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Țichil I, Mitre I, Zdrenghea MT, Bojan AS, Tomuleasa CI, Cenariu D. A Review of Key Regulators of Steady-State and Ineffective Erythropoiesis. J Clin Med 2024; 13:2585. [PMID: 38731114 PMCID: PMC11084473 DOI: 10.3390/jcm13092585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024] Open
Abstract
Erythropoiesis is initiated with the transformation of multipotent hematopoietic stem cells into committed erythroid progenitor cells in the erythroblastic islands of the bone marrow in adults. These cells undergo several stages of differentiation, including erythroblast formation, normoblast formation, and finally, the expulsion of the nucleus to form mature red blood cells. The erythropoietin (EPO) pathway, which is activated by hypoxia, induces stimulation of the erythroid progenitor cells and the promotion of their proliferation and survival as well as maturation and hemoglobin synthesis. The regulation of erythropoiesis is a complex and dynamic interaction of a myriad of factors, such as transcription factors (GATA-1, STAT5), cytokines (IL-3, IL-6, IL-11), iron metabolism and cell cycle regulators. Multiple microRNAs are involved in erythropoiesis, mediating cell growth and development, regulating oxidative stress, erythrocyte maturation and differentiation, hemoglobin synthesis, transferrin function and iron homeostasis. This review aims to explore the physiology of steady-state erythropoiesis and to outline key mechanisms involved in ineffective erythropoiesis linked to anemia, chronic inflammation, stress, and hematological malignancies. Studying aberrations in erythropoiesis in various diseases allows a more in-depth understanding of the heterogeneity within erythroid populations and the development of gene therapies to treat hematological disorders.
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Affiliation(s)
- Ioana Țichil
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
- Department of Haematology, “Ion Chiricuta” Institute of Oncology, 34–36 Republicii Street, 400015 Cluj-Napoca, Romania
| | - Ileana Mitre
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
| | - Mihnea Tudor Zdrenghea
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
- Department of Haematology, “Ion Chiricuta” Institute of Oncology, 34–36 Republicii Street, 400015 Cluj-Napoca, Romania
| | - Anca Simona Bojan
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
- Department of Haematology, “Ion Chiricuta” Institute of Oncology, 34–36 Republicii Street, 400015 Cluj-Napoca, Romania
| | - Ciprian Ionuț Tomuleasa
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
- Department of Haematology, “Ion Chiricuta” Institute of Oncology, 34–36 Republicii Street, 400015 Cluj-Napoca, Romania
- MEDFUTURE—Research Centre for Advanced Medicine, 8 Louis Pasteur Street, 400347 Cluj-Napoca, Romania
| | - Diana Cenariu
- Faculty of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu”, 8 Victor Babes Street, 400012 Cluj-Napoca, Romania; (I.M.); (M.T.Z.); (A.S.B.); (C.I.T.); (D.C.)
- MEDFUTURE—Research Centre for Advanced Medicine, 8 Louis Pasteur Street, 400347 Cluj-Napoca, Romania
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2
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Zhou Y, Dogiparthi VR, Ray S, Schaefer MA, Harris HL, Rowley MJ, Hewitt KJ. Defining a cohort of anemia-activated cis elements reveals a mechanism promoting erythroid precursor function. Blood Adv 2023; 7:6325-6338. [PMID: 36809789 PMCID: PMC10587717 DOI: 10.1182/bloodadvances.2022009163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/09/2023] [Accepted: 01/24/2023] [Indexed: 02/24/2023] Open
Abstract
Acute anemia elicits broad transcriptional changes in erythroid progenitors and precursors. We previously discovered a cis-regulatory transcriptional enhancer at the sterile alpha motif domain-14 enhancer locus (S14E), defined by a CANNTG-spacer-AGATAA composite motif and occupied by GATA1 and TAL1 transcription factors, is required for survival in severe anemia. However, S14E is only 1 of dozens of anemia-activated genes containing similar motifs. In a mouse model of acute anemia, we identified populations of expanding erythroid precursors, which increased expression of genes that contain S14E-like cis elements. We reveal that several S14E-like cis elements provide important transcriptional control of newly identified anemia-inducing genes, including the Ssx-2 interacting protein (Ssx2ip). Ssx2ip expression was determined to play an important role in erythroid progenitor/precursor cell activities, cell cycle regulation, and cell proliferation. Over a weeklong course of acute anemia recovery, we observed that erythroid gene activation mediated by S14E-like cis elements occurs during a phase coincident with low hematocrit and high progenitor activities, with distinct transcriptional programs activated at earlier and later time points. Our results define a genome-wide mechanism in which S14E-like enhancers control transcriptional responses during erythroid regeneration. These findings provide a framework to understand anemia-specific transcriptional mechanisms, ineffective erythropoiesis, anemia recovery, and phenotypic variability within human populations.
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Affiliation(s)
- Yichao Zhou
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | | | - Suhita Ray
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Meg A. Schaefer
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Hannah L. Harris
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - M. Jordan Rowley
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Kyle J. Hewitt
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
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3
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Wang X, Liu S, Yu J. Multi-lineage Differentiation from Hematopoietic Stem Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1442:159-175. [PMID: 38228964 DOI: 10.1007/978-981-99-7471-9_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The hematopoietic stem cells (HSCs) have the ability to differentiate and give rise to all mature blood cells. Commitment to differentiation progressively limits the self-renewal potential of the original HSCs by regulating the level of lineage-specific gene expression. In this review, we will summarize the current understanding of the molecular mechanisms underlying HSC differentiation toward erythroid, myeloid, and lymphocyte lineages. Moreover, we will decipher how the single-cell technologies advance the lineage-biased HSC subpopulations and their differentiation potential.
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Affiliation(s)
- Xiaoshuang Wang
- The State Key Laboratory for Complex, Severe, and Rare Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences / Peking Union Medical College, Beijing, China.
- The Institute of Blood Transfusion, Chinese Academy of Medical Sciences / Peking Union Medical College, Chengdu, China.
| | - Siqi Liu
- State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences / Peking Union Medical College, Beijing, China
| | - Jia Yu
- State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences / Peking Union Medical College, Beijing, China.
- The Institute of Blood Transfusion, Chinese Academy of Medical Sciences / Peking Union Medical College, Chengdu, China.
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4
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Ren K, Li E, Ji P. Proteome remodeling and organelle clearance in mammalian terminal erythropoiesis. Curr Opin Hematol 2022; 29:137-143. [PMID: 35441599 DOI: 10.1097/moh.0000000000000707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The differentiation from colony forming unit-erythroid (CFU-E) cells to mature enucleated red blood cells is named terminal erythropoiesis in mammals. Apart from enucleation, several unique features during these developmental stages include proteome remodeling and organelle clearance that are important to achieve hemoglobin enrichment. Here, we review the recent advances in the understanding of novel regulatory mechanisms in these processes, focusing on the master regulators that link these major events during terminal erythropoiesis. RECENT FINDINGS Comprehensive proteomic studies revealed a mismatch of protein abundance to their corresponding transcript abundance, which indicates that the proteome remodeling is regulated in a complex way from transcriptional control to posttranslational modifications. Key regulators in organelle clearance were also found to play critical roles in proteome remodeling. SUMMARY These studies demonstrate that the complexity of terminal erythropoiesis is beyond the conventional transcriptomic centric perspective. Posttranslational modifications such as ubiquitination are critical in terminal erythroid proteome remodeling that is also closely coupled with organelle clearance.
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Affiliation(s)
- Kehan Ren
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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5
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Temporal Gene Expression Profiles Reflect the Dynamics of Lymphoid Differentiation. Int J Mol Sci 2022; 23:ijms23031115. [PMID: 35163045 PMCID: PMC8834919 DOI: 10.3390/ijms23031115] [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: 12/14/2021] [Revised: 01/10/2022] [Accepted: 01/16/2022] [Indexed: 02/01/2023] Open
Abstract
Understanding the emergence of lymphoid committed cells from multipotent progenitors (MPP) is a great challenge in hematopoiesis. To gain deeper insight into the dynamic expression changes associated with these transitions, we report the quantitative transcriptome of two MPP subsets and the common lymphoid progenitor (CLP). While the transcriptome is rather stable between MPP2 and MPP3, expression changes increase with differentiation. Among those, we found that pioneer lymphoid genes such as Rag1, Mpeg1, and Dntt are expressed continuously from MPP2. Others, such as CD93, are CLP specific, suggesting their potential use as new markers to improve purification of lymphoid populations. Notably, a six-transcription factor network orchestrates the lymphoid differentiation program. Additionally, we pinpointed 24 long intergenic-non-coding RNA (lincRNA) differentially expressed through commitment and further identified seven novel forms. Collectively, our approach provides a comprehensive landscape of coding and non-coding transcriptomes expressed during lymphoid commitment.
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6
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Francis HS, Harold CL, Beagrie RA, King AJ, Gosden ME, Blayney JW, Jeziorska DM, Babbs C, Higgs DR, Kassouf MT. Scalable in vitro production of defined mouse erythroblasts. PLoS One 2022; 17:e0261950. [PMID: 34995303 PMCID: PMC8741028 DOI: 10.1371/journal.pone.0261950] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 12/14/2021] [Indexed: 01/23/2023] Open
Abstract
Mouse embryonic stem cells (mESCs) can be manipulated in vitro to recapitulate the process of erythropoiesis, during which multipotent cells undergo lineage specification, differentiation and maturation to produce erythroid cells. Although useful for identifying specific progenitors and precursors, this system has not been fully exploited as a source of cells to analyse erythropoiesis. Here, we establish a protocol in which characterised erythroblasts can be isolated in a scalable manner from differentiated embryoid bodies (EBs). Using transcriptional and epigenetic analysis, we demonstrate that this system faithfully recapitulates normal primitive erythropoiesis and fully reproduces the effects of natural and engineered mutations seen in primary cells obtained from mouse models. We anticipate this system to be of great value in reducing the time and costs of generating and maintaining mouse lines in a number of research scenarios.
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Affiliation(s)
- Helena S. Francis
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Caroline L. Harold
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert A. Beagrie
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Andrew J. King
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Matthew E. Gosden
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Joseph W. Blayney
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Danuta M. Jeziorska
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Christian Babbs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Douglas R. Higgs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Mira T. Kassouf
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
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7
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Identification of Potential Key lncRNAs in the Context of Mouse Myeloid Differentiation by Systematic Transcriptomics Analysis. Genes (Basel) 2021; 12:genes12050630. [PMID: 33922442 PMCID: PMC8146222 DOI: 10.3390/genes12050630] [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: 02/20/2021] [Revised: 04/09/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Hematopoietic differentiation is a well-orchestrated process by many regulators such as transcription factor and long non-coding RNAs (lncRNAs). However, due to the large number of lncRNAs and the difficulty in determining their roles, the study of lncRNAs is a considerable challenge in hematopoietic differentiation. Here, through gene co-expression network analysis over RNA-seq data generated from representative types of mouse myeloid cells, we obtained a catalog of potential key lncRNAs in the context of mouse myeloid differentiation. Then, employing a widely used in vitro cell model, we screened a novel lncRNA, named Gdal1 (Granulocytic differentiation associated lncRNA 1), from this list and demonstrated that Gdal1 was required for granulocytic differentiation. Furthermore, knockdown of Cebpe, a principal transcription factor of granulocytic differentiation regulation, led to down-regulation of Gdal1, but not vice versa. In addition, expression of genes involved in myeloid differentiation and its regulation, such as Cebpa, were influenced in Gdal1 knockdown cells with differentiation blockage. We thus systematically identified myeloid differentiation associated lncRNAs and substantiated the identification by investigation of one of these lncRNAs on cellular phenotype and gene regulation levels. This study promotes our understanding of the regulation of myeloid differentiation and the characterization of roles of lncRNAs in hematopoietic system.
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8
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Hypoxia Pathway Proteins are Master Regulators of Erythropoiesis. Int J Mol Sci 2020; 21:ijms21218131. [PMID: 33143240 PMCID: PMC7662373 DOI: 10.3390/ijms21218131] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Erythropoiesis is a complex process driving the production of red blood cells. During homeostasis, adult erythropoiesis takes place in the bone marrow and is tightly controlled by erythropoietin (EPO), a central hormone mainly produced in renal EPO-producing cells. The expression of EPO is strictly regulated by local changes in oxygen partial pressure (pO2) as under-deprived oxygen (hypoxia); the transcription factor hypoxia-inducible factor-2 induces EPO. However, erythropoiesis regulation extends beyond the well-established hypoxia-inducible factor (HIF)-EPO axis and involves processes modulated by other hypoxia pathway proteins (HPPs), including proteins involved in iron metabolism. The importance of a number of these factors is evident as their altered expression has been associated with various anemia-related disorders, including chronic kidney disease. Eventually, our emerging understanding of HPPs and their regulatory feedback will be instrumental in developing specific therapies for anemic patients and beyond.
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9
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Ferguson DCJ, Mokim JH, Meinders M, Moody ERR, Williams TA, Cooke S, Trakarnsanga K, Daniels DE, Ferrer-Vicens I, Shoemark D, Tipgomut C, Macinnes KA, Wilson MC, Singleton BK, Frayne J. Characterization and evolutionary origin of novel C 2H 2 zinc finger protein (ZNF648) required for both erythroid and megakaryocyte differentiation in humans. Haematologica 2020; 106:2859-2873. [PMID: 33054117 PMCID: PMC8561289 DOI: 10.3324/haematol.2020.256347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Indexed: 01/01/2023] Open
Abstract
Human ZNF648 is a novel poly C-terminal C2H2 zinc finger protein identified amongst the most dysregulated proteins in erythroid cells differentiated from iPSC. Its nuclear localisation and structure indicate it is likely a DNA-binding protein. Using a combination of ZNF648 overexpression in an iPSC line and primary adult erythroid cells, ZNF648 knockdown in primary adult erythroid cells and megakaryocytes, comparative proteomics and transcriptomics we show that ZNF648 is required for both erythroid and megakaryocyte differentiation. Orthologues of ZNF648 were detected across Mammals, Reptilia, Actinopterygii, in some Aves, Amphibia and Coelacanthiformes suggesting the gene originated in the common ancestor of Osteichthyes (Euteleostomi or bony fish). Conservation of the C-terminal zinc finger domain is higher, with some variation in zinc finger number but a core of at least six zinc fingers conserved across all groups, with the N-terminus recognisably similar within but not between major lineages. This suggests the N-terminus of ZNF648 evolves faster than the C-terminus, however this is not due to exon-shuffling as the entire coding region of ZNF648 is within a single exon. As for other such transcription factors, the N-terminus likely carries out regulatory functions, but showed no sequence similarity to any known domains. The greater functional constraint on the zinc finger domain suggests ZNF648 binds at least some similar regions of DNA in the different organisms. However, divergence of the N-terminal region may enable differential expression, allowing adaptation of function in the different organisms.
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Affiliation(s)
- Daniel C. J. Ferguson
- School of Biochemistry, University of Bristol, Bristol, UK,*DCJF and JHM contributed equally as co-first authors
| | - Juraidah Haji Mokim
- School of Biochemistry, University of Bristol, Bristol, UK,*DCJF and JHM contributed equally as co-first authors
| | | | | | - Tom A. Williams
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Sarah Cooke
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Kongtana Trakarnsanga
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Deborah E. Daniels
- School of Biochemistry, University of Bristol, Bristol, UK,NIHR Blood and Transplant Research Unit in Red Blood Cell Products, University of Bristol, Bristol, UK
| | | | | | - Chartsiam Tipgomut
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Katherine A. Macinnes
- School of Biochemistry, University of Bristol, Bristol, UK,NIHR Blood and Transplant Research Unit in Red Blood Cell Products, University of Bristol, Bristol, UK
| | | | - Belinda K. Singleton
- NIHR Blood and Transplant Research Unit in Red Blood Cell Products, University of Bristol, Bristol, UK,Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), Bristol, UK
| | - Jan Frayne
- School of Biochemistry, University of Bristol, BS8 1TD, UK.; NIHR Blood and Transplant Research Unit in Red blood cell products, University of Bristol, Bristol BS8 1TD, UK.
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10
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Hao Shi, Yan KK, Ding L, Qian C, Chi H, Yu J. Network Approaches for Dissecting the Immune System. iScience 2020; 23:101354. [PMID: 32717640 PMCID: PMC7390880 DOI: 10.1016/j.isci.2020.101354] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/21/2020] [Accepted: 07/08/2020] [Indexed: 02/06/2023] Open
Abstract
The immune system is a complex biological network composed of hierarchically organized genes, proteins, and cellular components that combat external pathogens and monitor the onset of internal disease. To meet and ultimately defeat these challenges, the immune system orchestrates an exquisitely complex interplay of numerous cells, often with highly specialized functions, in a tissue-specific manner. One of the major methodologies of systems immunology is to measure quantitatively the components and interaction levels in the immunologic networks to construct a computational network and predict the response of the components to perturbations. The recent advances in high-throughput sequencing techniques have provided us with a powerful approach to dissecting the complexity of the immune system. Here we summarize the latest progress in integrating omics data and network approaches to construct networks and to infer the underlying signaling and transcriptional landscape, as well as cell-cell communication, in the immune system, with a focus on hematopoiesis, adaptive immunity, and tumor immunology. Understanding the network regulation of immune cells has provided new insights into immune homeostasis and disease, with important therapeutic implications for inflammation, cancer, and other immune-mediated disorders.
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Affiliation(s)
- Hao Shi
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Koon-Kiu Yan
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Liang Ding
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Chenxi Qian
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jiyang Yu
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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11
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Valent P, Büsche G, Theurl I, Uras IZ, Germing U, Stauder R, Sotlar K, Füreder W, Bettelheim P, Pfeilstöcker M, Oberbauer R, Sperr WR, Geissler K, Schwaller J, Moriggl R, Béné MC, Jäger U, Horny HP, Hermine O. Normal and pathological erythropoiesis in adults: from gene regulation to targeted treatment concepts. Haematologica 2018; 103:1593-1603. [PMID: 30076180 PMCID: PMC6165792 DOI: 10.3324/haematol.2018.192518] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/30/2018] [Indexed: 12/12/2022] Open
Abstract
Pathological erythropoiesis with consequent anemia is a leading cause of symptomatic morbidity in internal medicine. The etiologies of anemia are complex and include reactive as well as neoplastic conditions. Clonal expansion of erythroid cells in the bone marrow may result in peripheral erythrocytosis and polycythemia but can also result in anemia when clonal cells are dysplastic and have a maturation arrest that leads to apoptosis and hinders migration, a constellation typically seen in the myelodysplastic syndromes. Rarely, clonal expansion of immature erythroid blasts results in a clinical picture resembling erythroid leukemia. Although several mechanisms underlying normal and abnormal erythropoiesis and the pathogenesis of related disorders have been deciphered in recent years, little is known about specific markers and targets through which prognosis and therapy could be improved in anemic or polycythemic patients. In order to discuss new markers, targets and novel therapeutic approaches in erythroid disorders and the related pathologies, a workshop was organized in Vienna in April 2017. The outcomes of this workshop are summarized in this review, which includes a discussion of new diagnostic and prognostic markers, the updated WHO classification, and an overview of new drugs used to stimulate or to interfere with erythropoiesis in various neoplastic and reactive conditions. The use and usefulness of established and novel erythropoiesis-stimulating agents for various indications, including myelodysplastic syndromes and other neoplasms, are also discussed.
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Affiliation(s)
- Peter Valent
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Austria .,Ludwig Boltzmann Cluster Oncology, Medical University of Vienna, Austria
| | - Guntram Büsche
- Institute of Pathology, Medizinische Hochschule Hannover, Germany
| | - Igor Theurl
- Department of Internal Medicine II, Medical University Innsbruck, Austria
| | - Iris Z Uras
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Austria
| | - Ulrich Germing
- Department of Hematology, Oncology and Clinical Immunology, Heinrich-Heine University, Düsseldorf, Germany
| | - Reinhard Stauder
- Department of Internal Medicine V, Medical University Innsbruck, Austria
| | - Karl Sotlar
- Institute of Pathology, Paracelsus Medical University Salzburg, Austria
| | - Wolfgang Füreder
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Austria
| | - Peter Bettelheim
- First Department of Internal Medicine, Elisabethinen Hospital, Linz, Austria
| | - Michael Pfeilstöcker
- Ludwig Boltzmann Cluster Oncology, Medical University of Vienna, Austria.,3Medical Department, Hanusch Hospital, Vienna, Austria
| | - Rainer Oberbauer
- Department of Nephrology and Dialysis, Medical University of Vienna, Austria
| | - Wolfgang R Sperr
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Austria.,Ludwig Boltzmann Cluster Oncology, Medical University of Vienna, Austria
| | - Klaus Geissler
- 5Medical Department for Hematology and Oncology, Hospital Hietzing, Vienna, Austria
| | - Jürg Schwaller
- Department of Biomedicine, University Children's Hospital Basel, Switzerland
| | - Richard Moriggl
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria.,Department of Biomedical Science, Institute of Animal Breeding and Genetics, University of Veterinary Medicine, Vienna, Austria
| | - Marie C Béné
- Hematology Biology, University Hospital, Nantes, France
| | - Ulrich Jäger
- Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Austria.,Ludwig Boltzmann Cluster Oncology, Medical University of Vienna, Austria
| | - Hans-Peter Horny
- Institute of Pathology, Ludwig-Maximilian University, Munich, Germany
| | - Olivier Hermine
- Imagine Institute, INSERM U 1163, CNRS 8654, Université Paris Descartes, Sorbonne, Paris Cité, France
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12
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Moore KS, von Lindern M. RNA Binding Proteins and Regulation of mRNA Translation in Erythropoiesis. Front Physiol 2018; 9:910. [PMID: 30087616 PMCID: PMC6066521 DOI: 10.3389/fphys.2018.00910] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022] Open
Abstract
Control of gene expression in erythropoiesis has to respond to signals that may emerge from intracellular processes or environmental factors. Control of mRNA translation allows for relatively rapid modulation of protein synthesis from the existing transcriptome. For instance, the protein synthesis rate needs to be reduced when reactive oxygen species or unfolded proteins accumulate in the cells, but also when iron supply is low or when growth factors are lacking in the environment. In addition, regulation of mRNA translation can be important as an additional layer of control on top of gene transcription, in which RNA binding proteins (RBPs) can modify translation of a set of transcripts to the cell’s actual protein requirement. The 5′ and 3′ untranslated regions of mRNA (5′UTR, 3′UTR) contain binding sites for general and sequence specific translation factors. They also contain secondary structures that may hamper scanning of the 5′UTR by translation complexes or may help to recruit translation factors. In addition, the term 5′UTR is not fully correct because many transcripts contain small open reading frames in their 5′UTR that are translated and contribute to regulation of mRNA translation. It is becoming increasingly clear that the transcriptome only partly predicts the proteome. The aim of this review is (i) to summarize how the availability of general translation initiation factors can selectively regulate transcripts because the 5′UTR contains secondary structures or short translated sequences, (ii) to discuss mechanisms that control the length of the mRNA poly(A) tail in relation to mRNA translation, and (iii) to give examples of sequence specific RBPs and their targets. We focused on transcripts and RBPs required for erythropoiesis. Whereas differentiation of erythroblasts to erythrocytes is orchestrated by erythroid transcription factors, the production of erythrocytes needs to respond to the availability of growth factors and nutrients, particularly the availability of iron.
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Affiliation(s)
- Kat S Moore
- Department of Hematopoiesis, Sanquin Research, and Landsteiner Laboratory, Amsterdam UMC, Amsterdam, Netherlands
| | - Marieke von Lindern
- Department of Hematopoiesis, Sanquin Research, and Landsteiner Laboratory, Amsterdam UMC, Amsterdam, Netherlands
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Gore AV, Pillay LM, Venero Galanternik M, Weinstein BM. The zebrafish: A fintastic model for hematopoietic development and disease. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e312. [PMID: 29436122 DOI: 10.1002/wdev.312] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 12/19/2022]
Abstract
Hematopoiesis is a complex process with a variety of different signaling pathways influencing every step of blood cell formation from the earliest precursors to final differentiated blood cell types. Formation of blood cells is crucial for survival. Blood cells carry oxygen, promote organ development and protect organs in different pathological conditions. Hematopoietic stem and progenitor cells (HSPCs) are responsible for generating all adult differentiated blood cells. Defects in HSPCs or their downstream lineages can lead to anemia and other hematological disorders including leukemia. The zebrafish has recently emerged as a powerful vertebrate model system to study hematopoiesis. The developmental processes and molecular mechanisms involved in zebrafish hematopoiesis are conserved with higher vertebrates, and the genetic and experimental accessibility of the fish and the optical transparency of its embryos and larvae make it ideal for in vivo analysis of hematopoietic development. Defects in zebrafish hematopoiesis reliably phenocopy human blood disorders, making it a highly attractive model system to screen small molecules to design therapeutic strategies. In this review, we summarize the key developmental processes and molecular mechanisms of zebrafish hematopoiesis. We also discuss recent findings highlighting the strengths of zebrafish as a model system for drug discovery against hematopoietic disorders. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cell Differentiation and Reversion Vertebrate Organogenesis > Musculoskeletal and Vascular Nervous System Development > Vertebrates: Regional Development Comparative Development and Evolution > Organ System Comparisons Between Species.
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Affiliation(s)
- Aniket V Gore
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Laura M Pillay
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Marina Venero Galanternik
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | - Brant M Weinstein
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
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Fujiwara T, Sasaki K, Saito K, Hatta S, Ichikawa S, Kobayashi M, Okitsu Y, Fukuhara N, Onishi Y, Harigae H. Forced FOG1 expression in erythroleukemia cells: Induction of erythroid genes and repression of myelo-lymphoid transcription factor PU.1. Biochem Biophys Res Commun 2017; 485:380-387. [PMID: 28216155 DOI: 10.1016/j.bbrc.2017.02.068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 11/27/2022]
Abstract
The transcription factor GATA-1-interacting protein Friend of GATA-1 (FOG1) is essential for proper transcriptional activation and repression of GATA-1 target genes; yet, the mechanisms by which FOG1 exerts its activating and repressing functions remain unknown. Forced FOG1 expression in human K562 erythroleukemia cells induced the expression of erythroid genes (SLC4A1, globins) but repressed that of GATA-2 and PU.1. A quantitative chromatin immunoprecipitation (ChIP) analysis demonstrated increased GATA-1 chromatin occupancy at both FOG1-activated as well as FOG1-repressed gene loci. However, while TAL1 chromatin occupancy was significantly increased at FOG1-activated gene loci, it was significantly decreased at FOG1-repressed gene loci. When FOG1 was overexpressed in TAL1-knocked down K562 cells, FOG1-mediated activation of HBA, HBG, and SLC4A1 was significantly compromised by TAL1 knockdown, suggesting that FOG1 may require TAL1 to activate GATA-1 target genes. Promoter analysis and quantitative ChIP analysis demonstrated that FOG1-mediated transcriptional repression of PU.1 would be mediated through a GATA-binding element located at its promoter, accompanied by significantly decreased H3 acetylation at lysine 4 and 9 (K4 and K9) as well as H3K4 trimethylation. Our results provide important mechanistic insight into the role of FOG1 in the regulation of GATA-1-regulated genes and suggest that FOG1 has an important role in inducing cells to differentiate toward the erythroid lineage rather than the myelo-lymphoid one by repressing the expression of PU.1.
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Affiliation(s)
- Tohru Fujiwara
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan.
| | - Katsuyuki Sasaki
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan; Department of Laboratory, Tohoku University Hospital, Sendai, 1-1 Seiryo-cho, Aoba-ku, Sendai 980-8574, Japan
| | - Kei Saito
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Shunsuke Hatta
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Satoshi Ichikawa
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Masahiro Kobayashi
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Yoko Okitsu
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Noriko Fukuhara
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Yasushi Onishi
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Hideo Harigae
- Department of Hematology and Rheumatology, Tohoku University Graduate School, Sendai, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
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15
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16
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Pimkin M, Kossenkov AV, Mishra T, Morrissey CS, Wu W, Keller CA, Blobel GA, Lee D, Beer MA, Hardison RC, Weiss MJ. Divergent functions of hematopoietic transcription factors in lineage priming and differentiation during erythro-megakaryopoiesis. Genome Res 2014; 24:1932-44. [PMID: 25319996 PMCID: PMC4248311 DOI: 10.1101/gr.164178.113] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, TAL1, and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary cultured megakaryocytes (MEG) and primary erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-associated cis-regulatory modules (CRMs) in multipotential progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential progenitor via overlapping and divergent functions of shared hematopoietic transcription factors.
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Affiliation(s)
- Maxim Pimkin
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA; Pediatric Residency Program, Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224, USA
| | - Andrew V Kossenkov
- Center for Systems and Computational Biology, The Wistar Institute, Philadelphia 19019, Pennsylvania, USA
| | - Tejaswini Mishra
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Christapher S Morrissey
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Weisheng Wu
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Cheryl A Keller
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Gerd A Blobel
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA; University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Dongwon Lee
- McKusick-Nathans Institute of Genetic Medicine and Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Michael A Beer
- McKusick-Nathans Institute of Genetic Medicine and Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Ross C Hardison
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania 16802, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Mitchell J Weiss
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA;
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McIver SC, Kang YA, DeVilbiss AW, O'Driscoll CA, Ouellette JN, Pope NJ, Camprecios G, Chang CJ, Yang D, Bouhassira EE, Ghaffari S, Bresnick EH. The exosome complex establishes a barricade to erythroid maturation. Blood 2014; 124:2285-97. [PMID: 25115889 PMCID: PMC4183988 DOI: 10.1182/blood-2014-04-571083] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 07/25/2014] [Indexed: 12/28/2022] Open
Abstract
Complex genetic networks control hematopoietic stem cell differentiation into progenitors that give rise to billions of erythrocytes daily. Previously, we described a role for the master regulator of erythropoiesis, GATA-1, in inducing genes encoding components of the autophagy machinery. In this context, the Forkhead transcription factor, Foxo3, amplified GATA-1-mediated transcriptional activation. To determine the scope of the GATA-1/Foxo3 cooperativity, and to develop functional insights, we analyzed the GATA-1/Foxo3-dependent transcriptome in erythroid cells. GATA-1/Foxo3 repressed expression of Exosc8, a pivotal component of the exosome complex, which mediates RNA surveillance and epigenetic regulation. Strikingly, downregulating Exosc8, or additional exosome complex components, in primary erythroid precursor cells induced erythroid cell maturation. Our results demonstrate a new mode of controlling erythropoiesis in which multiple components of the exosome complex are endogenous suppressors of the erythroid developmental program.
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Affiliation(s)
- Skye C McIver
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Yoon-A Kang
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Andrew W DeVilbiss
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Chelsea A O'Driscoll
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Jonathan N Ouellette
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Nathaniel J Pope
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Genis Camprecios
- Department of Developmental and Regenerative Biology, Mt. Sinai School of Medicine, New York, NY
| | - Chan-Jung Chang
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY; and
| | - David Yang
- Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison WI
| | - Eric E Bouhassira
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY; and
| | - Saghi Ghaffari
- Department of Developmental and Regenerative Biology, Mt. Sinai School of Medicine, New York, NY
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
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18
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Barrow JJ, Li Y, Hossain M, Huang S, Bungert J. Dissecting the function of the adult β-globin downstream promoter region using an artificial zinc finger DNA-binding domain. Nucleic Acids Res 2014; 42:4363-74. [PMID: 24497190 PMCID: PMC3985677 DOI: 10.1093/nar/gku107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Developmental stage-specific expression of the β-type globin genes is regulated by many cis- and trans-acting components. The adult β-globin gene contains an E-box located 60 bp downstream of the transcription start site that has been shown to bind transcription factor upstream stimulatory factor (USF) and to contribute to efficient in vitro transcription. We expressed an artificial zinc finger DNA-binding domain (ZF-DBD) targeting this site (+60 ZF-DBD) in murine erythroleukemia cells. Expression of the +60 ZF-DBD reduced the recruitment and elongation of RNA polymerase II (Pol II) at the adult β-globin gene and at the same time increased the binding of Pol II at locus control region (LCR) element HS2, suggesting that Pol II is transferred from the LCR to the globin gene promoters. Expression of the +60 ZF-DBD also reduced the frequency of interactions between the LCR and the adult β-globin promoter. ChIP-exonuclease-sequencing revealed that the +60ZF-DBD was targeted to the adult β-globin downstream promoter and that the binding of the ZF-DBD caused alterations in the association of USF2 containing protein complexes. The data demonstrate that targeting a ZF-DBD to the adult β-globin downstream promoter region interferes with the LCR-mediated recruitment and activity of Pol II.
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Affiliation(s)
- Joeva J Barrow
- Department of Biochemistry and Molecular Biology, Center for Epigenetics, Genetics Institute, Shands Cancer Center, Powell-Gene Therapy Center, University of Florida, Gainesville, 32610, FL, USA
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19
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Koury MJ. Abnormal erythropoiesis and the pathophysiology of chronic anemia. Blood Rev 2014; 28:49-66. [PMID: 24560123 DOI: 10.1016/j.blre.2014.01.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 01/17/2014] [Indexed: 12/14/2022]
Abstract
Erythropoiesis, the bone marrow production of erythrocytes by the proliferation and differentiation of hematopoietic cells, replaces the daily loss of 1% of circulating erythrocytes that are senescent. This daily output increases dramatically with hemolysis or hemorrhage. When erythrocyte production rate of erythrocytes is less than the rate of loss, chronic anemia develops. Normal erythropoiesis and specific abnormalities of erythropoiesis that cause chronic anemia are considered during three periods of differentiation: a) multilineage and pre-erythropoietin-dependent hematopoietic progenitors, b) erythropoietin-dependent progenitor cells, and c) terminally differentiating erythroblasts. These erythropoietic abnormalities are discussed in terms of their pathophysiological effects on the bone marrow cells and the resultant changes that can be detected in the peripheral blood using a clinical laboratory test, the complete blood count.
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Affiliation(s)
- Mark J Koury
- Division of Hematology/Oncology, Vanderbilt University and Veterans Affairs Tennessee Valley Healthcare System, 777 Preston Research Building, Nashville, TN 37232, USA.
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20
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TET2 plays an essential role in erythropoiesis by regulating lineage-specific genes via DNA oxidative demethylation in a zebrafish model. Mol Cell Biol 2014; 34:989-1002. [PMID: 24396069 DOI: 10.1128/mcb.01061-13] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Although epigenetic modulation is critical for a variety of cellular activities, its role in erythropoiesis remains poorly understood. Ten-eleven translocation (TET) molecules participate in methylcytosine (5mC) hydroxylation, which results in DNA demethylation in several biological processes. In this research, the role of TETs in erythropoiesis was investigated by using the zebrafish model, where three TET homologs were identified. These homologs share conserved structural domains with their mammalian counterparts. Zebrafish TETs mediate the conversion of 5mC to hydroxymethylcytosine (5hmC) in zebrafish embryos, and the deletion of TET2 inhibits erythropoiesis by suppressing the expression of the scl, gata-1, and cmyb genes. TET2-upregulated lineage-specific genes and erythropoiesis are closely associated with the occurrence of 5hmC and demethylation in the intermediate CpG promoters (ICPs) of scl, gata-1, cmyb, which frequently occur at specific regions or CpG sites of these ICPs. Moreover, TET2 regulates the formation and differentiation of erythroid progenitors, and deletion of TET2 leads to erythrocyte dysplasia and anemia. Here, we preliminarily proved that TET2 plays an essential role in erythrocyte development by regulating lineage-specific genes via DNA oxidative demethylation. This report is anticipated to broaden current information on hematopoiesis and pathogenesis of hematopoiesis-related diseases.
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Abstract
A systems approach to blood diseases can help make essential contributions to our ability to diagnose, treat, and perhaps even prevent common diseases in humans. Using blood as a window, one can study health and disease through this unique tool box with reactive biological fluids that mirrors the prevailing hemodynamics of the vessel walls and the various blood cell types. Many blood diseases, rare and common, can and have been exploited using systems biology approaches with successful results and therefore ideal models for systems medicine. More importantly, hematopoiesis offers one of the best studied systems with insight into stem cell biology, cellular interaction, development; linage programming and reprogramming that are influenced every day by the most mature and understood regulatory networks.
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Transcriptional regulation of haematopoietic stem cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 786:187-212. [PMID: 23696358 DOI: 10.1007/978-94-007-6621-1_11] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Haematopoietic stem cells (HSCs) are a rare cell population found in the bone marrow of adult mammals and are responsible for maintaining the entire haematopoietic system. Definitive HSCs are produced from mesoderm during embryonic development, from embryonic day 10 in the mouse. HSCs seed the foetal liver before migrating to the bone marrow around the time of birth. In the adult, HSCs are largely quiescent but have the ability to divide to self-renew and expand, or to proliferate and differentiate into any mature haematopoietic cell type. Both the specification of HSCs during development and their cellular choices once formed are tightly controlled at the level of transcription. Numerous transcriptional regulators of HSC specification, expansion, homeostasis and differentiation have been identified, primarily from analysis of mouse gene knockout experiments and transplantation assays. These include transcription factors, epigenetic modifiers and signalling pathway effectors. This chapter reviews the current knowledge of these HSC transcriptional regulators, predominantly focusing on the transcriptional regulation of mouse HSCs, although transcriptional regulation of human HSCs is also mentioned where relevant. Due to the breadth and maturity of this field, we have prioritised recently identified examples of HSC transcriptional regulators. We go on to highlight additional layers of control that regulate expression and activity of HSC transcriptional regulators and discuss how chromosomal translocations that result in fusion proteins of these HSC transcriptional regulators commonly drive leukaemias through transcriptional dysregulation.
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23
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Katsumura KR, DeVilbiss AW, Pope NJ, Johnson KD, Bresnick EH. Transcriptional mechanisms underlying hemoglobin synthesis. Cold Spring Harb Perspect Med 2013; 3:a015412. [PMID: 23838521 PMCID: PMC3753722 DOI: 10.1101/cshperspect.a015412] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The physiological switch in expression of the embryonic, fetal, and adult β-like globin genes has garnered enormous attention from investigators interested in transcriptional mechanisms and the molecular basis of hemoglobinopathies. These efforts have led to the discovery of cell type-specific transcription factors, unprecedented mechanisms of transcriptional coregulator function, genome biology principles, unique contributions of nuclear organization to transcription and cell function, and promising therapeutic targets. Given the vast literature accrued on this topic, this article will focus on the master regulator of erythroid cell development and function GATA-1, its associated proteins, and its frontline role in controlling hemoglobin synthesis. GATA-1 is a crucial regulator of genes encoding hemoglobin subunits and heme biosynthetic enzymes. GATA-1-dependent mechanisms constitute an essential regulatory core that nucleates additional mechanisms to achieve the physiological control of hemoglobin synthesis.
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Affiliation(s)
- Koichi R Katsumura
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Wisconsin Institute for Medical Research, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
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24
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Regalo G, Leutz A. Hacking cell differentiation: transcriptional rerouting in reprogramming, lineage infidelity and metaplasia. EMBO Mol Med 2013; 5:1154-64. [PMID: 23828660 PMCID: PMC3944458 DOI: 10.1002/emmm.201302834] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022] Open
Abstract
Initiating neoplastic cell transformation events are of paramount importance for the comprehension of regeneration and vanguard oncogenic processes but are difficult to characterize and frequently clinically overlooked. In epithelia, pre-neoplastic transformation stages are often distinguished by the appearance of phenotypic features of another differentiated tissue, termed metaplasia. In haemato/lymphopoietic malignancies, cell lineage ambiguity is increasingly recorded. Both, metaplasia and biphenotypic leukaemia/lymphoma represent examples of dysregulated cell differentiation that reflect a history of trans-differentiation and/or epigenetic reprogramming. Here we compare the similarity between molecular events of experimental cell trans-differentiation as an emerging therapeutic concept, with lineage confusion, as in metaplasia and dysplasia forecasting tumour development.
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Affiliation(s)
- Gonçalo Regalo
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany.
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25
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Pope NJ, Bresnick EH. Establishment of a cell-type-specific genetic network by the mediator complex component Med1. Mol Cell Biol 2013; 33:1938-55. [PMID: 23459945 PMCID: PMC3647965 DOI: 10.1128/mcb.00141-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 02/23/2013] [Indexed: 01/11/2023] Open
Abstract
The intense physiologic demand to generate vast numbers of red blood cells requires the establishment of a complex genetic network by the master regulatory transcription factor GATA-1 and its coregulators. This network dictates the genesis of enucleated erythrocytes by orchestrating the survival, proliferation, and differentiation of progenitor cells. In addition to the crucial GATA-1 coregulator Friend of GATA-1 (FOG-1), a component of the Mediator complex, Med1, facilitates GATA-1-dependent transcription at select target genes and controls erythropoiesis. It is not known to what extent Med1 contributes to GATA-1 function or whether Med1 controls a large or restricted cohort of genes that are not regulated by GATA-1. Using a genetic complementation assay in GATA-1-null erythroid cells, we demonstrate that Med1 and another Mediator component, Med25, regulate a restricted cohort of genes that are predominantly not controlled by GATA-1. Most of these genes were not regulated by Med1 in fibroblasts. Loss-of-function analyses with GATA-1-independent Med1 target genes indicate that Rrad, which encodes a small GTPase induced during human erythropoiesis, conferred erythroid cell survival. Thus, while Med1 is a context-dependent GATA-1 coregulator, it also exerts specialized functions in erythroid cells to control GATA-1-independent, cell-type-specific genes, which include candidate regulators of erythroid cell development and function.
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Affiliation(s)
- Nathaniel J Pope
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Xu J, Shao Z, Glass K, Bauer DE, Pinello L, Van Handel B, Hou S, Stamatoyannopoulos JA, Mikkola HKA, Yuan GC, Orkin SH. Combinatorial assembly of developmental stage-specific enhancers controls gene expression programs during human erythropoiesis. Dev Cell 2012; 23:796-811. [PMID: 23041383 DOI: 10.1016/j.devcel.2012.09.003] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 07/05/2012] [Accepted: 09/06/2012] [Indexed: 12/13/2022]
Abstract
Gene-distal enhancers are critical for tissue-specific gene expression, but their genomic determinants within a specific lineage at different stages of development are unknown. Here we profile chromatin state maps, transcription factor occupancy, and gene expression profiles during human erythroid development at fetal and adult stages. Comparative analyses of human erythropoiesis identify developmental stage-specific enhancers as primary determinants of stage-specific gene expression programs. We find that erythroid master regulators GATA1 and TAL1 act cooperatively within active enhancers but confer little predictive value for stage specificity. Instead, a set of stage-specific coregulators collaborates with master regulators and contributes to differential gene expression. We further identify and validate IRF2, IRF6, and MYB as effectors of an adult-stage expression program. Thus, the combinatorial assembly of lineage-specific master regulators and transcriptional coregulators within developmental stage-specific enhancers determines gene expression programs and temporal regulation of transcriptional networks in a mammalian genome.
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Affiliation(s)
- Jian Xu
- Division of Hematology/Oncology, Children's Hospital Boston and Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
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27
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Yang T, Jian W, Luo Y, Fu X, Noguchi C, Bungert J, Huang S, Qiu Y. Acetylation of histone deacetylase 1 regulates NuRD corepressor complex activity. J Biol Chem 2012; 287:40279-91. [PMID: 23014989 DOI: 10.1074/jbc.m112.349704] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND HDAC1-containing NuRD complex is required for GATA-1-mediated repression and activation. RESULTS GATA-1 associated with acetylated HDAC1-containing NuRD complex, which has no deacetylase activity, for gene activation. CONCLUSION Acetylated HDAC1 converts NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation program. SIGNIFICANCE HDAC1 acetylation may function as a master regulator for the activity of HDAC1 containing complexes. Histone deacetylases (HDACs) play important roles in regulating cell proliferation and differentiation. The HDAC1-containing NuRD complex is generally considered as a corepressor complex and is required for GATA-1-mediated repression. However, recent studies also show that the NuRD complex is involved in GATA-1-mediated gene activation. We tested whether the GATA-1-associated NuRD complex loses its deacetylase activity and commits the GATA-1 complex to become an activator during erythropoiesis. We found that GATA-1-associated deacetylase activity gradually decreased upon induction of erythroid differentiation. GATA-1-associated HDAC1 is increasingly acetylated after differentiation. It has been demonstrated earlier that acetylated HDAC1 has no deacetylase activity. Indeed, overexpression of an HDAC1 mutant, which mimics acetylated HDAC1, promotes GATA-1-mediated transcription and erythroid differentiation. Furthermore, during erythroid differentiation, acetylated HDAC1 recruitment is increased at GATA-1-activated genes, whereas it is significantly decreased at GATA-1-repressed genes. Interestingly, deacetylase activity is not required for Mi2 remodeling activity, suggesting that remodeling activity may be required for both activation and repression. Thus, our data suggest that NuRD can function as a coactivator or repressor and that acetylated HDAC1 converts the NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation.
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Affiliation(s)
- Tao Yang
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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28
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Delgado MD, Albajar M, Gomez-Casares MT, Batlle A, León J. MYC oncogene in myeloid neoplasias. Clin Transl Oncol 2012; 15:87-94. [PMID: 22911553 DOI: 10.1007/s12094-012-0926-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 07/24/2012] [Indexed: 01/13/2023]
Abstract
MYC is a transcription factor that regulates many critical genes for cell proliferation, differentiation, and biomass accumulation. MYC is one of the most prevalent oncogenes found to be altered in human cancer, being deregulated in about 50 % of tumors. Although MYC deregulation has been more frequently associated to lymphoma and lymphoblastic leukemia than to myeloid malignancies, a body of evidence has been gathered showing that MYC plays a relevant role in malignancies derived from the myeloid compartment. The myeloid leukemogenic activity of MYC has been demonstrated in different murine models. Not surprisingly, MYC has been found to be amplified or/and deregulated in the three major types of myeloid neoplasms: acute myeloid leukemia, myelodysplastic syndromes, and myeloproliferative neoplasms, including chronic myeloid leukemia. Here, we review the recent literature describing the involvement of MYC in myeloid tumors.
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Affiliation(s)
- M Dolores Delgado
- Group of Transcriptional Control and Cancer, Departamento de Biología Molecular, Facultad de Medicina, Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria, CSIC, SODERCAN, Avda Cardenal Herrera Oria s/n, 39011, Santander, Spain
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29
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Wang D, Rendon A, Ouwehand W, Wernisch L. Transcription factor co-localization patterns affect human cell type-specific gene expression. BMC Genomics 2012; 13:263. [PMID: 22721266 PMCID: PMC3441573 DOI: 10.1186/1471-2164-13-263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 06/12/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Cellular development requires the precise control of gene expression states. Transcription factors are involved in this regulatory process through their combinatorial binding with DNA. Information about transcription factor binding sites can help determine which combinations of factors work together to regulate a gene, but it is unclear how far the binding data from one cell type can inform about regulation in other cell types. RESULTS By integrating data on co-localized transcription factor binding sites in the K562 cell line with expression data across 38 distinct hematopoietic cell types, we developed regression models to describe the relationship between the expression of target genes and the transcription factors that co-localize nearby. With K562 binding sites identifying the predictors, the proportion of expression explained by the models is statistically significant only for monocytic cells (p-value< 0.001), which are closely related to K562. That is, cell type specific binding patterns are crucial for choosing the correct transcription factors for the model. Comparison of predictors obtained from binding sites in the GM12878 cell line with those from K562 shows that the amount of difference between binding patterns is directly related to the quality of the prediction. By identifying individual genes whose expression is predicted accurately by the binding sites, we are able to link transcription factors FOS, TAF1 and YY1 to a sparsely studied gene LRIG2. We also find that the activity of a transcription factor may be different depending on the cell type and the identity of other co-localized factors. CONCLUSION Our approach shows that gene expression can be explained by a modest number of co-localized transcription factors, however, information on cell-type specific binding is crucial for understanding combinatorial gene regulation.
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Affiliation(s)
- Dennis Wang
- MRC Biostatistics Unit, Institute of Public Health, Robinson Way, Cambridge, UK
| | - Augusto Rendon
- Department of Haematology, University of Cambridge, Long Road, Cambridge, UK
| | - Willem Ouwehand
- Department of Haematology, University of Cambridge, Long Road, Cambridge, UK
| | - Lorenz Wernisch
- Department of Haematology, University of Cambridge, Long Road, Cambridge, UK
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Baron MH, Isern J, Fraser ST. The embryonic origins of erythropoiesis in mammals. Blood 2012; 119:4828-37. [PMID: 22337720 PMCID: PMC3367890 DOI: 10.1182/blood-2012-01-153486] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 02/09/2012] [Indexed: 01/08/2023] Open
Abstract
Erythroid (red blood) cells are the first cell type to be specified in the postimplantation mammalian embryo and serve highly specialized, essential functions throughout gestation and postnatal life. The existence of 2 developmentally and morphologically distinct erythroid lineages, primitive (embryonic) and definitive (adult), was described for the mammalian embryo more than a century ago. Cells of the primitive erythroid lineage support the transition from rapidly growing embryo to fetus, whereas definitive erythrocytes function during the transition from fetal life to birth and continue to be crucial for a variety of normal physiologic processes. Over the past few years, it has become apparent that the ontogeny and maturation of these lineages are more complex than previously appreciated. In this review, we highlight some common and distinguishing features of the red blood cell lineages and summarize advances in our understanding of how these cells develop and differentiate throughout mammalian ontogeny.
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Affiliation(s)
- Margaret H Baron
- Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
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31
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Zhang L, Sankaran VG, Lodish HF. MicroRNAs in erythroid and megakaryocytic differentiation and megakaryocyte-erythroid progenitor lineage commitment. Leukemia 2012; 26:2310-6. [PMID: 22617791 DOI: 10.1038/leu.2012.137] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
MicroRNAs (miRNAs) are a class of small regulatory noncoding RNAs that modulate the expression of their target genes through either mRNA degradation or inhibition of protein translation. In recent years, miRNAs have been shown to be critical regulators of hematopoiesis and have important roles in the differentiation of specific lineages. Here, we summarize our current understanding of miRNAs involved in hematopoiesis with a focus on the role of miRNAs in regulating erythroid and megakaryocytic differentiation and megakaryocyte-erythroid progenitor lineage commitment.
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Affiliation(s)
- L Zhang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
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32
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Bresnick EH, Katsumura KR, Lee HY, Johnson KD, Perkins AS. Master regulatory GATA transcription factors: mechanistic principles and emerging links to hematologic malignancies. Nucleic Acids Res 2012; 40:5819-31. [PMID: 22492510 PMCID: PMC3401466 DOI: 10.1093/nar/gks281] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Numerous examples exist of how disrupting the actions of physiological regulators of blood cell development yields hematologic malignancies. The master regulator of hematopoietic stem/progenitor cells GATA-2 was cloned almost 20 years ago, and elegant genetic analyses demonstrated its essential function to promote hematopoiesis. While certain GATA-2 target genes are implicated in leukemogenesis, only recently have definitive insights emerged linking GATA-2 to human hematologic pathophysiologies. These pathophysiologies include myelodysplastic syndrome, acute myeloid leukemia and an immunodeficiency syndrome with complex phenotypes including leukemia. As GATA-2 has a pivotal role in the etiology of human cancer, it is instructive to consider mechanisms underlying normal GATA factor function/regulation and how dissecting such mechanisms may reveal unique opportunities for thwarting GATA-2-dependent processes in a therapeutic context. This article highlights GATA factor mechanistic principles, with a heavy emphasis on GATA-1 and GATA-2 functions in the hematopoietic system, and new links between GATA-2 dysregulation and human pathophysiologies.
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Affiliation(s)
- Emery H Bresnick
- Wisconsin Institutes for Medical Research, Paul Carbone Cancer Center, Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA.
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33
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Abstract
The discovery of the JAK2V617F mutation in most patients with Ph-negative myeloproliferative neoplasms has led to the development of JAK2 kinase inhibitors. However, JAK2 inhibitor therapy has shown limited efficacy and dose-limiting hematopoietic toxicities in clinical trials. In the present study, we describe the effects of vorinostat, a small-molecule inhibitor of histone deacetylase, against cells expressing JAK2V617F and in an animal model of polycythemia vera (PV). We found that vorinostat markedly inhibited proliferation and induced apoptosis in cells expressing JAK2V617F. In addition, vorinostat significantly inhibited JAK2V617F-expressing mouse and human PV hematopoietic progenitors. Biochemical analyses revealed significant inhibition of phosphorylation of JAK2, Stat5, Stat3, Akt, and Erk1/2 in vorinostat-treated, JAK2V617F-expressing human erythroleukemia (HEL) cells. Expression of JAK2V617F and several other genes, including GATA1, KLF1, FOG1, SCL, C/EPBα, PU.1, and NF-E2, was significantly down-regulated, whereas the expression of SOCS1 and SOCS3 was up-regulated by vorinostat treatment. More importantly, we observed that vorinostat treatment normalized the peripheral blood counts and markedly reduced splenomegaly in Jak2V617F knock-in mice compared with placebo treatment. Vorinostat treatment also decreased the mutant allele burden in mice. Our results suggest that vorinostat may have therapeutic potential for the treatment of PV and other JAK2V617F-associated myeloproliferative neoplasms.
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34
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Inferring rules of lineage commitment in haematopoiesis. Nat Cell Biol 2012; 14:287-94. [PMID: 22344032 DOI: 10.1038/ncb2442] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/12/2012] [Indexed: 12/15/2022]
Abstract
How the molecular programs of differentiated cells develop as cells transit from multipotency through lineage commitment remains unexplored. This reflects the inability to access cells undergoing commitment or located in the immediate vicinity of commitment boundaries. It remains unclear whether commitment constitutes a gradual process, or else represents a discrete transition. Analyses of in vitro self-renewing multipotent systems have revealed cellular heterogeneity with individual cells transiently exhibiting distinct biases for lineage commitment. Such systems can be used to molecularly interrogate early stages of lineage affiliation and infer rules of lineage commitment. In haematopoiesis, population-based studies have indicated that lineage choice is governed by global transcriptional noise, with self-renewing multipotent cells reversibly activating transcriptome-wide lineage-affiliated programs. We examine this hypothesis through functional and molecular analysis of individual blood cells captured from self-renewal cultures, during cytokine-driven differentiation and from primary stem and progenitor bone marrow compartments. We show dissociation between self-renewal potential and transcriptome-wide activation of lineage programs, and instead suggest that multipotent cells experience independent activation of individual regulators resulting in a low probability of transition to the committed state.
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35
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Lomelí H, Vázquez M. Emerging roles of the SUMO pathway in development. Cell Mol Life Sci 2011; 68:4045-64. [PMID: 21892772 PMCID: PMC11115048 DOI: 10.1007/s00018-011-0792-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 08/02/2011] [Accepted: 08/04/2011] [Indexed: 01/01/2023]
Abstract
Sumoylation is a reversible post-translational modification that targets a variety of proteins mainly within the nucleus, but also in the plasma membrane and cytoplasm of the cell. It controls diverse cellular mechanisms such as subcellular localization, protein-protein interactions, or transcription factor activity. In recent years, the use of several developmental model systems has unraveled many critical functions for the sumoylation system in the early life of diverse species. In particular, detailed analyses of mutant organisms in both the components of the SUMO pathway and their targets have established the importance of the SUMO system in early developmental processes, such as cell division, cell lineage commitment, specification, and/or differentiation. In addition, an increasing number of developmental proteins, including transcription factors and epigenetic regulators, have been identified as sumoylation substrates. Sumoylation acts on these targets through various mechanisms. For example, this modification has been involved in converting a transcription factor from an activator to a repressor or in regulating the localization and/or stability of numerous transcription factors. This review will summarize current information on the function of sumoylation in embryonic development in different species from yeast to mammals.
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Affiliation(s)
- Hilda Lomelí
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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36
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Abstract
Hematopoiesis is a process capable of generating millions of cells every second, as distributed in many cell types. The process is regulated by a number of transcription factors that regulate the differentiation along the distinct lineages and dictate the genetic program that defines each mature phenotype. Myc was first discovered as the oncogene of avian leukemogenic retroviruses; it was later found translocated in human lymphoma. From then on, evidence accumulated showing that c-Myc is one of the transcription factors playing a major role in hematopoiesis. The study of genetically modified mice with overexpression or deletion of Myc has shown that c-Myc is required for the correct balance between self-renewal and differentiation of hematopoietic stem cells (HSCs). Enforced Myc expression in mice leads to reduced HSC pools owing to loss of self-renewal activity at the expense of increased proliferation of progenitor cells and differentiation. c-Myc deficiency consistently results in the accumulation of HSCs. Other models with conditional Myc deletion have demonstrated that different lineages of hematopoietic cells differ in their requirement for c-Myc to regulate their proliferation and differentiation. When transgenic mice overexpress c-Myc or N-Myc in mature cells from the lymphoid or myeloid lineages, the result is lymphoma or leukemia. In agreement, enforced expression of c-Myc blocks the differentiation in several leukemia-derived cell lines capable of differentiating in culture. Not surprising, MYC deregulation is recurrently found in many types of human lymphoma and leukemia. Whereas MYC is deregulated by translocation in Burkitt lymphoma and, less frequently, other types of lymphoma, MYC is frequently overexpressed in acute lymphoblastic and myeloid leukemia, through mechanisms unrelated to chromosomal translocation, and is often associated with disease progression.
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Affiliation(s)
- M Dolores Delgado
- Departamento de Biología Molecular, Facultad de Medicina and Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-CSIC, Santander, Spain
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37
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Palii CG, Pasha R, Brand M. Lentiviral-mediated knockdown during ex vivo erythropoiesis of human hematopoietic stem cells. J Vis Exp 2011:2813. [PMID: 21785407 DOI: 10.3791/2813] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Erythropoiesis is a commonly used model system to study cell differentiation. During erythropoiesis, pluripotent adult human hematopoietic stem cells (HSCs) differentiate into oligopotent progenitors, committed precursors and mature red blood cells. This process is regulated for a large part at the level of gene expression, whereby specific transcription factors activate lineage-specific genes while concomitantly repressing genes that are specific to other cell types. Studies on transcription factors regulating erythropoiesis are often performed using human and murine cell lines that represent, to some extent, erythroid cells at given stages of differentiation. However transformed cell lines can only partially mimic erythroid cells and most importantly they do not allow one to comprehensibly study the dynamic changes that occur as cells progress through many stages towards their final erythroid fate. Therefore, a current challenge remains the development of a protocol to obtain relatively homogenous populations of primary HSCs and erythroid cells at various stages of differentiation in quantities that are sufficient to perform genomics and proteomics experiments. Here we describe an ex vivo cell culture protocol to induce erythroid differentiation from human hematopoietic stem/progenitor cells that have been isolated from either cord blood, bone marrow, or adult peripheral blood mobilized with G-CSF (leukapheresis). This culture system, initially developed by the Douay laboratory, uses cytokines and co-culture on mesenchymal cells to mimic the bone marrow microenvironment. Using this ex vivo differentiation protocol, we observe a strong amplification of erythroid progenitors, an induction of differentiation exclusively towards the erythroid lineage and a complete maturation to the stage of enucleated red blood cells. Thus, this system provides an opportunity to study the molecular mechanism of transcriptional regulation as hematopoietic stem cells progress along the erythroid lineage. Studying erythropoiesis at the transcriptional level also requires the ability to over-express or knockdown specific factors in primary erythroid cells. For this purpose, we use a lentivirus-mediated gene delivery system that allows for the efficient infection of both dividing and non-dividing cells. Here we show that we are able to efficiently knockdown the transcription factor TAL1 in primary human erythroid cells. In addition, GFP expression demonstrates an efficiency of lentiviral infection close to 90%. Thus, our protocol provides a highly useful system for characterization of the regulatory network of transcription factors that control erythropoiesis.
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Affiliation(s)
- Carmen G Palii
- The Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute
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38
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Chromatin-modifying agents promote the ex vivo production of functional human erythroid progenitor cells. Blood 2011; 117:4632-41. [DOI: 10.1182/blood-2010-10-314567] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Abstract
Presently, blood transfusion products (TPs) are composed of terminally differentiated cells with a finite life span. We have developed an ex vivo–generated TP composed of erythroid progenitor cells (EPCs) and precursors cells. Several histone deacetylase inhibitors (HDACIs) were used in vitro to promote the preferential differentiation of cord blood (CB) CD34+ cells to EPCs. A combination of cytokines and valproic acid (VPA): (1) promoted the greatest degree of EPC expansion, (2) led to the generation of EPCs which were capable of differentiating into the various stages of erythroid development, (3) led to epigenetic modifications (increased H3 acetylation) of promoters for erythroid-specific genes, which resulted in the acquisition of a gene expression pattern characteristic of primitive erythroid cells, and (4) promoted the generation of a TP that when infused into NOD/SCID mice produced mature RBCs containing both human adult and fetal globins as well Rh blood group Ag which persisted for 3 weeks and the retention of human EPCs and erythroid precursor cells within the BM of recipient mice. This ex vivo–generated EPC-TP likely represents a paradigm shift in transfusion medicine because of its potential to continue to generate additional RBCs after its infusion.
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39
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Lee HY, Johnson KD, Boyer ME, Bresnick EH. Relocalizing genetic loci into specific subnuclear neighborhoods. J Biol Chem 2011; 286:18834-44. [PMID: 21398517 DOI: 10.1074/jbc.m111.221481] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A poorly understood problem in genetics is how the three-dimensional organization of the nucleus contributes to establishment and maintenance of transcriptional networks. Genetic loci can reside in chromosome "territories" and undergo dynamic changes in subnuclear positioning. Such changes appear to be important for regulating transcription, although many questions remain regarding how loci reversibly transit in and out of their territories and the functional significance of subnuclear transitions. We addressed this issue using GATA-1, a master regulator of hematopoiesis implicated in human leukemogenesis, which often functions with the coregulator Friend of GATA-1 (FOG-1). In a genetic complementation assay in GATA-1-null cells, GATA-1 expels FOG-1-dependent target genes from the nuclear periphery during erythroid maturation, but the underlying mechanisms are unknown. We demonstrate that GATA-1 induces extrusion of the β-globin locus away from its chromosome territory at the nuclear periphery, and extrusion precedes the maturation-associated transcriptional surge and morphological transition. FOG-1 and its interactor Mi-2β, a chromatin remodeling factor commonly linked to repression, were required for locus extrusion. Erythroid Krüppel-like factor, a pivotal regulator of erythropoiesis that often co-occupies chromatin with GATA-1, also promoted locus extrusion. Disruption of transcriptional maintenance did not restore the locus subnuclear position that preceded activation. These results lead to a model for how a master developmental regulator relocalizes a locus into a new subnuclear neighborhood that is permissive for high level transcription as an early step in establishing a cell type-specific genetic network. Alterations in the regulatory milieu can abrogate maintenance without reversion of locus residency back to its original neighborhood.
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Affiliation(s)
- Hsiang-Ying Lee
- Wisconsin Institutes for Medical Research, Paul Carbone Cancer Center, Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705, USA
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40
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Role of helix-loop-helix proteins during differentiation of erythroid cells. Mol Cell Biol 2011; 31:1332-43. [PMID: 21282467 DOI: 10.1128/mcb.01186-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Helix-loop-helix (HLH) proteins play a profound role in the process of development and cellular differentiation. Among the HLH proteins expressed in differentiating erythroid cells are the ubiquitous proteins Myc, USF1, USF2, and TFII-I, as well as the hematopoiesis-specific transcription factor Tal1/SCL. All of these HLH proteins exhibit distinct functions during the differentiation of erythroid cells. For example, Myc stimulates the proliferation of erythroid progenitor cells, while the USF proteins and Tal1 regulate genes that specify the differentiated phenotype. This minireview summarizes the known activities of Myc, USF, TFII-I, and Tal11/SCL and discusses how they may function sequentially, cooperatively, or antagonistically in regulating expression programs during the differentiation of erythroid cells.
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41
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Abstract
Recent advances in biotechnology have resulted in cytometers capable of performing numerous correlated measurements of cells, often exceeding ten. In the near future, it is likely that this number will increase by fivefold and perhaps even higher. Traditional analysis strategies based on examining one measurement versus another are not suitable for high-dimensional data analysis because the number of measurement combinations expands geometrically with dimension, forming a kind of complexity barrier. This dimensionality barrier limits cytometry and other technologies from reaching their maximum potential in visualizing and analyzing important information embedded in high-dimensional data.This chapter describes efforts to break through this barrier and allow the visualization and analysis of any number of measurements with a new paradigm called Probability State Modeling (PSM). This new system creates a virtual progression variable based on probability that relates all measurements. PSM can produce a single graph that conveys more information about a sample than hundreds of traditional histograms. These PSM overlays reveal the rich interplay of phenotypic changes in cells as they differentiate. The end result is a deeper appreciation of the molecular genetic underpinnings of ontological processes in complex populations such as found in bone marrow and peripheral blood.Eventually these models will help investigators better understand normal and abnormal cellular progressions and will be a valuable general tool for the analysis and visualization of high-dimensional data.
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42
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Sun W, Yang S, Shen W, Li H, Gao Y, Zhu TH. Identification of DeltaEF1 as a novel target that is negatively regulated by LMO2 in T-cell leukemia. Eur J Haematol 2010; 85:508-19. [PMID: 20731704 DOI: 10.1111/j.1600-0609.2010.01519.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The lmo2 gene is a specific oncogene in T-cell leukemia, for its ectopic expression causes both increased pro-T-cell proliferation and differentiation arrest, leading to the onset of leukemia. Notably, DeltaEF1 (also known as ZEB1), a member of zinc finger-homeodomain family transcription factor, also exhibits crucial function in promoting T-cell differentiation. In this study, we found that DeltaEF1 was positively regulated by T-lineage-specific transcriptional regulator GATA3, while ectopically expressed LMO2 targeted to DeltaEF1 promoter by interaction with GATA3 and inhibited DeltaEF1 expression in transcriptional level. Moreover, LMO2 interacted with the N-terminal zinc finger domain of DeltaEF1 protein and inhibited its positive transcriptional regulatory function by this interaction. Taken together, our findings revealed that ectopically expressed LMO2 impaired the function of DeltaEF1 in both transcriptional and protein levels and identified DeltaEF1 as a novel pathogenic target of LMO2 in T-cell leukemia.
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Affiliation(s)
- Wei Sun
- Laboratory of Molecular Genetics, College of Medicine, Nankai University, Tianjin, China
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43
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Zein S, Li W, Ramakrishnan V, Lou TF, Sivanand S, Mackie A, Pace B. Identification of fetal hemoglobin-inducing agents using the human leukemia KU812 cell line. Exp Biol Med (Maywood) 2010; 235:1385-94. [PMID: 20975082 DOI: 10.1258/ebm.2010.010129] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Fetal hemoglobin (HbF) ameliorates the clinical severity of sickle cell disease; therefore continued research to identify efficacious HbF-inducing agents is desirable. In this study, we investigated KU812 leukemia cells that express the fetal γ-globin and adult β-globin genes, as a system for screening and discovery of novel HbF inducers. KU812 cells were analyzed in the presence or absence of fetal bovine serum and then expression levels of the globin genes, cell surface markers and transcription factors were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). For comparison, primary erythroid cells were grown in a two-phase liquid culture system. After drug inductions for 48-72 h, globin mRNA and HbF levels were quantified by RT-qPCR and enzyme-linked immunosorbent assay, respectively. Erythroid markers and transcription factors expression levels in KU812 cells were comparable to days 7-14 erythroid cells. We also tested several drugs including butyrate, trichostatin A, scriptaid, suberoylanilide hydroxamic acid and hydroxyurea, which induced γ-globin in KU812 cells; however, some agents also induced β-globin. A novel agent STI-571 was studied in the system, which non-selectively induced the globin genes. Additional studies showed comparable globin gene response patterns in KU812 and primary erythroid cells after treatments with the various drug inducers. Mechanisms of drug-mediated γ-globin induction in KU812 cells require signaling through the p38 mitogen-activated protein kinase pathway similar to that previously demonstrated in primary erythroid cells. These data suggest that KU812 cells serve as a good screening system to identify potential HbF inducers for the treatment of β-hemoglobinopathies.
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Affiliation(s)
- Sima Zein
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Specific erythroid-lineage defect in mice conditionally deficient for Mediator subunit Med1. Proc Natl Acad Sci U S A 2010; 107:21541-6. [PMID: 21098667 DOI: 10.1073/pnas.1005794107] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The Mediator complex forms the bridge between transcriptional activators and the RNA polymerase II. Med1 (also known as PBP or TRAP220) is a key component of Mediator that interacts with nuclear hormone receptors and GATA transcription factors. Here, we show dynamic recruitment of GATA-1, TFIIB, Mediator, and RNA polymerase II to the β-globin locus in induced mouse erythroid leukemia cells and in an erythropoietin-inducible hematopoietic progenitor cell line. Using Med1 conditional knockout mice, we demonstrate a specific block in erythroid development but not in myeloid or lymphoid development, highlighted by the complete absence of β-globin gene expression. Thus, Mediator subunit Med1 plays a pivotal role in erythroid development and in β-globin gene activation.
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Arnaud L, Saison C, Helias V, Lucien N, Steschenko D, Giarratana MC, Prehu C, Foliguet B, Montout L, de Brevern AG, Francina A, Ripoche P, Fenneteau O, Da Costa L, Peyrard T, Coghlan G, Illum N, Birgens H, Tamary H, Iolascon A, Delaunay J, Tchernia G, Cartron JP. A dominant mutation in the gene encoding the erythroid transcription factor KLF1 causes a congenital dyserythropoietic anemia. Am J Hum Genet 2010; 87:721-7. [PMID: 21055716 DOI: 10.1016/j.ajhg.2010.10.010] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 10/07/2010] [Accepted: 10/13/2010] [Indexed: 11/29/2022] Open
Abstract
The congenital dyserythropoietic anemias (CDAs) are inherited red blood cell disorders whose hallmarks are ineffective erythropoiesis, hemolysis, and morphological abnormalities of erythroblasts in bone marrow. We have identified a missense mutation in KLF1 of patients with a hitherto unclassified CDA. KLF1 is an erythroid transcription factor, and extensive studies in mouse models have shown that it plays a critical role in the expression of globin genes, but also in the expression of a wide spectrum of genes potentially essential for erythropoiesis. The unique features of this CDA confirm the key role of KLF1 during human erythroid differentiation. Furthermore, we show that the mutation has a dominant-negative effect on KLF1 transcriptional activity and unexpectedly abolishes the expression of the water channel AQP1 and the adhesion molecule CD44. Thus, the study of this disease-causing mutation in KLF1 provides further insights into the roles of this transcription factor during erythropoiesis in humans.
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Affiliation(s)
- Lionel Arnaud
- National Institute of Blood Transfusion, Paris, France.
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Li L, Lee JY, Gross J, Song SH, Dean A, Love PE. A requirement for Lim domain binding protein 1 in erythropoiesis. ACTA ACUST UNITED AC 2010; 207:2543-50. [PMID: 21041453 PMCID: PMC2989770 DOI: 10.1084/jem.20100504] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Lim domain-binding protein 1, a core subunit of complexes containing Scl, Gata1, and Lmo2, is needed continuously throughout erythropoiesis and megakaryopoiesis in adult mice. During erythrocyte development, the nuclear cofactor Lim domain binding protein 1 (Ldb1) functions as a core subunit of multiprotein DNA binding complexes that include the transcription factors Scl and Gata-1 and the Lim-only adapter Lmo2. Scl, Gata-1, and Lmo2 are each required for erythropoiesis, suggesting that Ldb1-nucleated transcription complexes regulate key steps during erythropoiesis. We documented a requirement for Ldb1 in erythropoiesis in mice. Analysis of ldb1−/− embryos revealed a critical requirement for Ldb1 during primitive erythropoiesis, and conditional inactivation of ldb1 at later stages of gestation and in adult mice demonstrated that Ldb1 is continuously required for both definitive erythropoiesis and megakaryopoiesis. Down-regulation of Ldb1 in erythroblasts inhibited the expression of multiple erythroid-specific and prosurvival genes. These results represent the first unequivocal demonstration of a role for Ldb1 in erythropoiesis in vivo and establish a critical function for Ldb1-nucleated complexes in regulating the erythroid/megakaryocyte transcriptional program.
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Affiliation(s)
- LiQi Li
- Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Transcriptional networks orchestrate complex developmental processes. Such networks are commonly instigated by master regulators of development. Considerable progress has been made in elucidating GATA factor-dependent genetic networks that control blood cell development. GATA-2 is required for the genesis and/or function of hematopoietic stem cells, whereas GATA-1 drives the differentiation of hematopoietic progenitors into a subset of the blood cell lineages. GATA-1 directly represses Gata2 transcription, and this involves GATA-1-mediated displacement of GATA-2 from chromatin, a process termed a GATA switch. GATA switches occur at numerous loci with critical functions, indicating that they are widely utilized developmental control tools.
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Affiliation(s)
- Emery H Bresnick
- Division of Hematology/Oncology, Department of Pharmacology, Paul Carbone Comprehensive Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705, USA.
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Abstract
Histone methylation is an important regulator of gene expression; its coordinated activity is critical in complex developmental processes such as hematopoiesis. Disruptor of telomere silencing 1-like (DOT1L) is a unique histone methyltransferase that specifically methylates histone H3 at lysine 79. We analyzed Dot1L-mutant mice to determine influence of this enzyme on embryonic hematopoiesis. Mutant mice developed more slowly than wild-type embryos and died between embryonic days 10.5 and 13.5, displaying a striking anemia, especially apparent in small vessels of the yolk sac. Further, a severe, selective defect in erythroid, but not myeloid, differentiation was observed. Erythroid progenitors failed to develop normally, showing retarded progression through the cell cycle, accumulation during G₀/G₁ stage, and marked increase in apoptosis in response to erythroid growth factors. GATA2, a factor essential for early erythropoiesis, was significantly reduced in Dot1L-deficient cells, whereas expression of PU.1, a transcription factor that inhibits erythropoiesis and promotes myelopoiesis, was increased. These data suggest a model whereby DOT1L-dependent lysine 79 of histone H3 methylation serves as a critical regulator of a differentiation switch during early hematopoiesis, regulating steady-state levels of GATA2 and PU.1 transcription, thus controlling numbers of circulating erythroid and myeloid cells.
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Inducible Fli-1 gene deletion in adult mice modifies several myeloid lineage commitment decisions and accelerates proliferation arrest and terminal erythrocytic differentiation. Blood 2010; 116:4795-805. [PMID: 20733157 DOI: 10.1182/blood-2010-02-270405] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This study investigated the role of the ETS transcription factor Fli-1 in adult myelopoiesis using new transgenic mice allowing inducible Fli-1 gene deletion. Fli-1 deletion in adult induced mild thrombocytopenia associated with a drastic decrease in large mature megakaryocytes number. Bone marrow bipotent megakaryocytic-erythrocytic progenitors (MEPs) increased by 50% without increase in erythrocytic and megakaryocytic common myeloid progenitor progeny, suggesting increased production from upstream stem cells. These MEPs were almost unable to generate pure colonies containing large mature megakaryocytes, but generated the same total number of colonies mainly identifiable as erythroid colonies containing a reduced number of more differentiated cells. Cytological and fluorescence-activated cell sorting analyses of MEP progeny in semisolid and liquid cultures confirmed the drastic decrease in large mature megakaryocytes but revealed a surprisingly modest (50%) reduction of CD41-positive cells indicating the persistence of a megakaryocytic commitment potential. Symmetrical increase and decrease of monocytic and granulocytic progenitors were also observed in the progeny of purified granulocytic-monocytic progenitors and common myeloid progenitors. In summary, this study indicates that Fli-1 controls several lineages commitment decisions at the stem cell, MEP, and granulocytic-monocytic progenitor levels, stimulates the proliferation of committed erythrocytic progenitors at the expense of their differentiation, and is a major regulator of late stages of megakaryocytic differentiation.
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Dumitriu B, Bhattaram P, Dy P, Huang Y, Quayum N, Jensen J, Lefebvre V. Sox6 is necessary for efficient erythropoiesis in adult mice under physiological and anemia-induced stress conditions. PLoS One 2010; 5:e12088. [PMID: 20711497 PMCID: PMC2918505 DOI: 10.1371/journal.pone.0012088] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 07/15/2010] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Definitive erythropoiesis is a vital process throughout life. Both its basal activity under physiological conditions and its increased activity under anemia-induced stress conditions are highly stimulated by the hormone erythropoietin. The transcription factor Sox6 was previously shown to enhance fetal erythropoiesis together and beyond erythropoietin signaling, but its importance in adulthood and mechanisms of action remain unknown. We used here Sox6 conditional null mice and molecular assays to address these questions. METHODOLOGY/PRINCIPAL FINDINGS Sox6fl/flErGFPCre adult mice, which lacked Sox6 in erythroid cells, exhibited compensated anemia, erythroid cell developmental defects, and anisocytotic, short-lived red cells under physiological conditions, proving that Sox6 promotes basal erythropoiesis. Tamoxifen treatment of Sox6fl/flCaggCreER mice induced widespread inactivation of Sox6 in a timely controlled manner and resulted in erythroblast defects before reticulocytosis, demonstrating that impaired erythropoiesis is a primary cause rather than consequence of anemia in the absence of Sox6. Twenty five percent of Sox6fl/flErGFPCre mice died 4 or 5 days after induction of acute anemia with phenylhydrazine. The others recovered slowly. They promptly increased their erythropoietin level and amplified their erythroid progenitor pool, but then exhibited severe erythroblast and reticulocyte defects. Sox6 is thus essential in the maturation phase of stress erythropoiesis that follows the erythropoietin-dependent amplification phase. Sox6 inactivation resulted in upregulation of embryonic globin genes, but embryonic globin chains remained scarce and apparently inconsequential. Sox6 inactivation also resulted in downregulation of erythroid terminal markers, including the Bcl2l1 gene for the anti-apoptotic factor Bcl-xL, and in vitro assays indicated that Sox6 directly upregulates Bcl2l1 downstream of and beyond erythropoietin signaling. CONCLUSIONS/SIGNIFICANCE This study demonstrates that Sox6 is necessary for efficient erythropoiesis in adult mice under both basal and stress conditions. It is primarily involved in enhancing the survival rate and maturation process of erythroid cells and acts at least in part by upregulating Bcl2l1.
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Affiliation(s)
- Bogdan Dumitriu
- Department of Cell Biology and Orthopaedic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
- Department of Internal Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Pallavi Bhattaram
- Department of Cell Biology and Orthopaedic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Peter Dy
- Department of Cell Biology and Orthopaedic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Yuanshuai Huang
- Department of Cell Biology and Orthopaedic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Nayeem Quayum
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Jan Jensen
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Véronique Lefebvre
- Department of Cell Biology and Orthopaedic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, United States of America
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