101
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Ebina W, Rossi DJ. Transcription factor-mediated reprogramming toward hematopoietic stem cells. EMBO J 2015; 34:694-709. [PMID: 25712209 DOI: 10.15252/embj.201490804] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
De novo generation of human hematopoietic stem cells (HSCs) from renewable cell types has been a long sought-after but elusive goal in regenerative medicine. Paralleling efforts to guide pluripotent stem cell differentiation by manipulating developmental cues, substantial progress has been made recently toward HSC generation via combinatorial transcription factor (TF)-mediated fate conversion, a paradigm established by Yamanaka's induction of pluripotency in somatic cells by mere four TFs. This review will integrate the recently reported strategies to directly convert a variety of starting cell types toward HSCs in the context of hematopoietic transcriptional regulation and discuss how these findings could be further developed toward the ultimate generation of therapeutic human HSCs.
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Affiliation(s)
- Wataru Ebina
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA
| | - Derrick J Rossi
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA Department of Pediatrics, Harvard Medical School, Boston, MA, USA Harvard Stem Cell Institute, Cambridge, MA, USA
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102
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Akada H, Akada S, Hutchison RE, Sakamoto K, Wagner KU, Mohi G. Critical role of Jak2 in the maintenance and function of adult hematopoietic stem cells. Stem Cells 2015; 32:1878-89. [PMID: 24677703 DOI: 10.1002/stem.1711] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 03/06/2014] [Accepted: 03/12/2014] [Indexed: 01/01/2023]
Abstract
Jak2, a member of the Janus kinase family of nonreceptor protein tyrosine kinases, is activated in response to a variety of cytokines, and functions in survival and proliferation of cells. An activating JAK2V617F mutation has been found in most patients with myeloproliferative neoplasms, and patients treated with Jak2 inhibitors show significant hematopoietic toxicities. However, the role of Jak2 in adult hematopoietic stem cells (HSCs) has not been clearly elucidated. Using a conditional Jak2 knockout allele, we have found that Jak2 deletion results in rapid loss of HSCs/progenitors leading to bone marrow failure and early lethality in adult mice. Jak2 deficiency causes marked impairment in HSC function, and the mutant HSCs are severely defective in reconstituting hematopoiesis in recipient animals. Jak2 deficiency also causes significant apoptosis and loss of quiescence in HSC-enriched LSK (Lin(-)Sca-1(+)c-Kit(+)) cells. Jak2-deficient LSK cells exhibit elevated reactive oxygen species levels and enhanced p38 MAPK activation. Mutant LSK cells also show defective Stat5, Erk, and Akt activation in response to thrombopoietin and stem cell factor. Gene expression analysis reveals significant downregulation of genes related to HSC quiescence and self-renewal in Jak2-deficient LSK cells. These data suggest that Jak2 plays a critical role in the maintenance and function of adult HSCs.
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Affiliation(s)
- Hajime Akada
- Department of Pharmacology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA
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103
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Nakamura-Ishizu A, Takizawa H, Suda T. The analysis, roles and regulation of quiescence in hematopoietic stem cells. Development 2015; 141:4656-66. [PMID: 25468935 DOI: 10.1242/dev.106575] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tissue homeostasis requires the presence of multipotent adult stem cells that are capable of efficient self-renewal and differentiation; some of these have been shown to exist in a dormant, or quiescent, cell cycle state. Such quiescence has been proposed as a fundamental property of hematopoietic stem cells (HSCs) in the adult bone marrow, acting to protect HSCs from functional exhaustion and cellular insults to enable lifelong hematopoietic cell production. Recent studies have demonstrated that HSC quiescence is regulated by a complex network of cell-intrinsic and -extrinsic factors. In addition, detailed single-cell analyses and novel imaging techniques have identified functional heterogeneity within quiescent HSC populations and have begun to delineate the topological organization of quiescent HSCs. Here, we review the current methods available to measure quiescence in HSCs and discuss the roles of HSC quiescence and the various mechanisms by which HSC quiescence is maintained.
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Affiliation(s)
- Ayako Nakamura-Ishizu
- Department of Cell Differentiation, The Sakaguchi Laboratory, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan Cancer Science Institute, National University of Singapore, 14 Medical Drive MD6, Centre for Translational Medicine, 117599 Singapore
| | - Hitoshi Takizawa
- Division of Hematology, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland
| | - Toshio Suda
- Department of Cell Differentiation, The Sakaguchi Laboratory, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan Cancer Science Institute, National University of Singapore, 14 Medical Drive MD6, Centre for Translational Medicine, 117599 Singapore
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104
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Dong CY, Liu XY, Wang N, Wang LN, Yang BX, Ren Q, Liang HY, Ma XT. Twist-1, A Novel Regulator of Hematopoietic Stem Cell Self-Renewal and Myeloid Lineage Development. Stem Cells 2014; 32:3173-82. [PMID: 25100001 DOI: 10.1002/stem.1803] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 07/15/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Cheng-Ya Dong
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Xiao-Yan Liu
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Nan Wang
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Li-Na Wang
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Bin-Xia Yang
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Qian Ren
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Hao-Yue Liang
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
| | - Xiao-Tong Ma
- State Key Laboratory of Experimental Hematology; Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College; Tianjin People's Republic of China
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105
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Li W, Huang K, Guo H, Cui G, Zhao S. Inhibition of non-small-cell lung cancer cell proliferation by Pbx1. Chin J Cancer Res 2014; 26:573-8. [PMID: 25400423 DOI: 10.3978/j.issn.1000-9604.2014.08.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 08/15/2014] [Indexed: 11/14/2022] Open
Abstract
Lung cancer is one of the most deadly human cancers and continues to be a major unsolved health problem worldwide. Here, we evaluate the function of Pbx1 in the proliferation of non-small-cell lung cancer (NSCLC). In contrast with its known proliferative function, we found that Pbx1 inhibits the proliferation of lung cancer cells. In particular, Pbx1-specific RNA interference resulted in increased proliferation in lung cancer cells. In addition, histone H3 phosphorylation was also increased following inhibition of Pbx1 expression. In contrast, Pbx1 overexpression repressed the proliferation of lung cancer cells and inhibited DNA synthesis. Collectively, our data indicate that Pbx1 inhibits proliferation in lung cancer cells, suggesting a complex role for Pbx1 in modulating the proliferation of cancer cells and making this protein a potential new target for lung cancer therapy.
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Affiliation(s)
- Weihao Li
- 1 Department of Thoracic Surgery, 2 Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Kai Huang
- 1 Department of Thoracic Surgery, 2 Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Haizhou Guo
- 1 Department of Thoracic Surgery, 2 Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Guanghui Cui
- 1 Department of Thoracic Surgery, 2 Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Song Zhao
- 1 Department of Thoracic Surgery, 2 Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
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106
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Willer A, Jakobsen JS, Ohlsson E, Rapin N, Waage J, Billing M, Bullinger L, Karlsson S, Porse BT. TGIF1 is a negative regulator of MLL-rearranged acute myeloid leukemia. Leukemia 2014; 29:1018-31. [PMID: 25349154 DOI: 10.1038/leu.2014.307] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 10/01/2014] [Accepted: 10/16/2014] [Indexed: 11/09/2022]
Abstract
Members of the TALE (three-amino-acid loop extension) family of atypical homeodomain-containing transcription factors are important downstream effectors of oncogenic fusion proteins involving the mixed lineage leukemia (MLL) gene. A well-characterized member of this protein family is MEIS1, which orchestrates a transcriptional program required for the maintenance of MLL-rearranged acute myeloid leukemia (AML). TGIF1/TGIF2 are relatively uncharacterized TALE transcription factors, which, in contrast to the remaining family, have been shown to act as transcriptional repressors. Given the general importance of this family in malignant hematopoiesis, we therefore tested the potential function of TGIF1 in the maintenance of MLL-rearranged AML. Gene expression analysis of MLL-rearranged patient blasts demonstrated reduced TGIF1 levels, and, in accordance, we find that forced expression of TGIF1 in MLL-AF9-transformed cells promoted differentiation and cell cycle exit in vitro, and delayed leukemic onset in vivo. Mechanistically, we show that TGIF1 interferes with a MEIS1-dependent transcriptional program by associating with MEIS1-bound regions in a competitive manner and that the MEIS1:TGIF1 ratio influence the clinical outcome. Collectively, these findings demonstrate that TALE family members can act both positively and negatively on transcriptional programs responsible for leukemic maintenance and provide novel insights into the regulatory gene expression circuitries in MLL-rearranged AML.
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Affiliation(s)
- A Willer
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - J S Jakobsen
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - E Ohlsson
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - N Rapin
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [4] The Bioinformatic Centre, Department of Biology, Faculty of Natural Sciences, University of Copenhagen, Copenhagen, Denmark
| | - J Waage
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [4] The Bioinformatic Centre, Department of Biology, Faculty of Natural Sciences, University of Copenhagen, Copenhagen, Denmark
| | - M Billing
- Molecular Medicine and Gene Therapy, Lund Stem Cell Centre, Lund, Sweden
| | - L Bullinger
- Department of Internal Medicine III, University Hospital of Ulm, Ulm, Germany
| | - S Karlsson
- Molecular Medicine and Gene Therapy, Lund Stem Cell Centre, Lund, Sweden
| | - B T Porse
- 1] The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark [2] Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark [3] Danish Stem Cell Centre (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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107
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Modica L, Iotti G, D’Avola A, Blasi F. Prep1 (pKnox1) regulates mouse embryonic HSC cycling and self-renewal affecting the Stat1-Sca1 IFN-dependent pathway. PLoS One 2014; 9:e107916. [PMID: 25233378 PMCID: PMC4169458 DOI: 10.1371/journal.pone.0107916] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/25/2014] [Indexed: 01/27/2023] Open
Abstract
A hypomorphic Prep1 mutation results in embryonic lethality at late gestation with a pleiotropic embryonic phenotype that includes defects in all hematopoietic lineages. Reduced functionality of the hematopoietic stem cells (HSCs) compartment might be responsible for the hematopoietic phenotype observed at mid-gestation. In this paper we demonstrate that Prep1 regulates the number of HSCs in fetal livers (FLs), their clonogenic potential and their ability to de novo generate the hematopoietic system in ablated hosts. Furthermore, we show that Prep1 controls the self-renewal ability of the FL HSC compartment as demonstrated by serial transplantation experiments. The premature exhaustion of Prep1 mutant HSCs correlates with the reduced quiescent stem cell pool thus suggesting that Prep1 regulates the self-renewal ability by controlling the quiescence/proliferation balance. Finally, we show that in FL HSCs Prep1 absence induces the interferon signaling pathway leading to premature cycling and exhaustion of fetal HSCs.
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Affiliation(s)
- Livia Modica
- Istituto FIRC di Oncologia Molecolare (IFOM), Milan, Italy
| | - Giorgio Iotti
- Istituto FIRC di Oncologia Molecolare (IFOM), Milan, Italy
| | | | - Francesco Blasi
- Istituto FIRC di Oncologia Molecolare (IFOM), Milan, Italy
- * E-mail:
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108
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Risolino M, Mandia N, Iavarone F, Dardaei L, Longobardi E, Fernandez S, Talotta F, Bianchi F, Pisati F, Spaggiari L, Harter PN, Mittelbronn M, Schulte D, Incoronato M, Di Fiore PP, Blasi F, Verde P. Transcription factor PREP1 induces EMT and metastasis by controlling the TGF-β-SMAD3 pathway in non-small cell lung adenocarcinoma. Proc Natl Acad Sci U S A 2014; 111:E3775-84. [PMID: 25157139 PMCID: PMC4246949 DOI: 10.1073/pnas.1407074111] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pre-B-cell leukemia homeobox (Pbx)-regulating protein-1 (Prep1) is a ubiquitous homeoprotein involved in early development, genomic stability, insulin sensitivity, and hematopoiesis. Previously we have shown that Prep1 is a haploinsufficient tumor suppressor that inhibits neoplastic transformation by competing with myeloid ecotropic integration site 1 for binding to the common heterodimeric partner Pbx1. Epithelial-mesenchymal transition (EMT) is controlled by complex networks of proinvasive transcription factors responsive to paracrine factors such as TGF-β. Here we show that, in addition to inhibiting primary tumor growth, PREP1 is a novel EMT inducer and prometastatic transcription factor. In human non-small cell lung cancer (NSCLC) cells, PREP1 overexpression is sufficient to trigger EMT, whereas PREP1 down-regulation inhibits the induction of EMT in response to TGF-β. PREP1 modulates the cellular sensitivity to TGF-β by inducing the small mothers against decapentaplegic homolog 3 (SMAD3) nuclear translocation through mechanisms dependent, at least in part, on PREP1-mediated transactivation of a regulatory element in the SMAD3 first intron. Along with the stabilization and accumulation of PBX1, PREP1 induces the expression of multiple activator protein 1 components including the proinvasive Fos-related antigen 1 (FRA-1) oncoprotein. Both FRA-1 and PBX1 are required for the mesenchymal changes triggered by PREP1 in lung tumor cells. Finally, we show that the PREP1-induced mesenchymal transformation correlates with significantly increased lung colonization by cells overexpressing PREP1. Accordingly, we have detected PREP1 accumulation in a large number of human brain metastases of various solid tumors, including NSCLC. These findings point to a novel role of the PREP1 homeoprotein in the control of the TGF-β pathway, EMT, and metastasis in NSCLC.
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Affiliation(s)
- Maurizio Risolino
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy
| | - Nadia Mandia
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy; Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy
| | - Francescopaolo Iavarone
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy
| | - Leila Dardaei
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy
| | - Elena Longobardi
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy
| | - Serena Fernandez
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy
| | - Francesco Talotta
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy
| | - Fabrizio Bianchi
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy; Department of Medicine, Surgery, and Dentistry, University of Milan, 20122 Milan, Italy
| | - Federica Pisati
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy
| | - Lorenzo Spaggiari
- Department of Medicine, Surgery, and Dentistry, University of Milan, 20122 Milan, Italy
| | - Patrick N Harter
- Neuroscience Center, Neurological Institute (Edinger Institut), 60528 Frankfurt, Germany; and
| | - Michel Mittelbronn
- Neuroscience Center, Neurological Institute (Edinger Institut), 60528 Frankfurt, Germany; and
| | - Dorothea Schulte
- Neuroscience Center, Neurological Institute (Edinger Institut), 60528 Frankfurt, Germany; and
| | | | - Pier Paolo Di Fiore
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy; Department of Medicine, Surgery, and Dentistry, University of Milan, 20122 Milan, Italy
| | - Francesco Blasi
- Institute of Molecular Oncology (IFOM) of the Italian Foundation for Cancer Research (FIRC), 20139 Milan, Italy;
| | - Pasquale Verde
- Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy; Istituto di Ricovero e Cura a Carattere Scientifico SDN (IRCCS SDN), 80142 Naples, Italy
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109
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Riddell J, Gazit R, Garrison BS, Guo G, Saadatpour A, Mandal PK, Ebina W, Volchkov P, Yuan GC, Orkin SH, Rossi DJ. Reprogramming committed murine blood cells to induced hematopoietic stem cells with defined factors. Cell 2014; 157:549-64. [PMID: 24766805 DOI: 10.1016/j.cell.2014.04.006] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/13/2014] [Accepted: 04/03/2014] [Indexed: 01/17/2023]
Abstract
Hematopoietic stem cells (HSCs) sustain blood formation throughout life and are the functional units of bone marrow transplantation. We show that transient expression of six transcription factors Run1t1, Hlf, Lmo2, Prdm5, Pbx1, and Zfp37 imparts multilineage transplantation potential onto otherwise committed lymphoid and myeloid progenitors and myeloid effector cells. Inclusion of Mycn and Meis1 and use of polycistronic viruses increase reprogramming efficacy. The reprogrammed cells, designated induced-HSCs (iHSCs), possess clonal multilineage differentiation potential, reconstitute stem/progenitor compartments, and are serially transplantable. Single-cell analysis revealed that iHSCs derived under optimal conditions exhibit a gene expression profile that is highly similar to endogenous HSCs. These findings demonstrate that expression of a set of defined factors is sufficient to activate the gene networks governing HSC functional identity in committed blood cells. Our results raise the prospect that blood cell reprogramming may be a strategy for derivation of transplantable stem cells for clinical application.
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Affiliation(s)
- Jonah Riddell
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Roi Gazit
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Brian S Garrison
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Guoji Guo
- Dana Farber/Boston Children's Hospital Cancer and Blood Disorders Center, Boston, MA 02116, USA
| | - Assieh Saadatpour
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA
| | - Pankaj K Mandal
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Wataru Ebina
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Pavel Volchkov
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA
| | - Guo-Cheng Yuan
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA
| | - Stuart H Orkin
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Dana Farber/Boston Children's Hospital Cancer and Blood Disorders Center, Boston, MA 02116, USA; Howard Hughes Medical Institute; Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Derrick J Rossi
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA.
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110
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Survivin modulates genes with divergent molecular functions and regulates proliferation of hematopoietic stem cells through Evi-1. Leukemia 2014; 29:433-40. [PMID: 24903482 PMCID: PMC4258188 DOI: 10.1038/leu.2014.183] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/13/2014] [Accepted: 05/30/2014] [Indexed: 12/19/2022]
Abstract
The inhibitor of apoptosis protein Survivin regulates hematopoiesis, although its mechanisms of regulation of hematopoietic stem cells (HSCs) remain largely unknown. While investigating conditional Survivin deletion in mice, we found that Survivin was highly expressed in phenotypically defined HSCs and Survivin deletion in mice resulted in significantly reduced total marrow HSC and progenitor cells (HPC). Transcriptional analysis of Survivin−/− HSCs revealed altered expression of multiple genes not previously linked to Survivin activity. In particular, Survivin deletion significantly reduced expression of the Evi-1 transcription factor indispensable for HSC function, and the downstream Evi-1 target genes Gata2, Pbx1 and Sall2. The loss of HSCs following Survivin deletion and impaired long-term HSC repopulating function could be partially rescued by ectopic Evi-1 expression in Survivin −/− HSCs. These data demonstrate that Survivin partially regulates HSC function by modulating the Evi-1transcription factor and its downstream targets and identify new genetic pathways in HSCs regulated by Survivin.
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111
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The deficiency of tumor suppressor prep1 accelerates the onset of meis1- hoxa9 leukemogenesis. PLoS One 2014; 9:e96711. [PMID: 24809472 PMCID: PMC4014505 DOI: 10.1371/journal.pone.0096711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/11/2014] [Indexed: 11/29/2022] Open
Abstract
Prep1 and Meis1 ortholog TALE transcription factors have opposing roles in tumorigenesis: Meis1 serves as an oncogene, Prep1 as a tumor suppressor. We now report that, Meis1 overexpression in primary Prep1-deficient (Prep1i/i) embryonic hematopoietic cells increases self-renewal potential of cells in vitro but not in vivo, whereas leukemia is instead obtained when Meis1 is combined with another oncogene, HoxA9. Prep1i/i Meis1-HoxA9-generated leukemic cells are less differentiated and grow more aggressively after the second passage in the mouse. These data indicate that Prep1 represents a barrier to the transforming activity of Meis1 in vitro, but its absence is not sufficient to induce early leukemogenesis. On the other hand, the Prep1i/i background appears to favor the insurgence of mutations that cause a more aggressive Meis1-HoxA9-generated leukemia. Indeed, the Prep1i/i leukemic cells upregulate the Polycomb protein Bmi-1 and expectedly down-regulate the Ink4a/Arf locus products. Finally, an important feature contributed by the Prep1i/i background is the post-transcriptional increase in Meis1 protein level.
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112
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Park SJ, Umemoto T, Saito-Adachi M, Shiratsuchi Y, Yamato M, Nakai K. Computational promoter modeling identifies the modes of transcriptional regulation in hematopoietic stem cells. PLoS One 2014; 9:e93853. [PMID: 24710559 PMCID: PMC3977923 DOI: 10.1371/journal.pone.0093853] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/07/2014] [Indexed: 01/19/2023] Open
Abstract
Extrinsic and intrinsic regulators are responsible for the tight control of hematopoietic stem cells (HSCs), which differentiate into all blood cell lineages. To understand the fundamental basis of HSC biology, we focused on differentially expressed genes (DEGs) in long-term and short-term HSCs, which are closely related in terms of cell development but substantially differ in their stem cell capacity. To analyze the transcriptional regulation of the DEGs identified in the novel transcriptome profiles obtained by our RNA-seq analysis, we developed a computational method to model the linear relationship between gene expression and the features of putative regulatory elements. The transcriptional regulation modes characterized here suggest the importance of transcription factors (TFs) that are expressed at steady state or at low levels. Remarkably, we found that 24 differentially expressed TFs targeting 21 putative TF-binding sites contributed significantly to transcriptional regulation. These TFs tended to be modulated by other nondifferentially expressed TFs, suggesting that HSCs can achieve flexible and rapid responses via the control of nondifferentially expressed TFs through a highly complex regulatory network. Our novel transcriptome profiles and new method are powerful tools for studying the mechanistic basis of cell fate decisions.
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Affiliation(s)
- Sung-Joon Park
- Human Genome Center, the Institute of Medical Science, the University of Tokyo, Tokyo, Japan
| | - Terumasa Umemoto
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan
| | - Mihoko Saito-Adachi
- Human Genome Center, the Institute of Medical Science, the University of Tokyo, Tokyo, Japan
| | - Yoshiko Shiratsuchi
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan
| | - Masayuki Yamato
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan
| | - Kenta Nakai
- Human Genome Center, the Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- * E-mail:
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113
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Abstract
The corepressor Rcor1 has been linked biochemically to hematopoiesis, but its function in vivo remains unknown. We show that mice deleted for Rcor1 are profoundly anemic and die in late gestation. Definitive erythroid cells from mutant mice arrest at the transition from proerythroblast to basophilic erythroblast. Remarkably, Rcor1 null erythroid progenitors cultured in vitro form myeloid colonies instead of erythroid colonies. The mutant proerythroblasts also aberrantly express genes of the myeloid lineage as well as genes typical of hematopoietic stem cells (HSCs) and/or progenitor cells. The colony-stimulating factor 2 receptor β subunit (Csf2rb), which codes for a receptor implicated in myeloid cytokine signaling, is a direct target for both Rcor1 and the transcription repressor Gfi1b in erythroid cells. In the absence of Rcor1, the Csf2rb gene is highly induced, and Rcor1(-/-) progenitors exhibit CSF2-dependent phospho-Stat5 hypersensitivity. Blocking this pathway can partially reduce myeloid colony formation by Rcor1-deficient erythroid progenitors. Thus, Rcor1 promotes erythropoiesis by repressing HSC and/or progenitor genes, as well as the genes and signaling pathways that lead to myeloid cell fate.
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114
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Ariki R, Morikawa S, Mabuchi Y, Suzuki S, Nakatake M, Yoshioka K, Hidano S, Nakauchi H, Matsuzaki Y, Nakamura T, Goitsuka R. Homeodomain transcription factor Meis1 is a critical regulator of adult bone marrow hematopoiesis. PLoS One 2014; 9:e87646. [PMID: 24498346 PMCID: PMC3911998 DOI: 10.1371/journal.pone.0087646] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/26/2013] [Indexed: 12/02/2022] Open
Abstract
Hematopoietic stem cells in the bone marrow have the capacity to both self-renew and to generate all cells of the hematopoietic system. The balance of these two activities is controlled by hematopoietic stem cell-intrinsic regulatory mechanisms as well as extrinsic signals from the microenvironment. Here we demonstrate that Meis1, a TALE family homeodomain transcription factor involved in numerous embryonic developmental processes, is selectively expressed in hematopoietic stem/progenitor cells. Conditional Meis1 knockout in adult hematopoietic cells resulted in a significant reduction in the hematopoietic stem/progenitor cells. Suppression of hematopoiesis by Meis1 deletion appears to be caused by impaired self-renewal activity and reduced cellular quiescence of hematopoietic stem/progenitor cells in a cell autonomous manner, resulting in stem cell exhaustion and defective long-term hematopoiesis. Meis1 deficiency down-regulated a subset of Pbx1-dependent hematopoietic stem cell signature genes, suggesting a functional link between them in the maintenance of hematopoietic stem/progenitor cells. These results show the importance of Meis1 in adult hematopoiesis.
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Affiliation(s)
- Reina Ariki
- Division of Development and Aging, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Satoru Morikawa
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Yo Mabuchi
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Sadafumi Suzuki
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Mayuka Nakatake
- Division of Carcinogenesis, The Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
| | - Kentaro Yoshioka
- Division of Development and Aging, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Shinya Hidano
- Division of Development and Aging, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Hiromitsu Nakauchi
- Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Yumi Matsuzaki
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Takuro Nakamura
- Division of Carcinogenesis, The Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan
- * E-mail: (TN); (RG)
| | - Ryo Goitsuka
- Division of Development and Aging, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
- * E-mail: (TN); (RG)
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115
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Mortalin and DJ-1 coordinately regulate hematopoietic stem cell function through the control of oxidative stress. Blood 2014; 123:41-50. [DOI: 10.1182/blood-2013-06-508333] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Key Points
Mitochondrial heat shock protein, mortalin, is essential for the maintenance of HSCs via the control of oxidative stress. Mortalin directly interact with DJ-1 to regulate ROS levels in the mitochondria of HSCs.
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116
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Abstract
TG-interacting factor 1 (TGIF1) is a transcriptional repressor that can modulate retinoic acid and transforming growth factor β signaling pathways. It is required for myeloid progenitor cell differentiation and survival, and mutations in the TGIF1 gene cause holoprosencephaly. Furthermore, we have previously observed that acute myelogenous leukemia (AML) patients with low TGIF1 levels had worse prognoses. Here, we explored the role of Tgif1 in murine hematopoietic stem cell (HSC) function. CFU assays showed that Tgif1(-/-) bone marrow cells produced more total colonies and had higher serial CFU potential. These effects were also observed in vivo, where Tgif1(-/-) bone marrow cells had higher repopulation potential in short- and long-term competitive repopulation assays than wild-type cells. Serial transplantation and replating studies showed that Tgif1(-/-) HSCs exhibited greater self-renewal and were less proliferative and more quiescent than wild-type cells, suggesting that Tgif1 is required for stem cells to enter the cell cycle. Furthermore, HSCs from Tgif1(+/-) mice had a phenotype similar to that of HSCs from Tgif1(-/-) mice, while bone marrow cells with overexpressing Tgif1 showed increased proliferation and lower survival in long-term transplant studies. Taken together, our data suggest that Tgif1 suppresses stem cell self-renewal and provide clues as to how reduced expression of TGIF1 may contribute to poor long-term survival in patients with AML.
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117
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Xu Y, Li W, Liu X, Ma H, Tu Z, Dai Y. Analysis of microRNA expression profile by small RNA sequencing in Down syndrome fetuses. Int J Mol Med 2013; 32:1115-25. [PMID: 24071828 DOI: 10.3892/ijmm.2013.1499] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/22/2013] [Indexed: 11/06/2022] Open
Abstract
Down syndrome (DS) is caused by trisomy of human chromosome 21 (Hsa21) and is associated with numerous deleterious phenotypes, including cognitive impairment, childhood leukemia and immune defects. Five Hsa21‑derived microRNAs (i.e., hsa-miR-99a, let-7c, miR-125b-2, miR-155 and miR-802) are involved in variable phenotypes of DS. However, the changes involved in the genome-wide microRNA expression of DS fetuses under the influence of trisomy 21 have yet to be determined. To investigate the expression characteristic of microRNAs during the development of DS fetuses and identify whether another microRNA gene resides in the Hsa21, Illumina high-throughput sequencing technology was employed to comprehensively characterize the microRNA expression profiles of the DS and normal fetal cord blood mononuclear cells (CBMCs). In total, 149 of 395 identified microRNAs were significantly differentially expressed (fold change >2.0 and P<0.001) and 2 of 181 candidate novel microRNAs were identified as residing within the ̔DS critical region̓ of human chromosome 21 (chr21q22.2‑22.3). Additionally, 7 of 14 Hsa21-derived microRNAs were detected, although not all seven were overexpressed in DS CBMCs compared with the control. Gene ontology enrichment analyses revealed that a set of abnormally expressed microRNAs were involved in the regulation of transcription, gene expression, cellular biosynthetic process and nucleic acid metabolic process. Significantly, most of the mRNA targets in these categories were associated with immune modulation (i.e., SOD1, MXD4, PBX1, BCLAF1 and FOXO1). Findings of the present study provided a considerable insight into understanding the expression characteristic of microRNAs in the DS fetal CBMCs. To the best of our knowledge, this is the first study to examine genome-wide microRNA expression profiles in the DS fetus. Differentially expressed microRNAs may be involved in hemopoietic abnormalities and the immune defects of DS fetuses and newborns.
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Affiliation(s)
- Yong Xu
- Clinical Medical Research Center, Pingshan People's Hospital, Shenzhen, Guangdong 518118, P.R. China
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118
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Transcriptional regulation of haematopoietic stem cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 786:187-212. [PMID: 23696358 DOI: 10.1007/978-94-007-6621-1_11] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Haematopoietic stem cells (HSCs) are a rare cell population found in the bone marrow of adult mammals and are responsible for maintaining the entire haematopoietic system. Definitive HSCs are produced from mesoderm during embryonic development, from embryonic day 10 in the mouse. HSCs seed the foetal liver before migrating to the bone marrow around the time of birth. In the adult, HSCs are largely quiescent but have the ability to divide to self-renew and expand, or to proliferate and differentiate into any mature haematopoietic cell type. Both the specification of HSCs during development and their cellular choices once formed are tightly controlled at the level of transcription. Numerous transcriptional regulators of HSC specification, expansion, homeostasis and differentiation have been identified, primarily from analysis of mouse gene knockout experiments and transplantation assays. These include transcription factors, epigenetic modifiers and signalling pathway effectors. This chapter reviews the current knowledge of these HSC transcriptional regulators, predominantly focusing on the transcriptional regulation of mouse HSCs, although transcriptional regulation of human HSCs is also mentioned where relevant. Due to the breadth and maturity of this field, we have prioritised recently identified examples of HSC transcriptional regulators. We go on to highlight additional layers of control that regulate expression and activity of HSC transcriptional regulators and discuss how chromosomal translocations that result in fusion proteins of these HSC transcriptional regulators commonly drive leukaemias through transcriptional dysregulation.
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119
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Yokoyama A, Ficara F, Murphy MJ, Meisel C, Hatanaka C, Kitabayashi I, Cleary ML. MLL becomes functional through intra-molecular interaction not by proteolytic processing. PLoS One 2013; 8:e73649. [PMID: 24040009 PMCID: PMC3769346 DOI: 10.1371/journal.pone.0073649] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/21/2013] [Indexed: 01/15/2023] Open
Abstract
The mixed lineage leukemia (MLL) protein is an epigenetic transcriptional regulator that controls proliferative expansion of immature hematopoietic progenitors, whose aberrant activation triggers leukemogenesis. A mature MLL protein is produced by formation of an intra-molecular complex and proteolytic cleavage. However the biological significance of these two post-transcriptional events remains unclear. To address their in vivo roles, mouse mutant alleles were created that exclusively express either a variant protein incapable of intra-molecular interaction (designated de) or an uncleavable mutant protein (designated uc). The de homozygous mice died during midgestation and manifested devastating failure in embryonic development and reduced numbers of hematopoietic progenitors, whereas uc homozygous mice displayed no apparent defects. Expression of MLL target genes was severely impaired in de homozygous fibroblasts but unaffected in uc homozygous fibroblasts. These results unequivocally demonstrate that intra-molecular complex formation is a crucial maturation step whereas proteolytic cleavage is dispensable for MLL-dependent gene activation and proliferation in vivo.
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Affiliation(s)
- Akihiko Yokoyama
- Laboratory for Malignancy Control Research, Kyoto University Graduate School of Medicine, Kyoto, Japan
- * E-mail: (AY); (MLC)
| | - Francesca Ficara
- Milan Unit, Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Milan, Italy
- Humanitas Clinical and Research Center, Rozzano, Italy
| | - Mark J. Murphy
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Christian Meisel
- Depertment of Neurology, University Clinic Carl Gustav Craus, Dresden, Germany
| | - Chikako Hatanaka
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan
| | - Issay Kitabayashi
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo, Japan
| | - Michael L. Cleary
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail: (AY); (MLC)
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120
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Yamada T, Park CS, Lacorazza HD. Genetic control of quiescence in hematopoietic stem cells. Cell Cycle 2013; 12:2376-83. [PMID: 23839041 PMCID: PMC3841317 DOI: 10.4161/cc.25416] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 01/08/2023] Open
Abstract
Cellular quiescence is a reversible cell cycle arrest that is poised to re-enter the cell cycle in response to a combination of cell-intrinsic factors and environmental cues. In hematopoietic stem cells, a coordinated balance between quiescence and differentiating proliferation ensures longevity and prevents both genetic damage and stem cell exhaustion. However, little is known about how all these processes are integrated at the molecular level. We will briefly review the environmental and intrinsic control of stem cell quiescence and discuss a new model that involves a protein-to-protein interaction between G0S2 and the phospho-nucleoprotein nucleolin in the cytosol.
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Affiliation(s)
- Takeshi Yamada
- Department of Pathology & Immunology; Baylor College of Medicine; Texas Children’s Hospital; Houston, TX USA
| | - Chun Shik Park
- Department of Pathology & Immunology; Baylor College of Medicine; Texas Children’s Hospital; Houston, TX USA
| | - H Daniel Lacorazza
- Department of Pathology & Immunology; Baylor College of Medicine; Texas Children’s Hospital; Houston, TX USA
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121
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Delineating the mixed lineage leukemia gene expression network in hematopoietic stem cells. Proc Natl Acad Sci U S A 2013; 110:11670-1. [PMID: 23824294 DOI: 10.1073/pnas.1310349110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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122
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Abstract
The histone methyltransferase Mixed Lineage Leukemia (MLL) is essential to maintain hematopoietic stem cells and is a leukemia protooncogene. Although clustered homeobox genes are well-characterized targets of MLL and MLL fusion oncoproteins, the range of Mll-regulated genes in normal hematopoietic cells remains unknown. Here, we identify and characterize part of the Mll-dependent transcriptional network in hematopoietic stem cells with an integrated approach by using conditional loss-of-function models, genomewide expression analyses, chromatin immunoprecipitation, and functional rescue assays. The Mll-dependent transcriptional network extends well beyond the previously appreciated Hox targets, is comprised of many characterized regulators of self-renewal, and contains target genes that are both dependent and independent of the MLL cofactor, Menin. Interestingly, PR-domain containing 16 emerged as a target gene that is uniquely effective at partially rescuing Mll-deficient hematopoietic stem and progenitor cells. This work highlights the tissue-specific nature of regulatory networks under the control of MLL/Trithorax family members and provides insight into the distinctions between the participation of MLL in normal hematopoiesis and in leukemia.
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123
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Rossi L, Lin KK, Boles NC, Yang L, King KY, Jeong M, Mayle A, Goodell MA. Less is more: unveiling the functional core of hematopoietic stem cells through knockout mice. Cell Stem Cell 2013; 11:302-17. [PMID: 22958929 DOI: 10.1016/j.stem.2012.08.006] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hematopoietic stem cells (HSCs) represent one of the first recognized somatic stem cell types. As such, nearly 200 genes have been examined for roles in HSC function in knockout mice. In this review, we compile the majority of these reports to provide a broad overview of the functional modules revealed by these genetic analyses and highlight some key regulatory pathways involved, including cell cycle control, Tgf-β signaling, Pten/Akt signaling, Wnt signaling, and cytokine signaling. Finally, we propose recommendations for characterization of HSC function in knockout mice to facilitate cross-study comparisons that would generate a more cohesive picture of HSC biology.
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Affiliation(s)
- Lara Rossi
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
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124
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Picchi J, Trombi L, Spugnesi L, Barachini S, Maroni G, Brodano GB, Boriani S, Valtieri M, Petrini M, Magli MC. HOX and TALE signatures specify human stromal stem cell populations from different sources. J Cell Physiol 2013; 228:879-89. [PMID: 23018864 DOI: 10.1002/jcp.24239] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 09/24/2012] [Indexed: 12/30/2022]
Abstract
Human stromal stem cell populations reside in different tissues and anatomical sites, however a critical question related to their efficient use in regenerative medicine is whether they exhibit equivalent biological properties. Here, we compared cellular and molecular characteristics of stromal stem cells derived from the bone marrow, at different body sites (iliac crest, sternum, and vertebrae) and other tissues (dental pulp and colon). In particular, we investigated whether homeobox genes of the HOX and TALE subfamilies might provide suitable markers to identify distinct stromal cell populations, as HOX proteins control cell positional identity and, together with their co-factors TALE, are involved in orchestrating differentiation of adult tissues. Our results show that stromal populations from different sources, although immunophenotypically similar, display distinct HOX and TALE signatures, as well as different growth and differentiation abilities. Stromal stem cells from different tissues are characterized by specific HOX profiles, differing in the number and type of active genes, as well as in their level of expression. Conversely, bone marrow-derived cell populations can be essentially distinguished for the expression levels of specific HOX members, strongly suggesting that quantitative differences in HOX activity may be crucial. Taken together, our data indicate that the HOX and TALE profiles provide positional, embryological and hierarchical identity of human stromal stem cells. Furthermore, our data suggest that cell populations derived from different body sites may not represent equivalent cell sources for cell-based therapeutical strategies for regeneration and repair of specific tissues.
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Affiliation(s)
- Jacopo Picchi
- Institute of Biomedical Technologies, National Research Council, Pisa, Italy
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125
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Ficara F, Crisafulli L, Lin C, Iwasaki M, Smith KS, Zammataro L, Cleary ML. Pbx1 restrains myeloid maturation while preserving lymphoid potential in hematopoietic progenitors. J Cell Sci 2013; 126:3181-91. [PMID: 23660001 DOI: 10.1242/jcs.125435] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The capacity of the hematopoietic system to promptly respond to peripheral demands relies on adequate pools of progenitors able to transiently proliferate and differentiate in a regulated manner. However, little is known about factors that may restrain progenitor maturation to maintain their reservoirs. Conditional knockout mice for the Pbx1 proto-oncogene have a significant reduction in lineage-restricted progenitors in addition to a profound defect in hematopoietic stem cell (HSC) self-renewal. Through analysis of purified progenitor proliferation, differentiation capacity and transcriptional profiling, we demonstrate that Pbx1 regulates the lineage-specific output of multipotent and oligopotent progenitors. In the absence of Pbx1 multipotent progenitor (MPP) and common myeloid progenitor (CMP) pools are reduced due to aberrantly rapid myeloid maturation. This is associated with premature expression of myeloid differentiation genes and decreased maintenance of proto-oncogene transcriptional pathways, including reduced expression of Meis1, a Pbx1 dimerization partner, and its subordinate transcriptional program. Conversely, Pbx1 maintains the lymphoid differentiation potential of lymphoid-primed MPPs (LMPPs) and common lymphoid progenitors (CLPs), whose reduction in the absence of Pbx1 is associated with a defect in lymphoid priming that is also present in CMPs, which persistently express lymphoid and HSC genes underlying a previously unappreciated lineage promiscuity that is maintained by Pbx1. These results demonstrate a role for Pbx1 in restraining myeloid maturation while maintaining lymphoid potential to appropriately regulate progenitor reservoirs.
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Affiliation(s)
- Francesca Ficara
- Milan Unit, Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Milan, Italy
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126
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Abstract
Stem cells are a unique population that lies at the summit of any, or at least most, biological systems. They can differentiate in a variety of mature cell types, but they also have the ability to self-renew, that is, the capacity to divide and retain all the features of the mother cell. The regulation of self-renewal has been studied for many years, but several aspects of this regulation are still vague. The combined decision to divide and self-renew or differentiate suggests that the mechanisms that regulate self-renewal and cell cycle activity are intermingled. While inactivation of many cell cycle regulators impacts the physiological and pathological biology of stem cells, the exact mechanisms that link the decision to enter the cell cycle and the choice of the cellular fate are poorly understood. The multiplicity of signals and pathways regulating self-renewal add to the complexity of the phenomenon. Here, I will review the described links between the cell cycle and self-renewal and discuss the role of the niche in the regulation of both mechanisms.
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Affiliation(s)
- Patrick Viatour
- Center for Childhood Cancer Research, The Children's Hospital of Philadelphia, Philadelphia, PA, USA ; Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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127
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Ataxin1L is a regulator of HSC function highlighting the utility of cross-tissue comparisons for gene discovery. PLoS Genet 2013; 9:e1003359. [PMID: 23555280 PMCID: PMC3610904 DOI: 10.1371/journal.pgen.1003359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/18/2013] [Indexed: 11/26/2022] Open
Abstract
Hematopoietic stem cells (HSCs) are rare quiescent cells that continuously replenish the cellular components of the peripheral blood. Observing that the ataxia-associated gene Ataxin-1-like (Atxn1L) was highly expressed in HSCs, we examined its role in HSC function through in vitro and in vivo assays. Mice lacking Atxn1L had greater numbers of HSCs that regenerated the blood more quickly than their wild-type counterparts. Molecular analyses indicated Atxn1L null HSCs had gene expression changes that regulate a program consistent with their higher level of proliferation, suggesting that Atxn1L is a novel regulator of HSC quiescence. To determine if additional brain-associated genes were candidates for hematologic regulation, we examined genes encoding proteins from autism- and ataxia-associated protein–protein interaction networks for their representation in hematopoietic cell populations. The interactomes were found to be highly enriched for proteins encoded by genes specifically expressed in HSCs relative to their differentiated progeny. Our data suggest a heretofore unappreciated similarity between regulatory modules in the brain and HSCs, offering a new strategy for novel gene discovery in both systems. Our labs, working separately on brain function and blood stem cells, noticed that a particular gene involved in movement disorders was also expressed in the blood system. We discovered through bone marrow transplantation experiments that this gene, called Ataxin-1-like, normally plays a role in restricting the number of blood-forming stem cells; stem cells lacking this gene were more numerous and more active. We wondered if this brain-blood similarity would hold for a larger number of genes, so we used bioinformatics approaches to compare large datasets our labs had generated from each system. We found that a surprising number of genes implicated in autism and ataxia by molecular studies were also highly expressed in blood-forming stem cells. We suggest that such cross-system comparisons could be used more widely to discover genes with important functions in brain and blood, but also perhaps other systems.
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128
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Magnusson M, Sierra MI, Sasidharan R, Prashad SL, Romero M, Saarikoski P, Van Handel B, Huang A, Li X, Mikkola HKA. Expansion on stromal cells preserves the undifferentiated state of human hematopoietic stem cells despite compromised reconstitution ability. PLoS One 2013; 8:e53912. [PMID: 23342037 PMCID: PMC3547050 DOI: 10.1371/journal.pone.0053912] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 12/04/2012] [Indexed: 12/15/2022] Open
Abstract
Lack of HLA-matched hematopoietic stem cells (HSC) limits the number of patients with life-threatening blood disorders that can be treated by HSC transplantation. So far, insufficient understanding of the regulatory mechanisms governing human HSC has precluded the development of effective protocols for culturing HSC for therapeutic use and molecular studies. We defined a culture system using OP9M2 mesenchymal stem cell (MSC) stroma that protects human hematopoietic stem/progenitor cells (HSPC) from differentiation and apoptosis. In addition, it facilitates a dramatic expansion of multipotent progenitors that retain the immunophenotype (CD34+CD38-CD90+) characteristic of human HSPC and proliferative potential over several weeks in culture. In contrast, transplantable HSC could be maintained, but not significantly expanded, during 2-week culture. Temporal analysis of the transcriptome of the ex vivo expanded CD34+CD38-CD90+ cells documented remarkable stability of most transcriptional regulators known to govern the undifferentiated HSC state. Nevertheless, it revealed dynamic fluctuations in transcriptional programs that associate with HSC behavior and may compromise HSC function, such as dysregulation of PBX1 regulated genetic networks. This culture system serves now as a platform for modeling human multilineage hematopoietic stem/progenitor cell hierarchy and studying the complex regulation of HSC identity and function required for successful ex vivo expansion of transplantable HSC.
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Affiliation(s)
- Mattias Magnusson
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Maria I. Sierra
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Rajkumar Sasidharan
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Sacha L. Prashad
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Melissa Romero
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Pamela Saarikoski
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Ben Van Handel
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Andy Huang
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Xinmin Li
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Hanna K. A. Mikkola
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, California, United States of America
- Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America
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129
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Yu Y, Wang J, Khaled W, Burke S, Li P, Chen X, Yang W, Jenkins NA, Copeland NG, Zhang S, Liu P. Bcl11a is essential for lymphoid development and negatively regulates p53. ACTA ACUST UNITED AC 2012; 209:2467-83. [PMID: 23230003 PMCID: PMC3526365 DOI: 10.1084/jem.20121846] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bcl11a regulates development of lymphoid cells in adult mice in part by inhibiting expression of p53. Transcription factors play important roles in lymphopoiesis. We have previously demonstrated that Bcl11a is essential for normal lymphocyte development in the mouse embryo. We report here that, in the adult mouse, Bcl11a is expressed in most hematopoietic cells and is highly enriched in B cells, early T cell progenitors, common lymphoid progenitors (CLPs), and hematopoietic stem cells (HSCs). In the adult mouse, Bcl11a deletion causes apoptosis in early B cells and CLPs and completely abolishes the lymphoid development potential of HSCs to B, T, and NK cells. Myeloid development, in contrast, is not obviously affected by the loss of Bcl11a. Bcl11a regulates expression of Bcl2, Bcl2-xL, and Mdm2, which inhibits p53 activities. Overexpression of Bcl2 and Mdm2, or p53 deficiency, rescues both lethality and proliferative defects in Bcl11a-deficient early B cells and enables the mutant CLPs to differentiate to lymphocytes. Bcl11a is therefore essential for lymphopoiesis and negatively regulates p53 activities. Deletion of Bcl11a may represent a new approach for generating a mouse model that completely lacks an adaptive immune system.
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Affiliation(s)
- Yong Yu
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
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130
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Lo Iacono N, Blair HC, Poliani PL, Marrella V, Ficara F, Cassani B, Facchetti F, Fontana E, Guerrini MM, Traggiai E, Schena F, Paulis M, Mantero S, Inforzato A, Valaperta S, Pangrazio A, Crisafulli L, Maina V, Kostenuik P, Vezzoni P, Villa A, Sobacchi C. Osteopetrosis rescue upon RANKL administration to Rankl(-/-) mice: a new therapy for human RANKL-dependent ARO. J Bone Miner Res 2012; 27:2501-10. [PMID: 22836362 DOI: 10.1002/jbmr.1712] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/15/2012] [Accepted: 07/03/2012] [Indexed: 01/16/2023]
Abstract
In the last decades the molecular basis of monogenic diseases has been largely unraveled, although their treatment has often remained unsatisfactory. Autosomal recessive osteopetrosis (ARO) belongs to the small group of genetic diseases that are usually treated with hematopoietic stem cell transplantation (HSCT). However, this approach is not effective in the recently identified form carrying mutations in the receptor activator of NF-κB ligand (RANKL) gene. In this subset, therapy replacement approach based on RANKL delivery has a strong rationale. Here we demonstrate that the systematic administration of RANKL for 1 month to Rankl(-/-) mice, which closely resemble the human disease, significantly improves the bone phenotype and has beneficial effects on bone marrow, spleen and thymus; major adverse effects arise only when mice are clearly overtreated. Overall, we provide evidence that the pharmacological administration of RANKL represents the appropriate treatment option for RANKL-deficient ARO patients, to be validated in a pilot clinical trial.
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Affiliation(s)
- Nadia Lo Iacono
- UOS/IRGB, Milan Unit, CNR, Milan, Italy; Humanitas Clinical and Research Center, Rozzano, Italy
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131
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Mendoza A, Bréart B, Ramos-Perez WD, Pitt LA, Gobert M, Sunkara M, Lafaille JJ, Morris AJ, Schwab SR. The transporter Spns2 is required for secretion of lymph but not plasma sphingosine-1-phosphate. Cell Rep 2012; 2:1104-10. [PMID: 23103166 DOI: 10.1016/j.celrep.2012.09.021] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 08/22/2012] [Accepted: 09/14/2012] [Indexed: 01/14/2023] Open
Abstract
Plasma sphingosine-1-phosphate (S1P) regulates vascular permeability, and plasma and lymph S1P guide lymphocyte egress from lymphoid organs. S1P is made intracellularly, and little is known about how S1P is delivered into circulatory fluids. Here, we find that mice without the major facilitator superfamily transporter Spns2 have a profound reduction in lymph S1P, but only a minor decrease in plasma S1P. Spns2-deficient mice have a redistribution of lymphocytes from the spleen to lymph nodes and a loss of circulating lymphocytes, consistent with normal egress from the spleen directed by plasma S1P and blocked egress from lymph nodes directed by lymph S1P. Spns2 is needed in endothelial cells to supply lymph S1P and support lymphocyte circulation. As a differential requirement for lymph and blood S1P, Spns2 may be an attractive target for immune suppressive drugs.
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Affiliation(s)
- Alejandra Mendoza
- Program in Molecular Pathogenesis and Department of Pathology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
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132
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Iotti G, Mejetta S, Modica L, Penkov D, Ponzoni M, Blasi F. Reduction of Prep1 levels affects differentiation of normal and malignant B cells and accelerates Myc driven lymphomagenesis. PLoS One 2012; 7:e48353. [PMID: 23133585 PMCID: PMC3485025 DOI: 10.1371/journal.pone.0048353] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 09/24/2012] [Indexed: 11/24/2022] Open
Abstract
The Prep1 homeodomain transcription factor has recently been recognized as a tumor suppressor. Among other features, haploinsufficiency of Prep1 is able to strongly accelerate the B-lymphomagenesis in EμMyc mice. Now we report that this occurs concomitantly with a change in the type of B-cell lymphomas generated by the Myc oncogene. Indeed, the tumors generated in the EμMyc-Prep1+/− mice are much more immature, being mostly made up of Pro-B or Pre-B cells, while those in the EμMyc-Prep1+/+ mice are more differentiated being invariably IgM+. Moreover, we show that Prep1 is in fact required for the differentiation of Pro-B and Pre-B cells into IgM+ lymphocytes and/or their proliferation, thus showing also how a normal function of Prep1 affects EμMyc lymphomagenesis. Finally, we show that the haploinsufficiency of Prep1 is accompanied with a major decrease of Myc-induced apoptosis and that the haploinsufficieny is sufficient for all these effects because the second allele of Prep1 is not lost even at late stages. Therefore, the tumor-suppressive activity of Prep1 is intertwined with both the interference with Myc-induced apoptosis as well as with natural developmental functions of the protein.
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Affiliation(s)
- Giorgio Iotti
- Laboratory of Transcriptional Regulation in Development and Cancer, IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milano, Italy
| | - Stefania Mejetta
- Laboratory of Transcriptional Regulation in Development and Cancer, IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milano, Italy
| | - Livia Modica
- Laboratory of Transcriptional Regulation in Development and Cancer, IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milano, Italy
| | - Dmitry Penkov
- Department of Basic Medicine, Moscow State University, Moscow, Russia
| | - Maurilio Ponzoni
- Department of Pathology, San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Blasi
- Laboratory of Transcriptional Regulation in Development and Cancer, IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milano, Italy
- * E-mail:
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133
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Abstract
The transcription factor Meis1 is expressed preferentially in hematopoietic stem cells (HSCs) and overexpressed in certain leukemias. However, the functions of Meis1 in hematopoiesis remain largely unknown. In the present study, we found that Meis1 is required for the maintenance of hematopoiesis under stress and over the long term, whereas steady-state hematopoiesis was sustained in the absence of Meis1 in inducible knock-out mice. BM cells of Meis1-deficient mice showed reduced colony formation and contained significantly fewer numbers of long-term HSCs, which exhibited loss of quiescence. Further, we found that Meis1 deletion led to the accumulation of reactive oxygen species in HSCs and decreased expression of genes implicated in hypoxia response. Finally, reactive oxygen species scavenging by N-acetyl cysteine or stabilization of hypoxia signaling by knockdown of the von-Hippel-Lindau (VHL) protein led to reversal of the effects of Meis1 deletion. The results of the present study demonstrate that Meis1 protects and preserves HSCs by restricting oxidative metabolism.
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134
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Abstract
The role of Meis1 in leukemia is well established, but its role in hematopoietic stem cells (HSCs) remains poorly understood. Previously, we showed that HSCs use glycolytic metabolism to meet their energy demands. However, the mechanism of regulation of HSC metabolism, and the importance of maintaining this distinct metabolic phenotype on HSC function has not been determined. More importantly, the primary function of Meis1 in HSCs remains unknown. Here, we examined the effect of loss of Meis1 on HSC function and metabolism. Inducible Meis1 deletion in adult mouse HSCs resulted in loss of HSC quiescence, and failure of bone marrow repopulation after transplantation. While we previously showed that Meis1 regulates Hif-1α transcription in vitro, we demonstrate here that loss of Meis1 results in down-regulation of both Hif-1α and Hif-2α in HSCs. This resulted in a shift to mitochondrial metabolism, increased reactive oxygen species production, and apoptosis of HSCs. Finally, we demonstrate that the effect of Meis1 knockout on HSCs is entirely mediated through reactive oxygen species where treatment of the Meis1 knockout mice with the scavenger N-acetylcystein restored HSC quiescence and rescued HSC function. These results uncover an important transcriptional network that regulates metabolism, oxidant defense, and maintenance of HSCs.
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135
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Sengupta M, Liang S, Potula HHS, Chang LJ, Morel L. The SLE-associated Pbx1-d isoform acts as a dominant-negative transcriptional regulator. Genes Immun 2012; 13:653-7. [PMID: 22992721 DOI: 10.1038/gene.2012.43] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pbx1 is a transcription factor involved in multiple cellular processes, including the maintenance of self-renewal of hematopoietic progenitors. We have shown that the CD4(+) T-cell expression of a novel splice isoform of Pbx1, Pbx1-d, is associated with lupus susceptibility in the NZM2410 mouse and in lupus patients. The function of Pbx1 in T cells is unknown, but the splicing out of the DNA-binding domain in Pbx1-d predicts a dominant-negative function. In support of this hypothesis, we have shown that Pbx1-d transduction accelerates differentiation of MC3T3-E1 osteoblast pregenitors and mimics the effect of short hairpin RNA silencing of Pbx1. Conversely, Pbx1-d transduction reduced the expression of Sox3, a gene strongly transactivated by Pbx1, and Pbx1-d did not bind the Sox3 promoter. These results constitute a first step towards the understanding on how Pbx1-d contributes to systemic autoimmunity in the NZM2410 mouse model as well as in lupus patients.
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Affiliation(s)
- M Sengupta
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32610, USA
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136
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Huang MM, Zhu J. The regulation of normal and leukemic hematopoietic stem cells by niches. CANCER MICROENVIRONMENT 2012; 5:295-305. [PMID: 23055016 DOI: 10.1007/s12307-012-0114-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/09/2012] [Indexed: 12/14/2022]
Abstract
The origin and propagation of normal and leukemic hematopoietic cells critically depend on their interplays with the hematopoietic microenvironment (or so-called niche), which represent important biological models for understanding organogenesis and tumorigenesis. Nevertheless, the anatomic and functional characterizations of the niche cells for normal hematopoietic stem cells (HSCs) have proved a formidable task. It is uncertain whether the combinational effects of a few sets of molecular niche elements, behind the long-sought cellular architectures with preferred anatomic locations, actually meets the functional definition of HSC niche. Moreover, even much less is known about the niche components for numerous types of leukemia-stem cells (LSCs) that originate via discrete cellular and molecular transforming mechanisms. However, one interesting scenario is emerging, i.e., the leukemia cells can positively remodel the hematopoietic microenvironment favorable for their competition over the normal hematopoiesis that co-exists within the same eco-system. This property probably represents a previously unappreciated essential trait of a functional LSC. Obviously, the further exploration into how the hematopoietic microenvironment interplay with normal or malignant hematopoiesis will shed light onto the designing of novel types of niche-targeting therapies for leukemia.
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Affiliation(s)
- Meng-Meng Huang
- State Key Laboratory for Medical Genomics and Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai, 200025, People's Republic of China
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137
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Necdin, a p53 target gene, regulates the quiescence and response to genotoxic stress of hematopoietic stem/progenitor cells. Blood 2012; 120:1601-12. [PMID: 22776820 DOI: 10.1182/blood-2011-11-393983] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently defined a critical role for p53 in regulating the quiescence of adult hematopoietic stem cells (HSCs) and identified necdin as a candidate p53 target gene. Necdin is a growth-suppressing protein and the gene encoding it is one of several that are deleted in patients with Prader-Willi syndrome. To define the intrinsic role of necdin in adult hematopoiesis, in the present study, we transplanted necdin-null fetal liver cells into lethally irradiated recipients. We show that necdin-null adult HSCs are less quiescent and more proliferative than normal HSCs, demonstrating the similar role of necdin and p53 in promoting HSC quiescence during steady-state conditions. However, wild-type recipients repopulated with necdin-null hematopoietic stem/progenitor cells show enhanced sensitivity to irradiation and chemotherapy, with increased p53-dependent apoptosis, myelosuppression, and mortality. Necdin controls the HSC response to genotoxic stress via both cell-cycle-dependent and cell-cycle-independent mechanisms, with the latter occurring in a Gas2L3-dependent manner. We conclude that necdin functions as a molecular switch in adult hematopoiesis, acting in a p53-like manner to promote HSC quiescence in the steady state, but suppressing p53-dependent apoptosis in response to genotoxic stress.
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138
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Hogart A, Lichtenberg J, Ajay SS, Anderson S, Margulies EH, Bodine DM. Genome-wide DNA methylation profiles in hematopoietic stem and progenitor cells reveal overrepresentation of ETS transcription factor binding sites. Genome Res 2012; 22:1407-18. [PMID: 22684279 PMCID: PMC3409254 DOI: 10.1101/gr.132878.111] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
DNA methylation is an essential epigenetic mark that is required for normal development. Knockout of the DNA methyltransferase enzymes in the mouse hematopoietic compartment reveals that methylation is critical for hematopoietic differentiation. To better understand the role of DNA methylation in hematopoiesis, we characterized genome-wide DNA methylation in primary mouse hematopoietic stem cells (HSCs), common myeloid progenitors (CMPs), and erythroblasts (ERYs). Methyl binding domain protein 2 (MBD) enrichment of DNA followed by massively parallel sequencing (MBD-seq) was used to map genome-wide DNA methylation. Globally, DNA methylation was most abundant in HSCs, with a 40% reduction in CMPs, and a 67% reduction in ERYs. Only 3% of peaks arise during differentiation, demonstrating a genome-wide decline in DNA methylation during erythroid development. Analysis of genomic features revealed that 98% of promoter CpG islands are hypomethylated, while 20%–25% of non-promoter CpG islands are methylated. Proximal promoter sequences of expressed genes are hypomethylated in all cell types, while gene body methylation positively correlates with gene expression in HSCs and CMPs. Elevated genome-wide DNA methylation in HSCs and the positive association between methylation and gene expression demonstrates that DNA methylation is a mark of cellular plasticity in HSCs. Using de novo motif discovery, we identified overrepresented transcription factor consensus binding motifs in methylated sequences. Motifs for several ETS transcription factors, including GABPA and ELF1, are overrepresented in methylated regions. Our genome-wide survey demonstrates that DNA methylation is markedly altered during myeloid differentiation and identifies critical regions of the genome and transcription factor programs that contribute to hematopoiesis.
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Affiliation(s)
- Amber Hogart
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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139
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Kataoka K, Kurokawa M. Ecotropic viral integration site 1, stem cell self-renewal and leukemogenesis. Cancer Sci 2012; 103:1371-7. [PMID: 22494115 DOI: 10.1111/j.1349-7006.2012.02303.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/02/2012] [Accepted: 04/08/2012] [Indexed: 12/27/2022] Open
Abstract
It has become evident that acute myeloid leukemia (AML) is organized as a cellular hierarchy initiated and maintained by a subset of self-renewing leukemia stem cells. Recent gene expression profile analysis of human leukemia stem cells and hematopoietic stem cell (HSC) populations identified a key transcriptional program shared by leukemia stem cells and HSC, which is associated with adverse outcomes in AML patients. One molecule that has been established as a pivotal regulator in fine-tuning of stem cell properties as well as a potent oncogenic determinant is ecotropic viral integration site 1 (EVI1). EVI1 is a transcription factor that has stem cell-specific expression pattern and is essential for the regulation of HSC self-renewal. This gene is notorious for its involvement in AML, as its activation confers extremely poor prognosis in patients with AML. Molecular analysis has identified a variety of gene products that are involved in HSC regulation as downstream targets or interacting proteins of EVI1. Thus, exploration of the molecular pathogenesis underlying EVI1-related leukemogenesis provides insight into how shared stemness transcriptional programs contribute to leukemia progression and therapeutic resistance in AML. Here, we review the current knowledge regarding the role of EVI1 in HSC self-renewal and leukemogenesis and highlight the relationship between stem cell self-renewal properties and adverse outcome in myeloid malignancies.
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Affiliation(s)
- Keisuke Kataoka
- Department of Hematology and Oncology, University of Tokyo, Tokyo, Japan
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140
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Abstract
Agrin, an extracellular matrix protein belonging to the heterogeneous family of heparan sulfate proteoglycans (HSPGs), is expressed by cells of the hematopoietic system but its role in leukocyte biology is not yet clear. Here we demonstrate that agrin has a crucial, nonredundant role in myeloid cell development and functions. We have identified lineage-specific alterations that affect maturation, survival and properties of agrin-deficient monocytic cells, and occur at stages later than stem cell precursors. Our data indicate that the cell-autonomous signals delivered by agrin are sensed by macrophages through the α-DC (DG) receptor and lead to the activation of signaling pathways resulting in rearrangements of the actin cytoskeleton during the phagocytic synapse formation and phosphorylation of extracellular signal-regulated kinases (Erk 1/2). Altogether, these data identify agrin as a novel player of innate immunity.
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141
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Myeloproliferation and hematopoietic stem cell dysfunction due to defective Notch receptor modification by O-fucose glycans. Semin Immunopathol 2012; 34:455-69. [DOI: 10.1007/s00281-012-0303-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 02/24/2012] [Indexed: 02/01/2023]
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142
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Abstract
Acute myeloid leukemia (AML) is one of the most common leukemias with a 20% 5-year event-free survival in adults and 50% overall survival in children, despite aggressive chemotherapy treatment and bone marrow transplantation. The incidence and mortality rates for acute leukemia have only slightly decreased over the last 20 years, and therefore greater understanding of the molecular mechanisms associated with leukemic progression is needed. To this end, a number of transcription factors that appear to play a central role in leukemogenesis are being investigated; among them is the cAMP response element binding protein (CREB). CREB is a transcription factor that can regulate downstream targets involving in various cellular functions including cell proliferation, survival, and differentiation. In several studies, the majority of bone marrow samples from patients with acute lymphoid and myeloid leukemia demonstrate CREB overexpression. Moreover, CREB overexpression is associated with a poor outcome in AML patients. This review summarizes the role of CREB in leukemogenesis.
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Affiliation(s)
- Er-Chieh Cho
- Division of Hematology/Oncology, Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1752, USA
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143
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Cuda CM, Li S, Liang S, Yin Y, Potula HHS, Xu Z, Sengupta M, Chen Y, Butfiloski E, Baker H, Chang LJ, Dozmorov I, Sobel ES, Morel L. Pre-B cell leukemia homeobox 1 is associated with lupus susceptibility in mice and humans. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 188:604-14. [PMID: 22180614 PMCID: PMC3253202 DOI: 10.4049/jimmunol.1002362] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sle1a.1 is part of the Sle1 susceptibility locus, which has the strongest association with lupus nephritis in the NZM2410 mouse model. In this study, we show that Sle1a.1 results in the production of activated and autoreactive CD4(+) T cells. Additionally, Sle1a.1 expression reduces the peripheral regulatory T cell pool, as well as induces a defective response of CD4(+) T cells to the retinoic acid expansion of TGF-β-induced regulatory T cells. At the molecular level, Sle1a.1 corresponds to an increased expression of a novel splice isoform of Pbx1, Pbx1-d. Pbx1-d overexpression is sufficient to induce an activated/inflammatory phenotype in Jurkat T cells and to decrease their apoptotic response to retinoic acid. PBX1-d is expressed more frequently in the CD4(+) T cells from lupus patients than from healthy controls, and its presence correlates with an increased central memory T cell population. These findings indicate that Pbx1 is a novel lupus susceptibility gene that regulates T cell activation and tolerance.
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Affiliation(s)
- Carla M. Cuda
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Shiwu Li
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Shujuan Liang
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Yiming Yin
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Hari Hara S.K. Potula
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Zhiwei Xu
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Mayami Sengupta
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Yifang Chen
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
| | - Edward Butfiloski
- Department of Medicine, Division of Rheumatology and Clinical Medicine, University of Florida, Gainesville, FL 32610
| | - Henry Baker
- Department of Microbiology and Molecular Genetics, University of Florida, Gainesville, FL 32610
| | - Lung-Ji Chang
- Department of Microbiology and Molecular Genetics, University of Florida, Gainesville, FL 32610
| | - Igor Dozmorov
- Pathology Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104
| | - Eric S. Sobel
- Department of Medicine, Division of Rheumatology and Clinical Medicine, University of Florida, Gainesville, FL 32610
| | - Laurence Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL 32610
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144
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Nestadt G, Wang Y, Grados MA, Riddle MA, Greenberg BD, Knowles JA, Fyer AJ, McCracken JT, Rauch SL, Murphy DL, Rasmussen SA, Cullen B, Piacentini J, Geller D, Pauls D, Bienvenu OJ, Chen Y, Liang KY, Goes FS, Maher B, Pulver AE, Shugart YY, Valle D, Samuels JF, Chang YC. Homeobox genes in obsessive-compulsive disorder. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:53-60. [PMID: 22095678 PMCID: PMC3250212 DOI: 10.1002/ajmg.b.32001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 10/20/2011] [Indexed: 11/07/2022]
Abstract
BACKGROUND Despite evidence that obsessive-compulsive disorder (OCD) is a familial neuropsychiatric condition, progress aimed at identifying genetic determinants of the disorder has been slow. The OCD Collaborative Genetics Study (OCGS) has identified several OCD susceptibility loci through linkage analysis. METHODS In this study we investigate two regions on chromosomes 15q and 1q by first refining the linkage region using additional short tandem repeat polymorphic (STRP) markers. We then performed association analysis on single nucleotide polymorphisms (SNP) genotyped (markers placed every 2-4 kb) in the linkage regions in the OCGS sample of 376 rigorously phenotyped affected families. RESULTS Three SNPs are most strongly associated with OCD: rs11854486 (P = 0.00005 [0.046 after adjustment for multiple tests]; genetic relative risk (GRR) = 11.1 homozygous and 1.6 heterozygous) and rs4625687 [P = 0.00007 (after adjustment = 0.06); GRR = 2.4] on 15q; and rs4387163 (P = 0.0002 (after adjustment = 0.08); GRR = 1.97) on 1q. The first SNP is adjacent to NANOGP8, the second SNP is in MEIS2, and the third is 150 kb between PBX1 and LMX1A. CONCLUSIONS All the genes implicated by association signals are homeobox genes and are intimately involved in neurodevelopment. PBX1 and MEIS2 exert their effects by the formation of a heterodimeric complex, which is involved in development of the striatum, a brain region involved in the pathophysiology of OCD. NANOGP8 is a retrogene of NANOG, a homeobox transcription factor known to be involved in regulation of neuronal development. These findings need replication; but support the hypothesis that genes involved in striatal development are implicated in the pathogenesis of OCD.
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Affiliation(s)
- G Nestadt
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287, USA.
| | - Y Wang
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - MA Grados
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - MA Riddle
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - BD Greenberg
- Department of Psychiatry and Human Behavior, Brown Medical School, Butler Hospital
| | - JA Knowles
- Department of Psychiatry, Keck Medical School, University of Southern California
| | - AJ Fyer
- College of Physicians and Surgeons at Columbia University
| | - JT McCracken
- Department of Psychiatry and Biobehavioral Sciences, School of Medicine, University of California, Los Angeles
| | - SL Rauch
- Departments of Psychiatry and Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital and Harvard Medical School
| | - DL Murphy
- Laboratory of Clinical Science, NIMH, NIH, Bethesda
| | - SA Rasmussen
- Department of Psychiatry and Human Behavior, Brown Medical School, Butler Hospital
| | - B Cullen
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - J Piacentini
- Department of Psychiatry and Biobehavioral Sciences, School of Medicine, University of California, Los Angeles
| | - D Geller
- Departments of Psychiatry and Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital and Harvard Medical School
| | - D Pauls
- Departments of Psychiatry and Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital and Harvard Medical School
| | - OJ Bienvenu
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - Y Chen
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University
| | - KY Liang
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University
| | - FS Goes
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - B Maher
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University
| | - AE Pulver
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - Y Y Shugart
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
,Genomic Research Branch, Division of Neuroscience and Basic Behavioral Science, National Institute of Mental Health, National Institutes of Health, Bethesda, MD
| | - D Valle
- Department of Pediatrics, School of Medicine, Johns Hopkins University
| | - JF Samuels
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University
| | - YC Chang
- Department of Medicine, University of Maryland School of Medicine
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145
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Yokoyama A, Ficara F, Murphy MJ, Meisel C, Naresh A, Kitabayashi I, Cleary ML. Proteolytically cleaved MLL subunits are susceptible to distinct degradation pathways. J Cell Sci 2011; 124:2208-19. [PMID: 21670200 DOI: 10.1242/jcs.080523] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The mixed lineage leukemia (MLL) proto-oncogenic protein is a histone-lysine N-methyltransferase that is produced by proteolytic cleavage and self-association of the respective functionally distinct subunits (MLL(N) and MLL(C)) to form a holocomplex involved in epigenetic transcriptional regulation. On the basis of studies in Drosophila it has been suggested that the separated subunits might also have distinct functions. In this study, we used a genetically engineered mouse line that lacked MLL(C) to show that the MLL(N)-MLL(C) holocomplex is responsible for MLL functions in various developmental processes. The stability of MLL(N) is dependent on its intramolecular interaction with MLL(C), which is mediated through the first and fourth plant homeodomain (PHD) fingers (PHD1 and PHD4) and the phenylalanine/tyrosine-rich (FYRN) domain of MLL(N). Free MLL(N) is destroyed by a mechanism that targets the FYRN domain, whereas free MLL(C) is exported to the cytoplasm and degraded by the proteasome. PHD1 is encoded by an alternatively spliced exon that is occasionally deleted in T-cell leukemia, and its absence produces an MLL mutant protein that is deficient for holocomplex formation. Therefore, this should be a loss-of-function mutant allele, suggesting that the known tumor suppression role of MLL may also apply to the T-cell lineage. Our data demonstrate that the dissociated MLL subunits are subjected to distinct degradation pathways and thus not likely to have separate functions unless the degradation mechanisms are inhibited.
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Affiliation(s)
- Akihiko Yokoyama
- Division of Hematological Malignancy, National Cancer Center Research Institute, Tokyo 104-0045, Japan.
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146
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Dnmt3a is essential for hematopoietic stem cell differentiation. Nat Genet 2011; 44:23-31. [PMID: 22138693 DOI: 10.1038/ng.1009] [Citation(s) in RCA: 812] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 10/25/2011] [Indexed: 02/07/2023]
Abstract
Loss of the de novo DNA methyltransferases Dnmt3a and Dnmt3b in embryonic stem cells obstructs differentiation; however, the role of these enzymes in somatic stem cells is largely unknown. Using conditional ablation, we show that Dnmt3a loss progressively impairs hematopoietic stem cell (HSC) differentiation over serial transplantation, while simultaneously expanding HSC numbers in the bone marrow. Dnmt3a-null HSCs show both increased and decreased methylation at distinct loci, including substantial CpG island hypermethylation. Dnmt3a-null HSCs upregulate HSC multipotency genes and downregulate differentiation factors, and their progeny exhibit global hypomethylation and incomplete repression of HSC-specific genes. These data establish Dnmt3a as a critical participant in the epigenetic silencing of HSC regulatory genes, thereby enabling efficient differentiation.
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147
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Abstract
Tissue and organ differentiation is tightly controlled to ensure proper development and function of the growing embryo as well as cells such as lymphocytes that differentiate throughout the adult stage. Therefore it is vital that the genes and the protein they encode that are involved in these processes function accurately. Hence, any mutation or error that occurs along the way can result in extensive damage, which is expressed in various ways in the embryo and can result in immune pathogenesis, including immunodeficiency and autoimmune diseases, when lymphocyte development is altered. A number of studies have been carried out to look at the genes regulating transcription in tissue differentiation, including the transcription factors Pbx1. This gene is of particular interest to us as we have identified that it is associated with systemic lupus erythematosus susceptibility (Cuda et al., in press). This perspective summarizes the known roles of Pbx1 in tissue differentiation as well as our recent findings associating genetic variations in Pbx1 to lupus susceptibility, and we will speculate on how this gene controls the maintenance of immune tolerance in T cells.
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Affiliation(s)
- Mayami Sengupta
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32610 USA
| | - Laurence Morel
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32610 USA
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148
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Kimura Y, Ding B, Imai N, Nolan DJ, Butler JM, Rafii S. c-Kit-mediated functional positioning of stem cells to their niches is essential for maintenance and regeneration of adult hematopoiesis. PLoS One 2011; 6:e26918. [PMID: 22046410 PMCID: PMC3202594 DOI: 10.1371/journal.pone.0026918] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/06/2011] [Indexed: 01/28/2023] Open
Abstract
The mechanism by which hematopoietic stem and progenitor cells (HSPCs) through interaction with their niches maintain and reconstitute adult hematopoietic cells is unknown. To functionally and genetically track localization of HSPCs with their niches, we employed novel mutant loxPs, lox66 and lox71 and Cre-recombinase technology to conditionally delete c-Kit in adult mice, while simultaneously enabling GFP expression in the c-Kit-deficient cells. Conditional deletion of c-Kit resulted in hematopoietic failure and splenic atrophy both at steady state and after marrow ablation leading to the demise of the treated adult mice. Within the marrow, the c-Kit-expressing GFP+ cells were positioned to Kit ligand (KL)-expressing niche cells. This c-Kit-mediated cellular adhesion was essential for long-term maintenance and expansion of HSPCs. These results lay the foundation for delivering KL within specific niches to maintain and restore hematopoiesis.
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Affiliation(s)
- Yuki Kimura
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (YK); (SR)
| | - Bisen Ding
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
- Ansary Stem Cell Institute, Weill Cornell Medical College, New York, New York, United States of America
- Howard Hughes Medical Institute, Weill Cornell Medical College, New York, New York, United States of America
| | - Norikazu Imai
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Daniel J. Nolan
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
- Ansary Stem Cell Institute, Weill Cornell Medical College, New York, New York, United States of America
- Howard Hughes Medical Institute, Weill Cornell Medical College, New York, New York, United States of America
| | - Jason M. Butler
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
- Ansary Stem Cell Institute, Weill Cornell Medical College, New York, New York, United States of America
- Howard Hughes Medical Institute, Weill Cornell Medical College, New York, New York, United States of America
| | - Shahin Rafii
- Department of Genetic Medicine, Weill Cornell Medical College, New York, New York, United States of America
- Ansary Stem Cell Institute, Weill Cornell Medical College, New York, New York, United States of America
- Howard Hughes Medical Institute, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (YK); (SR)
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149
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He S, Kim I, Lim MS, Morrison SJ. Sox17 expression confers self-renewal potential and fetal stem cell characteristics upon adult hematopoietic progenitors. Genes Dev 2011; 25:1613-27. [PMID: 21828271 DOI: 10.1101/gad.2052911] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A key question concerns the mechanisms that determine temporal identity in stem cells. Fetal hematopoietic stem cells (HSCs) differ from adult HSCs in terms of gene expression profile, surface marker expression, differentiation, and self-renewal capacity. We previously showed that the transcription factor SOX17 is expressed by fetal, but not adult, HSCs and is required for the maintenance of fetal and neonatal, but not adult, HSCs. In the current study, we show that ectopic expression of Sox17 in adult HSCs and transiently reconstituting multipotent progenitors was sufficient to confer increased self-renewal potential and the expression of fetal HSC genes, including fetal HSC surface markers. Sox17 expression enabled transiently reconstituting adult progenitors to give long-term multilineage reconstitution that resembled fetal hematopoiesis, including increased erythropoiesis, increased myelopoiesis, and decreased lymphopoiesis. Long-term ectopic expression of Sox17 eventually led to leukemogenesis. These data demonstrate that SOX17 is sufficient to confer fetal HSC characteristics to adult hematopoietic progenitors and is therefore a key determinant of fetal HSC identity.
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Affiliation(s)
- Shenghui He
- Howard Hughes Medical Institute, Life Sciences Institute, Department of Internal Medicine, Center for Stem Cell Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
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150
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Abstract
Maturation of hematopoietic stem cells (HSCs) from fetal to adult state and differentiation to progenitors are thought to follow a one-way street. In this issue of Genes & Development, He and colleagues (pp. 1613-1627) show that overexpression of Sox17 can convert adult multipotential progenitors to self-renewing HSCs that possess fetal properties. These findings challenge the irreversibility of hematopoietic development, and open up new perspectives to understand the different forms of HSC self-renewal at distinct stages of ontogeny and during transformation.
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Affiliation(s)
- Akanksha Chhabra
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
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