Edward S. Weiss
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
| | - Michael Wong
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Ivan Quach
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
| | - S. Y. Sandy Yeh
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Ashish R. Deshwar
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ian C. Scott
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
| | - Colin McKerlie
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Mark Henkelman
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Peter Backx
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jeremy Simpson
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lucy Osborne
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Janet Rossant
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Benoit Bruneau
- Gladstone Institute of Cardiovascular Disease, Department of Pediatrics, and Cardiovascular Research Institute, University of California, San Francisco, California, United States of America
| | - S. Lee Adamson
- Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
- Centre for Modeling Human Disease, Toronto Centre for Phenogenomics, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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25
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Abstract
PURPOSE OF REVIEW This review describes the genetics of unusual blood group phenotypes, particularly those with altered expression of Lutheran antigens, and how this area of study has informed our understanding of erythropoiesis in general and haemoglobin switching in particular. RECENT FINDINGS Mutations in erythroid transcription factors GATA1 (GATA1 binding protein 1) and KLF1 (Kruppel-like factor 1) cause benign and disease phenotypes in humans [X-linked Lu(a-b-) phenotype, In(Lu) blood group phenotype, hereditary persistence of foetal haemoglobin, borderline HbA(2), and congenital dyserythropoietic anaemia (CDA)]. These studies explain the occurrence of rare blood group phenotypes with simultaneous altered expression of antigens from several blood group systems and illuminate the role of KLF1 in gamma and delta globin gene regulation. SUMMARY The study of rare blood group phenotypes is a potent tool for discovery of mutations in human genes. Elucidation of the molecular basis of the rare In(Lu) phenotype revealed the first mutations in human KLF1. Subsequently, numerous additional mutations have been described, one of which causes a rare form of CDA. Analysis of the X-linked Lu(a-b-) phenotype revealed a mutation in the C-terminal domain of human GATA1. The apparent sensitivity of the Lutheran glycoprotein to alterations in GATA1 and KLF1 activity suggest that it could be a useful biomarker of erythroid transcription factor mutation.
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26
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Abstract
B-cell lymphoma 11A (BCL11A) downregulation in human primary adult erythroid progenitors results in elevated expression of fetal γ-globin. Recent reports showed that BCL11A expression is activated by KLF1, leading to γ-globin repression. To study regulation of erythropoiesis and globin expression by KLF1 and BCL11A in an in vivo model, we used mice carrying a human β-globin locus transgene with combinations of Klf1 knockout, Bcl11a floxed, and EpoR(Cre) knockin alleles. We found a higher percentage of reticulocytes in adult Klf1(wt/ko) mice and a mild compensated anemia in Bcl11a(cko/cko) mice. These phenotypes were more pronounced in compound Klf1(wt/ko)::Bcl11a(cko/cko) mice. Analysis of Klf1(wt/ko), Bcl11a(cko/cko), and Klf1(wt/ko)::Bcl11a(cko/cko) mutant embryos demonstrated increased expression of mouse embryonic globins during fetal development. Expression of human γ-globin remained high in Bcl11a(cko/cko) embryos during fetal development, and this was further augmented in Klf1(wt/ko)::Bcl11a(cko/cko) embryos. After birth, expression of human γ-globin and mouse embryonic globins decreased in Bcl11a(cko/cko) and Klf1(wt/ko)::Bcl11a(cko/cko) mice, but the levels remained much higher than those observed in control animals. Collectively, our data support an important role for the KLF1-BCL11A axis in erythroid maturation and developmental regulation of globin expression.
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27
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Yien YY, Bieker JJ. EKLF/KLF1, a tissue-restricted integrator of transcriptional control, chromatin remodeling, and lineage determination. Mol Cell Biol 2013; 33:4-13. [PMID: 23090966 PMCID: PMC3536305 DOI: 10.1128/mcb.01058-12] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Erythroid Krüppel-like factor (EKLF or KLF1) is a transcriptional regulator that plays a critical role in lineage-restricted control of gene expression. KLF1 expression and activity are tightly controlled in a temporal and differentiation stage-specific manner. The mechanisms by which KLF1 is regulated encompass a range of biological processes, including control of KLF1 RNA transcription, protein stability, localization, and posttranslational modifications. Intact KLF1 regulation is essential to correctly regulate erythroid function by gene transcription and to maintain hematopoietic lineage homeostasis by ensuring a proper balance of erythroid/megakaryocytic differentiation. In turn, KLF1 regulates erythroid biology by a wide variety of mechanisms, including gene activation and repression by regulation of chromatin configuration, transcriptional initiation and elongation, and localization of gene loci to transcription factories in the nucleus. An extensive series of biochemical, molecular, and genetic analyses has uncovered some of the secrets of its success, and recent studies are highlighted here. These reveal a multilayered set of control mechanisms that enable efficient and specific integration of transcriptional and epigenetic controls and that pave the way for proper lineage commitment and differentiation.
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Affiliation(s)
- Yvette Y. Yien
- Department of Developmental and Regenerative Biology
- Graduate School of Biological Sciences
| | - James J. Bieker
- Department of Developmental and Regenerative Biology
- Black Family Stem Cell Institute
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, New York, USA
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White RA, Silvey M, Logsdon DP. Research from the bedside to the lab bench & back. MISSOURI MEDICINE 2012; 109:195-198. [PMID: 22860286 PMCID: PMC6179705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Transgenic mice represent a unique opportunity in biomedical research to discover the genes underlying disease and understand how manipulating the function of single genes and proteins alters physiology in a whole animal system. These advances in biomedical research may accelerate the time between when basic discoveries are made and when the research can be 'translated', that is, when the research will positively impact the lives of patients. The purpose of this article is to present some examples of promising mouse models of human diseases.
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Affiliation(s)
- Robert A White
- Department of Biochemistry, Kansas City University of Medicine and Biosciences, USA.
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Gallienne AE, Dréau HMP, Schuh A, Old JM, Henderson S. Ten novel mutations in the erythroid transcription factor KLF1 gene associated with increased fetal hemoglobin levels in adults. Haematologica 2011; 97:340-3. [PMID: 22102705 DOI: 10.3324/haematol.2011.055442] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We investigated whether mutations in the KLF1 gene are associated with increased Hb F levels in ethnically diverse patients referred to our laboratory for hemoglobinopathy investigation. Functionally effective KLF1 mutations were identified in 11 out of 131 adult samples with an elevated Hb F level (1.5-25.0%). Eleven different mutations were identified, 9 of which were previously unreported. KLF1 mutations were not identified in a matched cohort of 121 samples with normal Hb F levels (<1.0%). A further novel KLF1 mutation was also found in a sickle cell disease patient with a Hb F level of 20.3% who had a particularly mild phenotype. Our results indicate KLF1 mutations could make a significant contribution to Hb F variance in malarial regions where hemogobinopathies are common. All the mutations identified were heterozygous providing further in vivo evidence that a single altered KLF1 allele is sufficient to increase Hb F levels.
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Affiliation(s)
- Alice E Gallienne
- National Haemoglobinopathy Reference Laboratory, Oxford Biomedical Research Centre-Haematology Molecular Diagnostic Service, John Radcliffe Hospital, Oxford, UK
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Abstract
PURPOSE OF REVIEW Congenital dyserythropoietic anemias (CDAs) are rare hereditary disorders characterized by ineffective erythropoiesis and by distinct morphological abnormalities of erythroblasts in the bone marrow. Characteristic morphological aberrations were the cornerstone of diagnosis, but following the identification of several causative genes, the molecular approach could represent a rapid tool for the identification of these conditions. This review presents advances in diagnosis and classification of CDAs. RECENT FINDINGS The classification of CDAs has long been based on morphological features. Now, the discovery of some of the responsible genes allows reconsideration of part of the classification. The first CDA partly accounted for genetically has been CDA 1, through the discovery in 2002 of the gene responsible, CDAN1, encoding codanin-1. Recently, the dramatic identification of the genes responsible for CDA II, SEC23B, and for a hitherto unnamed CDA, KLF1, took place. SEC23B encodes SEC23B which is a component of the coated vesicles transiting from the endoplasmic reticulum to the cis compartment of the Golgi apparatus. A unique mutation in KLF1, which encodes the erythroid transcription factor KLF1, causes major ultrastructural abnormalities, the persistence of embryonic and fetal hemoglobins, and the absence of some red cell membrane proteins. SUMMARY Studies of genotype-phenotype relationship, as has already been done for CDA II, will allow a more accurate prognosis. Identification of the responsible genes has opened new vistas for research on CDAs.
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Borg J, Patrinos GP, Felice AE, Philipsen S. Erythroid phenotypes associated with KLF1 mutations. Haematologica 2011; 96:635-8. [PMID: 21531944 DOI: 10.3324/haematol.2011.043265] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Genome-wide ChIP-Seq reveals a dramatic shift in the binding of the transcription factor erythroid Kruppel-like factor during erythrocyte differentiation. Blood 2011; 118:e139-48. [PMID: 21900194 DOI: 10.1182/blood-2011-05-355107] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Erythropoiesis is dependent on the activity of transcription factors, including the erythroid-specific erythroid Kruppel-like factor (EKLF). ChIP followed by massively parallel sequencing (ChIP-Seq) is a powerful, unbiased method to map trans-factor occupancy. We used ChIP-Seq to study the interactome of EKLF in mouse erythroid progenitor cells and more differentiated erythroblasts. We correlated these results with the nuclear distribution of EKLF, RNA-Seq analysis of the transcriptome, and the occupancy of other erythroid transcription factors. In progenitor cells, EKLF is found predominantly at the periphery of the nucleus, where EKLF primarily occupies the promoter regions of genes and acts as a transcriptional activator. In erythroblasts, EKLF is distributed throughout the nucleus, and erythroblast-specific EKLF occupancy is predominantly in intragenic regions. In progenitor cells, EKLF modulates general cell growth and cell cycle regulatory pathways, whereas in erythroblasts EKLF is associated with repression of these pathways. The EKLF interactome shows very little overlap with the interactomes of GATA1, GATA2, or TAL1, leading to a model in which EKLF directs programs that are independent of those regulated by the GATA factors or TAL1.
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Abstract
The cellular events that lead to terminal erythroid differentiation rely on the controlled interplay of extra- and intracellular regulatory factors. Their downstream effects are highly coordinated and result in the structural/morphologic and metabolic changes that uniquely characterize a maturing red blood cell. Erythroid Krüppel-like factor (EKLF/KLF1) is one of a very small number of intrinsic transcription factors that play a major role in regulating these events. This review covers 3 major aspects of erythropoiesis in which EKLF plays crucial functions: (1) at the megakaryocyte-erythroid progenitor stage, where it is involved in erythroid lineage commitment; (2) during the global expansion of erythroid gene expression in primitive and definitive lineages, where it plays a direct role in globin switching; and (3) during the terminal maturation of red cells, where it helps control exit from the cell cycle. We conclude by describing recent studies of mammalian EKLF/KLF1 mutations that lead to altered red cell phenotypes and disease.
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Affiliation(s)
- Miroslawa Siatecka
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, USA
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Mutations in the second zinc finger of human EKLF reduce promoter affinity but give rise to benign and disease phenotypes. Blood 2011; 118:3137-45. [PMID: 21778342 DOI: 10.1182/blood-2011-04-349985] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Mutations in the human erythroid Krüppel-like factor (EKLF) can lead to either anemia or the benign InLu phenotype. To elucidate the relationship between these mutations and the differing phenotypes, we prepared recombinant forms of wild-type and 5 mutant EKLF proteins and quantitated their binding affinity to a range of EKLF-regulated genes. Missense mutants (R328H, R328L, and R331G) from persons with InLu phenotype did not bind DNA. Hence, as with the heterozygous loss of function nonsense (L127X, S270X, and K292X) and frameshift (P190Lfs and R319Efs) EKLF mutations, monoallelic loss of EKLF does not result in haploinsufficiency at all loci. In contrast, K332Q has a slightly reduced DNA binding affinity (∼ 2-fold) for all promoters examined but exhibits a phenotype only in a compound heterozygote with a nonfunctional allele. E325K also has a reduced, but significant, binding affinity, particularly for the β-globin gene but results in a disease phenotype even with the wild-type allele expressed, although not as a classic dominant-negative mutant. E325K protein may therefore actively interfere with EKLF-dependent processes by destabilizing transcription complexes, providing a rational explanation for the severity of the disease phenotype. Our study highlights the critical role of residues within the second EKLF zinc finger domain.
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Systematic documentation and analysis of human genetic variation in hemoglobinopathies using the microattribution approach. Nat Genet 2011; 43:295-301. [PMID: 21423179 DOI: 10.1038/ng.785] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 02/11/2011] [Indexed: 01/11/2023]
Abstract
We developed a series of interrelated locus-specific databases to store all published and unpublished genetic variation related to hemoglobinopathies and thalassemia and implemented microattribution to encourage submission of unpublished observations of genetic variation to these public repositories. A total of 1,941 unique genetic variants in 37 genes, encoding globins and other erythroid proteins, are currently documented in these databases, with reciprocal attribution of microcitations to data contributors. Our project provides the first example of implementing microattribution to incentivise submission of all known genetic variation in a defined system. It has demonstrably increased the reporting of human variants, leading to a comprehensive online resource for systematically describing human genetic variation in the globin genes and other genes contributing to hemoglobinopathies and thalassemias. The principles established here will serve as a model for other systems and for the analysis of other common and/or complex human genetic diseases.
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Abstract
PURPOSE OF REVIEW The developmental switch from fetal to adult hemoglobin has long fascinated biologists and attracted hematologists given its importance for patients with hemoglobin disorders. New discoveries have reinvigorated the field of globin gene regulation. These results hold promise for improved treatment of the major hemoglobinopathies. RECENT FINDINGS Both genome-wide association studies and traditional linkage studies have identified several genetic loci involved in silencing fetal hemoglobin. BCL11A is a potent silencer of fetal hemoglobin in both mouse and humans. It controls the beta-globin gene cluster in concert with other factors. KLF1, a vital erythroid transcription factor, activates BCL11A and assists in coordinating the switch from fetal to adult hemoglobin. A regulatory network of cell-intrinsic and cell-extrinsic factors maintains the epigenetic homeostasis of the beta-globin cluster and accounts for the precise lineage-specific and developmental stage-specific regulation of the globin genes. SUMMARY With an improved understanding of pathways involved in the switch from fetal to adult hemoglobin, new targets have emerged for the treatment of the common hemoglobin disorders, sickle cell anemia and beta-thalassemia.
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Affiliation(s)
- Daniel E Bauer
- Children's Hospital Boston and Dana-Farber Cancer Institute, USA
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