1
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Phelan DE, Reddan B, Shigemura M, Sznajder JI, Crean D, Cummins EP. Orphan Nuclear Receptor Family 4A (NR4A) Members NR4A2 and NR4A3 Selectively Modulate Elements of the Monocyte Response to Buffered Hypercapnia. Int J Mol Sci 2024; 25:2852. [PMID: 38474099 PMCID: PMC10931687 DOI: 10.3390/ijms25052852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
Hypercapnia occurs when the partial pressure of carbon dioxide (CO2) in the blood exceeds 45 mmHg. Hypercapnia is associated with several lung pathologies and is transcriptionally linked to suppression of immune and inflammatory signalling through poorly understood mechanisms. Here we propose Orphan Nuclear Receptor Family 4A (NR4A) family members NR4A2 and NR4A3 as potential transcriptional regulators of the cellular response to hypercapnia in monocytes. Using a THP-1 monocyte model, we investigated the sensitivity of NR4A family members to CO2 and the impact of depleting NR4A2 and NR4A3 on the monocyte response to buffered hypercapnia (10% CO2) using RNA-sequencing. We observed that NR4A2 and NR4A3 are CO2-sensitive transcription factors and that depletion of NR4A2 and NR4A3 led to reduced CO2-sensitivity of mitochondrial and heat shock protein (Hsp)-related genes, respectively. Several CO2-sensitive genes were, however, refractory to depletion of NR4A2 and NR4A3, indicating that NR4As regulate certain elements of the cellular response to buffered hypercapnia but that other transcription factors also contribute. Bioinformatic analysis of conserved CO2-sensitive genes implicated several novel putative CO2-sensitive transcription factors, of which the ETS Proto-Oncogene 1 Transcription Factor (ETS-1) was validated to show increased nuclear expression in buffered hypercapnia. These data give significant insights into the understanding of immune responses in patients experiencing hypercapnia.
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Affiliation(s)
- David E. Phelan
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Ben Reddan
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Masahiko Shigemura
- Division of Thoracic Surgery, Northwestern University, Chicago, IL 60611, USA;
| | - Jacob I. Sznajder
- Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Daniel Crean
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Eoin P. Cummins
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
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2
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In vivo clonal tracking reveals evidence of haemangioblast and haematomesoblast contribution to yolk sac haematopoiesis. Nat Commun 2023; 14:41. [PMID: 36596806 PMCID: PMC9810727 DOI: 10.1038/s41467-022-35744-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 12/22/2022] [Indexed: 01/05/2023] Open
Abstract
During embryogenesis, haematopoietic and endothelial lineages emerge closely in time and space. It is thought that the first blood and endothelium derive from a common clonal ancestor, the haemangioblast. However, investigation of candidate haemangioblasts in vitro revealed the capacity for mesenchymal differentiation, a feature more compatible with an earlier mesodermal precursor. To date, no evidence for an in vivo haemangioblast has been discovered. Using single cell RNA-Sequencing and in vivo cellular barcoding, we have unravelled the ancestral relationships that give rise to the haematopoietic lineages of the yolk sac, the endothelium, and the mesenchyme. We show that the mesodermal derivatives of the yolk sac are produced by three distinct precursors with dual-lineage outcomes: the haemangioblast, the mesenchymoangioblast, and a previously undescribed cell type: the haematomesoblast. Between E5.5 and E7.5, this trio of precursors seeds haematopoietic, endothelial, and mesenchymal trajectories.
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3
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Menegatti S, de Kruijf M, Garcia‐Alegria E, Lacaud G, Kouskoff V. Transcriptional control of blood cell emergence. FEBS Lett 2019; 593:3304-3315. [PMID: 31432499 PMCID: PMC6916194 DOI: 10.1002/1873-3468.13585] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/09/2019] [Accepted: 08/14/2019] [Indexed: 01/06/2023]
Abstract
The haematopoietic system is established during embryonic life through a series of developmental steps that culminates with the generation of haematopoietic stem cells. Characterisation of the transcriptional network that regulates blood cell emergence has led to the identification of transcription factors essential for this process. Among the many factors wired within this complex regulatory network, ETV2, SCL and RUNX1 are the central components. All three factors are absolutely required for blood cell generation, each one controlling a precise step of specification from the mesoderm germ layer to fully functional blood progenitors. Insight into the transcriptional control of blood cell emergence has been used for devising protocols to generate blood cells de novo, either through reprogramming of somatic cells or through forward programming of pluripotent stem cells. Interestingly, the physiological process of blood cell generation and its laboratory-engineered counterpart have very little in common.
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Affiliation(s)
- Sara Menegatti
- Developmental Haematopoiesis GroupFaculty of Biology, Medicine and Healththe University of ManchesterUK
| | - Marcel de Kruijf
- Developmental Haematopoiesis GroupFaculty of Biology, Medicine and Healththe University of ManchesterUK
| | - Eva Garcia‐Alegria
- Developmental Haematopoiesis GroupFaculty of Biology, Medicine and Healththe University of ManchesterUK
| | - Georges Lacaud
- Cancer Research UK Stem Cell Biology GroupCancer Research UK Manchester InstituteThe University of ManchesterMacclesfieldUK
| | - Valerie Kouskoff
- Developmental Haematopoiesis GroupFaculty of Biology, Medicine and Healththe University of ManchesterUK
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4
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MAPK p38alpha Kinase Influences Haematopoiesis in Embryonic Stem Cells. Stem Cells Int 2019; 2019:5128135. [PMID: 31281375 PMCID: PMC6589316 DOI: 10.1155/2019/5128135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/14/2019] [Accepted: 04/28/2019] [Indexed: 01/23/2023] Open
Abstract
The activation of p38alpha kinase mediates cell response to various extracellular factors including many interleukins and growth factors important for haematopoiesis. The role of p38alpha kinase was previously analysed in particular haematopoietic cells. In this study and for the first time, the role of p38alpha kinase in haematopoiesis was studied using a model of continuous haematopoietic development in pluripotent embryonic stem cells in vitro. The expression of transcripts associated with haematopoiesis and the potential for the formation of specific haematopoietic cell colonies were compared between wild-type and mutant p38alpha gene-depleted cells. The absence of p38alpha kinase led to the inhibition of hemangioblast formation during the first step of haematopoiesis. Later, during differentiation, due to the lack of p38alpha kinase, erythrocyte maturation was impaired. Mutant p38α−/− cells also exhibited decreased potential with respect to the expansion of granulocyte colony-forming units. This effect was reversed in the absence of erythropoietin as shown by colony-forming unit assay in media for colony-forming unit granulocytes/macrophages. p38alpha kinase thus plays an important role in the differentiation of common myeloid precursor cells into granulocyte lineages.
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5
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Abstract
PURPOSE OF REVIEW Recent studies have established that haematopoietic stem cells (HSCs) remain quiescent in homeostatic conditions, and minimally contribute to haematopoietic homeostasis. However, they undergo extensive cell cycle and expansion upon bone marrow transplantation or haematopoietic injury to reestablish the haematopoietic system. Molecular basis for the HSC activation and expansion is not completely understood. Here, we review the recent study elucidating the role of the developmentally critical Ets transcription factor Etv2 in reestablishing haematopoietic system upon injury through promoting HSC regeneration. RECENT FINDINGS We recently demonstrated that the ETS transcription factor Etv2, a critical factor for haematopoietic and vascular development, is also required for haematopoietic regeneration. Etv2, which is silent in homeostatic HSCs, was transiently activated in regenerating HSPCs and was required for the HSC expansion and regeneration following bone marrow transplantation or haematopoietic injury. As such, while Etv2 is dispensable for maintaining HSCs in steady states, it is required for emergency haematopoiesis. SUMMARY Etv2 has been identified as a novel regulator of haematopoietic regeneration. Comprehensive understanding of the upstream regulators and downstream effectors of Etv2 in haematopoietic regeneration would be critical for fundamental understanding of haematopoietic stem cell biology, and the findings will be broadly applicable to clinical practice involving haematopoietic regenerative medicine; bone marrow transplantation, gene therapy and in-vitro HSC expansion.
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6
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Lopez‐Atalaya JP, Askew KE, Sierra A, Gomez‐Nicola D. Development and maintenance of the brain's immune toolkit: Microglia and non-parenchymal brain macrophages. Dev Neurobiol 2018; 78:561-579. [PMID: 29030904 PMCID: PMC6001428 DOI: 10.1002/dneu.22545] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 01/10/2023]
Abstract
Microglia and non-parenchymal macrophages located in the perivascular space, the meninges and the choroid plexus are independent immune populations that play vital roles in brain development, homeostasis, and tissue healing. Resident macrophages account for a significant proportion of cells in the brain and their density remains stable throughout the lifespan thanks to constant turnover. Microglia develop from yolk sac progenitors, later evolving through intermediate progenitors in a fine-tuned process in which intrinsic factors and external stimuli combine to progressively sculpt their cell type-specific transcriptional profiles. Recent evidence demonstrates that non-parenchymal macrophages are also generated during early embryonic development. In recent years, the development of powerful fate mapping approaches combined with novel genomic and transcriptomic methodologies have greatly expanded our understanding of how brain macrophages develop and acquire specialized functions, and how cell population dynamics are regulated. Here, we review the transcription factors, epigenetic remodeling, and signaling pathways orchestrating the embryonic development of microglia and non-parenchymal macrophages. Next, we describe the dynamics of the macrophage populations of the brain and discuss the role of progenitor cells, to gain a better understanding of their functions in the healthy and diseased brain. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 561-579, 2018.
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Affiliation(s)
- Jose P. Lopez‐Atalaya
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández‐Consejo Superior de Investigaciones Científicas (UMH‐CSIC), Avenida Ramón y Cajal, s/n, Sant Joan d'AlacantSpain
| | - Katharine E. Askew
- Southampton General Hospital, Biological Sciences, University of Southampton, South Lab&Path Block, LD80C, MP840SO166YDSouthamptonUnited Kingdom
| | - Amanda Sierra
- Achucarro Basque Center for NeuroscienceLeioa48940Spain
- Ikerbasque FoundationBilbao48013Spain
- University of the Basque Country EHU/UPVLeioa48940Spain
| | - Diego Gomez‐Nicola
- Southampton General Hospital, Biological Sciences, University of Southampton, South Lab&Path Block, LD80C, MP840SO166YDSouthamptonUnited Kingdom
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7
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Leong WZ, Tan SH, Ngoc PCT, Amanda S, Yam AWY, Liau WS, Gong Z, Lawton LN, Tenen DG, Sanda T. ARID5B as a critical downstream target of the TAL1 complex that activates the oncogenic transcriptional program and promotes T-cell leukemogenesis. Genes Dev 2018; 31:2343-2360. [PMID: 29326336 PMCID: PMC5795782 DOI: 10.1101/gad.302646.117] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 11/30/2017] [Indexed: 12/13/2022]
Abstract
Leong et al. identified ARID5B as a collaborating oncogenic factor involved in the transcriptional program in T-ALL. ARID5B positively regulates the expression of TAL1 and its regulatory partners and also activates the expression of the oncogene MYC. The oncogenic transcription factor TAL1/SCL induces an aberrant transcriptional program in T-cell acute lymphoblastic leukemia (T-ALL) cells. However, the critical factors that are directly activated by TAL1 and contribute to T-ALL pathogenesis are largely unknown. Here, we identified AT-rich interactive domain 5B (ARID5B) as a collaborating oncogenic factor involved in the transcriptional program in T-ALL. ARID5B expression is down-regulated at the double-negative 2–4 stages in normal thymocytes, while it is induced by the TAL1 complex in human T-ALL cells. The enhancer located 135 kb upstream of the ARID5B gene locus is activated under a superenhancer in T-ALL cells but not in normal T cells. Notably, ARID5B-bound regions are associated predominantly with active transcription. ARID5B and TAL1 frequently co-occupy target genes and coordinately control their expression. ARID5B positively regulates the expression of TAL1 and its regulatory partners. ARID5B also activates the expression of the oncogene MYC. Importantly, ARID5B is required for the survival and growth of T-ALL cells, and forced expression of ARID5B in immature thymocytes results in thymus retention, differentiation arrest, radioresistance, and tumor formation in zebrafish. Our results indicate that ARID5B reinforces the oncogenic transcriptional program by positively regulating the TAL1-induced regulatory circuit and MYC in T-ALL, thereby contributing to T-cell leukemogenesis.
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Affiliation(s)
- Wei Zhong Leong
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Shi Hao Tan
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Phuong Cao Thi Ngoc
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Stella Amanda
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Alice Wei Yee Yam
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Wei-Siang Liau
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Zhiyuan Gong
- Department of Biological Sciences, National University of Singapore, 117543 Singapore
| | - Lee N Lawton
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore
| | - Daniel G Tenen
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore.,Harvard Medical School, Boston, Massachusetts 02215, USA.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599 Singapore
| | - Takaomi Sanda
- Cancer Science Institute of Singapore, National University of Singapore, 117599 Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599 Singapore
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8
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Navarro-Montero O, Ayllon V, Lamolda M, López-Onieva L, Montes R, Bueno C, Ng E, Guerrero-Carreno X, Romero T, Romero-Moya D, Stanley E, Elefanty A, Ramos-Mejia V, Menendez P, Real PJ. RUNX1c Regulates Hematopoietic Differentiation of Human Pluripotent Stem Cells Possibly in Cooperation with Proinflammatory Signaling. Stem Cells 2017; 35:2253-2266. [PMID: 28869683 DOI: 10.1002/stem.2700] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 07/19/2017] [Accepted: 08/02/2017] [Indexed: 02/07/2023]
Abstract
Runt-related transcription factor 1 (Runx1) is a master hematopoietic transcription factor essential for hematopoietic stem cell (HSC) emergence. Runx1-deficient mice die during early embryogenesis due to the inability to establish definitive hematopoiesis. Here, we have used human pluripotent stem cells (hPSCs) as model to study the role of RUNX1 in human embryonic hematopoiesis. Although the three RUNX1 isoforms a, b, and c were induced in CD45+ hematopoietic cells, RUNX1c was the only isoform induced in hematoendothelial progenitors (HEPs)/hemogenic endothelium. Constitutive expression of RUNX1c in human embryonic stem cells enhanced the appearance of HEPs, including hemogenic (CD43+) HEPs and promoted subsequent differentiation into blood cells. Conversely, specific deletion of RUNX1c dramatically reduced the generation of hematopoietic cells from HEPs, indicating that RUNX1c is a master regulator of human hematopoietic development. Gene expression profiling of HEPs revealed a RUNX1c-induced proinflammatory molecular signature, supporting previous studies demonstrating proinflammatory signaling as a regulator of HSC emergence. Collectively, RUNX1c orchestrates hematopoietic specification of hPSCs, possibly in cooperation with proinflammatory signaling. Stem Cells 2017;35:2253-2266.
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Affiliation(s)
- Oscar Navarro-Montero
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Veronica Ayllon
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Mar Lamolda
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain.,Department of Biochemistry and Molecular Biology I, Faculty of Science, University of Granada, Granada, Spain
| | - Lourdes López-Onieva
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Rosa Montes
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Clara Bueno
- Josep Carreras Leukemia Research Institute and Biomedicine Department, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Elizabeth Ng
- Blood Cell Development and Disease Laboratory, Murdoch Childrens Research Institute. The Royal Children's Hospital, Parkville, Australia
| | - Xiomara Guerrero-Carreno
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Tamara Romero
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Damià Romero-Moya
- Josep Carreras Leukemia Research Institute and Biomedicine Department, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Ed Stanley
- Stem Cell Technology Laboratory, Murdoch Childrens Research Institute. The Royal Children's Hospital, Parkville, Australia
| | - Andrew Elefanty
- Blood Cell Development and Disease Laboratory, Murdoch Childrens Research Institute. The Royal Children's Hospital, Parkville, Australia
| | - Verónica Ramos-Mejia
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain
| | - Pablo Menendez
- Josep Carreras Leukemia Research Institute and Biomedicine Department, School of Medicine, University of Barcelona, Barcelona, Spain.,Instituciò Catalana de Reserca i EstudisAvançats (ICREA), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), ISCIII, Barcelona, Spain
| | - Pedro J Real
- Gene Regulation, Stem Cells and Development Group, Department of Genomic Oncology, GENYO: Centre for Genomics and Oncological Research Pfizer-University of Granada-Junta de Andalucía, PTS Granada, Granada, Spain.,Department of Biochemistry and Molecular Biology I, Faculty of Science, University of Granada, Granada, Spain
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9
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Runx transcription factors in the development and function of the definitive hematopoietic system. Blood 2017; 129:2061-2069. [PMID: 28179276 DOI: 10.1182/blood-2016-12-689109] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/29/2017] [Indexed: 01/01/2023] Open
Abstract
The Runx family of transcription factors (Runx1, Runx2, and Runx3) are highly conserved and encode proteins involved in a variety of cell lineages, including blood and blood-related cell lineages, during developmental and adult stages of life. They perform activation and repressive functions in the regulation of gene expression. The requirement for Runx1 in the normal hematopoietic development and its dysregulation through chromosomal translocations and loss-of-function mutations as found in acute myeloid leukemias highlight the importance of this transcription factor in the healthy blood system. Whereas another review will focus on the role of Runx factors in leukemias, this review will provide an overview of the normal regulation and function of Runx factors in hematopoiesis and focus particularly on the biological effects of Runx1 in the generation of hematopoietic stem cells. We will present the current knowledge of the structure and regulatory features directing lineage-specific expression of Runx genes, the models of embryonic and adult hematopoietic development that provide information on their function, and some of the mechanisms by which they affect hematopoietic function.
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10
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Aberrant activation of the GIMAP enhancer by oncogenic transcription factors in T-cell acute lymphoblastic leukemia. Leukemia 2016; 31:1798-1807. [PMID: 28028313 PMCID: PMC5529293 DOI: 10.1038/leu.2016.392] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 12/16/2022]
Abstract
The transcription factor TAL1/SCL is one of the most prevalent oncogenes in T-cell acute lymphoblastic leukemia (T-ALL), a malignant disorder resulting from leukemic transformation of thymus T-cell precursors. TAL1 is normally expressed in hematopoietic stem cells (HSCs) but is silenced in immature thymocytes. We hypothesize that TAL1 contributes to leukemogenesis by activating genes that are normally repressed in immature thymocytes. Herein, we identified a novel TAL1-regulated super-enhancer controlling the GIMAP locus, which resides within an insulated chromosomal locus in T-ALL cells. The GIMAP genes are expressed in HSCs and mature T-cells but are downregulated during the immature stage of thymocyte differentiation. The GIMAP enhancer is activated by TAL1, RUNX1 and GATA3 in human T-ALL cells but is repressed by E-proteins. Overexpression of human GIMAP genes in immature thymocytes alone does not induce tumorigenesis but accelerates leukemia development in zebrafish. Our results demonstrate that aberrant activation of the GIMAP enhancer contributes to T-cell leukemogenesis.
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11
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Lilly AJ, Costa G, Largeot A, Fadlullah MZH, Lie-A-Ling M, Lacaud G, Kouskoff V. Interplay between SOX7 and RUNX1 regulates hemogenic endothelial fate in the yolk sac. Development 2016; 143:4341-4351. [PMID: 27802172 DOI: 10.1242/dev.140970] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/12/2016] [Indexed: 02/01/2023]
Abstract
Endothelial to hematopoietic transition (EHT) is a dynamic process involving the shutting down of endothelial gene expression and switching on of hematopoietic gene transcription. Although the factors regulating EHT in hemogenic endothelium (HE) of the dorsal aorta have been relatively well studied, the molecular regulation of yolk sac HE remains poorly understood. Here, we show that SOX7 inhibits the expression of RUNX1 target genes in HE, while having no effect on RUNX1 expression itself. We establish that SOX7 directly interacts with RUNX1 and inhibits its transcriptional activity. Through this interaction we demonstrate that SOX7 hinders RUNX1 DNA binding as well as the interaction between RUNX1 and its co-factor CBFβ. Finally, we show by single-cell expression profiling and immunofluorescence that SOX7 is broadly expressed across the RUNX1+ yolk sac HE population compared with SOX17. Collectively, these data demonstrate for the first time how direct protein-protein interactions between endothelial and hematopoietic transcription factors regulate contrasting transcriptional programs during HE differentiation and EHT.
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Affiliation(s)
- Andrew J Lilly
- Stem Cell Hematopoiesis, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Guilherme Costa
- Stem Cell Hematopoiesis, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Anne Largeot
- Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Muhammad Z H Fadlullah
- Stem Cell Hematopoiesis, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Michael Lie-A-Ling
- Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Georges Lacaud
- Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
| | - Valerie Kouskoff
- Stem Cell Hematopoiesis, Cancer Research UK Manchester Institute, The University of Manchester, Manchester M20 4BX, UK
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12
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Reprogramming mouse fibroblasts into engraftable myeloerythroid and lymphoid progenitors. Nat Commun 2016; 7:13396. [PMID: 27869129 PMCID: PMC5121332 DOI: 10.1038/ncomms13396] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 09/27/2016] [Indexed: 12/15/2022] Open
Abstract
Recent efforts have attempted to convert non-blood cells into hematopoietic stem cells (HSCs) with the goal of generating blood lineages de novo. Here we show that hematopoietic transcription factors Scl, Lmo2, Runx1 and Bmi1 can convert a developmentally distant lineage (fibroblasts) into ‘induced hematopoietic progenitors' (iHPs). Functionally, iHPs generate acetylcholinesterase+ megakaryocytes and phagocytic myeloid cells in vitro and can also engraft immunodeficient mice, generating myeloerythoid and B-lymphoid cells for up to 4 months in vivo. Molecularly, iHPs transcriptionally resemble native Kit+ hematopoietic progenitors. Mechanistically, reprogramming factor Lmo2 implements a hematopoietic programme in fibroblasts by rapidly binding to and upregulating the Hhex and Gfi1 genes within days. Moreover the reprogramming transcription factors also require extracellular BMP and MEK signalling to cooperatively effectuate reprogramming. Thus, the transcription factors that orchestrate embryonic hematopoiesis can artificially reconstitute this programme in developmentally distant fibroblasts, converting them into engraftable blood progenitors. Direct reprogramming of closely-related lineages can generate hematopoietic stem cells. Here, the authors show hematopoietic transcription factors Scl, Lmo2, Runx1 and Bmi1 can reprogram fibroblasts into induced hematopoietic progenitors (iHPs), which are engraftable blood progenitors.
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13
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Abstract
Understanding how the blood system is formed is an ongoing fundamental research challenge. Developmental biology has provided many insights into the molecules and processes that affect the formation of the blood tissues, both in health and disease. It is of particular interest for clinical transplantation therapies to understand how hematopoietic stem cells (HSCs)-the self-renewing purveyors of the adult blood system that produce over 10 different functionally specialized cell lineages and over 10(11) cells daily-are generated during embryonic stages. Recent successes to reprogram the fate of adult differentiated cells to pluripotency and to other cell lineages now highlight the importance of identifying the cells and molecules that affect the in vivo developmental initiation of rare and robust transplantable HSCs. The close association of the developing hematopoietic and vascular system, hematopoietic cell mobility through the circulation, and the essential role of the embryonic hematopoietic system in adult hematopoietic cell development make this a formidable study. This chapter reviews the advances, controversies, and current state of our knowledge of the growing field of hematopoietic development, with a special focus on the regulation of the natural transdifferentiation of endothelial cells to HSCs within the developing embryo.
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Affiliation(s)
- E Dzierzak
- Erasmus MC, Rotterdam, The Netherlands; MRC Centre for Inflammation Research and MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom.
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14
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The RUNX1–PU.1 axis in the control of hematopoiesis. Int J Hematol 2015; 101:319-29. [DOI: 10.1007/s12185-015-1762-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 02/23/2015] [Indexed: 01/16/2023]
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15
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Li B, Ding L, Yang C, Kang B, Liu L, Story MD, Pace BS. Characterization of transcription factor networks involved in umbilical cord blood CD34+ stem cells-derived erythropoiesis. PLoS One 2014; 9:e107133. [PMID: 25211130 PMCID: PMC4161396 DOI: 10.1371/journal.pone.0107133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 08/11/2014] [Indexed: 11/19/2022] Open
Abstract
Fetal stem cells isolated from umbilical cord blood (UCB) possess a great capacity for proliferation and differentiation and serve as a valuable model system to study gene regulation. Expanded knowledge of the molecular control of hemoglobin synthesis will provide a basis for rational design of therapies for β-hemoglobinopathies. Transcriptome data are available for erythroid progenitors derived from adult stem cells, however studies to define molecular mechanisms controlling globin gene regulation during fetal erythropoiesis are limited. Here, we utilize UCB-CD34+ stem cells induced to undergo erythroid differentiation to characterize the transcriptome and transcription factor networks (TFNs) associated with the γ/β-globin switch during fetal erythropoiesis. UCB-CD34+ stem cells grown in the one-phase liquid culture system displayed a higher proliferative capacity than adult CD34+ stem cells. The γ/β-globin switch was observed after day 42 during fetal erythropoiesis in contrast to adult progenitors where the switch occurred around day 21. To gain insights into transcription factors involved in globin gene regulation, microarray analysis was performed on RNA isolated from UCB-CD34+ cell-derived erythroid progenitors harvested on day 21, 42, 49 and 56 using the HumanHT-12 Expression BeadChip. After data normalization, Gene Set Enrichment Analysis identified transcription factors (TFs) with significant changes in expression during the γ/β-globin switch. Forty-five TFs were silenced by day 56 (Profile-1) and 30 TFs were activated by day 56 (Profile-2). Both GSEA datasets were analyzed using the MIMI Cytoscape platform, which discovered TFNs centered on KLF4 and GATA2 (Profile-1) and KLF1 and GATA1 for Profile-2 genes. Subsequent shRNA studies in KU812 leukemia cells and human erythroid progenitors generated from UCB-CD34+ cells supported a negative role of MAFB in γ-globin regulation. The characteristics of erythroblasts derived from UCB-CD34+ stem cells including prolonged γ-globin expression combined with unique TFNs support novel mechanisms controlling the γ/β-globin switch during UCB-derived erythropoiesis.
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Affiliation(s)
- Biaoru Li
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
| | - Lianghao Ding
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Chinrang Yang
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Baolin Kang
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
| | - Li Liu
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Michael D. Story
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Betty S. Pace
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
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16
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Rat Stem-Cell Leukemia Gene Expression Increased during Testis Maturation. Biosci Biotechnol Biochem 2014; 76:2118-23. [DOI: 10.1271/bbb.120503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Tsuneto M, Kajikhina E, Seiler K, Reimer A, Tornack J, Bouquet C, Simmons S, Knoll M, Wolf I, Tokoyoda K, Hauser A, Hara T, Tani-ichi S, Ikuta K, Grün JR, Grützkau A, Engels N, Wienands J, Yanagisawa Y, Ohnishi K, Melchers F. Reprint of: Environments of B cell development. Immunol Lett 2014; 160:109-12. [PMID: 24852107 DOI: 10.1016/j.imlet.2014.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
B lymphocyte development in the mouse begins with the generation of long-term reconstituting, pluripotent hematopoietic stem cells, over multipotent myeloid/lymphoid progenitors and common lymphoid progenitors to B-lineage committed pro/pre B and pre B cells, which first express pre B cell receptors and then immunoglobulins, B cell receptors, to generate the repertoires of peripheral B cells. This development is influenced and guided by cells of non-hematopoietic and hematopoietic origins. We review here some of the recent developments, and our contributions in this fascinating field of developmental immunology.
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Affiliation(s)
- Motokazu Tsuneto
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Ekaterina Kajikhina
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Katharina Seiler
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Andreas Reimer
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Julia Tornack
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Corinne Bouquet
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Szandor Simmons
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Marko Knoll
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Ingrid Wolf
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany
| | - Koji Tokoyoda
- German Rheumatism Research Center (DRFZ), A Leibniz Institute, Berlin, Germany
| | - Anja Hauser
- German Rheumatism Research Center (DRFZ), A Leibniz Institute, Berlin, Germany
| | - Takahiro Hara
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Shizue Tani-ichi
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Koichi Ikuta
- Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Joachim R Grün
- German Rheumatism Research Center (DRFZ), A Leibniz Institute, Berlin, Germany
| | - Andreas Grützkau
- German Rheumatism Research Center (DRFZ), A Leibniz Institute, Berlin, Germany
| | - Niklas Engels
- Cellular and Molecular Immunology, University of Göttingen, Germany
| | - Jürgen Wienands
- Cellular and Molecular Immunology, University of Göttingen, Germany
| | - Yuki Yanagisawa
- Department of Immunology, National Institutes of Infectious Diseases, Tokyo, Japan
| | - Kazuo Ohnishi
- Department of Immunology, National Institutes of Infectious Diseases, Tokyo, Japan
| | - Fritz Melchers
- Max Planck Institute for Infection Biology, Lymphocyte Development Group, Berlin, Germany.
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18
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Samokhvalov IM. Deconvoluting the ontogeny of hematopoietic stem cells. Cell Mol Life Sci 2014; 71:957-78. [PMID: 23708646 PMCID: PMC11113969 DOI: 10.1007/s00018-013-1364-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 04/15/2013] [Accepted: 05/07/2013] [Indexed: 10/26/2022]
Abstract
Two different models describe the development of definitive hematopoiesis and hematopoietic stem cells (HSCs). In one of these, the visceral yolk sac serves as a starting point of relatively lengthy developmental process culminating in the fetal liver hematopoiesis. In another, the origin of adult hematopoiesis is split between the yolk sac and the dorsal aorta, which has a peculiar capacity to generate definitive HSCs. Despite a large amount of experimental data consistent with the latter view, it becomes increasingly unsustainable in the light of recent cell tracing studies. Moreover, analysis of the published studies supporting the aorta-centered version uncovers significant caveats in standard experimental approach and argumentation. As a result, the theory cannot offer feasible cellular mechanisms of the HSC emergence. This review summarizes key efforts to discern the developmental pathway of the adult-type HSCs and attempts to put forward a hypothesis on the inflammatory mechanisms of hematopoietic ontogenesis.
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Affiliation(s)
- Igor M Samokhvalov
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Science, 190 Kai Yuan Avenue, Science Park, Guangzhou, 510530, China,
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19
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Bonzanni N, Garg A, Feenstra KA, Schütte J, Kinston S, Miranda-Saavedra D, Heringa J, Xenarios I, Göttgens B. Hard-wired heterogeneity in blood stem cells revealed using a dynamic regulatory network model. Bioinformatics 2013; 29:i80-8. [PMID: 23813012 PMCID: PMC3694641 DOI: 10.1093/bioinformatics/btt243] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Motivation: Combinatorial interactions of transcription factors with cis-regulatory elements control the dynamic progression through successive cellular states and thus underpin all metazoan development. The construction of network models of cis-regulatory elements, therefore, has the potential to generate fundamental insights into cellular fate and differentiation. Haematopoiesis has long served as a model system to study mammalian differentiation, yet modelling based on experimentally informed cis-regulatory interactions has so far been restricted to pairs of interacting factors. Here, we have generated a Boolean network model based on detailed cis-regulatory functional data connecting 11 haematopoietic stem/progenitor cell (HSPC) regulator genes. Results: Despite its apparent simplicity, the model exhibits surprisingly complex behaviour that we charted using strongly connected components and shortest-path analysis in its Boolean state space. This analysis of our model predicts that HSPCs display heterogeneous expression patterns and possess many intermediate states that can act as ‘stepping stones’ for the HSPC to achieve a final differentiated state. Importantly, an external perturbation or ‘trigger’ is required to exit the stem cell state, with distinct triggers characterizing maturation into the various different lineages. By focusing on intermediate states occurring during erythrocyte differentiation, from our model we predicted a novel negative regulation of Fli1 by Gata1, which we confirmed experimentally thus validating our model. In conclusion, we demonstrate that an advanced mammalian regulatory network model based on experimentally validated cis-regulatory interactions has allowed us to make novel, experimentally testable hypotheses about transcriptional mechanisms that control differentiation of mammalian stem cells. Contact:j.heringa@vu.nl or ioannis.xenarios@isb-sib.ch or bg200@cam.ac.uk Supplementary information:Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Nicola Bonzanni
- IBIVU Centre for Integrative Bioinformatics, VU University Amsterdam, AIMMS Amsterdam Institute for Molecules Medicines and Systems, VU University Amsterdam, De Boelelaan 1081, NKI-AVL The Netherlands
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20
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Abstract
B lymphocyte development in the mouse begins with the generation of long-term reconstituting, pluripotent hematopoietic stem cells, over multipotent myeloid/lymphoid progenitors and common lymphoid progenitors to B-lineage committed pro/pre B and pre B cells, which first express pre B cell receptors and then immunoglobulins, B cell receptors, to generate the repertoires of peripheral B cells. This development is influenced and guided by cells of non-hematopoietic and hematopoietic origins. We review here some of the recent developments, and our contributions in this fascinating field of developmental immunology.
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21
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Zhen F, Lan Y, Yan B, Zhang W, Wen Z. Hemogenic endothelium specification and hematopoietic stem cell maintenance employ distinct Scl isoforms. Development 2013; 140:3977-85. [DOI: 10.1242/dev.097071] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent studies have shown that nascent hematopoietic stem cells (HSCs) derive directly from the ventral aortic endothelium (VAE) via endothelial to hematopoietic transition (EHT). However, whether EHT initiates from a random or predetermined subpopulation of VAE, as well as the molecular mechanism underlying this process, remain unclear. We previously reported that different zebrafish stem cell leukemia (scl) isoforms are differentially required for HSC formation in the ventral wall of the dorsal aorta. However, the exact stage at which these isoforms impact HSC development was not defined. Here, using in vivo time-lapse imaging of scl isoform-specific reporter transgenic zebrafish lines, we show that prior to EHT scl-β is selectively expressed in hemogenic endothelial cells, a unique subset of VAE cells possessing hemogenic potential, whereas scl-α is expressed later in nascent HSCs as they egress from VAE cells. In accordance with their expression, loss-of-function studies coupled with in vivo imaging analysis reveal that scl-β acts earlier to specify hemogenic endothelium, which is later transformed by runx1 into HSCs. Our results also reveal a previously unexpected role of scl-α in maintaining newly born HSCs in the aorta-gonads-mesonephros. Thus, our data suggest that a defined hemogenic endothelial population preset by scl-β supports the deterministic emergence of HSCs, and unravel the cellular mechanisms by which scl isoforms regulate HSC development.
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Affiliation(s)
- Fenghua Zhen
- State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Yahui Lan
- State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Bo Yan
- State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Wenqing Zhang
- Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Cell Biology, Southern Medical University, Guangzhou 510515, P.R. China
| | - Zilong Wen
- State Key Laboratory of Molecular Neuroscience, Center of Systems Biology and Human Health, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
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22
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Tornack J, Seiler K, Grützkau A, Grün JR, Onodera M, Melchers F, Tsuneto M. Ectopic Runx1 expression rescues Tal-1-deficiency in the generation of primitive and definitive hematopoiesis. PLoS One 2013; 8:e70116. [PMID: 23922928 PMCID: PMC3726448 DOI: 10.1371/journal.pone.0070116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/16/2013] [Indexed: 01/26/2023] Open
Abstract
The transcription factors SCL/Tal-1 and AML1/Runx1 control the generation of pluripotent hematopoietic stem cells (pHSC) and, thereby, primitive and definitive hematopoiesis, during embryonic development of the mouse from mesoderm. Thus, Runx1-deficient mice generate primitive, but not definitive hematopoiesis, while Tal-1-deficient mice are completely defective. Primitive as well as definitive hematopoiesis can be developed "in vitro" from embryonic stem cells (ESC). We show that wild type, as well as Tal-1(-/-) and Runx1(-/-) ESCs, induced to differentiation, all expand within 5 days to comparable numbers of Flk1(+) mesodermal cells. While wild type ESCs further differentiate to primitive and definitive erythrocytes, to c-fms(+)Gr1(+)Mac1(+) myeloid cells, and to B220(+)CD19(+) B- and CD4(+)/CD8(+) T-lymphoid cells, Runx1(-/-) ESCs, as expected, only develop primitive erythrocytes, and Tal-1(-/-) ESCs do not generate any hematopoietic cells. Retroviral transduction with Runx1 of Runx1(-/-) ESCs, differentiated for 4 days to mesoderm, rescues definitive erythropoiesis, myelopoiesis and lymphopoiesis, though only with 1-10% of the efficiencies of wild type ESC hematopoiesis. Surprisingly, Tal-1(-/-) ESCs can also be rescued at comparably low efficiencies to primitive and definitive erythropoiesis, and to myelopoiesis and lymphopoiesis by retroviral transduction with Runx1. These results suggest that Tal-1 expression is needed to express Runx1 in mesoderm, and that ectopic expression of Runx1 in mesoderm is sufficient to induce primitive as well as definitive hematopoiesis in the absence of Tal-1. Retroviral transduction of "in vitro" differentiating Tal-1(-/-) and Runx1(-/-) ESCs should be a useful experimental tool to probe selected genes for activities in the generation of hematopoietic progenitors "in vitro", and to assess the potential transforming activities in hematopoiesis of mutant forms of Tal-1 and Runx1 from acute myeloid leukemia and related tumors.
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Affiliation(s)
- Julia Tornack
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Katharina Seiler
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford, Connecticut, United States of America
| | | | | | - Masafumi Onodera
- National Research Institute for Child Health and Development, Tokyo, Japan
| | - Fritz Melchers
- Max Planck Institute for Infection Biology, Berlin, Germany
- * E-mail: (MT); (FM)
| | - Motokazu Tsuneto
- Max Planck Institute for Infection Biology, Berlin, Germany
- * E-mail: (MT); (FM)
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23
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Cellular reprogramming employing recombinant sox2 protein. Stem Cells Int 2012; 2012:549846. [PMID: 22693519 PMCID: PMC3368608 DOI: 10.1155/2012/549846] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 01/23/2012] [Indexed: 12/21/2022] Open
Abstract
Induced pluripotent stem (iPS) cells represent an attractive option for the derivation of patient-specific pluripotent cells for cell replacement therapies as well as disease modeling. To become clinically meaningful, safe iPS cells need to be generated exhibiting no permanent genetic modifications that are caused by viral integrations of the reprogramming transgenes. Recently, various experimental strategies have been applied to accomplish transgene-free derivation of iPS cells, including the use of nonintegrating viruses, episomal expression, or excision of transgenes after reprogramming by site-specific recombinases or transposases. A straightforward approach to induce reprogramming factors is the direct delivery of either synthetic mRNA or biologically active proteins. We previously reported the generation of cell-permeant versions of Oct4 (Oct4-TAT) and Sox2 (Sox2-TAT) proteins and showed that Oct4-TAT is reprogramming-competent, that is, it can substitute for Oct4-encoding virus. Here, we explore conditions for enhanced Sox2-TAT protein stabilization and functional delivery into somatic cells. We show that cell-permeant Sox2 protein can be stabilized by lipid-rich albumin supplements in serum replacement or low-serum-supplemented media. Employing optimized conditions for protein delivery, we demonstrate that Sox2-TAT protein is able to substitute for viral Sox2. Sox2-piPS cells express pluripotency-associated markers and differentiate into all three germ layers.
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24
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Curtis DJ, Salmon JM, Pimanda JE. Concise Review: Blood Relatives: Formation and regulation of hematopoietic stem cells by the basic helix-loop-helix transcription factors stem cell leukemia and lymphoblastic leukemia-derived sequence 1. Stem Cells 2012; 30:1053-8. [DOI: 10.1002/stem.1093] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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25
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Costa G, Kouskoff V, Lacaud G. Origin of blood cells and HSC production in the embryo. Trends Immunol 2012; 33:215-23. [PMID: 22365572 DOI: 10.1016/j.it.2012.01.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 01/13/2012] [Accepted: 01/18/2012] [Indexed: 12/13/2022]
Abstract
Hematopoietic stem cells (HSCs) are capable of self-renewal and differentiation into all blood cell types. During adult life, they reside in the bone marrow in a quiescent state. By contrast, in the growing embryo hematopoiesis is sequentially found in several developmental niches. This review provides an overview of the still controversial contribution of each of these embryonic sites to the final pool of adult HSCs and discusses new insights into the cellular origin and the molecular regulation implicated in the generation of blood progenitor cells. A better understanding of HSC development during ontogeny is essential to develop new strategies to amplify HSCs or to generate them from embryonic stem cells or by somatic cell reprogramming.
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Affiliation(s)
- Guilherme Costa
- Cancer Research UK Stem Cell Hematopoiesis Group, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
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26
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Tanaka Y, Joshi A, Wilson NK, Kinston S, Nishikawa S, Göttgens B. The transcriptional programme controlled by Runx1 during early embryonic blood development. Dev Biol 2012; 366:404-19. [PMID: 22554697 PMCID: PMC3430866 DOI: 10.1016/j.ydbio.2012.03.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 03/20/2012] [Accepted: 03/28/2012] [Indexed: 01/22/2023]
Abstract
Transcription factors have long been recognised as powerful regulators of mammalian development yet it is largely unknown how individual key regulators operate within wider regulatory networks. Here we have used a combination of global gene expression and chromatin-immunoprecipitation approaches during the early stages of haematopoietic development to define the transcriptional programme controlled by Runx1, an essential regulator of blood cell specification. Integrated analysis of these complementary genome-wide datasets allowed us to construct a global regulatory network model, which suggested that key regulators are activated sequentially during blood specification, but will ultimately collaborate to control many haematopoietically expressed genes. Using the CD41/integrin alpha 2b gene as a model, cellular and in vivo studies showed that CD41 is controlled by both Scl/Tal1 and Runx1 in fully specified blood cells, and initiation of CD41 expression in E7.5 embryos is severely compromised in the absence of Runx1. Taken together, this study represents the first global analysis of the transcriptional programme controlled by any key haematopoietic regulator during the process of early blood cell specification. Moreover, the concept of interplay between sequentially deployed core regulators is likely to represent a design principle widely applicable to the transcriptional control of mammalian development.
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Affiliation(s)
- Yosuke Tanaka
- Laboratory for Stem Cell Biology, RIKEN Center for Developmental Biology, Kobe, Japan
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27
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Schütte J, Moignard V, Göttgens B. Establishing the stem cell state: insights from regulatory network analysis of blood stem cell development. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2012; 4:285-95. [PMID: 22334489 DOI: 10.1002/wsbm.1163] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Transcription factors (TFs) have long been recognized as powerful regulators of cell-type identity and differentiation. As TFs function as constituents of regulatory networks, identification and functional characterization of key interactions within these wider networks will be required to understand how TFs exert their powerful biological functions. The formation of blood cells (hematopoiesis) represents a widely used model system for the study of cellular differentiation. Moreover, specific TFs or groups of TFs have been identified to control the various cell fate choices that must be made when blood stem cells differentiate into more than a dozen distinct mature blood lineages. Because of the relative ease of accessibility, the hematopoietic system represents an attractive experimental system for the development of regulatory network models. Here, we review the modeling efforts carried out to date, which have already provided new insights into the molecular control of blood cell development. We also explore potential areas of future study such as the need for new high-throughput technologies and a focus on studying dynamic cellular systems. Many leukemias arise as the result of mutations that cause transcriptional dysregulation, thus suggesting that a better understanding of transcriptional control mechanisms in hematopoiesis is of substantial biomedical relevance. Moreover, lessons learned from regulatory network analysis in the hematopoietic system are likely to inform research on less experimentally tractable tissues.
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Affiliation(s)
- Judith Schütte
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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28
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Kueh HY, Rothenberg EV. Regulatory gene network circuits underlying T cell development from multipotent progenitors. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2011; 4:79-102. [PMID: 21976153 DOI: 10.1002/wsbm.162] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Regulatory gene circuits enable stem and progenitor cells to detect and process developmental signals and make irreversible fate commitment decisions. To gain insight into the gene circuits underlying T cell fate decision making in progenitor cells, we generated an updated T-lymphocyte developmental gene regulatory network from genes and connections found in the literature. This reconstruction allowed us to identify candidate regulatory gene circuit elements underlying T cell fate decision making. Here, we examine the roles of these circuits in facilitating different aspects of the decision making process, and discuss experiments to further probe their structure and function.
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Affiliation(s)
- Hao Yuan Kueh
- Division of Biology, California Institute of Technology, Pasadena, CA, USA
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29
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Affiliation(s)
- Huiyuan Li
- State Key Laboratory of Experimental Haematology, Institute of Haematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin
| | - Haifeng Zhao
- State Key Laboratory of Experimental Haematology, Institute of Haematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin
| | - Donghai Wang
- Department of Haematology, Peking University First Hospital, Beijing, China
| | - Renchi Yang
- State Key Laboratory of Experimental Haematology, Institute of Haematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin
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30
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Krumsiek J, Marr C, Schroeder T, Theis FJ. Hierarchical differentiation of myeloid progenitors is encoded in the transcription factor network. PLoS One 2011; 6:e22649. [PMID: 21853041 PMCID: PMC3154193 DOI: 10.1371/journal.pone.0022649] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 06/27/2011] [Indexed: 11/29/2022] Open
Abstract
Hematopoiesis is an ideal model system for stem cell biology with advanced experimental access. A systems view on the interactions of core transcription factors is important for understanding differentiation mechanisms and dynamics. In this manuscript, we construct a Boolean network to model myeloid differentiation, specifically from common myeloid progenitors to megakaryocytes, erythrocytes, granulocytes and monocytes. By interpreting the hematopoietic literature and translating experimental evidence into Boolean rules, we implement binary dynamics on the resulting 11-factor regulatory network. Our network contains interesting functional modules and a concatenation of mutual antagonistic pairs. The state space of our model is a hierarchical, acyclic graph, typifying the principles of myeloid differentiation. We observe excellent agreement between the steady states of our model and microarray expression profiles of two different studies. Moreover, perturbations of the network topology correctly reproduce reported knockout phenotypes in silico. We predict previously uncharacterized regulatory interactions and alterations of the differentiation process, and line out reprogramming strategies.
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Affiliation(s)
- Jan Krumsiek
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, München, Germany
| | - Carsten Marr
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, München, Germany
| | - Timm Schroeder
- Institute of Stem Cell Research, Helmholtz Zentrum München, München, Germany
| | - Fabian J. Theis
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, München, Germany
- Department of Mathematics, Technische Universität München, München, Germany
- * E-mail:
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31
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A Runx1-Smad6 rheostat controls Runx1 activity during embryonic hematopoiesis. Mol Cell Biol 2011; 31:2817-26. [PMID: 21576367 DOI: 10.1128/mcb.01305-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The oncogenic transcription factor Runx1 is required for the specification of definitive hematopoietic stem cells (HSC) in the developing embryo. The activity of this master regulator is tightly controlled during development. The transcription factors that upregulate the expression of Runx1 also upregulate the expression of Smad6, the inhibitory Smad, which controls Runx1 activity by targeting it to the proteasome. Here we show that Runx1, in conjunction with Fli1, Gata2, and Scl, directly regulates the expression of Smad6 in the aorta-gonad-mesonephros (AGM) region in the developing embryo, where HSCs originate. Runx1 regulates Smad6 activity via a novel upstream enhancer, and Runx1 null embryos show reduced Smad6 transcripts in the yolk-sac and c-Kit-positive fetal liver cells. By directly regulating the expression of Smad6, Runx1 sets up a functional rheostat to control its own activity. The perturbation of this rheostat, using a proteasomal inhibitor, results in an increase in Runx1 and Smad6 levels that can be directly attributed to increased Runx1 binding to tissue-specific regulatory elements of these genes. Taken together, we describe a scenario in which a key hematopoietic transcription factor controls its own expression levels by transcriptionally controlling its controller.
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Hannah R, Joshi A, Wilson NK, Kinston S, Göttgens B. A compendium of genome-wide hematopoietic transcription factor maps supports the identification of gene regulatory control mechanisms. Exp Hematol 2011; 39:531-41. [PMID: 21338655 DOI: 10.1016/j.exphem.2011.02.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 02/09/2011] [Accepted: 02/14/2011] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Key regulators of blood stem cell differentiation into the various mature hematopoietic lineages are commonly encoded by transcription factor genes. Elucidation of transcriptional regulatory mechanisms therefore holds great promise in advancing our understanding of both normal and malignant hematopoiesis. Recent technological advances have enabled the generation of genome-wide transcription factor binding maps using chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-Seq). However, transcription factors operate in a combinatorial fashion suggesting that integrated analysis of genome-wide maps for multiple transcription factors will be essential to fully exploit these new genome-scale data sets. MATERIALS AND METHODS Here we have generated a compendium that integrates 53 ChIP-Seq studies covering 30 factors across all major hematopoietic lineages with a total of 754,380 binding peaks. We also used transgenic mouse assays to validate a newly predicted transcriptional enhancer. RESULTS Integrated analysis of all 53 ChIP-Seq studies demonstrated that cell-type identity exerts a larger influence on global transcription factor binding patterns than the nature of the individual transcription factors. Furthermore, regions highlighted by multifactor binding within specific gene loci overlap with known regulatory elements and also provide a useful guide for identifying novel elements, as demonstrated by transgenic analysis of a previously unrecognized enhancer in the Maml3 gene locus. CONCLUSIONS The ChIP-Seq compendium described here provides a valuable resource for the wider research community by accelerating the discovery of transcriptional mechanisms operating in the hematopoietic system.
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Affiliation(s)
- Rebecca Hannah
- University of Cambridge, Department of Haematology, Cambridge Institute for Medical Research, Hills Road, Cambridge, UK
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Genetic engineering of mammalian cells by direct delivery of FLP recombinase protein. Methods 2011; 53:386-93. [DOI: 10.1016/j.ymeth.2010.12.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 11/24/2010] [Accepted: 12/17/2010] [Indexed: 11/23/2022] Open
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Wilson NK, Foster SD, Wang X, Knezevic K, Schütte J, Kaimakis P, Chilarska PM, Kinston S, Ouwehand WH, Dzierzak E, Pimanda JE, de Bruijn MFTR, Göttgens B. Combinatorial transcriptional control in blood stem/progenitor cells: genome-wide analysis of ten major transcriptional regulators. Cell Stem Cell 2011; 7:532-44. [PMID: 20887958 DOI: 10.1016/j.stem.2010.07.016] [Citation(s) in RCA: 535] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2010] [Revised: 06/10/2010] [Accepted: 07/21/2010] [Indexed: 11/16/2022]
Abstract
Combinatorial transcription factor (TF) interactions control cellular phenotypes and, therefore, underpin stem cell formation, maintenance, and differentiation. Here, we report the genome-wide binding patterns and combinatorial interactions for ten key regulators of blood stem/progenitor cells (SCL/TAL1, LYL1, LMO2, GATA2, RUNX1, MEIS1, PU.1, ERG, FLI-1, and GFI1B), thus providing the most comprehensive TF data set for any adult stem/progenitor cell type to date. Genome-wide computational analysis of complex binding patterns, followed by functional validation, revealed the following: first, a previously unrecognized combinatorial interaction between a heptad of TFs (SCL, LYL1, LMO2, GATA2, RUNX1, ERG, and FLI-1). Second, we implicate direct protein-protein interactions between four key regulators (RUNX1, GATA2, SCL, and ERG) in stabilizing complex binding to DNA. Third, Runx1(+/-)::Gata2(+/-) compound heterozygous mice are not viable with severe hematopoietic defects at midgestation. Taken together, this study demonstrates the power of genome-wide analysis in generating novel functional insights into the transcriptional control of stem and progenitor cells.
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Affiliation(s)
- Nicola K Wilson
- University of Cambridge Department of Haematology, Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK
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Swiers G, de Bruijn M, Speck NA. Hematopoietic stem cell emergence in the conceptus and the role of Runx1. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2011; 54:1151-63. [PMID: 20711992 DOI: 10.1387/ijdb.103106gs] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hematopoietic stem cells (HSCs) are functionally defined as cells that upon transplantation into irradiated or otherwise immunocompromised adult organisms provide long-term reconstitution of the entire hematopoietic system. They emerge in the vertebrate conceptus around midgestation. Genetic studies have identified a number of transcription factors and signaling molecules that act at the onset of hematopoiesis, and have begun to delineate the molecular mechanisms underlying the formation of HSCs. One molecule that has been a particularly useful marker of this developmental event in multiple species is Runx1 (also known as AML1, Pebp2alpha). Runx1 is a sequence-specific DNA-binding protein, that along with its homologues Runx2 and Runx3 and their shared non-DNA binding subunit CBFbeta, constitute a small family of transcription factors called core-binding factors (CBFs). Runx1 is famous for its role in HSC emergence, and notorious for its involvement in leukemia, as chromosomal rearrangements and inactivating mutations in the human RUNX1 gene are some of the most common events in de novo and therapy-related acute myelogenous leukemia, myelodysplastic syndrome and acute lymphocytic leukemia. Here we will review the role of Runx1 in HSC emergence in the mouse conceptus and describe some of the genetic pathways that operate upstream and downstream of this gene. Where relevant, we will include data obtained from other species and embryonic stem (ES) cell differentiation cultures.
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Affiliation(s)
- Gemma Swiers
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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Wilson NK, Calero-Nieto FJ, Ferreira R, Göttgens B. Transcriptional regulation of haematopoietic transcription factors. Stem Cell Res Ther 2011; 2:6. [PMID: 21345252 PMCID: PMC3092146 DOI: 10.1186/scrt47] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The control of differential gene expression is central to all metazoan biology. Haematopoiesis represents one of the best understood developmental systems where multipotent blood stem cells give rise to a range of phenotypically distinct mature cell types, all characterised by their own distinctive gene expression profiles. Small combinations of lineage-determining transcription factors drive the development of specific mature lineages from multipotent precursors. Given their powerful regulatory nature, it is imperative that the expression of these lineage-determining transcription factors is under tight control, a fact underlined by the observation that their misexpression commonly leads to the development of leukaemia. Here we review recent studies on the transcriptional control of key haematopoietic transcription factors, which demonstrate that gene loci contain multiple modular regulatory regions within which specific regulatory codes can be identified, that some modular elements cooperate to mediate appropriate tissue-specific expression, and that long-range approaches will be necessary to capture all relevant regulatory elements. We also explore how changes in technology will impact on this area of research in the future.
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Affiliation(s)
- Nicola K Wilson
- University of Cambridge Department of Haematology, Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK.
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Li L, Jothi R, Cui K, Lee JY, Cohen T, Gorivodsky M, Tzchori I, Zhao Y, Hayes SM, Bresnick EH, Zhao K, Westphal H, Love PE. Nuclear adaptor Ldb1 regulates a transcriptional program essential for the maintenance of hematopoietic stem cells. Nat Immunol 2011; 12:129-36. [PMID: 21186366 PMCID: PMC3766981 DOI: 10.1038/ni.1978] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 12/01/2010] [Indexed: 01/15/2023]
Abstract
The nuclear adaptor Ldb1 functions as a core component of multiprotein transcription complexes that regulate differentiation in diverse cell types. In the hematopoietic lineage, Ldb1 forms a complex with the non-DNA-binding adaptor Lmo2 and the transcription factors E2A, Scl and GATA-1 (or GATA-2). Here we demonstrate a critical and continuous requirement for Ldb1 in the maintenance of both fetal and adult mouse hematopoietic stem cells (HSCs). Deletion of Ldb1 in hematopoietic progenitors resulted in the downregulation of many transcripts required for HSC maintenance. Genome-wide profiling by chromatin immunoprecipitation followed by sequencing (ChIP-Seq) identified Ldb1 complex-binding sites at highly conserved regions in the promoters of genes involved in HSC maintenance. Our results identify a central role for Ldb1 in regulating the transcriptional program responsible for the maintenance of HSCs.
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Affiliation(s)
- LiQi Li
- Section on Cellular & Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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Taoudi S, Bee T, Hilton A, Knezevic K, Scott J, Willson TA, Collin C, Thomas T, Voss AK, Kile BT, Alexander WS, Pimanda JE, Hilton DJ. ERG dependence distinguishes developmental control of hematopoietic stem cell maintenance from hematopoietic specification. Genes Dev 2011; 25:251-62. [PMID: 21245161 DOI: 10.1101/gad.2009211] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Although many genes are known to be critical for early hematopoiesis in the embryo, it remains unclear whether distinct regulatory pathways exist to control hematopoietic specification versus hematopoietic stem cell (HSC) emergence and function. Due to their interaction with key regulators of hematopoietic commitment, particular interest has focused on the role of the ETS family of transcription factors; of these, ERG is predicted to play an important role in the initiation of hematopoiesis, yet we do not know if or when ERG is required. Using in vitro and in vivo models of hematopoiesis and HSC development, we provide strong evidence that ERG is at the center of a distinct regulatory program that is not required for hematopoietic specification or differentiation but is critical for HSC maintenance during embryonic development. We show that, from the fetal period, ERG acts as a direct upstream regulator of Gata2 and Runx1 gene activity. Without ERG, physiological HSC maintenance fails, leading to the rapid exhaustion of definitive hematopoiesis.
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Affiliation(s)
- Samir Taoudi
- Molecular Medicine Division, The Walter and Eliza Institute of Medical Research, Melbourne, Parkville, Victoria 3052, Australia.
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Rosselló CA, Torres M. Gene transfer by electroporation into hemogenic endothelium in the avian embryo. Dev Dyn 2010; 239:1748-54. [PMID: 20503370 DOI: 10.1002/dvdy.22317] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Hematopoiesis is the dynamic process whereby blood cells are continuously produced in an organism. Blood cell production is sustained by a population of self-renewing multipotent hematopoietic stem cells (HSCs) throughout the life of an organism. Cells with definitive HSC properties appear in the mid-gestation embryo as dense clusters of cells budding from the floor of the aorta, and that of the vitelline and umbilical arteries in the aorta-gonads-mesonephros region. Attempts to genetically modify the aortic floor from which these HSCs arise have been unsuccessful in the mouse, since the regulation of gene expression in the hemogenic endothelium is largely unknown. Here we report the implementation of gene transfer by electroporation into dorsal aortic endothelial cells in the chick embryo. This approach provides a quick and reproducible method of generating gain/loss-of-function models to investigate the function of genes involved in HSC birth.
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Affiliation(s)
- Catalina Ana Rosselló
- Department of Cardiovascular Developmental Biology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
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40
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Panepucci RA, Oliveira LHB, Zanette DL, Viu Carrara RDC, Araujo AG, Orellana MD, Bonini de Palma PV, Menezes CCBO, Covas DT, Zago MA. Increased levels of NOTCH1, NF-kappaB, and other interconnected transcription factors characterize primitive sets of hematopoietic stem cells. Stem Cells Dev 2010; 19:321-32. [PMID: 19686049 DOI: 10.1089/scd.2008.0397] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
As previously shown, higher levels of NOTCH1 and increased NF-kappaB signaling is a distinctive feature of the more primitive umbilical cord blood (UCB) CD34+ hematopoietic stem cells (HSCs), as compared to bone marrow (BM). Differences between BM and UCB cell composition also account for this finding. The CD133 marker defines a more primitive cell subset among CD34+ HSC with a proposed hemangioblast potential. To further evaluate the molecular basis related to the more primitive characteristics of UCB and CD133+ HSC, immunomagnetically purified human CD34+ and CD133+ cells from BM and UCB were used on gene expression microarrays studies. UCB CD34+ cells contained a significantly higher proportion of CD133+ cells than BM (70% and 40%, respectively). Cluster analysis showed that BM CD133+ cells grouped with the UCB cells (CD133+ and CD34+) rather than to BM CD34+ cells. Compared with CD34+ cells, CD133+ had a higher expression of many transcription factors (TFs). Promoter analysis on all these TF genes revealed a significantly higher frequency (than expected by chance) of NF-kappaB-binding sites (BS), including potentially novel NF-kappaB targets such as RUNX1, GATA3, and USF1. Selected transcripts of TF related to primitive hematopoiesis and self-renewal, such as RUNX1, GATA3, USF1, TAL1, HOXA9, HOXB4, NOTCH1, RELB, and NFKB2 were evaluated by real-time PCR and were all significantly positively correlated. Taken together, our data indicate the existence of an interconnected transcriptional network characterized by higher levels of NOTCH1, NF-kappaB, and other important TFs on more primitive HSC sets.
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Affiliation(s)
- Rodrigo Alexandre Panepucci
- Department of Clinical Medicine of the Faculty of Medicine of Ribeirao Preto-USP, Center for Cell Therapy and Regional Blood Center, Araraquara, São Paulo, Brazil.
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Immune-related zinc finger gene ZFAT is an essential transcriptional regulator for hematopoietic differentiation in blood islands. Proc Natl Acad Sci U S A 2010; 107:14199-204. [PMID: 20660741 DOI: 10.1073/pnas.1002494107] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
TAL1 plays pivotal roles in vascular and hematopoietic developments through the complex with LMO2 and GATA1. Hemangioblasts, which have a differentiation potential for both endothelial and hematopoietic lineages, arise in the primitive streak and migrate into the yolk sac to form blood islands, where primitive hematopoiesis occurs. ZFAT (a zinc-finger gene in autoimmune thyroid disease susceptibility region/an immune-related transcriptional regulator containing 18 C(2)H(2)-type zinc-finger domains and one AT-hook) was originally identified as an immune-related transcriptional regulator containing 18 C(2)H(2)-type zinc-finger domains and one AT-hook, and is highly conserved among species. ZFAT is thought to be a critical transcription factor involved in immune-regulation and apoptosis; however, developmental roles for ZFAT remain unknown. Here we show that Zfat-deficient (Zfat(-/-)) mice are embryonic-lethal, with impaired differentiation of hematopoietic progenitor cells in blood islands, where ZFAT is exactly expressed. Expression levels of Tal1, Lmo2, and Gata1 in Zfat(-/-) yolk sacs are much reduced compared with those of wild-type mice, and ChIP-PCR analysis revealed that ZFAT binds promoter regions for these genes in vivo. Furthermore, profound reduction in TAL1, LMO2, and GATA1 protein expressions are observed in Zfat(-/-) blood islands. Taken together, these results suggest that ZFAT is indispensable for mouse embryonic development and functions as a critical transcription factor for primitive hematopoiesis through direct-regulation of Tal1, Lmo2, and Gata1. Elucidation of ZFAT functions in hematopoiesis might lead to a better understanding of transcriptional networks in differentiation and cellular programs of hematopoietic lineage and provide useful information for applied medicine in stem cell therapy.
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Stock K, Nolden L, Edenhofer F, Quandel T, Brüstle O. Transcription factor-based modulation of neural stem cell differentiation using direct protein transduction. Cell Mol Life Sci 2010; 67:2439-49. [PMID: 20352468 PMCID: PMC2889284 DOI: 10.1007/s00018-010-0347-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 02/16/2010] [Accepted: 03/08/2010] [Indexed: 01/12/2023]
Abstract
In contrast to conventional gene transfer strategies, the direct introduction of recombinant proteins into cells bypasses the risk of insertional mutagenesis and offers an alternative to genetic intervention. Here, we explore whether protein transduction of the gliogenic transcription factor Nkx2.2 can be used to promote oligodendroglial differentiation of mouse embryonic stem cell (ESC)-derived neural stem cells (NSC). To that end, a recombinant cell-permeant form of Nkx2.2 protein was generated. Exposure of ESC-derived NSC to the recombinant protein and initiation of differentiation resulted in a two-fold increase in the number of oligodendrocytes. Furthermore, Nkx2.2-transduced cells exhibited a more mature oligodendroglial phenotype. Comparative viral gene transfer studies showed that the biological effect of Nkx2.2 protein transduction is comparable to that obtained by lentiviral transduction. The results of this proof-of-concept study depict direct intracellular delivery of transcription factors as alternative modality to control lineage differentiation in NSC cultures without genetic modification.
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Affiliation(s)
- Kristin Stock
- Stem Cell Engineering Group, Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Bonn, Germany
- Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Lars Nolden
- Stem Cell Engineering Group, Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Bonn, Germany
- Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Frank Edenhofer
- Stem Cell Engineering Group, Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Bonn, Germany
- Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Tamara Quandel
- Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
| | - Oliver Brüstle
- Institute of Reconstructive Neurobiology, LIFE and BRAIN Center, University of Bonn and Hertie Foundation, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
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Gfi1 expression is controlled by five distinct regulatory regions spread over 100 kilobases, with Scl/Tal1, Gata2, PU.1, Erg, Meis1, and Runx1 acting as upstream regulators in early hematopoietic cells. Mol Cell Biol 2010; 30:3853-63. [PMID: 20516218 DOI: 10.1128/mcb.00032-10] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The growth factor independence 1 (Gfi1) gene was originally discovered in the hematopoietic system, where it functions as a key regulator of stem cell homeostasis, as well as neutrophil and T-cell development. Outside the blood system, Gfi1 is essential for inner-ear hair and intestinal secretory cell differentiation. To understand the regulatory hierarchies within which Gfi1 operates to control these diverse biological functions, we used a combination of comparative genomics, locus-wide chromatin immunoprecipitation assays, functional validation in cell lines, and extensive transgenic mouse assays to identify and characterize the complete ensemble of Gfi1 regulatory elements. This concerted effort identified five distinct regulatory elements spread over 100kb each driving expression in transgenic mice to a subdomain of endogenous Gfi1. Detailed characterization of an enhancer 35 kb upstream of Gfi1 demonstrated activity in the dorsal aorta region and fetal liver in transgenic mice, which was bound by key stem cell transcription factors Scl/Tal1, PU.1/Sfpi1, Runx1, Erg, Meis1, and Gata2. Taken together, our results reveal the regulatory regions responsible for Gfi1 expression and importantly establish that Gfi1 expression at the sites of hematopoietic stem cell (HSC) emergence is controlled by key HSC regulators, thus integrating Gfi1 into the wider HSC regulatory networks.
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Modeling reveals bistability and low-pass filtering in the network module determining blood stem cell fate. PLoS Comput Biol 2010; 6:e1000771. [PMID: 20463872 PMCID: PMC2865510 DOI: 10.1371/journal.pcbi.1000771] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 03/30/2010] [Indexed: 01/15/2023] Open
Abstract
Combinatorial regulation of gene expression is ubiquitous in eukaryotes with multiple inputs converging on regulatory control elements. The dynamic properties of these elements determine the functionality of genetic networks regulating differentiation and development. Here we propose a method to quantitatively characterize the regulatory output of distant enhancers with a biophysical approach that recursively determines free energies of protein-protein and protein-DNA interactions from experimental analysis of transcriptional reporter libraries. We apply this method to model the Scl-Gata2-Fli1 triad—a network module important for cell fate specification of hematopoietic stem cells. We show that this triad module is inherently bistable with irreversible transitions in response to physiologically relevant signals such as Notch, Bmp4 and Gata1 and we use the model to predict the sensitivity of the network to mutations. We also show that the triad acts as a low-pass filter by switching between steady states only in response to signals that persist for longer than a minimum duration threshold. We have found that the auto-regulation loops connecting the slow-degrading Scl to Gata2 and Fli1 are crucial for this low-pass filtering property. Taken together our analysis not only reveals new insights into hematopoietic stem cell regulatory network functionality but also provides a novel and widely applicable strategy to incorporate experimental measurements into dynamical network models. Hematopoiesis—blood cell development—has long served as a model for study of cellular differentiation and its control by underlying gene regulatory networks. The Scl-Gata2-Fli1 triad is a network module essential for the development of hematopoietic stem cells but its mechanistic role is not well understood. The transcription factors Scl, Gata2 and Fli1 act in combination to upregulate transcription of each other via distal enhancer site binding. Similar network architectures are essential in other multipotent cell lines. We propose a method that uses experimental results to circumvent the difficulties of mathematically modeling the combinatorial regulation of this triad module. Using this dynamical model we show that the triad exhibits robust bistable behavior. Environmental signals can irreversibly switch the triad between stable states in a manner that reflects the unidirectional switching in the formation and subsequent differentiation of hematopoietic stem cells. We also show that the triad makes reliable decisions in noisy environments by only switching in response to transient signals that persist longer than the threshold duration. These results suggest that the Scl-Gata2-Fli1 module possibly functions as a control switch for hematopoietic stem cell development. The proposed method can be extended for quantitative characterization of other combinatorial gene regulatory modules.
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Nagel S, Venturini L, Meyer C, Kaufmann M, Scherr M, Drexler HG, MacLeod RA. Multiple mechanisms induce ectopic expression of LYL1 in subsets of T-ALL cell lines. Leuk Res 2010; 34:521-8. [DOI: 10.1016/j.leukres.2009.06.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/09/2009] [Accepted: 06/17/2009] [Indexed: 12/01/2022]
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Yang WC, Patel KG, Lee J, Ghebremariam YT, Wong HE, Cooke JP, Swartz JR. Cell-free production of transducible transcription factors for nuclear reprogramming. Biotechnol Bioeng 2010; 104:1047-58. [PMID: 19718703 DOI: 10.1002/bit.22517] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Ectopic expression of a defined set of transcription factors chosen from Oct3/4, Sox2, c-Myc, Klf4, Nanog, and Lin28 can directly reprogram somatic cells to pluripotency. These reprogrammed cells are referred to as induced pluripotent stem cells (iPSCs). To date, iPSCs have been successfully generated using lentiviruses, retroviruses, adenoviruses, plasmids, transposons, and recombinant proteins. Nucleic acid-based approaches raise concerns about genomic instability. In contrast, a protein-based approach for iPSC generation can avoid DNA integration concerns as well as provide greater control over the concentration, timing, and sequence of transcription factor stimulation. Researchers recently demonstrated that polyarginine peptide conjugation can deliver recombinant protein reprogramming factor (RF) cargoes into cells and reprogram somatic cells into iPSCs. However, the protein-based approach requires a significant amount of protein for the reprogramming process. Producing fusion RFs in the large amounts required for this approach using traditional heterologous in vivo production methods is difficult and cumbersome since toxicity, product aggregation, and proteolysis by endogenous proteases limit yields. In this work, we show that cell-free protein synthesis (CFPS) is a viable option for producing soluble and functional transducible transcription factors for nuclear reprogramming. We used an E. coli-based CFPS system to express the above set of six human RFs as fusion proteins, each with a nona-arginine (R9) protein transduction domain. Using the flexibility offered by the CFPS platform, we successfully addressed proteolysis and protein solubility problems to produce full-length and soluble R9-RF fusions. We subsequently showed that R9-Oct3/4, R9-Sox2, and R9-Nanog exhibit cognate DNA-binding activities, R9-Nanog translocates across the plasma and nuclear membranes, and R9-Sox2 exerts transcriptional activity on a known downstream gene target.
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Affiliation(s)
- William C Yang
- Department of Bioengineering, Stanford University, California 94305, USA
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Abstract
The protein transduction technique enables the direct delivery of biologically active material into mammalian cells [for review see 1,2]. For this one can make use of the translocating ability of so-called cell penetrating peptides (CPPs), also designated as protein transduction domains (PTDs). The TAT-CPP derived from the human immunodeficiency virus type 1 (HIV-1) Tat (trans-activator of transcription) protein has been widely used. The positively charged TAT promotes cell permeability thereby overcoming the barriers of the cellular membrane by endocytosis or/and direct membrane penetration2. In combination with a nuclear localization signal (NLS) fusion proteins are able to enter the nucleus exhibiting functionality. Our video presentation demonstrates, as an exemplification for the engineering of cell-permeable proteins, the construction, production and application of a cell-permeable version of the DNA-modifying enzyme Cre. Cre is a site-specific recombinase that is able to recognize and recombine 34 base pair loxP sites in mammalian cells in vitro and in vivo. Therefore the Cre/loxP system is widely used to conditionally induce mutations in the genome of living cells3,4. The delivery of active Cre recombinase to cells, however, represents a limitation. We describe the pSESAME vector system, which allows a direct insertion of the gene-of-interest and provides a platform to rapidly clone different domains and tags used within the vector in a convenient and standardized manner. Rearranging of the different tags has been shown to modify the biochemical properties of the fusion proteins providing a possibility to achieve higher yield and better solubility. We demonstrate how to express and purify recombinant cell-permeant proteins in and from E. coli. The functionality of the recombinant Cre protein is finally validated in cell culture by assessing its intracellular recombinase activity.
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Affiliation(s)
- Bernhard Münst
- Stem Cell Engineering Group, Institute of Reconstructive Neurobiology, University of Bonn - Life & Brain Center and Hertie Foundation
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48
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Lausen J, Pless O, Leonard F, Kuvardina ON, Koch B, Leutz A. Targets of the Tal1 transcription factor in erythrocytes: E2 ubiquitin conjugase regulation by Tal1. J Biol Chem 2009; 285:5338-46. [PMID: 20028976 DOI: 10.1074/jbc.m109.030296] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Tal1 transcription factor is essential for the development of the hematopoietic system and plays a role during definitive erythropoiesis in the adult. Despite the importance of Tal1 in erythropoiesis, only a small number of erythroid differentiation target genes are known. A chromatin precipitation and cloning approach was established to uncover novel Tal1 target genes in erythropoiesis. The BirA tag/BirA ligase biotinylation system in combination with streptavidin chromatin precipitation (Strep-CP) was used to co-precipitate genomic DNA bound to Tal1. Tal1 was found to bind in the vicinity of 31 genes including the E2-ubiquitin conjugase UBE2H gene. Binding of Tal1 to UBE2H was confirmed by chromatin immunoprecipitation. UBE2H expression is increased during erythroid differentiation of hCD34(+) cells. Tal1 expression activated UBE2H expression, whereas Tal1 knock-down reduced UBE2H expression and ubiquitin transfer activity. This study identifies parts of the ubiquitinylation machinery as a cellular target downstream of the transcription factor Tal1 and provides novel insights into Tal1-regulated erythropoiesis.
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Affiliation(s)
- Jörn Lausen
- Georg-Speyer-Haus, Institute for Biomedical Research, D-60596 Frankfurt (Main), Germany.
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49
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Ottersbach K, Smith A, Wood A, Göttgens B. Ontogeny of haematopoiesis: recent advances and open questions. Br J Haematol 2009; 148:343-55. [PMID: 19863543 DOI: 10.1111/j.1365-2141.2009.07953.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Unravelling the embryonic origins of the haematopoietic system has been the subject of sustained research for more than a century. Nevertheless, many important questions are still either unanswered or remain a matter of intense debate. Recent progress in mouse and embryonic stem cell model systems as well as imaging and post-genomic technologies has provided new insights into many of these open questions. Here we place into context recent reports on the anatomical site of blood stem cell emergence and, using red blood cells as an example, illustrate how the development of stem cells and the other blood lineages is both temporally and spatially decoupled. In addition, we outline how embryonic stem cell assays are increasingly used as a powerful surrogate for studying lineage relationships and developmental potential of early embryonic blood progenitors. Finally, we review how recent progress in the reconstruction of transcriptional regulatory networks is beginning to define the connectivity between key regulators that control early blood development. In light of these rapid recent advances, research into the embryonic origins of the haematopoietic system should remain one of the most vibrant disciplines within the wider field of haematology for the foreseeable future.
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Affiliation(s)
- Katrin Ottersbach
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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50
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Foster SD, Oram SH, Wilson NK, Göttgens B. From genes to cells to tissues--modelling the haematopoietic system. MOLECULAR BIOSYSTEMS 2009; 5:1413-20. [PMID: 19763334 DOI: 10.1039/b907225j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Haematopoiesis (or blood formation) in general and haematopoietic stem cells more specifically represent some of the best studied mammalian developmental systems. Sophisticated purification protocols coupled with powerful biological assays permit functional analysis of highly purified cell populations both in vitro and in vivo. However, despite several decades of intensive research, the sheer complexity of the haematopoietic system means that many important questions remain unanswered or even unanswerable with current experimental tools. Scientists have therefore increasingly turned to modelling to tackle complexity at multiple levels ranging from networks of genes to the behaviour of cells and tissues. Early modelling attempts of gene regulatory networks have focused on core regulatory circuits but have more recently been extended to genome-wide datasets such as expression profiling and ChIP-sequencing data. Modelling of haematopoietic cells and tissues has provided insight into the importance of phenotypic heterogeneity for the differentiation of normal progenitor cells as well as a greater understanding of treatment response for particular pathologies such as chronic myeloid leukaemia. Here we will review recent progress in attempts to reconstruct segments of the haematopoietic system. A variety of modelling strategies will be covered from small-scale, protein-DNA or protein-protein interactions to large scale reconstructions. Also discussed will be examples of how stochastic modelling may be applied to multi cell systems such as those seen in normal and malignant haematopoiesis.
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Affiliation(s)
- Samuel D Foster
- Haematopoietic Stem Cell Laboratory, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Rd, Cambridge, CB2 0XY
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