1
|
Hwang Y, Hidalgo D, Socolovsky M. The shifting shape and functional specializations of the cell cycle during lineage development. WIREs Mech Dis 2020; 13:e1504. [PMID: 32916032 DOI: 10.1002/wsbm.1504] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 06/29/2020] [Accepted: 07/08/2020] [Indexed: 12/12/2022]
Abstract
Essentially all cell cycling in multicellular organisms in vivo takes place in the context of lineage differentiation. This notwithstanding, the regulation of the cell cycle is often assumed to be generic, independent of tissue or developmental stage. Here we review developmental-stage-specific cell cycle adaptations that may influence developmental decisions, in mammalian erythropoiesis and in other lineages. The length of the cell cycle influences the balance between self-renewal and differentiation in multiple tissues, and may determine lineage fate. Shorter cycles contribute to the efficiency of reprogramming somatic cells into induced pluripotency stem cells and help maintain the pluripotent state. While the plasticity of G1 length is well established, the speed of S phase is emerging as a novel regulated parameter that may influence cell fate transitions in the erythroid lineage, in neural tissue and in embryonic stem cells. A slow S phase may stabilize the self-renewal state, whereas S phase shortening may favor a cell fate change. In the erythroid lineage, functional approaches and single-cell RNA-sequencing show that a key transcriptional switch, at the transition from self-renewal to differentiation, is synchronized with and dependent on S phase. This specific S phase is shorter, as a result of a genome-wide increase in the speed of replication forks. Furthermore, there is progressive shortening in G1 in the period preceding this switch. Together these studies suggest an integrated regulatory landscape of the cycle and differentiation programs, where cell cycle adaptations are controlled by, and in turn feed back on, the propagation of developmental trajectories. This article is categorized under: Biological Mechanisms > Cell Fates Developmental Biology > Stem Cell Biology and Regeneration Developmental Biology > Lineages.
Collapse
Affiliation(s)
- Yung Hwang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Daniel Hidalgo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Merav Socolovsky
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| |
Collapse
|
2
|
Stress Erythropoiesis is a Key Inflammatory Response. Cells 2020; 9:cells9030634. [PMID: 32155728 PMCID: PMC7140438 DOI: 10.3390/cells9030634] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 02/27/2020] [Accepted: 03/03/2020] [Indexed: 12/21/2022] Open
Abstract
Bone marrow medullary erythropoiesis is primarily homeostatic. It produces new erythrocytes at a constant rate, which is balanced by the turnover of senescent erythrocytes by macrophages in the spleen. Despite the enormous capacity of the bone marrow to produce erythrocytes, there are times when it is unable to keep pace with erythroid demand. At these times stress erythropoiesis predominates. Stress erythropoiesis generates a large bolus of new erythrocytes to maintain homeostasis until steady state erythropoiesis can resume. In this review, we outline the mechanistic differences between stress erythropoiesis and steady state erythropoiesis and show that their responses to inflammation are complementary. We propose a new hypothesis that stress erythropoiesis is induced by inflammation and plays a key role in maintaining erythroid homeostasis during inflammatory responses.
Collapse
|
3
|
Mon EE, Wei FY, Ahmad RNR, Yamamoto T, Moroishi T, Tomizawa K. Regulation of mitochondrial iron homeostasis by sideroflexin 2. J Physiol Sci 2018; 69:359-373. [PMID: 30570704 PMCID: PMC6373408 DOI: 10.1007/s12576-018-0652-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/10/2018] [Indexed: 02/08/2023]
Abstract
Mitochondrial iron is indispensable for heme biosynthesis and iron–sulfur cluster assembly. Several mitochondrial transmembrane proteins have been implicated to function in the biosynthesis of heme and iron–sulfur clusters by transporting reaction intermediates. However, several mitochondrial proteins related to iron metabolism remain uncharacterized. Here, we show that human sideroflexin 2 (SFXN2), a member of the SFXN protein family, is involved in mitochondrial iron metabolism. SFXN2 is an evolutionarily conserved protein that localized to mitochondria via its transmembrane domain. SFXN2-knockout (KO) cells had an increased mitochondrial iron content, which was associated with decreases in the heme content and heme-dependent enzyme activities. By contrast, the activities of iron–sulfur cluster-dependent enzymes were unchanged in SFXN2-KO cells. Moreover, abnormal iron metabolism impaired mitochondrial respiration in SFXN2-KO cells and accelerated iron-mediated death of these cells. Our findings demonstrate that SFXN2 functions in mitochondrial iron metabolism by regulating heme biosynthesis.
Collapse
Affiliation(s)
- Ei Ei Mon
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Fan-Yan Wei
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan. .,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan.
| | - Raja Norazireen Raja Ahmad
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Takahiro Yamamoto
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Toshiro Moroishi
- Department of Molecular Enzymology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.,Center for Metabolic Regulation of Healthy Aging, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan
| | - Kazuhito Tomizawa
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan. .,Center for Metabolic Regulation of Healthy Aging, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan. .,Neutron Therapy Research Center, Okayama University, Okayama, 700-8558, Japan.
| |
Collapse
|
4
|
Tusi BK, Wolock SL, Weinreb C, Hwang Y, Hidalgo D, Zilionis R, Waisman A, Huh JR, Klein AM, Socolovsky M. Population snapshots predict early haematopoietic and erythroid hierarchies. Nature 2018; 555:54-60. [PMID: 29466336 PMCID: PMC5899604 DOI: 10.1038/nature25741] [Citation(s) in RCA: 242] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/11/2018] [Indexed: 12/18/2022]
Abstract
The formation of red blood cells begins with the differentiation of multipotent haematopoietic progenitors. Reconstructing the steps of this differentiation represents a general challenge in stem-cell biology. Here we used single-cell transcriptomics, fate assays and a theory that allows the prediction of cell fates from population snapshots to demonstrate that mouse haematopoietic progenitors differentiate through a continuous, hierarchical structure into seven blood lineages. We uncovered coupling between the erythroid and the basophil or mast cell fates, a global haematopoietic response to erythroid stress and novel growth factor receptors that regulate erythropoiesis. We defined a flow cytometry sorting strategy to purify early stages of erythroid differentiation, completely isolating classically defined burst-forming and colony-forming progenitors. We also found that the cell cycle is progressively remodelled during erythroid development and during a sharp transcriptional switch that ends the colony-forming progenitor stage and activates terminal differentiation. Our work showcases the utility of linking transcriptomic data to predictive fate models, and provides insights into lineage development in vivo.
Collapse
Affiliation(s)
- Betsabeh Khoramian Tusi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| | - Samuel L. Wolock
- Department of Systems Biology, Harvard Medical School, Boston, MA
| | - Caleb Weinreb
- Department of Systems Biology, Harvard Medical School, Boston, MA
| | - Yung Hwang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| | - Daniel Hidalgo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| | - Rapolas Zilionis
- Department of Systems Biology, Harvard Medical School, Boston, MA
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Jun R. Huh
- Division of Immunology, Department of Microbiology and Immunobiology and Evergrande Center for Immunological Diseases, Harvard Medical School and Brigham and Women’s Hospital, Boston, Massachusetts 02115, USA
| | - Allon M. Klein
- Department of Systems Biology, Harvard Medical School, Boston, MA
| | - Merav Socolovsky
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA
| |
Collapse
|
5
|
Extramedullary erythropoiesis in the adult liver requires BMP-4/Smad5-dependent signaling. Exp Hematol 2009; 37:549-58. [PMID: 19375646 DOI: 10.1016/j.exphem.2009.01.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 11/21/2022]
Abstract
OBJECTIVE In mice, homeostatic erythropoiesis occurs primarily in the bone marrow. However, in response to acute anemia, bone morphogenetic proteins 4 (BMP-4)-dependent stress erythropoiesis occurs in the adult spleen. BMP-4 can also regulate stress erythropoiesis in the fetal liver. In humans, erythropoiesis occurs in the bone marrow. However, in certain pathological conditions, extramedullary erythropoiesis is observed, where it can occur in several organs, including the liver. Given these observations, we propose to investigate whether the BMP-4-dependent stress erythropoiesis pathway can regulate extramedullary erythropoiesis in the livers of splenectomized mice. MATERIALS AND METHODS Using splenectomized wild-type and flexed-tail (f) mice, which have a defect in BMP-4 signaling, we compared their recovery from phenylhydrazine-induced hemolytic anemia and characterized the expansion of stress burst-forming unit-erythroid in the livers of these mice during the recovery period. RESULTS Our analysis indicates that in the absence of a spleen, stress erythropoiesis occurs in the murine liver. During the recovery, stress burst-forming unit-erythroid are expanded in the livers of splenectomized mice in response to BMP-4 expressed in the liver. f/f mice, which exhibit a defect in splenic stress erythropoiesis do not compensate for this defect by upregulating liver stress erythropoiesis. Furthermore, splenectomized f/f mice exhibit a defect in liver stress erythropoiesis, which demonstrates a role for the BMP-4-dependent stress erythropoiesis pathway in extramedullary erythropoiesis in the adult liver. CONCLUSIONS Our data indicate that the BMP-4-dependent stress erythropoiesis pathway regulates extramedullary stress erythropoiesis, which occurs primarily in the murine spleen or in the case of splenectomized mice, in the adult liver.
Collapse
|
6
|
McReynolds LJ, Tucker J, Mullins MC, Evans T. Regulation of hematopoiesis by the BMP signaling pathway in adult zebrafish. Exp Hematol 2008; 36:1604-1615. [PMID: 18973974 DOI: 10.1016/j.exphem.2008.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2007] [Revised: 08/12/2008] [Accepted: 08/21/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE The zebrafish is an established model system for studying the embryonic emergence of tissues and organs, including the hematopoietic system. We hypothesized that key signaling pathways controlling embryonic hematopoiesis continue to be important in the adult, and we sought to develop approaches to test this in zebrafish, focused on the bone morphogenetic protein (BMP) signaling pathway. Functions for this pathway in adult hematopoiesis have been challenging to probe in other models. MATERIALS AND METHODS Several approaches tested the function of BMP signaling during adult zebrafish hematopoiesis. First, we evaluated steady-state hematopoiesis in adult fish that are heterozygous for mutant alleles of Smad5, or are homozygous for mutant alleles, and rescued to adulthood by injection of RNA encoding Smad5. Second, we tested the relative ability of smad5 mutant fish to recover from hemolytic anemia. Third, we generated a transgenic line that targets the expression of a dominant-negative BMP receptor to adult-stage Gata1+ progenitor cells. RESULTS Adult fish with a strong mutant smad5 allele are anemic at steady state and, in addition, respond to hemolytic anemia with kinetics that are altered compared to wild-type fish. Fish expressing a mutant BMP receptor in early Gata1+ definitive progenitors generate excessive eosinophils. CONCLUSIONS Our study provides proof of principle that regulation of adult hematopoiesis can be studied in zebrafish by altering specific pathways. We show that the BMP signaling pathway is relevant for adult hematopoiesis to maintain steady state erythropoiesis, control the erythropoietic response following stress anemia, and to generate normal numbers of eosinophils.
Collapse
Affiliation(s)
- Lisa J McReynolds
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | | | | |
Collapse
|
7
|
Porayette P, Paulson RF. BMP4/Smad5 dependent stress erythropoiesis is required for the expansion of erythroid progenitors during fetal development. Dev Biol 2008; 317:24-35. [PMID: 18374325 PMCID: PMC2409149 DOI: 10.1016/j.ydbio.2008.01.047] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 01/27/2008] [Accepted: 01/29/2008] [Indexed: 11/24/2022]
Abstract
The rapid growth of the embryo places severe demands on the ability of the cardiovascular system to deliver oxygen to cells. To meet this need, erythroid progenitors rapidly expand in the fetal liver microenvironment such that by E14.5, erythropoiesis predominates in the fetal liver. In this report we show that the BMP4/Smad5 dependent stress erythropoiesis pathway plays a key role in the expansion of erythroid progenitors in the fetal liver. These data show that the fetal liver contains two populations of erythroid progenitors. One population resembles the steady state erythroid progenitors found in the adult bone marrow. While the second population exhibits the properties of stress erythroid progenitors found in adult spleen. Here we demonstrate that defects in BMP4/Smad5 signaling preferentially affect the expansion of the stress erythroid progenitors in the fetal liver leading to fetal anemia. These data suggest that steady state erythropoiesis is unable to generate sufficient erythrocytes to maintain the rapid growth of the embryo leading to the induction of the BMP4 dependent stress erythropoiesis pathway. These observations underscore the similarities between fetal erythropoiesis and stress erythropoiesis.
Collapse
Affiliation(s)
- Prashanth Porayette
- The Huck Institutes of the Life Sciences, Molecular Medicine Option at The Pennsylvania State University, University Park, PA 16802
| | - Robert F. Paulson
- The Department of Veterinary and Biomedical Sciences, Molecular Medicine Option at The Pennsylvania State University, University Park, PA 16802
- The Center for Molecular, Immunology and Infectious Disease, Molecular Medicine Option at The Pennsylvania State University, University Park, PA 16802
- The Huck Institutes of the Life Sciences, Molecular Medicine Option at The Pennsylvania State University, University Park, PA 16802
| |
Collapse
|
8
|
Abstract
Hematopoietic stem cells (HSC) play critical roles in maintaining blood cell production for the lifetime of the organism. Considerable progress has been made in their isolation from mouse bone marrow to high levels of purity based on a combination of cell-surface phenotype and functional characteristics. In addition, in vitro assays have been established that provide important tools for study of hematopoietic differentiation from HSC and for differentiation to generate HSC from embryonic stem cells. Although these in vitro studies provide a window on the temporal function and differentiation of HSC progeny, the transplantation assay still serves as the gold standard for quantitative and qualitative analysis of murine HSC biology. There are now many flavors of syngeneic and xenogeneic HSC transplant, all focused on quantitative assessment of repopulating function. As a vehicle for genetic modification of HSC, retroviral-mediated gene transfer followed by transplantation has had a major impact upon our understanding of genetic disorders, gene therapy, and leukemogenesis. This overview chapter summarizes the growing number of tools available for HSC research and specifically ties together the methods in chapters of the second edition of Hematopoietic Stem Cell Protocols.
Collapse
Affiliation(s)
- William Tse
- Department of Medicine, Division of Hematology-Oncology, Center for Stem Cell and Regenerative Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | |
Collapse
|
9
|
An intronic sequence mutated in flexed-tail mice regulates splicing of Smad5. Mamm Genome 2007; 18:852-60. [PMID: 18060457 DOI: 10.1007/s00335-007-9074-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 10/10/2007] [Indexed: 10/22/2022]
Abstract
Recent work has identified a growing body of evidence that subtle changes in noncoding sequences can result in significant pathology. These mutations, which would have been called silent polymorphisms in the past, affect gene transcription and mRNA splicing and lead to drastic changes in gene expression. Previous work from our lab has characterized the murine flexed-tail (f) mutation, which encodes Smad5, a transcription factor that functions downstream of the receptors for bone morphogenetic proteins (BMPs). f/f mice are unable to rapidly respond to acute anemia. Our analysis of these mice led to the development of a new model for stress erythropoiesis, where BMP4 expression in the spleen leads to the Smad5-dependent expansion of a specialized population of stress erythroid progenitors during the recovery from acute anemia. f/f mutant mice exhibit a defect in Smad5 mRNA splicing in the spleen such that the majority of Smad5 transcripts are two misspliced mRNAs. One of these mRNAs encodes a truncated form of Smad5 that inhibits BMP4 signaling when overexpressed. Here we show that a mutation in a poly(T) element in intron 4 causes the splicing defect in f/f mutant mice. This subtle mutation (loss of 1 or 2 Ts in a 16-T element) results in defects in splicing throughout the Smad5 gene. Furthermore, we show that this mutation results in tissue-specific splicing defects, which may explain why f/f mice are viable when Smad5-/- mice are embryonic lethal.
Collapse
|
10
|
Friend virus utilizes the BMP4-dependent stress erythropoiesis pathway to induce erythroleukemia. J Virol 2007; 82:382-93. [PMID: 17942544 DOI: 10.1128/jvi.02487-06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
More than 50 years of genetic analysis has identified a number of host genes that are required for the expansion of infected cells during the progression of Friend-virus-induced erythroleukemia. In this report, we show that Friend virus induces the bone morphogenetic protein 4 (BMP4)-dependent stress erythropoiesis pathway in the spleen, which rapidly amplifies target cells, propagating their infection and resulting in acute splenomegaly. This mechanism mimics the response to acute anemia, in which BMP4 expressed in the spleen drives the expansion of a specialized population of stress erythroid progenitors. Previously we demonstrated that these progenitors, termed stress BFU-E, are targets for Friend virus in the spleen (A. Subramanian, H. E. Teal, P. H. Correll, and R. F. Paulson, J. Virol. 79:14586-14594, 2005). Here, we extend those findings by showing that Friend virus infects two distinct populations of bone marrow cells. One population, when infected, differentiates into mature erythrocytes in an Epo-independent manner, while a second population migrates to the spleen after infection, where it induces BMP4 expression and acts as a reservoir of virus. The activation of the stress erythropoiesis pathway in the spleen by Friend virus results in the rapid expansion of stress BFU-E, providing abundant target cells for viral infection. These observations suggest a novel mechanism by which a virus induces a stress response pathway that amplifies target cells for the virus, leading to acute expansion of infected cells.
Collapse
|
11
|
Abstract
Acute anemia initiates a systemic response that results in the rapid mobilization and differentiation of erythroid progenitors in the adult spleen. The flexed-tail (f) mutant mice exhibit normal steady-state erythropoiesis but are unable to rapidly respond to acute erythropoietic stress. Here, we show that f/f mutant mice have a mutation in Madh5. Our analysis shows that BMP4/Madh5-dependent signaling, regulated by hypoxia, initiates the differentiation and expansion of erythroid progenitors in the spleen. These findings suggest a new model where stress erythroid progenitors, resident in the spleen, are poised to respond to changes in the microenvironment induced by acute anemia.
Collapse
Affiliation(s)
- Laurie E Lenox
- Department of Veterinary Science, Graduate Program in Biochemistry, Microbiology and Molecular Biology, and Huck Institute for Life Sciences Cell and Developmental Biology Option, Pennsylvania State University, University Park, PA 16802, USA
| | | | | |
Collapse
|
12
|
Socolovsky M, Nam H, Fleming MD, Haase VH, Brugnara C, Lodish HF. Ineffective erythropoiesis in Stat5a(-/-)5b(-/-) mice due to decreased survival of early erythroblasts. Blood 2001; 98:3261-73. [PMID: 11719363 DOI: 10.1182/blood.v98.12.3261] [Citation(s) in RCA: 547] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Erythropoietin (Epo) controls red cell production in the basal state and during stress. Epo binding to its receptor, EpoR, on erythroid progenitors leads to rapid activation of the transcription factor Stat5. Previously, fetal anemia and increased apoptosis of fetal liver erythroid progenitors were found in Stat5a(-/-)5b(-/-) mice. However, the role of Stat5 in adult erythropoiesis was not clear. The present study shows that some adult Stat5a(-/-)5b(-/-) mice have a near-normal hematocrit but are deficient in generating high erythropoietic rates in response to stress. Further, many adult Stat5a(-/-)5b(-/-) mice have persistent anemia despite a marked compensatory expansion in their erythropoietic tissue. Analysis of erythroblast maturation in Stat5a(-/-)5b(-/-) hematopoietic tissue shows a dramatic increase in early erythroblast numbers, but these fail to progress in differentiation. Decreased expression of bcl-x(L) and increased apoptosis in Stat5a(-/-)5b(-/-) early erythroblasts correlate with the degree of anemia. Hence, Stat5 controls a rate-determining step regulating early erythroblast survival.
Collapse
Affiliation(s)
- M Socolovsky
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | | | | | | | | | | |
Collapse
|
13
|
Fleming MD, Campagna DR, Haslett JN, Trenor CC, Andrews NC. A mutation in a mitochondrial transmembrane protein is responsible for the pleiotropic hematological and skeletal phenotype of flexed-tail (f/f) mice. Genes Dev 2001; 15:652-7. [PMID: 11274051 PMCID: PMC312659 DOI: 10.1101/gad.873001] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have studied the flexed-tail (f) mouse to gain insight into mammalian mitochondrial iron metabolism. Flexed-tail animals have axial skeletal abnormalities and a transient embryonic and neonatal anemia characterized by pathologic intramitochondrial iron deposits in erythrocytes. Mitochondrial iron accumulation is the hallmark of sideroblastic anemias, which typically result from defects in heme biosynthesis or other pathways that lead to abnormal erythroid mitochondrial iron utilization. To clone the f gene, we used positional cloning techniques, and identified a frameshift mutation in a mitochondrial transmembrane protein. The mutated gene, Sfxn1, is the prototype of a novel family of evolutionarily conserved proteins present in eukaryotes.
Collapse
Affiliation(s)
- M D Fleming
- Department of Pathology, Children's Hospital, Boston, Massachusetts 02115, USA
| | | | | | | | | |
Collapse
|
14
|
Urlando C, Krasnoshtein F, Heddle JA, Buchwald M. Assessment of the flexed-tail mouse as a possible model for Fanconi anemia: analysis of mitomycin C-induced micronuclei. Mutat Res 1996; 370:99-106. [PMID: 8879267 DOI: 10.1016/0165-1218(96)00044-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Fanconi anemia (FA) is a rare, autosomal recessive disorder characterized by elevated frequencies of chromosome aberrations, hypersensitivity to DNA cross-linking agents and predisposition to cancer. At least 5 complementation groups (FA-A to FA-E) underlie FA and the gene defective in FA-C (FAC) has been cloned. The mouse orthologue, Fac, maps in close proximity to the f locus, on chromosome 13, which codes for the flexed-tail mouse phenotype, raising the possibility that f and Fac are synonymous. If this were the case flexed-tail mice could be used as mouse models for FA-C to help determine the basic defect and to evaluate clinical intervention and gene therapy. To further characterize the flexed-tail mouse, the frequency of micronuclei (a measure of chromosomal aberrations) induced by mitomycin C (MMC), an alkylating and DNA cross-linking agent, was analyzed in peripheral blood and bone marrow erythrocytes. Although a higher spontaneous micronucleus frequency was seen in flexed tail mice in comparison to wild-type mice, the sensitivity to MMC was not elevated. This result suggests that f and Fac are different genes and that the flexed-tail mouse is not a model for FA-C.
Collapse
Affiliation(s)
- C Urlando
- Department of Biology, York University, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
15
|
McCulloch EA. Stem cell renewal and determination during clonal expansion in normal and leukaemic haemopoiesis. Cell Prolif 1993; 26:399-425. [PMID: 9087532 DOI: 10.1111/j.1365-2184.1993.tb00129.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Normal haemopoiesis is a cellular hierarchy headed by pluripotent stem cells capable of both self renewal and, after determination, the generation of differentiating lineages that end in terminal functional cells. The role of stem cells is crucial because only these have the capacity to generate clonal populations during development or after injury. During clonal expansion the cells are affected by many sets of receptors and ligands. These belong to at least two classes: one consists of growth factors that bind cell surface receptors and initiate signalling events; the other class contains receptors which act as ligand-dependent transcription factors such as the intracellular steroid superfamily. In spite of this elaborate regulatory apparatus, control during clonal expansion is lax, perhaps stochastic, as evident from the great heterogeneity disclosed by examining the cellular compositions of haemopoietic clones. It may be that the large number of signals impinging on binary possible outcomes (for example self-renewal or determination) serve to set probabilities rather than to determine outcomes. In leukaemia, many of the features of normal haemopoiesis are retained. The disease begins as transformations in normal stem cells; after additional leukaemogenic events clonal expansion yields malignant populations which are clonal in each affected individual. These dominant clonal populations retain the hierarchical organization found in the normal, the major difference is that post-deterministic divisions in leukaemia yield descendants that retain primitive (blast) morphology although proliferative capacity is lost. In acute myeloblastic leukaemia (AML) cell culture methods are available that permit the measurement of clonogenic blast stem cells. These methods have shown that regulatory mechanisms active in normal haemopoiesis are retained in AML, including lax regulation during clonal expansion. The biological features of blast stems cells displayed by the culture technique reflect in part, events in vivo, as associations have been found between results in cell culture and clinical outcome. Thus, study of leukaemic populations provides a challenge for basic science and an opportunity for successful application in control of disease.
Collapse
Affiliation(s)
- E A McCulloch
- Department of Medical Biophysics, the University of Toronto, Canada
| |
Collapse
|
16
|
Wiktor-Jedrzejczak W, Szczylik C, Górnas P, Sharkis SJ, Ahmed A. Haematopoiesis in mice heterozygous for the W trait: defective formation of transient endogenous spleen colonies. CELL AND TISSUE KINETICS 1981; 14:211-7. [PMID: 7471166 DOI: 10.1111/j.1365-2184.1981.tb00524.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
It has been determined that W/+ and Wv/+ heterozygous mice, as compared with normal +/+ homozygous littermates, form significantly lower numbers of transient 5-day endogenous spleen colonies in response to X-irradiation. This defect was evident for doses of irradiation between 2-6 Gy (200-600 rad) and was associated with a slightly increased radiosensitivity of the assayed precursor cells (TE-CFU) in W heterozygotic mice. Moreover, the defect was transplantable, i.e., intrinsic to the marrow cells and not to the microenvironment, and was not associated with a similar decrease in cells which form erythropoietic bursts in vitro (BFUe). This study provides a cellular basis for increased radiosensitivity of W/+ and Wv/+ mice and suggests that the 'W' mutation is semi-dominant, both with respect to the white spotting and TE-CFU formation.
Collapse
|
17
|
|
18
|
Wiktor-Jedrzejczak W, Ahmed A, Sharkis SJ, McKee A, Sell KW. Defective transient endogenous spleen colony formation in S1/S1d mice. J Cell Physiol 1979; 99:31-5. [PMID: 379025 DOI: 10.1002/jcp.1040990105] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
WCB6F1 mice of the genotype S1/S1d did not form transient 5-day endogenous spleen colonies following midlethal irradiation, either spontaneously or in response to postirradiation bleeding. Their hematologically normal (+/+) littermates produced colonies equivalent in number and morphologic type to a normal strain (D2B6F1), as evaluated by both macroscopic and microscopic criteria. Bone marrow cells from S1/S1d mice, when transplanted into lethally irradiated +/+ mice, were able to generate equivalent numbers of transient endogenous spleen colonies (TE-CFUs), as compared to that obtained when syngeneic +/+ marrow cells were injected into lethally irradiated +/+ recipients. A defective growth of an early class of hematopoietic progenitor cells, resulting in the clinical course of the S1/S1d anemia is suggested and confirms previous reports on the microenvironmental nature of this abnormality.
Collapse
|
19
|
|
20
|
Van Zant G, Goldwasser E. The effects of erythropoietin in vitro on spleen colony-forming cells. J Cell Physiol 1977; 90:241-51. [PMID: 838778 DOI: 10.1002/jcp.1040900210] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Erythropoietin (epo) added to liquid cultures of mouse bone marrow cells effected both the numbers of spleen colony-forming cells (CFU) in the cultures and the types of spleen colonies formed from these cells in irradiated hosts. Epo caused an increase in the number of CFU detected in cultures on the second day; this effect persisted through day 10, with the maximal increase occurring on the seventh day. The magnitude of the rise on day 7 was proportional to the amount of epo added. The increase in spleen colonies found with cells cultured in the presence of epo was due solely to erythroid colonies. After seven days in culture without epo, there was a peak of cells that formed non-erythroid colonies. This peak did not appear when the cells were cultured in the presence of epo.
Collapse
|
21
|
Cole RJ, Regan T. Haemopoietic progenitor cells in prenatal congenitally anaemic 'flexed-tailed' (f/f) mice. Br J Haematol 1976; 33:387-94. [PMID: 1276083 DOI: 10.1111/j.1365-2141.1976.tb03555.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The incidences of erythroid colony forming cells (CFUe) and granulocyte-macrophage colony forming cells (CFUc) have been measured in 11-18 d prenatal livers of mice of genotype f/f and nearly congenic +/+ controls. In normal fetal livers numbers of CFUe (cells able to form colonies of 16 or more cells after 72 h in vitro) rise to a maximum on day 14 of gestation and represent c 1% of total fetal liver cells. In f/f fetal livers, peak values for numbers and proportions of CFUe are 50% of normal. The f/f lesion does not reduce the numbers of CFUc in fetal liver. Since this deficiency in CFUe parallels deficiencies of similar magnitude in spleen-colony forming units (CFUs) and erythroblasts in the liver, and erythrocytes in the blood, of f/f fetuses it is concluded that the f/f lesion is expressed at an early stage of haemopoietic development in prenatal life. The possibility that restricted haem synthesis is the primary effect of the f/f genotype and responsible for disturbances of both haemopoietic cellular proliferation and haemoglobin synthesis is examined.
Collapse
|
22
|
Nigon V, Godet J. Genetic and morphogenetic factors in hemoglobin synthesis during higher vertebrate development: an approach to cell differentiation mechanisms. INTERNATIONAL REVIEW OF CYTOLOGY 1976; 46:79-176. [PMID: 791882 DOI: 10.1016/s0074-7696(08)60991-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
23
|
Gregory CJ, McCulloch EA, Till JE. Transient erythropoietic spleen colonies: effects of erythropoietin in normal and genetically anemic W/Wv mice. J Cell Physiol 1975; 86:1-8. [PMID: 1176537 DOI: 10.1002/jcp.1040860102] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Properties of the cells (TE-CFU) that give rise within four to six days to transient endogenous erythropoietic spleen colonies in irradiated mice have been investigated. The results obtained indicate that (1) erythropoietic maturation within such colonies is highly erythropoietin-dependent, (2) the population size of TE-CFU is not erythropoietin-dependent, (3) initial exposure to a high dose of erythropoietin followed by continuing exposure to lower doses is required for maximal efficiency of colony formation by TE-CFU, (4) successful transplantation of TE-CFU has not been achieved, but they appear among the progeny of transplanted hemopoietic cells, (5) TE-CFU are defective in mice of genotype W/Wv. These findings are consistent with the view that the TE-CFU assay detects a class of early erythropoietin-sensitive progenitor cells committed to erythropoietic diffferentiation, rather than "abortive" colony formation by pluripotent stem cells.
Collapse
|