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Jalnapurkar SS, Pawar A, George SS, Antony C, Grana J, Gurbuxani S, Paralkar VR. PHF6 suppresses self-renewal of leukemic stem cells in AML. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.06.573649. [PMID: 38260439 PMCID: PMC10802281 DOI: 10.1101/2024.01.06.573649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Acute myeloid leukemia is characterized by uncontrolled proliferation of self-renewing myeloid progenitors. PHF6 is a chromatin-binding protein mutated in myeloid leukemias, and its loss increases mouse HSC self-renewal without malignant transformation. We report here that Phf6 knockout increases the aggressiveness of Hoxa9-driven AML over serial transplantation, and increases the frequency of leukemia initiating cells. We define the in vivo hierarchy of Hoxa9-driven AML and identify a population that we term the 'LIC-e' (leukemia initiating cells enriched) population. We find that Phf6 loss has context-specific transcriptional effects, skewing the LIC-e transcriptome to a more stem-like state. We demonstrate that LIC-e accumulation in Phf6 knockout AML occurs not due to effects on cell cycle or apoptosis, but due to an increase in the fraction of its progeny that retain LIC-e identity. Overall, our work indicates that Phf6 loss increases AML self-renewal through context-specific effects on leukemia stem cells.
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Affiliation(s)
- Sapana S Jalnapurkar
- Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Aishwarya Pawar
- Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Biomedical Graduate Studies, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Subin S George
- Institute for Biomedical Informatics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Charles Antony
- Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jason Grana
- Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Sandeep Gurbuxani
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Vikram R Paralkar
- Division of Hematology and Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
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2
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Robbins DJ, Pavletich TS, Patil AT, Pahopos D, Lasarev M, Polaki US, Gahvari ZJ, Bresnick EH, Matson DR. Linking GATA2 to myeloid dysplasia and complex cytogenetics in adult myelodysplastic neoplasm and acute myeloid leukemia. Blood Adv 2024; 8:80-92. [PMID: 38029365 PMCID: PMC10787255 DOI: 10.1182/bloodadvances.2023011554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/07/2023] [Accepted: 11/27/2023] [Indexed: 12/01/2023] Open
Abstract
ABSTRACT GATA binding protein 2 (GATA2) is a conserved zinc finger transcription factor that regulates the emergence and maintenance of complex genetic programs driving development and function of hematopoietic stem and progenitor cells (HSPCs). Patients born with monoallelic GATA2 mutations develop myelodysplastic neoplasm (MDS) and acute myeloid leukemia (AML), whereas acquired GATA2 mutations are reported in 3% to 5% of sporadic AML cases. The mechanisms by which aberrant GATA2 activity promotes MDS and AML are incompletely understood. Efforts to understand GATA2 in basic biology and disease will be facilitated by the development of broadly efficacious antibodies recognizing physiologic levels of GATA2 in diverse tissue types and assays. Here, we purified a polyclonal anti-GATA2 antibody and generated multiple highly specific anti-GATA2 monoclonal antibodies, optimized them for immunohistochemistry on patient bone marrow bioosy samples, and analyzed GATA2 expression in adults with healthy bone marrow, MDS, and acute leukemia. In healthy bone marrow, GATA2 was detected in mast cells, subsets of CD34+ HSPCs, E-cadherin-positive erythroid progenitors, and megakaryocytes. In MDS, GATA2 expression correlates with bone marrow blast percentage, positively correlates with myeloid dysplasia and complex cytogenetics, and is a nonindependent negative predictor of overall survival. In acute leukemia, the percent of GATA2+ blasts closely associates with myeloid lineage, whereas a subset of lymphoblastic and undifferentiated leukemias with myeloid features also express GATA2. However, the percent of GATA2+ blasts in AML is highly variable. Elevated GATA2 expression in AML blasts correlates with peripheral neutropenia and complex AML cytogenetics but, unlike in MDS, does not predict survival.
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Affiliation(s)
- Daniel J. Robbins
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
| | - Tatiana S. Pavletich
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
| | - Apoorva T. Patil
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
| | - Demetra Pahopos
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
| | - Michael Lasarev
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI
| | - Usha S. Polaki
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
| | | | - Emery H. Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
- Wisconsin Blood Cancer Research Institute, University of Wisconsin-Madison, Madison, WI
| | - Daniel R. Matson
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI
- Wisconsin Blood Cancer Research Institute, University of Wisconsin-Madison, Madison, WI
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3
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Schaefer MA, Roy P, Chava S, Meyerson A, Duncan AL, Chee L, Hewitt KJ. Physiological and regenerative functions of sterile-α motif protein-14 in hematopoiesis. Exp Hematol 2023; 128:38-47. [PMID: 37722652 PMCID: PMC10947990 DOI: 10.1016/j.exphem.2023.09.003] [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: 08/29/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/20/2023]
Abstract
Sterile α-motif domain-14 (Samd14) protein expression increases the regenerative capacity of the erythroid system. Samd14 is transcriptionally upregulated and promotes cell signaling via the receptor tyrosine kinase Kit in a critical window of acute erythroid regeneration. We generated a hematopoietic-specific conditional Samd14 knockout mouse model (Samd14-CKO) to study the role of Samd14 in hematopoiesis. The Samd14-CKO mouse was viable and exhibited no steady-state hematopoietic phenotype. Samd14-CKO mice were hypersensitive to 5-fluorouracil, resulting in more severe anemia during recovery and impaired erythroid progenitor colony formation. Ex vivo, Samd14-CKO hematopoietic progenitors were defective in their ability to form mast cells. Samd14-CKO mast cells exhibited altered Kit/stem cell factor (SCF), IL-3/IL-3R signaling, and less granularity than Samd14-FL/FL cells. Our findings indicate that Samd14 promotes both erythroid and mast cell functions. The Samd14-CKO mouse phenotype exhibits striking similarities to the KitW/W-v mice, which carry Kit mutations resulting in reduced tyrosine kinase-dependent signaling, causing mast cell and erythroid abnormalities. The Samd14-CKO mouse model is a new tool for studying hematologic pathologies involving Kit signaling.
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Affiliation(s)
- Meg A Schaefer
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Pooja Roy
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Srinivas Chava
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Ainsley Meyerson
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Andrew L Duncan
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Linda Chee
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Kyle J Hewitt
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE.
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4
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Zhou Y, Dogiparthi VR, Ray S, Schaefer MA, Harris HL, Rowley MJ, Hewitt KJ. Defining a cohort of anemia-activated cis elements reveals a mechanism promoting erythroid precursor function. Blood Adv 2023; 7:6325-6338. [PMID: 36809789 PMCID: PMC10587717 DOI: 10.1182/bloodadvances.2022009163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/09/2023] [Accepted: 01/24/2023] [Indexed: 02/24/2023] Open
Abstract
Acute anemia elicits broad transcriptional changes in erythroid progenitors and precursors. We previously discovered a cis-regulatory transcriptional enhancer at the sterile alpha motif domain-14 enhancer locus (S14E), defined by a CANNTG-spacer-AGATAA composite motif and occupied by GATA1 and TAL1 transcription factors, is required for survival in severe anemia. However, S14E is only 1 of dozens of anemia-activated genes containing similar motifs. In a mouse model of acute anemia, we identified populations of expanding erythroid precursors, which increased expression of genes that contain S14E-like cis elements. We reveal that several S14E-like cis elements provide important transcriptional control of newly identified anemia-inducing genes, including the Ssx-2 interacting protein (Ssx2ip). Ssx2ip expression was determined to play an important role in erythroid progenitor/precursor cell activities, cell cycle regulation, and cell proliferation. Over a weeklong course of acute anemia recovery, we observed that erythroid gene activation mediated by S14E-like cis elements occurs during a phase coincident with low hematocrit and high progenitor activities, with distinct transcriptional programs activated at earlier and later time points. Our results define a genome-wide mechanism in which S14E-like enhancers control transcriptional responses during erythroid regeneration. These findings provide a framework to understand anemia-specific transcriptional mechanisms, ineffective erythropoiesis, anemia recovery, and phenotypic variability within human populations.
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Affiliation(s)
- Yichao Zhou
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | | | - Suhita Ray
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Meg A. Schaefer
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Hannah L. Harris
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - M. Jordan Rowley
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Kyle J. Hewitt
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
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5
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Ray S, Hewitt K. Sticky, Adaptable, and Many-sided: SAM protein versatility in normal and pathological hematopoietic states. Bioessays 2023; 45:e2300022. [PMID: 37318311 PMCID: PMC10527593 DOI: 10.1002/bies.202300022] [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: 02/01/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023]
Abstract
With decades of research seeking to generalize sterile alpha motif (SAM) biology, many outstanding questions remain regarding this multi-tool protein module. Recent data from structural and molecular/cell biology has begun to reveal new SAM modes of action in cell signaling cascades and biomolecular condensation. SAM-dependent mechanisms underlie blood-related (hematologic) diseases, including myelodysplastic syndromes and leukemias, prompting our focus on hematopoiesis for this review. With the increasing coverage of SAM-dependent interactomes, a hypothesis emerges that SAM interaction partners and binding affinities work to fine tune cell signaling cascades in developmental and disease contexts, including hematopoiesis and hematologic disease. This review discusses what is known and remains unknown about the standard mechanisms and neoplastic properties of SAM domains and what the future might hold for developing SAM-targeted therapies.
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Affiliation(s)
- Suhita Ray
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Kyle Hewitt
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, 68198, United States
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6
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Johnson KD, Jung MM, Tran VL, Bresnick EH. Interferon regulatory factor-8-dependent innate immune alarm senses GATA2 deficiency to alter hematopoietic differentiation and function. Curr Opin Hematol 2023; 30:117-123. [PMID: 37254854 PMCID: PMC10236032 DOI: 10.1097/moh.0000000000000763] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
PURPOSE OF REVIEW Recent discoveries have provided evidence for mechanistic links between the master regulator of hematopoiesis GATA2 and the key component of interferon and innate immunity signaling pathways, interferon-regulatory factor-8 (IRF8). These links have important implications for the control of myeloid differentiation in physiological and pathological states. RECENT FINDINGS GATA2 deficiency resulting from loss of the Gata2 -77 enhancer in progenitors triggers an alarm that instigates the transcriptional induction of innate immune signaling and distorts a myeloid differentiation program. This pathological alteration renders progenitors hyperresponsive to interferon γ, toll-like receptor and interleukin-6 signaling and impaired in granulocyte-macrophage colony-stimulating factor signaling. IRF8 upregulation in -77-/- progenitors promotes monocyte and dendritic cell differentiation while suppressing granulocytic differentiation. As PU.1 promotes transcription of Irf8 and other myeloid and B-lineage genes, GATA2-mediated repression of these genes opposes the PU.1-dependent activating mechanism. SUMMARY As GATA2 deficiency syndrome is an immunodeficiency disorder often involving myelodysplastic syndromes and acute myeloid leukemia, elucidating how GATA2 commissions and decommissions genome activity and developmental regulatory programs will unveil mechanisms that go awry when GATA2 levels and/or activities are disrupted.
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Affiliation(s)
- Kirby D Johnson
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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Tran VL, Liu P, Katsumura KR, Kim E, Schoff BM, Johnson KD, Bresnick EH. Restricting genomic actions of innate immune mediators on fetal hematopoietic progenitor cells. iScience 2023; 26:106297. [PMID: 36950124 PMCID: PMC10025987 DOI: 10.1016/j.isci.2023.106297] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/03/2023] [Accepted: 02/24/2023] [Indexed: 03/15/2023] Open
Abstract
Innate immune signaling protects against pathogens, controls hematopoietic development, and functions in oncogenesis, yet the relationship between these mechanisms is undefined. Downregulating the GATA2 transcription factor in fetal hematopoietic progenitor cells upregulates genes encoding innate immune regulators, increases Interferon-γ (IFNγ) signaling, and disrupts differentiation. We demonstrate that deletion of an enhancer that confers GATA2 expression in fetal progenitors elevated Toll-like receptor (TLR) TLR1/2 and TLR2/6 expression and signaling. Rescue by expressing GATA2 downregulated elevated TLR signaling. IFNγ amplified TLR1/2 and TLR2/6 signaling in GATA2-deficient progenitors, synergistically activating cytokine/chemokine genes and elevating cytokine/chemokine production in myeloid cell progeny. Genomic analysis of how innate immune signaling remodels the GATA2-deficient progenitor transcriptome revealed hypersensitive responses at innate immune genes harboring motifs for signal-dependent transcription factors and factors not linked to these mechanisms. As GATA2 establishes a transcriptome that constrains innate immune signaling, insufficient GATA2 renders fetal progenitor cells hypersensitive to innate immune signaling.
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Affiliation(s)
- Vu L. Tran
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Peng Liu
- Department of Biostatistics and Biomedical Informatics, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Koichi R. Katsumura
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Erin Kim
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Bjorn M. Schoff
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Kirby D. Johnson
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Emery H. Bresnick
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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8
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Jung MM, Shen S, Botten GA, Olender T, Katsumura KR, Johnson KD, Soukup AA, Liu P, Zhang Q, Jensvold ZD, Lewis PW, Beagrie RA, Low JK, Yang L, Mackay JP, Godley LA, Brand M, Xu J, Keles S, Bresnick EH. Pathogenic human variant that dislocates GATA2 zinc fingers disrupts hematopoietic gene expression and signaling networks. J Clin Invest 2023; 133:e162685. [PMID: 36809258 PMCID: PMC10065080 DOI: 10.1172/jci162685] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 02/16/2023] [Indexed: 02/23/2023] Open
Abstract
Although certain human genetic variants are conspicuously loss of function, decoding the impact of many variants is challenging. Previously, we described a patient with leukemia predisposition syndrome (GATA2 deficiency) with a germline GATA2 variant that inserts 9 amino acids between the 2 zinc fingers (9aa-Ins). Here, we conducted mechanistic analyses using genomic technologies and a genetic rescue system with Gata2 enhancer-mutant hematopoietic progenitor cells to compare how GATA2 and 9aa-Ins function genome-wide. Despite nuclear localization, 9aa-Ins was severely defective in occupying and remodeling chromatin and regulating transcription. Variation of the inter-zinc finger spacer length revealed that insertions were more deleterious to activation than repression. GATA2 deficiency generated a lineage-diverting gene expression program and a hematopoiesis-disrupting signaling network in progenitors with reduced granulocyte-macrophage colony-stimulating factor (GM-CSF) and elevated IL-6 signaling. As insufficient GM-CSF signaling caused pulmonary alveolar proteinosis and excessive IL-6 signaling promoted bone marrow failure and GATA2 deficiency patient phenotypes, these results provide insight into mechanisms underlying GATA2-linked pathologies.
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Affiliation(s)
- Mabel Minji Jung
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, and
| | - Siqi Shen
- Department of Biostatistics and Biomedical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Giovanni A. Botten
- Children’s Medical Center Research Institute, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Thomas Olender
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute–General Hospital, Ottawa, Ontario, Canada
| | - Koichi R. Katsumura
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, and
| | - Kirby D. Johnson
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, and
| | - Alexandra A. Soukup
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, and
| | - Peng Liu
- Department of Biostatistics and Biomedical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Qingzhou Zhang
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute–General Hospital, Ottawa, Ontario, Canada
| | - Zena D. Jensvold
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Peter W. Lewis
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Robert A. Beagrie
- MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jason K.K. Low
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Lihua Yang
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Joel P. Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Lucy A. Godley
- Section of Hematology/Oncology, The University of Chicago, Chicago, Illinois, USA
| | - Marjorie Brand
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Jian Xu
- Children’s Medical Center Research Institute, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sunduz Keles
- Department of Biostatistics and Biomedical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Emery H. Bresnick
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, and
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Ray S, Chee L, Zhou Y, Schaefer MA, Naldrett MJ, Alvarez S, Woods NT, Hewitt K. Functional requirements for a Samd14-capping protein complex in stress erythropoiesis. eLife 2022; 11:76497. [PMID: 35713400 PMCID: PMC9282853 DOI: 10.7554/elife.76497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 06/06/2022] [Indexed: 11/18/2022] Open
Abstract
Acute anemia induces rapid expansion of erythroid precursors and accelerated differentiation to replenish erythrocytes. Paracrine signals—involving cooperation between stem cell factor (SCF)/Kit signaling and other signaling inputs—are required for the increased erythroid precursor activity in anemia. Our prior work revealed that the sterile alpha motif (SAM) domain 14 (Samd14) gene increases the regenerative capacity of the erythroid system in a mouse genetic model and promotes stress-dependent Kit signaling. However, the mechanism underlying Samd14’s role in stress erythropoiesis is unknown. We identified a protein-protein interaction between Samd14 and the α- and β-heterodimers of the F-actin capping protein (CP) complex. Knockdown of the CP β subunit increased erythroid maturation in murine ex vivo cultures and decreased colony forming potential of stress erythroid precursors. In a genetic complementation assay for Samd14 activity, our results revealed that the Samd14-CP interaction is a determinant of erythroid precursor cell levels and function. Samd14-CP promotes SCF/Kit signaling in CD71med spleen erythroid precursors. Given the roles of Kit signaling in hematopoiesis and Samd14 in Kit pathway activation, this mechanism may have pathological implications in acute/chronic anemia. Anemia is a condition in which the body has a shortage of healthy red blood cells to carry enough oxygen to support its organs. A range of factors are known to cause anemia, including traumatic blood loss, toxins or nutritional deficiency. An estimated one-third of all women of reproductive age are anemic, which can cause tiredness, weakness and shortness of breath. Severe anemia drives the release of hormones and growth factors, leading to a rapid regeneration of precursor red blood cells to replenish the supply in the blood. To understand how red blood cell regeneration is controlled, Ray et al. studied proteins involved in regenerating blood using mice in which anemia had been induced with chemicals. Previous research had shown that the protein Samd14 is produced at higher quantities in individuals with anemia, and is involved with the recovery of lost red blood cells. However, it is not known how the Samd14 protein plays a role in regenerating blood cells, or whether Samd14 interacts with other proteins required for red blood cell production. To shed light on these questions, mouse cells exposed to anemia conditions were used to see what proteins Samd14 binds to. Purifying Samd14 revealed that it interacts with the actin capping protein. This interaction relies on a specific region of Samd14 that is similar to regions in other proteins that bind capping proteins. Ray et al. found that the interaction between Samd14 and the actin capping protein increased the signals needed for the development and survival of new red blood cells. These results identify a signaling mechanism that, if disrupted, could cause anemia to develop. They lead to a better understanding of how our bodies recover from anemia, and potential avenues to treat this condition.
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Affiliation(s)
- Suhita Ray
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, United States
| | - Linda Chee
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, United States
| | - Yichao Zhou
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, United States
| | - Meg A Schaefer
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, United States
| | - Michael J Naldrett
- Proteomics and Metabolomics Facility, University of Nebraska-Lincoln, Lincoln, United States
| | - Sophie Alvarez
- Proteomics and Metabolomics Facility, University of Nebraska-Lincoln, Lincoln, United States
| | - Nicholas T Woods
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, United States
| | - Kyle Hewitt
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, United States
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10
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Human GATA2 mutations and hematologic disease: how many paths to pathogenesis? Blood Adv 2021; 4:4584-4592. [PMID: 32960960 DOI: 10.1182/bloodadvances.2020002953] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/21/2020] [Indexed: 01/19/2023] Open
Abstract
The surge of human genetic information, enabled by increasingly facile and economically feasible genomic technologies, has accelerated discoveries on the relationship of germline genetic variation to hematologic diseases. For example, germline variation in GATA2, encoding a vital transcriptional regulator of multilineage hematopoiesis, creates a predisposition to bone marrow failure and acute myeloid leukemia termed GATA2 deficiency syndrome. More than 300 GATA2 variants representing missense, truncating, and noncoding enhancer mutations have been documented. Although these variants can diminish GATA2 expression and/or function, the functional ramifications of many variants are unknown. Studies using genetic rescue and knockin mouse systems have established that GATA2 mutations differentially affect molecular processes in distinct target genes and within a single target cell. Considering that target genes for a transcription factor can differ in sensitivity to altered levels of the factor, and transcriptional mechanisms are often cell type specific, the context-dependent consequences of GATA2 mutations in experimental systems portend the complex phenotypes and interindividual variation of GATA2 deficiency syndrome. This review documents GATA2 human genetics and the state of efforts to traverse from physiological insights to pathogenic mechanisms.
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11
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Mast Cell-Derived SAMD14 Is a Novel Regulator of the Human Prostate Tumor Microenvironment. Cancers (Basel) 2021; 13:cancers13061237. [PMID: 33799802 PMCID: PMC7999778 DOI: 10.3390/cancers13061237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/08/2021] [Accepted: 03/08/2021] [Indexed: 02/07/2023] Open
Abstract
Mast cells (MCs) are important cellular components of the tumor microenvironment and are significantly associated with poor patient outcomes in prostate cancer and other solid cancers. The promotion of tumor progression partly involves heterotypic interactions between MCs and cancer-associated fibroblasts (CAFs), which combine to potentiate a pro-tumor extracellular matrix and promote epithelial cell invasion and migration. Thus far, the interactions between MCs and CAFs remain poorly understood. To identify molecular changes that may alter resident MC function in the prostate tumor microenvironment, we profiled the transcriptome of human prostate MCs isolated from patient-matched non-tumor and tumor-associated regions of fresh radical prostatectomy tissue. Transcriptomic profiling revealed a distinct gene expression profile of MCs isolated from prostate tumor regions, including the downregulation of SAMD14, a putative tumor suppressor gene. Proteomic profiling revealed that overexpression of SAMD14 in HMC-1 altered the secretion of proteins associated with immune regulation and extracellular matrix processes. To assess MC biological function within a model of the prostate tumor microenvironment, HMC-1-SAMD14+ conditioned media was added to co-cultures of primary prostatic CAFs and prostate epithelium. HMC-1-SAMD14+ secretions were shown to reduce the deposition and alignment of matrix produced by CAFs and suppress pro-tumorigenic prostate epithelial morphology. Overall, our data present the first profile of human MCs derived from prostate cancer patient specimens and identifies MC-derived SAMD14 as an important mediator of MC phenotype and function within the prostate tumor microenvironment.
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Karayel Ö, Xu P, Bludau I, Velan Bhoopalan S, Yao Y, Ana Rita FC, Santos A, Schulman BA, Alpi AF, Weiss MJ, Mann M. Integrative proteomics reveals principles of dynamic phosphosignaling networks in human erythropoiesis. Mol Syst Biol 2020; 16:e9813. [PMID: 33259127 PMCID: PMC7706838 DOI: 10.15252/msb.20209813] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 12/21/2022] Open
Abstract
Human erythropoiesis is an exquisitely controlled multistep developmental process, and its dysregulation leads to numerous human diseases. Transcriptome and epigenome studies provided insights into system-wide regulation, but we currently lack a global mechanistic view on the dynamics of proteome and post-translational regulation coordinating erythroid maturation. We established a mass spectrometry (MS)-based proteomics workflow to quantify and dynamically track 7,400 proteins and 27,000 phosphorylation sites of five distinct maturation stages of in vitro reconstituted erythropoiesis of CD34+ HSPCs. Our data reveal developmental regulation through drastic proteome remodeling across stages of erythroid maturation encompassing most protein classes. This includes various orchestrated changes in solute carriers indicating adjustments to altered metabolic requirements. To define the distinct proteome of each maturation stage, we developed a computational deconvolution approach which revealed stage-specific marker proteins. The dynamic phosphoproteomes combined with a kinome-targeted CRISPR/Cas9 screen uncovered coordinated networks of erythropoietic kinases and pinpointed downregulation of c-Kit/MAPK signaling axis as key driver of maturation. Our system-wide view establishes the functional dynamic of complex phosphosignaling networks and regulation through proteome remodeling in erythropoiesis.
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Affiliation(s)
- Özge Karayel
- Department of Proteomics and Signal TransductionMax Planck Institute of BiochemistryMartinsriedGermany
| | - Peng Xu
- Department of HematologySt. Jude Children’s Research HospitalMemphisTNUSA
| | - Isabell Bludau
- Department of Proteomics and Signal TransductionMax Planck Institute of BiochemistryMartinsriedGermany
| | | | - Yu Yao
- Department of HematologySt. Jude Children’s Research HospitalMemphisTNUSA
| | - Freitas Colaco Ana Rita
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Alberto Santos
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Brenda A Schulman
- Department of Molecular Machines and SignalingMax Planck Institute of BiochemistryMartinsriedGermany
| | - Arno F Alpi
- Department of Molecular Machines and SignalingMax Planck Institute of BiochemistryMartinsriedGermany
| | - Mitchell J Weiss
- Department of HematologySt. Jude Children’s Research HospitalMemphisTNUSA
| | - Matthias Mann
- Department of Proteomics and Signal TransductionMax Planck Institute of BiochemistryMartinsriedGermany
- Novo Nordisk Foundation Center for Protein ResearchFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
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Liu P, Soukup AA, Bresnick EH, Dewey CN, Keleş S. PRAM: a novel pooling approach for discovering intergenic transcripts from large-scale RNA sequencing experiments. Genome Res 2020; 30:1655-1666. [PMID: 32958497 PMCID: PMC7605252 DOI: 10.1101/gr.252445.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/27/2020] [Indexed: 11/25/2022]
Abstract
Publicly available RNA-seq data is routinely used for retrospective analysis to elucidate new biology. Novel transcript discovery enabled by joint analysis of large collections of RNA-seq data sets has emerged as one such analysis. Current methods for transcript discovery rely on a '2-Step' approach where the first step encompasses building transcripts from individual data sets, followed by the second step that merges predicted transcripts across data sets. To increase the power of transcript discovery from large collections of RNA-seq data sets, we developed a novel '1-Step' approach named Pooling RNA-seq and Assembling Models (PRAM) that builds transcript models from pooled RNA-seq data sets. We demonstrate in a computational benchmark that 1-Step outperforms 2-Step approaches in predicting overall transcript structures and individual splice junctions, while performing competitively in detecting exonic nucleotides. Applying PRAM to 30 human ENCODE RNA-seq data sets identified unannotated transcripts with epigenetic and RAMPAGE signatures similar to those of recently annotated transcripts. In a case study, we discovered and experimentally validated new transcripts through the application of PRAM to mouse hematopoietic RNA-seq data sets. We uncovered new transcripts that share a differential expression pattern with a neighboring gene Pik3cg implicated in human hematopoietic phenotypes, and we provided evidence for the conservation of this relationship in human. PRAM is implemented as an R/Bioconductor package.
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Affiliation(s)
- Peng Liu
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Alexandra A Soukup
- Department of Cell and Regenerative Biology, Wisconsin Blood Cancer Research Institute, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53705, USA
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, Wisconsin Blood Cancer Research Institute, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53705, USA
| | - Colin N Dewey
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wisconsin 53706, USA.,Department of Computer Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Sündüz Keleş
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wisconsin 53706, USA.,Department of Statistics, University of Wisconsin, Madison, Wisconsin 53706, USA
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Blood disease-causing and -suppressing transcriptional enhancers: general principles and GATA2 mechanisms. Blood Adv 2020; 3:2045-2056. [PMID: 31289032 DOI: 10.1182/bloodadvances.2019000378] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 05/29/2019] [Indexed: 12/16/2022] Open
Abstract
Intensive scrutiny of human genomes has unveiled considerable genetic variation in coding and noncoding regions. In cancers, including those of the hematopoietic system, genomic instability amplifies the complexity and functional consequences of variation. Although elucidating how variation impacts the protein-coding sequence is highly tractable, deciphering the functional consequences of variation in noncoding regions (genome reading), including potential transcriptional-regulatory sequences, remains challenging. A crux of this problem is the sheer abundance of gene-regulatory sequence motifs (cis elements) mediating protein-DNA interactions that are intermixed in the genome with thousands of look-alike sequences lacking the capacity to mediate functional interactions with proteins in vivo. Furthermore, transcriptional enhancers harbor clustered cis elements, and how altering a single cis element within a cluster impacts enhancer function is unpredictable. Strategies to discover functional enhancers have been innovated, and human genetics can provide vital clues to achieve this goal. Germline or acquired mutations in functionally critical (essential) enhancers, for example at the GATA2 locus encoding a master regulator of hematopoiesis, have been linked to human pathologies. Given the human interindividual genetic variation and complex genetic landscapes of hematologic malignancies, enhancer corruption, creation, and expropriation by new genes may not be exceedingly rare mechanisms underlying disease predisposition and etiology. Paradigms arising from dissecting essential enhancer mechanisms can guide genome-reading strategies to advance fundamental knowledge and precision medicine applications. In this review, we provide our perspective of general principles governing the function of blood disease-linked enhancers and GATA2-centric mechanisms.
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LDB1 Enforces Stability on Direct and Indirect Oncoprotein Partners in Leukemia. Mol Cell Biol 2020; 40:MCB.00652-19. [PMID: 32229578 DOI: 10.1128/mcb.00652-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/14/2020] [Indexed: 12/22/2022] Open
Abstract
The LMO2/LDB1 macromolecular complex is critical in hematopoietic stem and progenitor cell specification and in the development of acute leukemia. This complex is comprised of core subunits of LMO2 and LDB1 as well as single-stranded DNA-binding protein (SSBP) cofactors and DNA-binding basic helix-loop-helix (bHLH) and GATA transcription factors. We analyzed the steady-state abundance and kinetic stability of LMO2 and its partners via Halo protein tagging in conjunction with variant proteins deficient in binding their respective direct protein partners. We discovered a hierarchy of protein stabilities (with half-lives in descending order) as follows: LDB1 > SSBP > LMO2 > TAL1. Importantly, LDB1 is a remarkably stable protein that confers enhanced stability upon direct and indirect partners, thereby nucleating the formation of the multisubunit protein complex. The data imply that free subunits are more rapidly degraded than those incorporated within the LMO2/LDB1 complex. Our studies provided significant insights into LMO2/LDB1 macromolecular protein complex assembly and stability, which has implications for understanding its role in blood cell formation and for therapeutically targeting this complex in human leukemias.
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16
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Ray S, Chee L, Matson DR, Palermo NY, Bresnick EH, Hewitt KJ. Sterile α-motif domain requirement for cellular signaling and survival. J Biol Chem 2020; 295:7113-7125. [PMID: 32241909 PMCID: PMC7242717 DOI: 10.1074/jbc.ra119.011895] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 04/01/2020] [Indexed: 01/21/2023] Open
Abstract
Hundreds of sterile α-motif (SAM) domains have predicted structural similarities and are reported to bind proteins, lipids, or RNAs. However, the majority of these domains have not been analyzed functionally. Previously, we demonstrated that a SAM domain-containing protein, SAMD14, promotes SCF/proto-oncogene c-Kit (c-Kit) signaling, erythroid progenitor function, and erythrocyte regeneration. Deletion of a Samd14 enhancer (Samd14-Enh), occupied by GATA2 and SCL/TAL1 transcription factors, reduces SAMD14 expression in bone marrow and spleen and is lethal in a hemolytic anemia mouse model. To rigorously establish whether Samd14-Enh deletion reduces anemia-dependent c-Kit signaling by lowering SAMD14 levels, we developed a genetic rescue assay in murine Samd14-Enh-/- primary erythroid precursor cells. SAMD14 expression at endogenous levels rescued c-Kit signaling. The conserved SAM domain was required for SAMD14 to increase colony-forming activity, c-Kit signaling, and progenitor survival. To elucidate the molecular determinants of SAM domain function in SAMD14, we substituted its SAM domain with distinct SAM domains predicted to be structurally similar. The chimeras were less effective than SAMD14 itself in rescuing signaling, survival, and colony-forming activities. Thus, the SAMD14 SAM domain has attributes that are distinct from other SAM domains and underlie SAMD14 function as a regulator of cellular signaling and erythrocyte regeneration.
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Affiliation(s)
- Suhita Ray
- Department of Genetics, Cell Biology and Anatomy, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Linda Chee
- Department of Genetics, Cell Biology and Anatomy, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Daniel R Matson
- University of Wisconsin-Madison Blood Research Program, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Nick Y Palermo
- Holland Computing Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Emery H Bresnick
- University of Wisconsin-Madison Blood Research Program, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Kyle J Hewitt
- Department of Genetics, Cell Biology and Anatomy, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
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Soukup AA, Bresnick EH. GATA2 +9.5 enhancer: from principles of hematopoiesis to genetic diagnosis in precision medicine. Curr Opin Hematol 2020; 27:163-171. [PMID: 32205587 PMCID: PMC7331797 DOI: 10.1097/moh.0000000000000576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW By establishing mechanisms that deliver oxygen to sustain cells and tissues, fight life-threatening pathogens and harness the immune system to eradicate cancer cells, hematopoietic stem and progenitor cells (HSPCs) are vital in health and disease. The cell biological framework for HSPC generation has been rigorously developed, yet recent single-cell transcriptomic analyses have unveiled permutations of the hematopoietic hierarchy that differ considerably from the traditional roadmap. Deploying mutants that disrupt specific steps in hematopoiesis constitutes a powerful strategy for deconvoluting the complex cell biology. It is striking that a single transcription factor, GATA2, is so crucial for HSPC generation and function, and therefore it is instructive to consider mechanisms governing GATA2 expression and activity. The present review focuses on an essential GATA2 enhancer (+9.5) and how +9.5 mutants inform basic and clinical/translational science. RECENT FINDINGS +9.5 is essential for HSPC generation and function during development and hematopoietic regeneration. Human +9.5 mutations cause immunodeficiency, myelodysplastic syndrome, and acute myeloid leukemia. Qualitatively and quantitatively distinct contributions of +9.5 cis-regulatory elements confer context-dependent enhancer activity. The discovery of +9.5 and its mutant alleles spawned fundamental insights into hematopoiesis, and given its role to suppress blood disease emergence, clinical centers test for mutations in this sequence to diagnose the cause of enigmatic cytopenias. SUMMARY Multidisciplinary approaches to discover and understand cis-regulatory elements governing expression of key regulators of hematopoiesis unveil biological and mechanistic insights that provide the logic for innovating clinical applications.
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Xu X, Chang X, Xu Y, Deng P, Wang J, Zhang C, Zhu X, Chen S, Dai D. SAMD14 promoter methylation is strongly associated with gene expression and poor prognosis in gastric cancer. Int J Clin Oncol 2020; 25:1105-1114. [PMID: 32206938 DOI: 10.1007/s10147-020-01647-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/20/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND Gastric cancer (GC) is the fifth most common malignancy worldwide and the third leading cause of cancer-related mortality. In recent years, SAMD14 has been studied in various malignant cancers; however, little is known about the exact mechanisms of SAMD14 involvement in carcinogenesis and malignant progression. METHODS 60 paired GC-normal gastric tissues were evaluated for their SAMD14 mRNA expression in relation to SAMD14 gene promoter methylation. GC patient survival was assessed by Kaplan-Meier analyses and a Cox's proportional hazard model was employed for multivariate analyses. RESULTS SAMD14 expression was significantly inversely correlated with the Borrmann type (P = 0.017), lymph node metastasis (P = 0.006) and tumor-node-metastasis (TNM) stage (P = 0.033). Methylation-specific PCR (MSP) revealed hyper-methylation of the SAMD14 promoter in 56.7% (34/60) of the primary GC tissues tested and in 10% (6/60) of matched non-malignant tissues. The SAMD14 promoter methylation status was also related to pathological differentiation, Borrmann type, TNM stage and lymph node metastasis. The results showed SAMD14 expression was significantly downregulated in Borrmann type, lymph node metastasis and TNM stage, which showed significantly higher methylation. SAMD14 promoter hyper-methylation was significantly associated with a poor prognosis and could serve as an independent marker for survival using multivariate Cox regression analysis. CONCLUSIONS Our results indicated that promoter methylation was a key mechanism contributing to the downregulation of SAMD14 in GC. SAMD14 may be an epigenetically silenced tumor suppressor gene, and hyper-methylation of the SAMD14 promoter may serve as a biomarker to predict the clinical outcome of GC.
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Affiliation(s)
- Xiaoyang Xu
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
- Department of Surgery, Fushun Mining Bureau General Hospital of Liaoning Health Industry Group (the Seventh Affiliated Hospital of China Medical University), Fushun, China
| | - Xiaojing Chang
- Department of Radiotherapy, The Second Hospital, Hebei Medical University, Shijiazhuang, China
| | - Yan Xu
- The First Department of Radiotherapy, Fushun Fourth Hospital, Fushun, China
| | - Peng Deng
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
| | - Jiang Wang
- Department of Surgery, Fushun Mining Bureau General Hospital of Liaoning Health Industry Group (the Seventh Affiliated Hospital of China Medical University), Fushun, China
| | - Chundong Zhang
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
| | - Xinjiang Zhu
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
| | - Shuchen Chen
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
| | - Dongqiu Dai
- Department of Gastrointestinal Surgery and Cancer Center, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China.
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19
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Lu Z, Hong CC, Kong G, Assumpção ALFV, Ong IM, Bresnick EH, Zhang J, Pan X. Polycomb Group Protein YY1 Is an Essential Regulator of Hematopoietic Stem Cell Quiescence. Cell Rep 2019; 22:1545-1559. [PMID: 29425509 PMCID: PMC6140794 DOI: 10.1016/j.celrep.2018.01.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 10/25/2017] [Accepted: 01/08/2018] [Indexed: 01/04/2023] Open
Abstract
Yin yang 1 (YY1) is a ubiquitous transcription factor and mammalian polycomb group protein (PcG) with important functions to regulate embryonic development, lineage differentiation, and cell proliferation. YY1 mediates stable PcG-dependent transcriptional repression via recruitment of PcG proteins that catalyze histone modifications. Many questions remain unanswered regarding how cell- and tissue-specificity is achieved by PcG proteins. Here, we demonstrate that a conditional knockout of Yy1 in hematopoietic stem cells (HSCs) decreases long-term repopulating activity and ectopic YY1 expression expands HSCs. Although the YY1 PcG domain is required for Igk chain rearrangement in B cells, the YY1 mutant lacking the PcG domain retained the capacity to stimulate HSC self-renewal. YY1 deficiency deregulated the genetic network governing HSC cell proliferation and impaired stem cell factor/c-Kit signaling, disrupting mechanisms conferring HSC quiescence. These results reveal a mechanism for how a ubiquitously expressed transcriptional repressor mediates lineage-specific functions to control adult hematopoiesis. Lu et al. investigate the function of the polycomb group (PcG) protein YY1 in hematopoietic stem cells. Independent of its REPO domain/PcG function, YY1 promotes hematopoietic stem cell selfrenewal and quiescence, suggesting that REPO domain/PcG function is not utilized in all contexts within the hematopoietic hierarchy.
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Affiliation(s)
- Zhanping Lu
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Dr., Madison, WI 57306, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Courtney C Hong
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Dr., Madison, WI 57306, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Guangyao Kong
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave., Madison, WI 53705, USA; National Local Joint Engineering Research Center of Biodiagnostics and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, PRC; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Anna L F V Assumpção
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Dr., Madison, WI 57306, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Irene M Ong
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave., Madison, WI 53705, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave., Madison, WI 53705, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Jing Zhang
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave., Madison, WI 53705, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA
| | - Xuan Pan
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Dr., Madison, WI 57306, USA; Carbone Cancer Center, UW-Madison Blood Research Program, Madison, WI 53706, USA.
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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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21
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Churpek JE, Bresnick EH. Transcription factor mutations as a cause of familial myeloid neoplasms. J Clin Invest 2019; 129:476-488. [PMID: 30707109 DOI: 10.1172/jci120854] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The initiation and evolution of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are driven by genomic events that disrupt multiple genes controlling hematopoiesis. Human genetic studies have discovered germline mutations in single genes that instigate familial MDS/AML. The best understood of these genes encode transcription factors, such as GATA-2, RUNX1, ETV6, and C/EBPα, which establish and maintain genetic networks governing the genesis and function of blood stem and progenitor cells. Many questions remain unanswered regarding how genes and circuits within these networks function in physiology and disease and whether network integrity is exquisitely sensitive to or efficiently buffered from perturbations. In familial MDS/AML, mutations change the coding sequence of a gene to generate a mutant protein with altered activity or introduce frameshifts or stop codons or disrupt regulatory elements to alter protein expression. Each mutation has the potential to exert quantitatively and qualitatively distinct influences on networks. Consistent with this mechanistic diversity, disease onset is unpredictable and phenotypic variability can be considerable. Efforts to elucidate mechanisms and forge prognostic and therapeutic strategies must therefore contend with a spectrum of patient-specific leukemogenic scenarios. Here we illustrate mechanistic advances in our understanding of familial MDS/AML syndromes caused by germline mutations of hematopoietic transcription factors.
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Affiliation(s)
- Jane E Churpek
- Section of Hematology/Oncology and Center for Clinical Cancer Genetics, The University of Chicago, Chicago, Illinois, USA
| | - Emery H Bresnick
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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22
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Shukla A, Huangfu D. Decoding the noncoding genome via large-scale CRISPR screens. Curr Opin Genet Dev 2018; 52:70-76. [PMID: 29913329 DOI: 10.1016/j.gde.2018.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/30/2018] [Accepted: 06/04/2018] [Indexed: 12/14/2022]
Abstract
Large portions of the human genome harbor functional noncoding elements, which can regulate a variety of biological processes and have important implications for disease risk and therapeutic outcomes. However, assigning specific functions to noncoding sequences remains a major challenge. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein (Cas) systems have emerged as a powerful approach for targeted genome and epigenome perturbation. CRISPR systems are now harnessed for high-throughput screening of the noncoding genome to uncover functional regulatory elements and to define their precise functions with superior speed. Here, we summarize the various tools developed for such screens in mammalian systems and discuss screening methods and technical considerations. We further highlight screens that are already transforming our understanding of gene regulation and disease mechanisms, consider the impact of such discoveries on the development of new therapeutics, and provide our viewpoint on the challenges for future development of the field.
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Affiliation(s)
- Abhijit Shukla
- Sloan Kettering Institute, 1275 York Avenue, New York, New York 10065, USA
| | - Danwei Huangfu
- Sloan Kettering Institute, 1275 York Avenue, New York, New York 10065, USA.
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23
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Mehta C, Johnson KD, Gao X, Ong IM, Katsumura KR, McIver SC, Ranheim EA, Bresnick EH. Integrating Enhancer Mechanisms to Establish a Hierarchical Blood Development Program. Cell Rep 2018; 20:2966-2979. [PMID: 28930689 DOI: 10.1016/j.celrep.2017.08.090] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/30/2017] [Accepted: 08/25/2017] [Indexed: 12/20/2022] Open
Abstract
Hematopoietic development requires the transcription factor GATA-2, and GATA-2 mutations cause diverse pathologies, including leukemia. GATA-2-regulated enhancers increase Gata2 expression in hematopoietic stem/progenitor cells and control hematopoiesis. The +9.5-kb enhancer activates transcription in endothelium and hematopoietic stem cells (HSCs), and its deletion abrogates HSC generation. The -77-kb enhancer activates transcription in myeloid progenitors, and its deletion impairs differentiation. Since +9.5-/- embryos are HSC deficient, it was unclear whether the +9.5 functions in progenitors or if GATA-2 expression in progenitors solely requires -77. We further dissected the mechanisms using -77;+9.5 compound heterozygous (CH) mice. The embryonic lethal CH mutation depleted megakaryocyte-erythrocyte progenitors (MEPs). While the +9.5 suffices for HSC generation, the -77 and +9.5 must reside on one allele to induce MEPs. The -77 generated burst-forming unit-erythroid through the induction of GATA-1 and other GATA-2 targets. The enhancer circuits controlled signaling pathways that orchestrate a GATA factor-dependent blood development program.
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Affiliation(s)
- Charu Mehta
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Kirby D Johnson
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Xin Gao
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Irene M Ong
- UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI 53705, USA
| | - Koichi R Katsumura
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Skye C McIver
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Erik A Ranheim
- Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Emery H Bresnick
- UW-Madison Blood Research Program, Department of Cell and Regenerative Biology, Wisconsin Institutes for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; UW Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA.
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Bresnick EH, Hewitt KJ, Mehta C, Keles S, Paulson RF, Johnson KD. Mechanisms of erythrocyte development and regeneration: implications for regenerative medicine and beyond. Development 2018; 145:145/1/dev151423. [PMID: 29321181 DOI: 10.1242/dev.151423] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hemoglobin-expressing erythrocytes (red blood cells) act as fundamental metabolic regulators by providing oxygen to cells and tissues throughout the body. Whereas the vital requirement for oxygen to support metabolically active cells and tissues is well established, almost nothing is known regarding how erythrocyte development and function impact regeneration. Furthermore, many questions remain unanswered relating to how insults to hematopoietic stem/progenitor cells and erythrocytes can trigger a massive regenerative process termed 'stress erythropoiesis' to produce billions of erythrocytes. Here, we review the cellular and molecular mechanisms governing erythrocyte development and regeneration, and discuss the potential links between these events and other regenerative processes.
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Affiliation(s)
- Emery H Bresnick
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Kyle J Hewitt
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Charu Mehta
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Sunduz Keles
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Robert F Paulson
- Department of Veterinary and Biomedical Sciences, Center for Molecular Immunology and Infectious Disease, Penn State University, University Park, PA 16802, USA
| | - Kirby D Johnson
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
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25
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McIver SC, Hewitt KJ, Gao X, Mehta C, Zhang J, Bresnick EH. Dissecting Regulatory Mechanisms Using Mouse Fetal Liver-Derived Erythroid Cells. Methods Mol Biol 2018; 1698:67-89. [PMID: 29076084 DOI: 10.1007/978-1-4939-7428-3_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Multipotent hematopoietic stem cells differentiate into an ensemble of committed progenitor cells that produce the diverse blood cells essential for life. Physiological mechanisms governing hematopoiesis, and mechanistic aberrations underlying non-malignant and malignant hematologic disorders, are often very similar in mouse and man. Thus, mouse models provide powerful systems for unraveling mechanisms that control hematopoietic stem/progenitor cell (HSPC) function in their resident microenvironments in vivo. Ex vivo systems, involving the culture of HSPCs generated in vivo, allow one to dissociate microenvironment-based and cell intrinsic mechanisms, and therefore have considerable utility. Dissecting mechanisms controlling cellular proliferation and differentiation is facilitated by the use of primary cells, since mutations and chromosome aberrations in immortalized and cancer cell lines corrupt normal mechanisms. Primary erythroid precursor cells can be expanded or differentiated in culture to yield large numbers of progeny at discrete maturation stages. We described a robust method for isolation, culture, and analysis of primary mouse erythroid precursor cells and their progeny.
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Affiliation(s)
- Skye C McIver
- Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 4009 WIMR, 1111 Highland Ave, Madison, WI, 53705, USA.,UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA
| | - Kyle J Hewitt
- Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 4009 WIMR, 1111 Highland Ave, Madison, WI, 53705, USA.,UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA
| | - Xin Gao
- Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 4009 WIMR, 1111 Highland Ave, Madison, WI, 53705, USA.,UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA
| | - Charu Mehta
- Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 4009 WIMR, 1111 Highland Ave, Madison, WI, 53705, USA.,UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA
| | - Jing Zhang
- UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA.,McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, WI, 53705, USA
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 4009 WIMR, 1111 Highland Ave, Madison, WI, 53705, USA. .,UW-Madison Blood Research Program, University of Wisconsin, Madison, WI, 53705, USA.
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26
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Hewitt KJ, Katsumura KR, Matson DR, Devadas P, Tanimura N, Hebert AS, Coon JJ, Kim JS, Dewey CN, Keles S, Hao S, Paulson RF, Bresnick EH. GATA Factor-Regulated Samd14 Enhancer Confers Red Blood Cell Regeneration and Survival in Severe Anemia. Dev Cell 2017; 42:213-225.e4. [PMID: 28787589 DOI: 10.1016/j.devcel.2017.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/05/2017] [Accepted: 07/11/2017] [Indexed: 12/31/2022]
Abstract
An enhancer with amalgamated E-box and GATA motifs (+9.5) controls expression of the regulator of hematopoiesis GATA-2. While similar GATA-2-occupied elements are common in the genome, occupancy does not predict function, and GATA-2-dependent genetic networks are incompletely defined. A "+9.5-like" element resides in an intron of Samd14 (Samd14-Enh) encoding a sterile alpha motif (SAM) domain protein. Deletion of Samd14-Enh in mice strongly decreased Samd14 expression in bone marrow and spleen. Although steady-state hematopoiesis was normal, Samd14-Enh-/- mice died in response to severe anemia. Samd14-Enh stimulated stem cell factor/c-Kit signaling, which promotes erythrocyte regeneration. Anemia activated Samd14-Enh by inducing enhancer components and enhancer chromatin accessibility. Thus, a GATA-2/anemia-regulated enhancer controls expression of an SAM domain protein that confers survival in anemia. We propose that Samd14-Enh and an ensemble of anemia-responsive enhancers are essential for erythrocyte regeneration in stress erythropoiesis, a vital process in pathologies, including β-thalassemia, myelodysplastic syndrome, and viral infection.
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Affiliation(s)
- Kyle J Hewitt
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Koichi R Katsumura
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Daniel R Matson
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Prithvia Devadas
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Nobuyuki Tanimura
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | - Joshua J Coon
- Department of Chemistry, UW-Madison, Madison, WI, USA; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jin-Soo Kim
- Center for Genome Engineering, Institute for Basic Science and Department of Chemistry, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, South Korea
| | - Colin N Dewey
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Sunduz Keles
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Siyang Hao
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Robert F Paulson
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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27
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Zhao H, Xu C, Lee TJ, Liu F, Choi K. ETS transcription factor ETV2/ER71/Etsrp in hematopoietic and vascular development, injury, and regeneration. Dev Dyn 2017; 246:318-327. [DOI: 10.1002/dvdy.24483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 12/17/2022] Open
Affiliation(s)
- Haiyong Zhao
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis Missouri
| | - Canxin Xu
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis Missouri
| | - Tae-Jin Lee
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis Missouri
| | - Fang Liu
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis Missouri
| | - Kyunghee Choi
- Department of Pathology and Immunology; Washington University School of Medicine; St. Louis Missouri
- Developmental; Regenerative, and Stem Cell Biology Program, Washington University School of Medicine; St. Louis Missouri
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28
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Abstract
The discovery of the GATA binding protein (GATA factor) transcription factor family revolutionized hematology. Studies of GATA proteins have yielded vital contributions to our understanding of how hematopoietic stem and progenitor cells develop from precursors, how progenitors generate red blood cells, how hemoglobin synthesis is regulated, and the molecular underpinnings of nonmalignant and malignant hematologic disorders. This thrilling journey began with mechanistic studies on a β-globin enhancer- and promoter-binding factor, GATA-1, the founding member of the GATA family. This work ushered in the cloning of related proteins, GATA-2-6, with distinct and/or overlapping expression patterns. Herein, we discuss how the hematopoietic GATA factors (GATA-1-3) function via a battery of mechanistic permutations, which can be GATA factor subtype, cell type, and locus specific. Understanding this intriguing protein family requires consideration of how the mechanistic permutations are amalgamated into circuits to orchestrate processes of interest to the hematologist and more broadly.
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29
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Hasegawa A, Shimizu R. GATA1 Activity Governed by Configurations of cis-Acting Elements. Front Oncol 2017; 6:269. [PMID: 28119852 PMCID: PMC5220053 DOI: 10.3389/fonc.2016.00269] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/19/2016] [Indexed: 01/19/2023] Open
Abstract
The transcription factor GATA1 regulates the expression of essential erythroid and megakaryocytic differentiation genes through binding to the DNA consensus sequence WGATAR. The GATA1 protein has four functional domains, including two centrally located zinc-finger domains and two transactivation domains at the N- and C-termini. These functional domains play characteristic roles in the elaborate regulation of diversified GATA1 target genes, each of which exhibits a unique expression profile. Three types of GATA1-related hematological malignancies have been reported. One is a structural mutation in the GATA1 gene, resulting in the production of a short form of GATA1 that lacks the N-terminal transactivation domain and is found in Down syndrome-related acute megakaryocytic leukemia. The other two are cis-acting regulatory mutations affecting expression of the Gata1 gene, which have been shown to cause acute erythroblastic leukemia and myelofibrosis in mice. Therefore, imbalanced gene regulation caused by qualitative and quantitative changes in GATA1 is thought to be involved in specific hematological disease pathogenesis. In the present review, we discuss recent advances in understanding the mechanisms of differential transcriptional regulation by GATA1 during erythroid differentiation, with special reference to the binding kinetics of GATA1 at conformation-specific binding sites.
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Affiliation(s)
- Atsushi Hasegawa
- Department of Molecular Hematology, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ritsuko Shimizu
- Department of Molecular Hematology, Tohoku University Graduate School of Medicine, Sendai, Japan; Medical Mega-Bank Organization, Tohoku University, Sendai, Japan
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30
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Zuo C, Chen K, Keleş S. A MAD-Bayes Algorithm for State-Space Inference and Clustering with Application to Querying Large Collections of ChIP-Seq Data Sets. J Comput Biol 2016; 24:472-485. [PMID: 27835030 DOI: 10.1089/cmb.2016.0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Current analytic approaches for querying large collections of chromatin immunoprecipitation followed by sequencing (ChIP-seq) data from multiple cell types rely on individual analysis of each data set (i.e., peak calling) independently. This approach discards the fact that functional elements are frequently shared among related cell types and leads to overestimation of the extent of divergence between different ChIP-seq samples. Methods geared toward multisample investigations have limited applicability in settings that aim to integrate 100s to 1000s of ChIP-seq data sets for query loci (e.g., thousands of genomic loci with a specific binding site). Recently, Zuo et al. developed a hierarchical framework for state-space matrix inference and clustering, named MBASIC, to enable joint analysis of user-specified loci across multiple ChIP-seq data sets. Although this versatile framework estimates both the underlying state-space (e.g., bound vs. unbound) and also groups loci with similar patterns together, its Expectation-Maximization-based estimation structure hinders its applicability with large number of loci and samples. We address this limitation by developing MAP-based asymptotic derivations from Bayes (MAD-Bayes) framework for MBASIC. This results in a K-means-like optimization algorithm that converges rapidly and hence enables exploring multiple initialization schemes and flexibility in tuning. Comparison with MBASIC indicates that this speed comes at a relatively insignificant loss in estimation accuracy. Although MAD-Bayes MBASIC is specifically designed for the analysis of user-specified loci, it is able to capture overall patterns of histone marks from multiple ChIP-seq data sets similar to those identified by genome-wide segmentation methods such as ChromHMM and Spectacle.
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Affiliation(s)
- Chandler Zuo
- Department of Statistics, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison , Madison, Wisconsin
| | - Kailei Chen
- Department of Statistics, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison , Madison, Wisconsin
| | - Sündüz Keleş
- Department of Statistics, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison , Madison, Wisconsin
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31
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McIver SC, Katsumura KR, Davids E, Liu P, Kang YA, Yang D, Bresnick EH. Exosome complex orchestrates developmental signaling to balance proliferation and differentiation during erythropoiesis. eLife 2016; 5. [PMID: 27543448 PMCID: PMC5040589 DOI: 10.7554/elife.17877] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022] Open
Abstract
Since the highly conserved exosome complex mediates the degradation and processing of multiple classes of RNAs, it almost certainly controls diverse biological processes. How this post-transcriptional RNA-regulatory machine impacts cell fate decisions and differentiation is poorly understood. Previously, we demonstrated that exosome complex subunits confer an erythroid maturation barricade, and the erythroid transcription factor GATA-1 dismantles the barricade by transcriptionally repressing the cognate genes. While dissecting requirements for the maturation barricade in Mus musculus, we discovered that the exosome complex is a vital determinant of a developmental signaling transition that dictates proliferation/amplification versus differentiation. Exosome complex integrity in erythroid precursor cells ensures Kit receptor tyrosine kinase expression and stem cell factor/Kit signaling, while preventing responsiveness to erythropoietin-instigated signals that promote differentiation. Functioning as a gatekeeper of this developmental signaling transition, the exosome complex controls the massive production of erythroid cells that ensures organismal survival in homeostatic and stress contexts. DOI:http://dx.doi.org/10.7554/eLife.17877.001 Red blood cells supply an animal’s tissues with the oxygen they need to survive. These cells circulate for a certain amount of time before they die. To replenish the red blood cells that are lost, first a protein called stem cell factor (SCF) instructs stem cells and precursor cells to proliferate, and a second protein, known as erythropoietin, then signals to these cells to differentiate into mature red blood cells. It is important to maintain this balance between these two processes because too much proliferation can lead to cancer while too much differentiation will exhaust the supply of stem cells. Previous work has shown that a collection of proteins called the exosome complex can block steps leading towards mature red blood cells. The exosome complex controls several processes within cells by modifying or degrading a variety of messenger RNAs, the molecules that serve as intermediates between DNA and protein. However, it was not clear how the exosome complex sets up the differentiation block and whether it is somehow connected to the signaling from SCF and erythropoietin. McIver et al. set out to address this issue by isolating precursor cells with the potential to become red blood cells from mouse fetal livers and experimentally reducing the levels of the exosome complex. The experiments showed that these cells were no longer able to respond when treated with SCF in culture, whereas the control cells responded as normal. Further experiments showed that cells with less of the exosome complex also made less of a protein named Kit. Normally, SCF interacts with Kit to instruct cells to multiply. Lastly, although the experimental cells could no longer respond to these proliferation signals, they could react to erythropoietin, which promotes differentiation. Thus, normal levels of the exosome complex keep the delicate balance between proliferation and differentiation, which is crucial to the development of red blood cells. In future, it will be important to study the exosome complex in living mice and in human cells, and to see whether it also controls other signaling pathways. Furthermore, it is worth exploring whether this new knowledge can help efforts to produce red blood cells on an industrial scale, which could then be used to treat patients with conditions such as anemia. DOI:http://dx.doi.org/10.7554/eLife.17877.002
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Affiliation(s)
- Skye C McIver
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Koichi R Katsumura
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Elsa Davids
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Peng Liu
- Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Yoon-A Kang
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - David Yang
- Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, United States
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, United States.,UW-Madison Blood Research Program, University of Wisconsin School of Medicine and Public Health, Madison, United States.,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, United States
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32
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Integrated genome-scale analysis of the transcriptional regulatory landscape in a blood stem/progenitor cell model. Blood 2016; 127:e12-23. [DOI: 10.1182/blood-2015-10-677393] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/07/2016] [Indexed: 12/20/2022] Open
Abstract
Key Points
New genome-wide maps for 17 TFs, 3 histone modifications, DNase I sites, Hi-C, and Promoter Capture Hi-C in a stem/progenitor model. Integrated analysis shows that chromatin loops in a stem/progenitor model are characterized by specific TF occupancy patterns.
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33
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DeVilbiss AW, Tanimura N, McIver SC, Katsumura KR, Johnson KD, Bresnick EH. Navigating Transcriptional Coregulator Ensembles to Establish Genetic Networks: A GATA Factor Perspective. Curr Top Dev Biol 2016; 118:205-44. [PMID: 27137658 DOI: 10.1016/bs.ctdb.2016.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Complex developmental programs require orchestration of intrinsic and extrinsic signals to control cell proliferation, differentiation, and survival. Master regulatory transcription factors are vital components of the machinery that transduce these stimuli into cellular responses. This is exemplified by the GATA family of transcription factors that establish cell type-specific genetic networks and control the development and homeostasis of systems including blood, vascular, adipose, and cardiac. Dysregulated GATA factor activity/expression underlies anemia, immunodeficiency, myelodysplastic syndrome, and leukemia. Parameters governing the capacity of a GATA factor expressed in multiple cell types to generate cell type-specific transcriptomes include selective coregulator usage and target gene-specific chromatin states. As knowledge of GATA-1 mechanisms in erythroid cells constitutes a solid foundation, we will focus predominantly on GATA-1, while highlighting principles that can be extrapolated to other master regulators. GATA-1 interacts with ubiquitous and lineage-restricted transcription factors, chromatin modifying/remodeling enzymes, and other coregulators to activate or repress transcription and to maintain preexisting transcriptional states. Major unresolved issues include: how does a GATA factor selectively utilize diverse coregulators; do distinct epigenetic landscapes and nuclear microenvironments of target genes dictate coregulator requirements; and do gene cohorts controlled by a common coregulator ensemble function in common pathways. This review will consider these issues in the context of GATA factor-regulated hematopoiesis and from a broader perspective.
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Affiliation(s)
- A W DeVilbiss
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - N Tanimura
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - S C McIver
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - K R Katsumura
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - K D Johnson
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - E H Bresnick
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States.
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34
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Abstract
SCL, a transcription factor of the basic helix-loop-helix family, is a master regulator of hematopoiesis. Scl specifies lateral plate mesoderm to a hematopoietic fate and establishes boundaries by inhibiting the cardiac lineage. A combinatorial interaction between Scl and Vegfa/Flk1 sets in motion the first wave of primitive hematopoiesis. Subsequently, definitive hematopoietic stem cells (HSCs) emerge from the embryo proper via an endothelial-to-hematopoietic transition controlled by Runx1, acting with Scl and Gata2. Past this stage, Scl in steady state HSCs is redundant with Lyl1, a highly homologous factor. However, Scl is haploinsufficient in stress response, when a rare subpopulation of HSCs with very long term repopulating capacity is called into action. SCL activates transcription by recruiting a core complex on DNA that necessarily includes E2A/HEB, GATA1-3, LIM-only proteins LMO1/2, LDB1, and an extended complex comprising ETO2, RUNX1, ERG, or FLI1. These interactions confer multifunctionality to a complex that can control cell proliferation in erythroid progenitors or commitment to terminal differentiation through variations in single component. Ectopic SCL and LMO1/2 expression in immature thymocytes activates of a stem cell gene network and reprogram cells with a finite lifespan into self-renewing preleukemic stem cells (pre-LSCs), an initiating event in T-cell acute lymphoblastic leukemias. Interestingly, fate conversion of fibroblasts to hematoendothelial cells requires not only Scl and Lmo2 but also Gata2, Runx1, and Erg, indicating a necessary collaboration between these transcription factors for hematopoietic reprogramming. Nonetheless, full reprogramming into self-renewing multipotent HSCs may require additional factors and most likely, a permissive microenvironment.
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Affiliation(s)
- T Hoang
- Laboratory of Hematopoiesis and Leukemia, Institute of Research in Immunology and Cancer (IRIC), University of Montreal, Montreal, QC, Canada.
| | - J A Lambert
- Laboratory of Hematopoiesis and Leukemia, Institute of Research in Immunology and Cancer (IRIC), University of Montreal, Montreal, QC, Canada
| | - R Martin
- Laboratory of Hematopoiesis and Leukemia, Institute of Research in Immunology and Cancer (IRIC), University of Montreal, Montreal, QC, Canada
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35
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Hewitt KJ, Johnson KD, Gao X, Keles S, Bresnick EH. The Hematopoietic Stem and Progenitor Cell Cistrome: GATA Factor-Dependent cis-Regulatory Mechanisms. Curr Top Dev Biol 2016; 118:45-76. [PMID: 27137654 PMCID: PMC8572122 DOI: 10.1016/bs.ctdb.2016.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Transcriptional regulators mediate the genesis and function of the hematopoietic system by binding complex ensembles of cis-regulatory elements to establish genetic networks. While thousands to millions of any given cis-element resides in a genome, how transcriptional regulators select these sites and how site attributes dictate functional output is not well understood. An instructive system to address this problem involves the GATA family of transcription factors that control vital developmental and physiological processes and are linked to multiple human pathologies. Although GATA factors bind DNA motifs harboring the sequence GATA, only a very small subset of these abundant motifs are occupied in genomes. Mechanistic studies revealed a unique configuration of a GATA factor-regulated cis-element consisting of an E-box and a downstream GATA motif separated by a short DNA spacer. GATA-1- or GATA-2-containing multiprotein complexes at these composite elements control transcription of genes critical for hematopoietic stem cell emergence in the mammalian embryo, hematopoietic progenitor cell regulation, and erythroid cell maturation. Other constituents of the complex include the basic helix-loop-loop transcription factor Scl/TAL1, its heterodimeric partner E2A, and the Lim domain proteins LMO2 and LDB1. This chapter reviews the structure/function of E-box-GATA composite cis-elements, which collectively constitute an important sector of the hematopoietic stem and progenitor cell cistrome.
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Affiliation(s)
- Kyle J. Hewitt
- University of Wisconsin School of Medicine and Public Health, Department of Cell and Regenerative Biology, Carbone Cancer Center, Madison, WI 53705,UW-Madison Blood Research Program
| | - Kirby D. Johnson
- University of Wisconsin School of Medicine and Public Health, Department of Cell and Regenerative Biology, Carbone Cancer Center, Madison, WI 53705,UW-Madison Blood Research Program
| | - Xin Gao
- University of Wisconsin School of Medicine and Public Health, Department of Cell and Regenerative Biology, Carbone Cancer Center, Madison, WI 53705,UW-Madison Blood Research Program
| | - Sunduz Keles
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health
| | - Emery H. Bresnick
- University of Wisconsin School of Medicine and Public Health, Department of Cell and Regenerative Biology, Carbone Cancer Center, Madison, WI 53705,UW-Madison Blood Research Program,Corresponding author:
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36
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Tanimura N, Miller E, Igarashi K, Yang D, Burstyn JN, Dewey CN, Bresnick EH. Mechanism governing heme synthesis reveals a GATA factor/heme circuit that controls differentiation. EMBO Rep 2015; 17:249-65. [PMID: 26698166 DOI: 10.15252/embr.201541465] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 11/24/2015] [Indexed: 12/18/2022] Open
Abstract
Metal ion-containing macromolecules have fundamental roles in essentially all biological processes throughout the evolutionary tree. For example, iron-containing heme is a cofactor in enzyme catalysis and electron transfer and an essential hemoglobin constituent. To meet the intense demand for hemoglobin assembly in red blood cells, the cell type-specific factor GATA-1 activates transcription of Alas2, encoding the rate-limiting enzyme in heme biosynthesis, 5-aminolevulinic acid synthase-2 (ALAS-2). Using genetic editing to unravel mechanisms governing heme biosynthesis, we discovered a GATA factor- and heme-dependent circuit that establishes the erythroid cell transcriptome. CRISPR/Cas9-mediated ablation of two Alas2 intronic cis elements strongly reduces GATA-1-induced Alas2 transcription, heme biosynthesis, and surprisingly, GATA-1 regulation of other vital constituents of the erythroid cell transcriptome. Bypassing ALAS-2 function in Alas2 cis element-mutant cells by providing its catalytic product 5-aminolevulinic acid rescues heme biosynthesis and the GATA-1-dependent genetic network. Heme amplifies GATA-1 function by downregulating the heme-sensing transcriptional repressor Bach1 and via a Bach1-insensitive mechanism. Through this dual mechanism, heme and a master regulator collaborate to orchestrate a cell type-specific transcriptional program that promotes cellular differentiation.
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Affiliation(s)
- Nobuyuki Tanimura
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Eli Miller
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University School of Medicine, Sendai, Japan
| | - David Yang
- Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Judith N Burstyn
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Colin N Dewey
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Emery H Bresnick
- Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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