1
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Yusuf RZ, Saez B, Sharda A, van Gastel N, Yu VWC, Baryawno N, Scadden EW, Acharya S, Chattophadhyay S, Huang C, Viswanathan V, S'aulis D, Cobert J, Sykes DB, Keibler MA, Das S, Hutchinson JN, Churchill M, Mukherjee S, Lee D, Mercier F, Doench J, Bullinger L, Logan DJ, Schreiber S, Stephanopoulos G, Rizzo WB, Scadden DT. Aldehyde dehydrogenase 3a2 protects AML cells from oxidative death and the synthetic lethality of ferroptosis inducers. Blood 2020; 136:1303-1316. [PMID: 32458004 PMCID: PMC7483435 DOI: 10.1182/blood.2019001808] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 04/26/2020] [Indexed: 12/22/2022] Open
Abstract
Metabolic alterations in cancer represent convergent effects of oncogenic mutations. We hypothesized that a metabolism-restricted genetic screen, comparing normal primary mouse hematopoietic cells and their malignant counterparts in an ex vivo system mimicking the bone marrow microenvironment, would define distinctive vulnerabilities in acute myeloid leukemia (AML). Leukemic cells, but not their normal myeloid counterparts, depended on the aldehyde dehydrogenase 3a2 (Aldh3a2) enzyme that oxidizes long-chain aliphatic aldehydes to prevent cellular oxidative damage. Aldehydes are by-products of increased oxidative phosphorylation and nucleotide synthesis in cancer and are generated from lipid peroxides underlying the non-caspase-dependent form of cell death, ferroptosis. Leukemic cell dependence on Aldh3a2 was seen across multiple mouse and human myeloid leukemias. Aldh3a2 inhibition was synthetically lethal with glutathione peroxidase-4 (GPX4) inhibition; GPX4 inhibition is a known trigger of ferroptosis that by itself minimally affects AML cells. Inhibiting Aldh3a2 provides a therapeutic opportunity and a unique synthetic lethality to exploit the distinctive metabolic state of malignant cells.
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MESH Headings
- Aldehyde Oxidoreductases/genetics
- Aldehyde Oxidoreductases/physiology
- Aldehydes/pharmacology
- Animals
- Carbolines/pharmacology
- Cell Line, Tumor
- Cyclohexylamines/pharmacology
- Cytarabine/administration & dosage
- Doxorubicin/administration & dosage
- Ferroptosis/drug effects
- Hematopoiesis/physiology
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/enzymology
- Leukemia, Myeloid, Acute/pathology
- Lipid Peroxidation
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myeloid-Lymphoid Leukemia Protein/physiology
- Neoplasm Proteins/deficiency
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Oleic Acid/pharmacology
- Oncogene Proteins, Fusion/physiology
- Oxidation-Reduction
- Oxidative Stress
- Phenylenediamines/pharmacology
- Phospholipid Hydroperoxide Glutathione Peroxidase/antagonists & inhibitors
- Phospholipid Hydroperoxide Glutathione Peroxidase/physiology
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Affiliation(s)
- Rushdia Zareen Yusuf
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Borja Saez
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Azeem Sharda
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Nick van Gastel
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Ninib Baryawno
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Elizabeth W Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Sanket Acharya
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | | | - Cherrie Huang
- Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA
| | - Vasanthi Viswanathan
- Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA
| | - Dana S'aulis
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE
| | - Julien Cobert
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - David B Sykes
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | | | - Sudeshna Das
- Department of Neurology, Massachusetts General Hospital, Boston, MA
| | - John N Hutchinson
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA; and
| | - Michael Churchill
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Siddhartha Mukherjee
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Dongjun Lee
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - Francois Mercier
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
| | - John Doench
- Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA
| | - Lars Bullinger
- Department of Hematology, Oncology and Tumor Immunology, Charité University Medicine, Berlin, Germany
| | - David J Logan
- Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA
| | - Stuart Schreiber
- Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA
| | | | - William B Rizzo
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA
- Department of Stem Cell and Regenerative Biology and
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA
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2
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Yen J, Fiorino M, Liu Y, Paula S, Clarkson S, Quinn L, Tschantz WR, Klock H, Guo N, Russ C, Yu VWC, Mickanin C, Stevenson SC, Lee C, Yang Y. TRIAMF: A New Method for Delivery of Cas9 Ribonucleoprotein Complex to Human Hematopoietic Stem Cells. Sci Rep 2018; 8:16304. [PMID: 30389991 PMCID: PMC6214993 DOI: 10.1038/s41598-018-34601-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/16/2018] [Indexed: 02/07/2023] Open
Abstract
CRISPR/Cas9 mediated gene editing of patient-derived hematopoietic stem and progenitor cells (HSPCs) ex vivo followed by autologous transplantation of the edited HSPCs back to the patient can provide a potential cure for monogenic blood disorders such as β-hemoglobinopathies. One challenge for this strategy is efficient delivery of the ribonucleoprotein (RNP) complex, consisting of purified Cas9 protein and guide RNA, into HSPCs. Because β-hemoglobinopathies are most prevalent in developing countries, it is desirable to have a reliable, efficient, easy-to-use and cost effective delivery method. With this goal in mind, we developed TRansmembrane Internalization Assisted by Membrane Filtration (TRIAMF), a new method to quickly and effectively deliver RNPs into HSPCs by passing a RNP and cell mixture through a filter membrane. We achieved robust gene editing in HSPCs using TRIAMF and demonstrated that the multilineage colony forming capacities and the competence for engraftment in immunocompromised mice of HSPCs were preserved post TRIAMF treatment. TRIAMF is a custom designed system using inexpensive components and has the capacity to process HSPCs at clinical scale.
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Affiliation(s)
- Jonathan Yen
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Michael Fiorino
- NIBR Informatics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Yi Liu
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Steve Paula
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Scott Clarkson
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Lisa Quinn
- Biotherapeutic and Analytical Tech, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - William R Tschantz
- Biotherapeutic and Analytical Tech, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Heath Klock
- Biotherapeutics & Biotechnology, The Genomics Institute of the Novartis Research Foundation, La Jolla, California, USA
| | - Ning Guo
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Carsten Russ
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Vionnie W C Yu
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Craig Mickanin
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Susan C Stevenson
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Cameron Lee
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Yi Yang
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA.
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3
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Hekmatnejad B, Yu VWC, Addison W, Mandic V, Pellicelli M, Arabian A, St-Arnaud R. FIAT Deletion Increases Bone Mass But Does Not Prevent High-Fat-Diet-Induced Metabolic Complications. Endocrinology 2017; 158:264-276. [PMID: 27906582 PMCID: PMC5413077 DOI: 10.1210/en.2016-1867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 11/23/2016] [Indexed: 12/28/2022]
Abstract
Factor inhibiting activating transcription factor 4 (ATF4)-mediated transcription (FIAT) interacts with ATF4 to repress its transcriptional activity. We performed a phenotypic analysis of Fiat-deficient male mice (Fiat-/Y) at 8 and 16 weeks of age. Microcomputed tomography analysis of the distal femur demonstrated 46% and 13% age-dependent increases in trabecular bone volume and thickness, respectively, in Fiat-/Y mice. Cortical bone measurements at the femoral midshaft revealed a substantial increase in cortical thickness in older Fiat-/Y mice. Bone gain was related to increased mineral apposition rate and increased osteoblast function. Femoral stiffness and strength were substantially increased in Fiat-/Y compared with wild-type (WT) mice. We also investigated whether FIAT contributes to metabolic function. When fed standard mouse chow, Fiat-/Y animals were glucose-tolerant. However, when fed a high-fat diet (HFD) for 8 weeks, Fiat-/Y mice gained more weight than control mice, with a specific increase in white adipose tissue fat mass. The increase in fat mass was due to reduced energy expenditure, which correlated with reduced fatty acid oxidation and lipolysis in the adipose tissue of mutant mice. The expression of the Scd1 gene, involved in lipogenesis, was upregulated in the subcutaneous adipose tissue of Fiat-/Y mice. Moreover, HFD-fed Fiat-/Y mice exhibited increased circulating leptin and insulin levels relative to WT mice, demonstrating that endocrine abnormalities are associated with the disturbance in energy balance. We conclude that Fiat-/Y mice exhibited an anabolic bone phenotype but displayed increased susceptibility to developing metabolic-related disorders when consuming an HFD.
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Affiliation(s)
- Bahareh Hekmatnejad
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
- Human Genetics,
| | - Vionnie W. C. Yu
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
- Human Genetics,
| | - William Addison
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
| | - Vice Mandic
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
| | - Martin Pellicelli
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
- Human Genetics,
| | - Alice Arabian
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
| | - René St-Arnaud
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Quebec H4A 0A9, Canada;
- Human Genetics,
- Surgery, and
- Medicine, McGill University, Montreal, Quebec H3A 2T5, Canada; and
- Research Institute, McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
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4
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Yu VWC, Lymperi S, Oki T, Jones A, Swiatek P, Vasic R, Ferraro F, Scadden DT. Distinctive Mesenchymal-Parenchymal Cell Pairings Govern B Cell Differentiation in the Bone Marrow. Stem Cell Reports 2016; 7:220-35. [PMID: 27453006 PMCID: PMC4982987 DOI: 10.1016/j.stemcr.2016.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 11/25/2022] Open
Abstract
Bone marrow niches for hematopoietic progenitor cells are not well defined despite their critical role in blood homeostasis. We previously found that cells expressing osteocalcin, a marker of mature osteolineage cells, regulate the production of thymic-seeding T lymphoid progenitors. Here, using a selective cell deletion strategy, we demonstrate that a subset of mesenchymal cells expressing osterix, a marker of bone precursors in the adult, serve to regulate the maturation of early B lymphoid precursors by promoting pro-B to pre-B cell transition through insulin-like growth factor 1 (IGF-1) production. Loss of Osx+ cells or Osx-specific deletion of IGF-1 led to a failure of B cell maturation and the impaired adaptive immune response. These data highlight the notion that bone marrow is a composite of specialized niches formed by pairings of specific mesenchymal cells with parenchymal stem or lineage committed progenitor cells, thereby providing distinctive functional units to regulate hematopoiesis. Loss of Osx+ osteolineage cells halted B cell maturation and caused immune failure Mice with Osx+ cell-specific deletion of IGF-1 phenocopied Osx+ cell ablated mice Osx+ cell promotes pro-B to pre-B cell transition through IGF-1 production Specialized niche cell-hematopoietic progenitor pairings regulate hematopoiesis
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Affiliation(s)
- Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Stefania Lymperi
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Toshihiko Oki
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Alexandra Jones
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Peter Swiatek
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Radovan Vasic
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA
| | - Francesca Ferraro
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA; Department of Medicine, Pennsylvania Hospital, University of Pennsylvania Health System, 800 Spruce Street, Philadelphia, PA 19107, USA.
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Boston, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02139, USA; Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Stem Cell Institute, 185 Cambridge Street, Boston, MA 02115, USA.
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5
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Abstract
Stem cells do not thrive without their niche. The bone marrow microenvironment is where hematopoietic stem cells maintain their cell state while receiving physiological input to modify their activity in response to changing physiological demands. The complexity of the bone marrow microenvironment is being unraveled and indicates that multiple different cell types contribute to the regulation of stem and progenitor cells. Further, it is becoming evident that the bone marrow represents a composite of niches with different components and different functional roles in hematopoiesis. It is now evident that alterations in specific stromal cells that comprise the bone marrow microenvironment can contribute to hematologic pathology. In this chapter, we will review the history of the niche concept, evolving information about its components and how niche dysfunction may contribute to disease.
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Affiliation(s)
- V W C Yu
- Massachusetts General Hospital, Boston, MA, United States; Harvard Stem Cell Institute, Cambridge, MA, United States; Harvard University, Cambridge, MA, United States
| | - D T Scadden
- Massachusetts General Hospital, Boston, MA, United States; Harvard Stem Cell Institute, Cambridge, MA, United States; Harvard University, Cambridge, MA, United States.
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6
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Yu VWC, Lymperi S, Ferraro F, Scadden DT. Transcriptome comparison of distinct osteolineage subsets in the hematopoietic stem cell niche using a triple fluorescent transgenic mouse model. Genom Data 2015; 5:318-9. [PMID: 26484277 PMCID: PMC4583650 DOI: 10.1016/j.gdata.2015.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/01/2015] [Indexed: 10/25/2022]
Abstract
The bone marrow niche is recognized as a central player in maintaining and regulating the behavior of hematopoietic stem and progenitor cells. Specific gain-of and loss-of function experiments perturbing a range of osteolineage cells or their secreted proteins had been shown to affect stem cell maintenance (Calvi et al, 2003 [1]; Stier et al., 2005 [2]; Zhang et al., 2003 [3]; Nilsson et al., 2005 [4]; Greenbaum et al., 2013 [5]) and engraftment (Adam et al., 2006, 2009 [6,7]). We used specific in vivo cell deletion approaches to dissect the niche cell-parenchymal cell dependency in a complex bone marrow microenvironment. Endogenous deletion of osteocalcin-expressing (Ocn(+)) cells led to a loss of T immune cells (Yu et al., 2015 [8]. Ocn(+) cells express the Notch ligand DLL4 to communicate with T-competent progenitors, and thereby ensuring T precursor production and expression of chemotactic molecules on their cell surface for subsequent thymic seeding. In contrast, depletion of osterix-expressing (Osx(+)) osteoprogenitors led to reduced B immune cells. These distinct hematopoietic phenotypes suggest specific pairing of mesenchymal niche cells and parenchymal hematopoietic cells in the bone marrow to create unique functional units to support hematopoiesis. Here, we present the global gene expression profiles of these osteolineage subtypes utilizing a triple fluorescent transgenic mouse model (OsxCre(+);Rosa-mCh(+);Ocn:Topaz(+)) that labels Osx(+) cells red, Ocn(+) cells green, and Osx(+) Ocn(+) cells yellow. This system allows isolation of distinct osteolineage subsets within the same animal by flow cytometry. Array data that have been described in our study [8] are also publically available from NCBI Gene Expression Omnibus (GEO) with the accession number GSE66042. Differences in gene expression may correlate with functional difference in supporting hematopoiesis.
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Affiliation(s)
- Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Stefania Lymperi
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Francesca Ferraro
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
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7
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Wang W, Yu S, Zimmerman G, Wang Y, Myers J, Yu VWC, Huang D, Huang X, Shim J, Huang Y, Xin W, Qiao P, Yan M, Xin W, Scadden DT, Stanley P, Lowe JB, Huang AY, Siebel CW, Zhou L. Notch Receptor-Ligand Engagement Maintains Hematopoietic Stem Cell Quiescence and Niche Retention. Stem Cells 2015; 33:2280-93. [PMID: 25851125 DOI: 10.1002/stem.2031] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/21/2015] [Indexed: 01/05/2023]
Abstract
Notch is long recognized as a signaling molecule important for stem cell self-renewal and fate determination. Here, we reveal a novel adhesive role of Notch-ligand engagement in hematopoietic stem and progenitor cells (HSPCs). Using mice with conditional loss of O-fucosylglycans on Notch EGF-like repeats important for the binding of Notch ligands, we report that HSPCs with faulty ligand binding ability display enhanced cycling accompanied by increased egress from the marrow, a phenotype mainly attributed to their reduced adhesion to Notch ligand-expressing stromal cells and osteoblastic cells and their altered occupation in osteoblastic niches. Adhesion to Notch ligand-bearing osteoblastic or stromal cells inhibits wild type but not O-fucosylglycan-deficient HSPC cycling, independent of RBP-JK -mediated canonical Notch signaling. Furthermore, Notch-ligand neutralizing antibodies induce RBP-JK -independent HSPC egress and enhanced HSPC mobilization. We, therefore, conclude that Notch receptor-ligand engagement controls HSPC quiescence and retention in the marrow niche that is dependent on O-fucosylglycans on Notch.
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Affiliation(s)
- Weihuan Wang
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Shuiliang Yu
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Grant Zimmerman
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yiwei Wang
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jay Myers
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Dan Huang
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Xiaoran Huang
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jeongsup Shim
- Department of Pathology, Genentech, Inc., South San Francisco, California, USA
| | - Yuanshuai Huang
- Department of Blood Transfusion, Affiliated Hospital of Luzhou Medical College, Luzhou, Sichuan Province, People's Republic of China
| | - William Xin
- University School, Hunting Valley, Ohio, USA
| | - Peter Qiao
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Minhong Yan
- Department of Molecular Biology Oncology, Genentech, Inc., South San Francisco, California, USA
| | - Wei Xin
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Pamela Stanley
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York, USA
| | - John B Lowe
- Department of Pathology, Genentech, Inc., South San Francisco, California, USA
| | - Alex Y Huang
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Christian W Siebel
- Department of Molecular Biology Oncology, Genentech, Inc., South San Francisco, California, USA
| | - Lan Zhou
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
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8
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Yu VWC, Saez B, Cook C, Lotinun S, Pardo-Saganta A, Wang YH, Lymperi S, Ferraro F, Raaijmakers MHGP, Wu JY, Zhou L, Rajagopal J, Kronenberg HM, Baron R, Scadden DT. Specific bone cells produce DLL4 to generate thymus-seeding progenitors from bone marrow. ACTA ACUST UNITED AC 2015; 212:759-74. [PMID: 25918341 PMCID: PMC4419348 DOI: 10.1084/jem.20141843] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 03/26/2015] [Indexed: 12/12/2022]
Abstract
Osteocalcin (Ocn)-expressing bone marrow cells produce the Notch ligand DLL4, and this is required for lymphoid progenitor cells to seed the thymus. Production of the cells that ultimately populate the thymus to generate α/β T cells has been controversial, and their molecular drivers remain undefined. Here, we report that specific deletion of bone-producing osteocalcin (Ocn)-expressing cells in vivo markedly reduces T-competent progenitors and thymus-homing receptor expression among bone marrow hematopoietic cells. Decreased intrathymic T cell precursors and decreased generation of mature T cells occurred despite normal thymic function. The Notch ligand DLL4 is abundantly expressed on bone marrow Ocn+ cells, and selective depletion of DLL4 from these cells recapitulated the thymopoietic abnormality. These data indicate that specific mesenchymal cells in bone marrow provide key molecular drivers enforcing thymus-seeding progenitor generation and thereby directly link skeletal biology to the production of T cell–based adaptive immunity.
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Affiliation(s)
- Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Borja Saez
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Colleen Cook
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Sutada Lotinun
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02215 Department of Physiology and STAR on Craniofacial and Skeletal Disorders, Chulalongkorn University, Bangkok 10330, Thailand
| | - Ana Pardo-Saganta
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Departments of Internal Medicine and Pediatrics, Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA 02215
| | - Ying-Hua Wang
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Stefania Lymperi
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Francesca Ferraro
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
| | - Marc H G P Raaijmakers
- Department of Hematology and Erasmus Stem Cell Institute, Erasmus University Medical Center Cancer Institute, 3015 CE Rotterdam, Netherlands
| | - Joy Y Wu
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02215
| | - Lan Zhou
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106
| | - Jayaraj Rajagopal
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Departments of Internal Medicine and Pediatrics, Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA 02215
| | - Henry M Kronenberg
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02215
| | - Roland Baron
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02215 Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02215
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02215 Harvard Stem Cell Institute, Cambridge, MA 02215 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02215
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Wang YH, Israelsen WJ, Lee D, Yu VWC, Jeanson NT, Clish CB, Cantley LC, Vander Heiden MG, Scadden DT. Cell-state-specific metabolic dependency in hematopoiesis and leukemogenesis. Cell 2014; 158:1309-1323. [PMID: 25215489 DOI: 10.1016/j.cell.2014.07.048] [Citation(s) in RCA: 261] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 06/09/2014] [Accepted: 07/16/2014] [Indexed: 12/21/2022]
Abstract
The balance between oxidative and nonoxidative glucose metabolism is essential for a number of pathophysiological processes. By deleting enzymes that affect aerobic glycolysis with different potencies, we examine how modulating glucose metabolism specifically affects hematopoietic and leukemic cell populations. We find that a deficiency in the M2 pyruvate kinase isoform (PKM2) reduces the levels of metabolic intermediates important for biosynthesis and impairs progenitor function without perturbing hematopoietic stem cells (HSCs), whereas lactate dehydrogenase A (LDHA) deletion significantly inhibits the function of both HSCs and progenitors during hematopoiesis. In contrast, leukemia initiation by transforming alleles putatively affecting either HSCs or progenitors is inhibited in the absence of either PKM2 or LDHA, indicating that the cell-state-specific responses to metabolic manipulation in hematopoiesis do not apply to the setting of leukemia. This finding suggests that fine-tuning the level of glycolysis may be explored therapeutically for treating leukemia while preserving HSC function.
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Affiliation(s)
- Ying-Hua Wang
- Center for Regenerative Medicine and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - William J Israelsen
- Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dongjun Lee
- Center for Regenerative Medicine and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Vionnie W C Yu
- Center for Regenerative Medicine and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nathaniel T Jeanson
- Center for Regenerative Medicine and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Clary B Clish
- Metabolite Profiling Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lewis C Cantley
- Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - David T Scadden
- Center for Regenerative Medicine and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02114, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
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10
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Velardi E, Tsai JJ, Holland AM, Wertheimer T, Yu VWC, Zakrzewski JL, Tuckett AZ, Singer NV, West ML, Smith OM, Young LF, Kreines FM, Levy ER, Boyd RL, Scadden DT, Dudakov JA, van den Brink MRM. Sex steroid blockade enhances thymopoiesis by modulating Notch signaling. ACTA ACUST UNITED AC 2014; 211:2341-9. [PMID: 25332287 PMCID: PMC4235646 DOI: 10.1084/jem.20131289] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Velardi et al. show that sex steroids regulate thymopoiesis by directly modulating Notch signaling, and provide a novel clinical strategy to boost immune regeneration. Paradoxical to its importance for generating a diverse T cell repertoire, thymic function progressively declines throughout life. This process has been at least partially attributed to the effects of sex steroids, and their removal promotes enhanced thymopoiesis and recovery from immune injury. We show that one mechanism by which sex steroids influence thymopoiesis is through direct inhibition in cortical thymic epithelial cells (cTECs) of Delta-like 4 (Dll4), a Notch ligand crucial for the commitment and differentiation of T cell progenitors in a dose-dependent manner. Consistent with this, sex steroid ablation (SSA) led to increased expression of Dll4 and its downstream targets. Importantly, SSA induced by luteinizing hormone-releasing hormone (LHRH) receptor antagonism bypassed the surge in sex steroids caused by LHRH agonists, the gold standard for clinical ablation of sex steroids, thereby facilitating increased Dll4 expression and more rapid promotion of thymopoiesis. Collectively, these findings not only reveal a novel mechanism underlying improved thymic regeneration upon SSA but also offer an improved clinical strategy for successfully boosting immune function.
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Affiliation(s)
- Enrico Velardi
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Department of Clinical and Experimental Medicine, University of Perugia, 06122 Perugia, Italy
| | - Jennifer J Tsai
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY 10021
| | - Amanda M Holland
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY 10021 MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham B15 2TT, England, UK
| | - Tobias Wertheimer
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Division of Hematology and Oncology, Department of Medicine, Freiburg University Medical Center, Albert-Ludwigs-University, 79106 Freiburg, Germany
| | - Vionnie W C Yu
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114 Harvard Stem Cell Institute, Cambridge, MA 02138 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138
| | - Johannes L Zakrzewski
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Andrea Z Tuckett
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Natalie V Singer
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Mallory L West
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Odette M Smith
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Lauren F Young
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Fabiana M Kreines
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Emily R Levy
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
| | - Richard L Boyd
- Department of Anatomy and Developmental Biology, Monash University, Melbourne 3800, Australia
| | - David T Scadden
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114 Harvard Stem Cell Institute, Cambridge, MA 02138 Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138
| | - Jarrod A Dudakov
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Department of Anatomy and Developmental Biology, Monash University, Melbourne 3800, Australia
| | - Marcel R M van den Brink
- Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Immunology Program, Department of Medicine, and Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY 10021
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11
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Hekmatnejad B, Mandic V, Yu VWC, Akhouayri O, Arabian A, St-Arnaud R. Altered gene dosage confirms the genetic interaction between FIAT and αNAC. Gene 2014; 538:328-33. [PMID: 24440290 DOI: 10.1016/j.gene.2014.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 01/04/2014] [Indexed: 10/25/2022]
Abstract
Factor inhibiting ATF4-mediated transcription (FIAT) interacts with Nascent polypeptide associated complex and coregulator alpha (αNAC). In cultured osteoblastic cells, this interaction contributes to maximal FIAT-mediated inhibition of Osteocalcin (Ocn) gene transcription. We set out to demonstrate the physiological relevance of this interaction by altering gene dosage in compound Fiat and Naca (encoding αNAC) heterozygous mice. Compound Naca(+/-); Fiat(+/-) heterozygous animals were viable, developed normally, and exhibited no significant difference in body weight compared with control littermate genotypes. Animals with a single Fiat allele had reduced Fiat mRNA expression without changes in the expression of related family members. Expression of the osteocyte differentiation marker Dmp1 was elevated in compound heterozygotes. Static histomorphometry parameters were assessed at 8weeks of age using microcomputed tomography (μCT). Trabecular measurements were not different between genotypes. Cortical thickness and area were not affected by gene dosage, but we measured a significant increase in cortical porosity in compound heterozygous mice, without changes in biomechanical parameters. The bone phenotype of compound Naca(+/-); Fiat(+/-) heterozygotes confirms that FIAT and αNAC are part of a common genetic pathway and support a role for the FIAT/αNAC interaction in normal bone physiology.
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Affiliation(s)
- Bahareh Hekmatnejad
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada; Department of Human Genetics, McGill University, Montreal, Quebec H3A 2T5, Canada
| | - Vice Mandic
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada; Department of Human Genetics, McGill University, Montreal, Quebec H3A 2T5, Canada
| | - Vionnie W C Yu
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada; Department of Human Genetics, McGill University, Montreal, Quebec H3A 2T5, Canada
| | - Omar Akhouayri
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada; Department of Human Genetics, McGill University, Montreal, Quebec H3A 2T5, Canada
| | - Alice Arabian
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada
| | - René St-Arnaud
- Research Unit, Shriners Hospital for Children - Canada, Montreal, Quebec H3G 1A6, Canada; Department of Human Genetics, McGill University, Montreal, Quebec H3A 2T5, Canada; Department of Surgery, McGill University, Montreal, Quebec H3A 2T5, Canada; Department of Medicine, McGill University, Montreal, Quebec H3A 2T5, Canada.
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Yu VWC, Akhouayri O, St-Arnaud R. FIAT is co-expressed with its dimerization target ATF4 in early osteoblasts, but not in osteocytes. Gene Expr Patterns 2009; 9:335-40. [PMID: 19232401 DOI: 10.1016/j.gep.2009.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 02/04/2009] [Accepted: 02/05/2009] [Indexed: 10/25/2022]
Abstract
FIAT represses osteocalcin gene transcription by heterodimerizing with ATF4 and preventing it from binding to DNA. We report here the expression profiles of FIAT and ATF4 during osteoblastogenesis. Messenger RNA levels for the osteoblast transcriptional regulators Satb2, Runx2, Fiat, and Atf4 were quantified using real-time reverse-transcription PCR (RT-qPCR) and respective protein levels monitored by immunodetection in differentiating primary osteoblast cultures. Satb2, Fiat, and Atf4 mRNA levels remained constant throughout the differentiation sequence, whereas Runx2 transcript levels were significantly increased by 12 days post-confluency. Using immunofluorescence, the SATB2, RUNX2, and ATF4 signals appeared to increase as a function of time in culture. FIAT protein expression was readily detected in early cultures, but signal intensity decreased thereafter. When immunoblotting was used to quantify the relative amounts of FIAT and ATF4 proteins, the expression levels of the two proteins were found to be inversely correlated. The decrease in FIAT protein levels coincided with increased binding of ATF4 to the osteocalcin gene promoter, and with increased osteocalcin expression measured by RT-qPCR or immunoblotting. Immunohistochemistry of long bones from mice at E16.5 and 2 days post-natal revealed that both proteins are initially expressed in osteoblasts. In adult bone, FIAT was detected in osteocytes, while ATF4 expression was observed in active osteoblasts and lining cells, but not in osteocytes. Taken together, these data support the idea that a stoichiometric excess of ATF4 over FIAT in mature osteoblasts releases ATF4 from sequestration by FIAT, thereby allowing ATF4 homodimerization and subsequent transactivation of the osteocalcin gene.
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Affiliation(s)
- Vionnie W C Yu
- Genetics Unit, Shriners Hospital for Children, 1529 Cedar Avenue, Montreal, Que., Canada H3G 1A6
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13
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Abstract
The ATF4 transcription factor is a key regulator of osteoblast differentiation that controls osteocalcin gene transcription and type I collagen protein synthesis. We have characterized factor-inhibiting ATF4-mediated transcription (FIAT), a leucine zipper protein that dimerizes with ATF4 to form inactive dimers that cannot bind DNA. Overexpression of FIAT in osteoblasts of transgenic mice inhibited osteocalcin gene transcription and reduced osteoblastic activity, leading to osteopenia (Yu et al. [2005] J Cell Biol 169:591-601). We therefore hypothesized that inhibition of FIAT would enhance ATF4 activity, leading to increased osteocalcin transcription, type I collagen synthesis, and mineralization. We used small interfering RNAs (siRNA) to knockdown FIAT in pools of MC3T3-E1 cells stably transfected with 1.3 kb of the mouse osteocalcin gene promoter driving expression of luciferase. Stable expression of the FIAT siRNA sequence inhibited FIAT expression without significantly affecting the level of total or Ribosomal S6 Kinase-2-phosphorylated ATF4 protein. Occupancy of the osteocalcin proximal promoter by ATF4 was increased and transcription of the osteocalcin-promoter-dependent luciferase reporter showed earlier onset and increased levels. Similarly, endogenous osteocalcin gene expression was enhanced in primary osteoblasts transfected with the FIAT siRNA. FIAT knockdown cells also displayed higher expression of bone sialoprotein, increased type I collagen protein synthesis, and enhanced mineralization. These data suggest that inhibition of FIAT expression increases ATF4 activity and confirm the important role of FIAT in osteoblast function.
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Affiliation(s)
- Vionnie W C Yu
- Genetics Unit, Shriners Hospital for Children, Montreal, Quebec, Canada H3G 1A6
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14
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Yu VWC, Gauthier C, St-Arnaud R. FIAT represses bone matrix mineralization by interacting with ATF4 through its second leucine zipper. J Cell Biochem 2008; 105:859-65. [PMID: 18680144 DOI: 10.1002/jcb.21881] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have characterized FIAT, a 66 kDa leucine zipper (LZ) protein that dimerizes with activating transcription factor 4 (ATF4) to form inactive dimers that cannot bind DNA. Computer analysis identifies three putative LZ motifs within the FIAT amino acid sequence. We have used deletion- and/or site-specific mutagenesis to individually inactivate these motifs in order to identify the functional LZ that mediates the FIAT-ATF4 interaction. Amino acids 194-222 that encode the FIAT LZ2 were deleted (mutant FIAT ZIP2 DEL). We inactivated each zipper individually by replacing two or three leucine residues within each zipper by alanine residues. The engineered mutations were L142A/L149A (mutant M1, first zipper), L208A/L215A/L222A (mutant M2, second zipper), and L441A/L448A (mutant M3, third zipper). MC3T3-E1 osteoblastic cells with an integrated 1.3 kb mouse osteocalcin gene promoter fragment driving expression of luciferase were transfected with expression vectors for ATF4 and the various FIAT deletion- or site-specific mutants. Inhibition of ATF4-mediated transcription was compared between wild-type (WT) and LZ FIAT mutants. The deletion mutant FIAT ZIP2 DEL and the sequence-specific M2 mutant did not interact with ATF4 and were unable to inhibit ATF4-mediated transcription. The M1 or M3 mutations did not affect the ability of FIAT to contact ATF4 or to inhibit its transcriptional activity. Stable expression of WT FIAT in osteoblastic cells inhibited mineralization, but not expression of the FIAT ZIP2 DEL and M2 mutants. This structure-function analysis reveals that FIAT interacts with ATF4 and modulates its activity through its second leucine zipper motif.
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Affiliation(s)
- Vionnie W C Yu
- Genetics Unit, Shriners Hospital for Children, Montreal, Quebec, Canada
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St-Arnaud R, Arabian A, Yu VWC, Akhouayri O, Knutson JC, Strugnell SA. 1α,24(S)(OH)2D2 normalizes bone morphology and serum parathyroid hormone without hypercalcemia in 25-hydroxyvitamin D-1-hydroxylase (CYP27B1)-deficient mice, an animal model of vitamin D deficiency with secondary hyperparathyroidism. J Endocrinol Invest 2008; 31:711-7. [PMID: 18852532 DOI: 10.1007/bf03346420] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Vitamin D compounds are effective in managing elevated PTH levels in secondary hyperparathyroidism (SHPT) of renal failure. However, undesired increases in serum calcium and phosphorus associated with compounds such as calcitriol [1,25(OH)2D3] has prompted a search for compounds with improved safety profiles. 1alpha,24(S)(OH)2D2 (1,24(OH)2D2) is a vitamin D2 metabolite with low calcium-mo bilizing activity in vivo. We studied the efficacy of 1,24(OH)2D2 in mice lacking the CYP27B1 enzyme [25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-OHase)], a novel vitamin D deficiency model with SHPT. MATERIALS AND METHODS 1alpha-OHase-deficient (-/-) mice and normal (+/-) heterozygous littermates re ceived 1,24(OH)2D2 (100, 300, 1000, and 3000 pg/g/day) or 1,25(OH)2D3 (30, 300, and 500 pg/g/day) for 5 weeks via daily sc injection. Control groups received vehicle. RESULTS Vehicle-treated 1alpha-OHase-deficient mice were hypocalcemic and had greatly elevated serum PTH. 1,24(OH)2D2 at doses above 300 pg/g/day normalized serum calcium, serum PTH, bone growth plate morphology, and other bone parameters. No hy percalcemia was observed at any dose of 1,24(OH)2D2 in normal or 1alpha-OHase-deficient animals. In contrast, 1,25(OH)2D3 at only 30 pg/g/day normalized calcemia, serum PTH, and bone parameters, but at higher doses completely suppressed PTH and caused hypercalcemia in both 1alpha-OHase-deficient and normal mice. Treatment with 500 pg/g/day of 1,25(OH)2D3 also induced osteomalacia in normal animals. CONCLUSION 1,25(OH)2D3 was maximally active at 10-fold lower doses than 1,24(OH)2D2, but induced hypercalcemia and osteomalacia at high doses. 1,24(OH)2D2 normalized serum calcium, serum PTH, and bone histomorphometry without hypercalcemia in 1alpha-OHase-deficient mice with SHPT.
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Affiliation(s)
- R St-Arnaud
- Genetics Unit, Shriners Hospital for Children, Montreal, Quebec, Canada.
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Abstract
The basic domain-leucine zipper protein, activating transcription factor 4 (ATF4), was recently shown to control key aspects of osteoblast biology. ATF4 regulates the timely onset of osteoblast differentiation, the synthesis of type I collagen, and the transcription of the osteocalcin and RANKL (receptor activator of NFkappa-B ligand) genes. Accordingly, the levels and activity of ATF4 are under tight control through mechanisms that include protein stability and phosphorylation. We have uncovered yet another mode of inhibition of ATF4 through its interaction with the leucine zipper protein FIAT (Factor Inhibiting ATF4-mediated Transcription, also described as gamma-taxilin). FIAT/gamma-taxilin localizes to the nucleus in osteoblasts and dimerizes with ATF4 to form inactive dimers, because it does not contain a DNA-binding basic domain moiety. The interaction of FIAT/gamma-taxilin with ATF4 thus inhibits ATF4-mediated transcription. Transgenic mice overexpressing FIAT/gamma-taxilin show osteopenia and reduced expression of the ATF4 target gene, osteocalcin. Interestingly, FIAT/gamma-taxilin also interacts with the transcriptional co-activator alphaNAC (Nascent polypeptide associated complex And Coactivator alpha), suggesting alternative, non-mutually exclusive mechanisms contributing to the inhibition of ATF4-dependent osteocalcin gene transcription by FIAT/gamma-taxilin.
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Affiliation(s)
- Vionnie W C Yu
- Genetics Unit, Shriners Hospital for Children, 1529 Cedar Avenue, Montreal (Quebec), Canada H3G 1A6
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Yu VWC, Ambartsoumian G, Verlinden L, Moir JM, Prud'homme J, Gauthier C, Roughley PJ, St-Arnaud R. FIAT represses ATF4-mediated transcription to regulate bone mass in transgenic mice. ACTA ACUST UNITED AC 2005; 169:591-601. [PMID: 15911876 PMCID: PMC2171686 DOI: 10.1083/jcb.200412139] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We report the characterization of factor inhibiting activating transcription factor 4 (ATF4)–mediated transcription (FIAT), a leucine zipper nuclear protein. FIAT interacted with ATF4 to inhibit binding of ATF4 to DNA and block ATF4-mediated transcription of the osteocalcin gene in vitro. Transgenic mice overexpressing FIAT in osteoblasts also had reduced osteocalcin gene expression and decreased bone mineral density, bone volume, mineralized volume, trabecular thickness, trabecular number, and decreased rigidity of long bones. Mineral homeostasis, osteoclast number and activity, and osteoblast proliferation and apoptosis were unchanged in transgenics. Expression of osteoblastic differentiation markers was largely unaffected and type I collagen synthesis was unchanged. Mineral apposition rate was reduced in transgenic mice, suggesting that the lowered bone mass was due to a decline in osteoblast activity. This cell-autonomous decrease in osteoblast activity was confirmed by measuring reduced alkaline phosphatase activity and mineralization in primary osteoblast cultures. These results show that FIAT regulates bone mass accrual and establish FIAT as a novel transcriptional regulator of osteoblastic function.
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Affiliation(s)
- Vionnie W C Yu
- Genetics Unit, Shriners Hospital for Children, Montreal, Quebec, Canada H3G 1A6
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