1
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Wang L, Liu F, Zhang G, Su H, Sun J. A novel Ush transcription factor involving in hematopoiesis of Eriocheir sinensis. Comp Biochem Physiol B Biochem Mol Biol 2021; 259:110703. [PMID: 34915123 DOI: 10.1016/j.cbpb.2021.110703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/04/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022]
Abstract
The FOG transcriptional factor is a co-regulator that recognizes and binds to the GATA N-terminal zinc-finger domain and participates in hemocyte production and differentiation. In this study, an FOG-like gene, Ush, was characterized from Eriocheir sinensis, which consists of an 897 bp full-length open reading frame, encoding a polypeptide of 298 amino acids with four ZnF_C2H2 domains. The EsUsh mRNA transcripts were mainly expressed in the hematopoietic tissue (HPT) and hemocytes, and were significantly higher in hyalinocytes than semi-granulocytes and granulocytes, which were separated by Percoll gradient centrifugation. The transcription levels of EsUsh were found to be significantly upregulated in HPT, but downregulated in hemocytes after exsanguination. By using flow cytometry to determine the percentage of hemocyte sub-population after exsanguination, the percentage of hyalinocytes was found to significantly downregulated, while the percentage of granulocytes was significantly upregulated. Silencing EsUsh by dsRNA interference significantly decreased the percentage of hyalinocytes and small granulocytes, and increased the percentage of medium granulocytes and large granulocytes. Such findings suggest that EsUsh might be involved in hemocyte production and differentiation, especially in promoting hyalinocyte formation and limiting granulocyte generation and differentiation.
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Affiliation(s)
- Liyan Wang
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Tianjin 300387, China,.
| | - Fang Liu
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Tianjin 300387, China
| | - Guangcheng Zhang
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Tianjin 300387, China
| | - Hui Su
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Tianjin 300387, China
| | - Jinsheng Sun
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Tianjin 300387, China,.
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2
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Zheng Q, Gao N, Sun Q, Li X, Wang Y, Xiao H. bfc, a novel serpent co-factor for the expression of croquemort, regulates efferocytosis in Drosophila melanogaster. PLoS Genet 2021; 17:e1009947. [PMID: 34860835 PMCID: PMC8673676 DOI: 10.1371/journal.pgen.1009947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 12/15/2021] [Accepted: 11/15/2021] [Indexed: 01/01/2023] Open
Abstract
Efferocytosis is the process by which phagocytes recognize, engulf, and digest (or clear) apoptotic cells during development. Impaired efferocytosis is associated with developmental defects and autoimmune diseases. In Drosophila melanogaster, recognition of apoptotic cells requires phagocyte surface receptors, including the scavenger receptor CD36-related protein, Croquemort (Crq, encoded by crq). In fact, Crq expression is upregulated in the presence of apoptotic cells, as well as in response to excessive apoptosis. Here, we identified a novel gene bfc (booster for croquemort), which plays a role in efferocytosis, specifically the regulation of the crq expression. We found that Bfc protein interacts with the zinc finger domain of the GATA transcription factor Serpent (Srp), to enhance its direct binding to the crq promoter; thus, they function together in regulating crq expression and efferocytosis. Overall, we show that Bfc serves as a Srp co-factor to upregulate the transcription of the crq encoded receptor, and consequently boosts macrophage efferocytosis in response to excessive apoptosis. Therefore, this study clarifies how phagocytes integrate apoptotic cell signals to mediate efferocytosis.
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Affiliation(s)
- Qian Zheng
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Ning Gao
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Qiling Sun
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Xiaowen Li
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Yanzhe Wang
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Hui Xiao
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
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3
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Eleftherianos I, Heryanto C, Bassal T, Zhang W, Tettamanti G, Mohamed A. Haemocyte-mediated immunity in insects: Cells, processes and associated components in the fight against pathogens and parasites. Immunology 2021; 164:401-432. [PMID: 34233014 PMCID: PMC8517599 DOI: 10.1111/imm.13390] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 06/28/2021] [Indexed: 12/27/2022] Open
Abstract
The host defence of insects includes a combination of cellular and humoral responses. The cellular arm of the insect innate immune system includes mechanisms that are directly mediated by haemocytes (e.g., phagocytosis, nodulation and encapsulation). In addition, melanization accompanying coagulation, clot formation and wound healing, nodulation and encapsulation processes leads to the formation of cytotoxic redox-cycling melanin precursors and reactive oxygen and nitrogen species. However, demarcation between cellular and humoral immune reactions as two distinct categories is not straightforward. This is because many humoral factors affect haemocyte functions and haemocytes themselves are an important source of many humoral molecules. There is also a considerable overlap between cellular and humoral immune functions that span from recognition of foreign intruders to clot formation. Here, we review these immune reactions starting with the cellular mechanisms that limit haemolymph loss and participate in wound healing and clot formation and advancing to cellular functions that are critical in restricting pathogen movement and replication. This information is important because it highlights that insect cellular immunity is controlled by a multilayered system, different components of which are activated by different pathogens or during the different stages of the infection.
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Affiliation(s)
- Ioannis Eleftherianos
- Infection and Innate Immunity LaboratoryDepartment of Biological SciencesInstitute for Biomedical SciencesThe George Washington UniversityWashingtonDCUSA
| | - Christa Heryanto
- Infection and Innate Immunity LaboratoryDepartment of Biological SciencesInstitute for Biomedical SciencesThe George Washington UniversityWashingtonDCUSA
| | - Taha Bassal
- Department of EntomologyFaculty of ScienceCairo UniversityGizaEgypt
| | - Wei Zhang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural BioengineeringKey Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityGuiyangChina
| | - Gianluca Tettamanti
- Department of Biotechnology and Life SciencesUniversity of InsubriaVareseItaly
- BAT Center‐Interuniversity Center for Studies on Bioinspired Agro‐Environmental TechnologyUniversity of Napoli Federico IINapoliItaly
| | - Amr Mohamed
- Department of EntomologyFaculty of ScienceCairo UniversityGizaEgypt
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4
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Dib A, Zanet J, Mancheno-Ferris A, Gallois M, Markus D, Valenti P, Marques-Prieto S, Plaza S, Kageyama Y, Chanut-Delalande H, Payre F. Pri smORF Peptides Are Wide Mediators of Ecdysone Signaling, Contributing to Shape Spatiotemporal Responses. Front Genet 2021; 12:714152. [PMID: 34527021 DOI: 10.3389/fgene.2021.714152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/28/2021] [Indexed: 11/13/2022] Open
Abstract
There is growing evidence that peptides encoded by small open-reading frames (sORF or smORF) can fulfill various cellular functions and define a novel class regulatory molecules. To which extend transcripts encoding only smORF peptides compare with canonical protein-coding genes, yet remain poorly understood. In particular, little is known on whether and how smORF-encoding RNAs might need tightly regulated expression within a given tissue, at a given time during development. We addressed these questions through the analysis of Drosophila polished rice (pri, a.k.a. tarsal less or mille pattes), which encodes four smORF peptides (11-32 amino acids in length) required at several stages of development. Previous work has shown that the expression of pri during epidermal development is regulated in the response to ecdysone, the major steroid hormone in insects. Here, we show that pri transcription is strongly upregulated by ecdysone across a large panel of cell types, suggesting that pri is a core component of ecdysone response. Although pri is produced as an intron-less short transcript (1.5 kb), genetic assays reveal that the developmental functions of pri require an unexpectedly large array of enhancers (spanning over 50 kb), driving a variety of spatiotemporal patterns of pri expression across developing tissues. Furthermore, we found that separate pri enhancers are directly activated by the ecdysone nuclear receptor (EcR) and display distinct regulatory modes between developmental tissues and/or stages. Alike major developmental genes, the expression of pri in a given tissue often involves several enhancers driving apparently redundant (or shadow) expression, while individual pri enhancers can harbor pleiotropic functions across tissues. Taken together, these data reveal the broad role of Pri smORF peptides in ecdysone signaling and show that the cis-regulatory architecture of the pri gene contributes to shape distinct spatial and temporal patterns of ecdysone response throughout development.
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Affiliation(s)
- Azza Dib
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Jennifer Zanet
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Alexandra Mancheno-Ferris
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Maylis Gallois
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Damien Markus
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Philippe Valenti
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Simon Marques-Prieto
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Serge Plaza
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - Yuji Kageyama
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan.,Biosignal Research Center, Kobe University, Kobe, Japan
| | - Hélène Chanut-Delalande
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
| | - François Payre
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, Toulouse, France
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5
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Ush regulates hemocyte-specific gene expression, fatty acid metabolism and cell cycle progression and cooperates with dNuRD to orchestrate hematopoiesis. PLoS Genet 2021; 17:e1009318. [PMID: 33600407 PMCID: PMC7891773 DOI: 10.1371/journal.pgen.1009318] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/20/2020] [Indexed: 12/13/2022] Open
Abstract
The generation of lineage-specific gene expression programmes that alter proliferation capacity, metabolic profile and cell type-specific functions during differentiation from multipotent stem cells to specialised cell types is crucial for development. During differentiation gene expression programmes are dynamically modulated by a complex interplay between sequence-specific transcription factors, associated cofactors and epigenetic regulators. Here, we study U-shaped (Ush), a multi-zinc finger protein that maintains the multipotency of stem cell-like hemocyte progenitors during Drosophila hematopoiesis. Using genomewide approaches we reveal that Ush binds to promoters and enhancers and that it controls the expression of three gene classes that encode proteins relevant to stem cell-like functions and differentiation: cell cycle regulators, key metabolic enzymes and proteins conferring specific functions of differentiated hemocytes. We employ complementary biochemical approaches to characterise the molecular mechanisms of Ush-mediated gene regulation. We uncover distinct Ush isoforms one of which binds the Nucleosome Remodeling and Deacetylation (NuRD) complex using an evolutionary conserved peptide motif. Remarkably, the Ush/NuRD complex specifically contributes to the repression of lineage-specific genes but does not impact the expression of cell cycle regulators or metabolic genes. This reveals a mechanism that enables specific and concerted modulation of functionally related portions of a wider gene expression programme. Finally, we use genetic assays to demonstrate that Ush and NuRD regulate enhancer activity during hemocyte differentiation in vivo and that both cooperate to suppress the differentiation of lamellocytes, a highly specialised blood cell type. Our findings reveal that Ush coordinates proliferation, metabolism and cell type-specific activities by isoform-specific cooperation with an epigenetic regulator.
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6
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She M, Tang M, Jiang T, Zeng Q. The Roles of the LIM Domain Proteins in Drosophila Cardiac and Hematopoietic Morphogenesis. Front Cardiovasc Med 2021; 8:616851. [PMID: 33681304 PMCID: PMC7928361 DOI: 10.3389/fcvm.2021.616851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/04/2021] [Indexed: 12/20/2022] Open
Abstract
Drosophila melanogaster has been used as a model organism for study on development and pathophysiology of the heart. LIM domain proteins act as adaptors or scaffolds to promote the assembly of multimeric protein complexes. We found a total of 75 proteins encoded by 36 genes have LIM domain in Drosophila melanogaster by the tools of SMART, FLY-FISH, and FlyExpress, and around 41.7% proteins with LIM domain locate in lymph glands, muscles system, and circulatory system. Furthermore, we summarized functions of different LIM domain proteins in the development and physiology of fly heart and hematopoietic systems. It would be attractive to determine whether it exists a probable "LIM code" for the cycle of different cell fates in cardiac and hematopoietic tissues. Next, we aspired to propose a new research direction that the LIM domain proteins may play an important role in fly cardiac and hematopoietic morphogenesis.
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Affiliation(s)
- Meihua She
- Department of Biochemistry and Molecular Biology, College of Hengyang Medical, University of South China, Hengyang, China
| | - Min Tang
- Department of Biochemistry and Molecular Biology, College of Hengyang Medical, University of South China, Hengyang, China
| | - Tingting Jiang
- Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Qun Zeng
- Department of Biochemistry and Molecular Biology, College of Hengyang Medical, University of South China, Hengyang, China
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7
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Koranteng F, Cha N, Shin M, Shim J. The Role of Lozenge in Drosophila Hematopoiesis. Mol Cells 2020; 43:114-120. [PMID: 31992020 PMCID: PMC7057836 DOI: 10.14348/molcells.2019.0249] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/04/2019] [Indexed: 01/20/2023] Open
Abstract
Drosophila hematopoiesis is comparable to mammalian differentiation of myeloid lineages, and therefore, has been a useful model organism in illustrating the molecular and genetic basis for hematopoiesis. Multiple novel regulators and signals have been uncovered using the tools of Drosophila genetics. A Runt domain protein, lozenge, is one of the first players recognized and closely studied in the hematopoietic lineage specification. Here, we explore the role of lozenge in determination of prohemocytes into a special class of hemocyte, namely the crystal cell, and discuss molecules and signals controlling the lozenge function and its implication in immunity and stress response. Given the highly conserved nature of Runt domain in both invertebrates and vertebrates, studies in Drosophila will enlighten our perspectives on Runx-mediated development and pathologies.
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Affiliation(s)
| | - Nuri Cha
- Department of Life Science, Hanyang University, Seoul 04763, Korea
| | - Mingyu Shin
- Department of Life Science, Hanyang University, Seoul 04763, Korea
| | - Jiwon Shim
- Department of Life Science, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Science, Hanyang University, Seoul 04763, Korea
- Research Institute for Convergence of Basic Sciences, Hanyang University, Seoul 0476, Korea
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8
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Lepesant JMJ, Iampietro C, Galeota E, Augé B, Aguirrenbengoa M, Mercé C, Chaubet C, Rocher V, Haenlin M, Waltzer L, Pelizzola M, Di Stefano L. A dual role of dLsd1 in oogenesis: regulating developmental genes and repressing transposons. Nucleic Acids Res 2020; 48:1206-1224. [PMID: 31799607 PMCID: PMC7026653 DOI: 10.1093/nar/gkz1142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 11/05/2019] [Accepted: 11/23/2019] [Indexed: 11/14/2022] Open
Abstract
The histone demethylase LSD1 is a key chromatin regulator that is often deregulated in cancer. Its ortholog, dLsd1 plays a crucial role in Drosophila oogenesis; however, our knowledge of dLsd1 function is insufficient to explain its role in the ovary. Here, we have performed genome-wide analysis of dLsd1 binding in the ovary, and we document that dLsd1 is preferentially associated to the transcription start site of developmental genes. We uncovered an unanticipated interplay between dLsd1 and the GATA transcription factor Serpent and we report an unexpected role for Serpent in oogenesis. Besides, our transcriptomic data show that reducing dLsd1 levels results in ectopic transposable elements (TE) expression correlated with changes in H3K4me2 and H3K9me2 at TE loci. In addition, our results suggest that dLsd1 is required for Piwi dependent TE silencing. Hence, we propose that dLsd1 plays crucial roles in establishing specific gene expression programs and in repressing transposons during oogenesis.
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Affiliation(s)
- Julie M J Lepesant
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Carole Iampietro
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Eugenia Galeota
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia (IIT), Milan 20139, Italy
| | - Benoit Augé
- CBD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Marion Aguirrenbengoa
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Clemèntine Mercé
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France.,School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Camille Chaubet
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Vincent Rocher
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Marc Haenlin
- CBD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
| | - Lucas Waltzer
- CBD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France.,Université Clermont Auvergne, CNRS, INSERM, GReD, Clermont-Ferrand F-63000, France
| | - Mattia Pelizzola
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia (IIT), Milan 20139, Italy
| | - Luisa Di Stefano
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31062, France
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9
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Creed TM, Baldeosingh R, Eberly CL, Schlee CS, Kim M, Cutler JA, Pandey A, Civin CI, Fossett NG, Kingsbury TJ. The PAX-SIX-EYA-DACH network modulates GATA-FOG function in fly hematopoiesis and human erythropoiesis. Development 2020; 147:dev.177022. [PMID: 31806659 DOI: 10.1242/dev.177022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 11/25/2019] [Indexed: 12/15/2022]
Abstract
The GATA and PAX-SIX-EYA-DACH transcriptional networks (PSEDNs) are essential for proper development across taxa. Here, we demonstrate novel PSEDN roles in vivo in Drosophila hematopoiesis and in human erythropoiesis in vitro Using Drosophila genetics, we show that PSEDN members function with GATA to block lamellocyte differentiation and maintain the prohemocyte pool. Overexpression of human SIX1 stimulated erythroid differentiation of human erythroleukemia TF1 cells and primary hematopoietic stem-progenitor cells. Conversely, SIX1 knockout impaired erythropoiesis in both cell types. SIX1 stimulation of erythropoiesis required GATA1, as SIX1 overexpression failed to drive erythroid phenotypes and gene expression patterns in GATA1 knockout cells. SIX1 can associate with GATA1 and stimulate GATA1-mediated gene transcription, suggesting that SIX1-GATA1 physical interactions contribute to the observed functional interactions. In addition, both fly and human SIX proteins regulated GATA protein levels. Collectively, our findings demonstrate that SIX proteins enhance GATA function at multiple levels, and reveal evolutionarily conserved cooperation between the GATA and PSEDN networks that may regulate developmental processes beyond hematopoiesis.
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Affiliation(s)
- T Michael Creed
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Rajkumar Baldeosingh
- Center for Vascular and Inflammatory Diseases University of Maryland School of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Christian L Eberly
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Caroline S Schlee
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - MinJung Kim
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jevon A Cutler
- McKusick-Nathans Institute of Genetic Medicine, Departments of Biological Chemistry, Oncology and Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine, Departments of Biological Chemistry, Oncology and Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Curt I Civin
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Nancy G Fossett
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA .,Center for Vascular and Inflammatory Diseases University of Maryland School of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Tami J Kingsbury
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA .,Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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10
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Chatterjee A, Aavula K, Nongthomba U. Beadex, a homologue of the vertebrate LIM domain only protein, is a novel regulator of crystal cell development in Drosophila melanogaster. J Genet 2019; 98:107. [PMID: 31819023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Haematopoiesis is a complex process in which the regulatory mechanisms of several implicated transcription factors remain uncertain. Drosophila melanogaster is an excellent model to resolve the unanswered questions about the blood cell development. This study describes the role of Beadex, a Drosophila homologue of LIM domain only 2 (LMO2), in haematopoiesis. Mutants of Beadex were analysed for blood cell abnormalities. Crystal cells, a subset of haemocytes, were significantly more in Beadex hypermorphic flies. Similarly, Beadex misexpression in prohemocytes altered the crystal cell numbers. Stage-specific misexpression analyses demonstrated that Beadex functions after the prohemocytes enter the crystal cell lineage. We also discovered that Pannier-U-shaped complex is a negative regulator of the crystal cell differentiation and is possibly negatively regulated by Beadex through its interaction with Pannier. We, therefore, suggest the mechanism of two novel regulators of crystal cell specification-Beadex and Pannier-during Drosophila haematopoiesis.
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Affiliation(s)
- Arunita Chatterjee
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru 560 012, India.
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11
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CHATTERJEE ARUNITA, AAVULA KUMAR, NONGTHOMBA UPENDRA. Beadex, a homologue of the vertebrate LIM domain only protein, is a novel regulator of crystal cell development in Drosophila melanogaster. J Genet 2019. [DOI: 10.1007/s12041-019-1154-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Gisselbrecht SS, Palagi A, Kurland JV, Rogers JM, Ozadam H, Zhan Y, Dekker J, Bulyk ML. Transcriptional Silencers in Drosophila Serve a Dual Role as Transcriptional Enhancers in Alternate Cellular Contexts. Mol Cell 2019; 77:324-337.e8. [PMID: 31704182 DOI: 10.1016/j.molcel.2019.10.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/15/2019] [Accepted: 10/01/2019] [Indexed: 12/26/2022]
Abstract
A major challenge in biology is to understand how complex gene expression patterns are encoded in the genome. While transcriptional enhancers have been studied extensively, few transcriptional silencers have been identified, and they remain poorly understood. Here, we used a novel strategy to screen hundreds of sequences for tissue-specific silencer activity in whole Drosophila embryos. Almost all of the transcriptional silencers that we identified were also active enhancers in other cellular contexts. These elements are bound by more transcription factors than non-silencers. A subset of these silencers forms long-range contacts with promoters. Deletion of a silencer caused derepression of its target gene. Our results challenge the common practice of treating enhancers and silencers as separate classes of regulatory elements and suggest the possibility that thousands or more bifunctional CRMs remain to be discovered in Drosophila and 104-105 in humans.
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Affiliation(s)
- Stephen S Gisselbrecht
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Alexandre Palagi
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Doctoral School of Life and Health Sciences, University of Nice Sophia Antipolis, 06560 Valbonne, France
| | - Jesse V Kurland
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Julia M Rogers
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Hakan Ozadam
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Ye Zhan
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA; Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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13
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Pillidge Z, Bray SJ. SWI/SNF chromatin remodeling controls Notch-responsive enhancer accessibility. EMBO Rep 2019; 20:embr.201846944. [PMID: 30914409 DOI: 10.15252/embr.201846944] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 12/18/2022] Open
Abstract
Notch signaling plays a key role in many cell fate decisions during development by directing different gene expression programs via the transcription factor CSL, known as Su(H) in Drosophila Which target genes are responsive to Notch signaling is influenced by the chromatin state of enhancers, yet how this is regulated is not fully known. Detecting a specific increase in the histone variant H3.3 in response to Notch signaling, we tested which chromatin remodelers or histone chaperones are required for the changes in enhancer accessibility to Su(H) binding. We show a crucial role for the Brahma SWI/SNF chromatin remodeling complex, including the actin-related BAP55 subunit, in conferring enhancer accessibility and enabling the transcriptional response to Notch activity. The Notch-responsive regions have high levels of nucleosome turnover which depend on the Brahma complex, increase in magnitude with Notch signaling, and primarily involve histone H3.3. Together these results highlight the importance of SWI/SNF-mediated nucleosome turnover in rendering enhancers responsive to Notch.
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Affiliation(s)
- Zoe Pillidge
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Sarah J Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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Abhyankar V, Kaduskar B, Kamat SS, Deobagkar D, Ratnaparkhi GS. Drosophila DNA/RNA methyltransferase contributes to robust host defense in aging animals by regulating sphingolipid metabolism. ACTA ACUST UNITED AC 2018; 221:jeb.187989. [PMID: 30254027 DOI: 10.1242/jeb.187989] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/17/2018] [Indexed: 12/20/2022]
Abstract
Drosophila methyltransferase (Mt2) has been implicated in the methylation of both DNA and tRNA. In this study, we demonstrate that loss of Mt2 activity leads to an age-dependent decline of immune function in the adult fly. A newly eclosed adult has mild immune defects that are exacerbated in a 15 day old Mt2-/- fly. The age-dependent effects appear to be systemic, including disturbances in lipid metabolism, changes in cell shape of hemocytes and significant fold-changes in levels of transcripts related to host defense. Lipid imbalance, as measured by quantitative lipidomics, correlates with immune dysfunction, with high levels of immunomodulatory lipids, sphingosine-1-phosphate (S1P) and ceramides, along with low levels of storage lipids. Activity assays on fly lysates confirm the age-dependent increase in S1P and concomitant reduction of S1P lyase activity. We hypothesize that Mt2 functions to regulate genetic loci such as S1P lyase and this regulation is essential for robust host defense as the animal ages. Our study uncovers novel links between age--dependent Mt2 function, innate immune response and lipid homeostasis.
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Affiliation(s)
- Varada Abhyankar
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India
| | - Bhagyashree Kaduskar
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Siddhesh S Kamat
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Deepti Deobagkar
- Department of Zoology, Savitribai Phule Pune University, Pune 411007, India .,Center of Advanced Studies, Department of Zoology, Savitribai Phule Pune University, Pune 411007, India
| | - Girish S Ratnaparkhi
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
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15
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Baldeosingh R, Gao H, Wu X, Fossett N. Hedgehog signaling from the Posterior Signaling Center maintains U-shaped expression and a prohemocyte population in Drosophila. Dev Biol 2018; 441:132-145. [PMID: 29966604 PMCID: PMC6064674 DOI: 10.1016/j.ydbio.2018.06.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 12/15/2022]
Abstract
Hematopoietic progenitor choice between multipotency and differentiation is tightly regulated by intrinsic factors and extrinsic signals from the surrounding microenvironment. The Drosophila melanogaster hematopoietic lymph gland has emerged as a powerful tool to investigate mechanisms that regulate hematopoietic progenitor choice in vivo. The lymph gland contains progenitor cells, which share key characteristics with mammalian hematopoietic progenitors such as quiescence, multipotency and niche-dependence. The lymph gland is zonally arranged, with progenitors located in medullary zone, differentiating cells in the cortical zone, and the stem cell niche or Posterior Signaling Center (PSC) residing at the base of the medullary zone (MZ). This arrangement facilitates investigations into how signaling from the microenvironment controls progenitor choice. The Drosophila Friend of GATA transcriptional regulator, U-shaped, is a conserved hematopoietic regulator. To identify additional novel intrinsic and extrinsic regulators that interface with U-shaped to control hematopoiesis, we conducted an in vivo screen for factors that genetically interact with u-shaped. Smoothened, a downstream effector of Hedgehog signaling, was one of the factors identified in the screen. Here we report our studies that characterized the relationship between Smoothened and U-shaped. We showed that the PSC and Hedgehog signaling are required for U-shaped expression and that U-shaped is an important intrinsic progenitor regulator. These observations identify a potential link between the progenitor regulatory machinery and extrinsic signals from the PSC. Furthermore, we showed that both Hedgehog signaling and the PSC are required to maintain a subpopulation of progenitors. This led to a delineation of PSC-dependent versus PSC-independent progenitors and provided further evidence that the MZ progenitor population is heterogeneous. Overall, we have identified a connection between a conserved hematopoietic master regulator and a putative stem cell niche, which adds to our understanding of how signals from the microenvironment regulate progenitor multipotency.
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Affiliation(s)
- Rajkumar Baldeosingh
- Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Hongjuan Gao
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Xiaorong Wu
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Nancy Fossett
- Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Abstract
Runx genes have been identified in all metazoans and considerable conservation of function observed across a wide range of phyla. Thus, insight gained from studying simple model organisms is invaluable in understanding RUNX biology in higher animals. Consequently, this chapter will focus on the Runx genes in the diploblasts, which includes sea anemones and sponges, as well as the lower triploblasts, including the sea urchin, nematode, planaria and insect. Due to the high degree of functional redundancy amongst vertebrate Runx genes, simpler model organisms with a solo Runx gene, like C. elegans, are invaluable systems in which to probe the molecular basis of RUNX function within a whole organism. Additionally, comparative analyses of Runx sequence and function allows for the development of novel evolutionary insights. Strikingly, recent data has emerged that reveals the presence of a Runx gene in a protist, demonstrating even more widespread occurrence of Runx genes than was previously thought. This review will summarize recent progress in using invertebrate organisms to investigate RUNX function during development and regeneration, highlighting emerging unifying themes.
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Affiliation(s)
- S Hughes
- Faculteit Techniek, Hogeschool van Arnhem en Nijmegen, Laan van Scheut 2, 6503 GL, Nijmegen, The Netherlands
| | - A Woollard
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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17
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The Friend of GATA Transcriptional Co-Regulator, U-Shaped, Is a Downstream Antagonist of Dorsal-Driven Prohemocyte Differentiation in Drosophila. PLoS One 2016; 11:e0155372. [PMID: 27163255 PMCID: PMC4862636 DOI: 10.1371/journal.pone.0155372] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 04/27/2016] [Indexed: 12/11/2022] Open
Abstract
Recent studies suggest that mammalian hematopoietic stem and progenitor cells (HSPCs) respond directly to infection and inflammatory signaling. These signaling pathways also regulate HSPCs during steady-state conditions (absence of infection), and dysregulation may lead to cancer or age-related loss of progenitor repopulation capacity. Toll-like receptors (TLRs) are a major class of pathogen recognition receptors, and are expressed on the surface of immune effector cells and HSPCs. TLR/NF-κB activation promotes HSPCs differentiation; however, the mechanisms by which this signaling pathway alters the intrinsic transcriptional landscape are not well understood. Although Drosophila prohemocytes are the functional equivalent of mammalian HSPCs, a prohemocyte-specific function for Toll signaling has not been reported. Using Drosophila transgenics, we identified prohemocyte-specific roles for Toll pathway members, Dorsal and Cactus. We showed that Dorsal is required to limit the size of the progenitor pool. Additionally, we showed that activation of Toll signaling in prohemocytes drives differentiation in a manner that is analogous to TLR/NF-κB-driven HSPC differentiation. This was accomplished by showing that over-expression of Dorsal, or knockdown of Cactus, promotes differentiation. We also investigated whether Dorsal and Cactus control prohemocyte differentiation by regulating a key intrinsic prohemocyte factor, U-shaped (Ush), which is known to promote multipotency and block differentiation. We showed that Dorsal repressed Ush expression levels to promote differentiation, whereas Cactus maintained Ush levels to block differentiation. Additionally, we showed that another Toll antagonist, Lesswright, also maintained the level of Ush to block differentiation and promote proliferative quiescence. Collectively, these results identify a novel role for Ush as a downstream target of Toll signaling.
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18
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Söderhäll I. Crustacean hematopoiesis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 58:129-141. [PMID: 26721583 DOI: 10.1016/j.dci.2015.12.009] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/12/2015] [Accepted: 12/13/2015] [Indexed: 06/05/2023]
Abstract
Crustacean hemocytes are important mediators of immune reactions, and the regulation of hemocyte homeostasis is of utmost importance for the health of these animals. This review discusses the current knowledge on the lineages, synthesis and differentiation of hemocytes in crustaceans. Hematopoietic tissues, their origins, and the regulation of hematopoiesis during molting, seasonal variation and infection are discussed. Furthermore, studies concerning the molecular regulation of hemocyte formation in crustaceans are also described, and the different lineages and their molecular markers are discussed and compared with several insect species. Signaling pathways and the regulation of hematopoiesis by transcription factors are typically conserved among these arthropods, whereas cytokines and growth factors are more variable and species specific. However, considering the great diversity among the crustaceans, one should be cautious in drawing general conclusions from studies of only a few species.
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Affiliation(s)
- Irene Söderhäll
- Department of Comparative Physiology, Uppsala University, Norbyvägen 18 A, 752 36 Uppsala, Sweden.
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19
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Gao H, Wu X, Simon L, Fossett N. Antioxidants maintain E-cadherin levels to limit Drosophila prohemocyte differentiation. PLoS One 2014; 9:e107768. [PMID: 25226030 PMCID: PMC4167200 DOI: 10.1371/journal.pone.0107768] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 08/12/2014] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial reactive oxygen species (ROS) regulate a variety of biological processes by networking with signal transduction pathways to maintain homeostasis and support adaptation to stress. In this capacity, ROS have been shown to promote the differentiation of progenitor cells, including mammalian embryonic and hematopoietic stem cells and Drosophila hematopoietic progenitors (prohemocytes). However, many questions remain about how ROS alter the regulatory machinery to promote progenitor differentiation. Here, we provide evidence for the hypothesis that ROS reduce E-cadherin levels to promote Drosophila prohemocyte differentiation. Specifically, we show that knockdown of the antioxidants, Superoxide dismutatase 2 and Catalase reduce E-cadherin protein levels prior to the loss of Odd-skipped-expressing prohemocytes. Additionally, over-expression of E-cadherin limits prohemocyte differentiation resulting from paraquat-induced oxidative stress. Furthermore, two established targets of ROS, Enhancer of Polycomb and FOS, control the level of E-cadherin protein expression. Finally, we show that knockdown of either Superoxide dismutatase 2 or Catalase leads to an increase in the E-cadherin repressor, Serpent. As a result, antioxidants and targets of ROS can control E-cadherin protein levels, and over-expression of E-cadherin can ameliorate the prohemocyte response to oxidative stress. Collectively, these data strongly suggest that ROS promote differentiation by reducing E-cadherin levels. In mammalian systems, ROS promote embryonic stem cell differentiation, whereas E-cadherin blocks differentiation. However, it is not known if elevated ROS reduce E-cadherin to promote embryonic stem cell differentiation. Thus, our findings may have identified an important mechanism by which ROS promote stem/progenitor cell differentiation.
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Affiliation(s)
- Hongjuan Gao
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Xiaorong Wu
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - LaTonya Simon
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, Baltimore, MD, United States of America
| | - Nancy Fossett
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, United States of America
- * E-mail:
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20
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Gao H, Wu X, Fossett N. Drosophila E-cadherin functions in hematopoietic progenitors to maintain multipotency and block differentiation. PLoS One 2013; 8:e74684. [PMID: 24040319 PMCID: PMC3764055 DOI: 10.1371/journal.pone.0074684] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 08/07/2013] [Indexed: 01/12/2023] Open
Abstract
A fundamental question in stem cell biology concerns the regulatory strategies that control the choice between multipotency and differentiation. Drosophila blood progenitors or prohemocytes exhibit key stem cell characteristics, including multipotency, quiescence, and niche dependence. As a result, studies of Drosophila hematopoiesis have provided important insights into the molecular mechanisms that control these processes. Here, we show that E-cadherin is an important regulator of prohemocyte fate choice, maintaining prohemocyte multipotency and blocking differentiation. These functions are reminiscent of the role of E-cadherin in mammalian embryonic stem cells. We also show that mis-expression of E-cadherin in differentiating hemocytes disrupts the boundary between these cells and undifferentiated prohemocytes. Additionally, upregulation of E-cadherin in differentiating hemocytes increases the number of intermediate cell types expressing the prohemocyte marker, Patched. Furthermore, our studies indicate that the Drosophila GATA transcriptional co-factor, U-shaped, is required for E-cadherin expression. Consequently, E-cadherin is a downstream target of U-shaped in the maintenance of prohemocyte multipotency. In contrast, we showed that forced expression of the U-shaped GATA-binding partner, Serpent, repressed E-cadherin expression and promoted lamellocyte differentiation. Thus, U-shaped may maintain E-cadherin expression by blocking the inhibitory activity of Serpent. Collectively, these observations suggest that GATA:FOG complex formation regulates E-cadherin levels and, thereby, the choice between multipotency and differentiation. The work presented in this report further defines the molecular basis of prohemocyte cell fate choice, which will provide important insights into the mechanisms that govern stem cell biology.
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Affiliation(s)
- Hongjuan Gao
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Xiaorong Wu
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Nancy Fossett
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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21
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Terriente-Felix A, Li J, Collins S, Mulligan A, Reekie I, Bernard F, Krejci A, Bray S. Notch cooperates with Lozenge/Runx to lock haemocytes into a differentiation programme. Development 2013; 140:926-37. [PMID: 23325760 DOI: 10.1242/dev.086785] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The diverse functions of Notch signalling imply that it must elicit context-specific programmes of gene expression. With the aim of investigating how Notch drives cells to differentiate, we have used a genome-wide approach to identify direct Notch targets in Drosophila haemocytes (blood cells), where Notch promotes crystal cell differentiation. Many of the identified Notch-regulated enhancers contain Runx and GATA motifs, and we demonstrate that binding of the Runx protein Lozenge (Lz) is required for enhancers to be competent to respond to Notch. Functional studies of targets, such as klumpfuss (ERG/WT1 family) and pebbled/hindsight (RREB1 homologue), show that Notch acts both to prevent the cells adopting alternate cell fates and to promote morphological characteristics associated with crystal cell differentiation. Inappropriate activity of Klumpfuss perturbs the differentiation programme, resulting in melanotic tumours. Thus, by acting as a master regulator, Lz directs Notch to activate selectively a combination of target genes that correctly locks cells into the differentiation programme.
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Affiliation(s)
- Ana Terriente-Felix
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
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22
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Garcia MA, Alvarez MS, Sailem H, Bousgouni V, Sero J, Bakal C. Differential RNAi screening provides insights into the rewiring of signalling networks during oxidative stress. MOLECULAR BIOSYSTEMS 2013; 8:2605-13. [PMID: 22790786 DOI: 10.1039/c2mb25092f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reactive Oxygen Species (ROS) are a natural by-product of cellular growth and proliferation, and are required for fundamental processes such as protein-folding and signal transduction. However, ROS accumulation, and the onset of oxidative stress, can negatively impact cellular and genomic integrity. Signalling networks have evolved to respond to oxidative stress by engaging diverse enzymatic and non-enzymatic antioxidant mechanisms to restore redox homeostasis. The architecture of oxidative stress response networks during periods of normal growth, and how increased ROS levels dynamically reconfigure these networks are largely unknown. In order to gain insight into the structure of signalling networks that promote redox homeostasis we first performed genome-scale RNAi screens to identify novel suppressors of superoxide accumulation. We then infer relationships between redox regulators by hierarchical clustering of phenotypic signatures describing how gene inhibition affects superoxide levels, cellular viability, and morphology across different genetic backgrounds. Genes that cluster together are likely to act in the same signalling pathway/complex and thus make "functional interactions". Moreover we also calculate differential phenotypic signatures describing the difference in cellular phenotypes following RNAi between untreated cells and cells submitted to oxidative stress. Using both phenotypic signatures and differential signatures we construct a network model of functional interactions that occur between components of the redox homeostasis network, and how such interactions become rewired in the presence of oxidative stress. This network model predicts a functional interaction between the transcription factor Jun and the IRE1 kinase, which we validate in an orthogonal assay. We thus demonstrate the ability of systems-biology approaches to identify novel signalling events.
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Affiliation(s)
- Mar Arias Garcia
- Chester Beatty Laboratories, Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London, UK.
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Fossett N. Signal transduction pathways, intrinsic regulators, and the control of cell fate choice. Biochim Biophys Acta Gen Subj 2012; 1830:2375-84. [PMID: 22705942 DOI: 10.1016/j.bbagen.2012.06.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 05/10/2012] [Accepted: 06/07/2012] [Indexed: 12/14/2022]
Abstract
BACKGROUND Information regarding changes in organismal status is transmitted to the stem cell regulatory machinery by a limited number of signal transduction pathways. Consequently, these pathways derive their functional specificity through interactions with stem cell intrinsic master regulators, notably transcription factors. Identifying the molecular underpinnings of these interactions is critical to understanding stem cell function. SCOPE OF REVIEW This review focuses on studies in Drosophila that identify the gene regulatory basis for interactions between three different signal transduction pathways and an intrinsic master transcriptional regulator in the context of hematopoietic stem-like cell fate choice. Specifically, the interface between the GATA:FOG regulatory complex and the JAK/STAT, BMP, and Hedgehog pathways is examined. MAJOR CONCLUSIONS The GATA:FOG complex coordinates information transmitted by at least three different signal transduction pathways as a means to control stem-like cell fate choice. This illustrates emerging principles concerning regulation of stem cell function and describes a gene regulatory link between changes in organismal status and stem cell response. GENERAL SIGNIFICANCE The Drosophila model system offers a powerful approach to identify the molecular basis of how stem cells receive, interpret, and then respond to changes in organismal status. This article is part of a Special Issue entitled: Biochemistry of Stem Cells.
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Affiliation(s)
- Nancy Fossett
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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24
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Tokusumi Y, Tokusumi T, Stoller-Conrad J, Schulz RA. Serpent, suppressor of hairless and U-shaped are crucial regulators of hedgehog niche expression and prohemocyte maintenance during Drosophila larval hematopoiesis. Development 2010; 137:3561-8. [PMID: 20876645 DOI: 10.1242/dev.053728] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The lymph gland is a specialized organ for hematopoiesis, utilized during larval development in Drosophila. This tissue is composed of distinct cellular domains populated by blood cell progenitors (the medullary zone), niche cells that regulate the choice between progenitor quiescence and hemocyte differentiation [the posterior signaling center (PSC)], and mature blood cells of distinct lineages (the cortical zone). Cells of the PSC express the Hedgehog (Hh) signaling molecule, which instructs cells within the neighboring medullary zone to maintain a hematopoietic precursor state while preventing hemocyte differentiation. As a means to understand the regulatory mechanisms controlling Hh production, we characterized a PSC-active transcriptional enhancer that drives hh expression in supportive niche cells. Our findings indicate that a combination of positive and negative transcriptional inputs program the precise PSC expression of the instructive Hh signal. The GATA factor Serpent (Srp) is essential for hh activation in niche cells, whereas the Suppressor of Hairless [Su(H)] and U-shaped (Ush) transcriptional regulators prevent hh expression in blood cell progenitors and differentiated hemocytes. Furthermore, Srp function is required for the proper differentiation of niche cells. Phenotypic analyses also indicated that the normal activity of all three transcriptional regulators is essential for maintaining the progenitor population and preventing premature hemocyte differentiation. Together, these studies provide mechanistic insights into hh transcriptional regulation in hematopoietic progenitor niche cells, and demonstrate the requirement of the Srp, Su(H) and Ush proteins in the control of niche cell differentiation and blood cell precursor maintenance.
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Affiliation(s)
- Yumiko Tokusumi
- Department of Biological Sciences, University of Notre Dame, 147 Galvin Life Sciences Hall, Notre Dame, IN 46556, USA
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25
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A genome-wide RNA interference screen identifies a differential role of the mediator CDK8 module subunits for GATA/ RUNX-activated transcription in Drosophila. Mol Cell Biol 2010; 30:2837-48. [PMID: 20368357 DOI: 10.1128/mcb.01625-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription factors of the RUNX and GATA families play key roles in the control of cell fate choice and differentiation, notably in the hematopoietic system. During Drosophila hematopoiesis, the RUNX factor Lozenge and the GATA factor Serpent cooperate to induce crystal cell differentiation. We used Serpent/Lozenge-activated transcription as a paradigm to identify modulators of GATA/RUNX activity by a genome-wide RNA interference screen in cultured Drosophila blood cells. Among the 129 factors identified, several belong to the Mediator complex. Mediator is organized in three modules plus a regulatory "CDK8 module," composed of Med12, Med13, CycC, and Cdk8, which has long been thought to behave as a single functional entity. Interestingly, our data demonstrate that Med12 and Med13 but not CycC or Cdk8 are essential for Serpent/Lozenge-induced transactivation in cell culture. Furthermore, our in vivo analysis of crystal cell development show that, while the four CDK8 module subunits control the emergence and the proliferation of this lineage, only Med12 and Med13 regulate its differentiation. We thus propose that Med12/Med13 acts as a coactivator for Serpent/Lozenge during crystal cell differentiation independently of CycC/Cdk8. More generally, we suggest that the set of conserved factors identified herein may regulate GATA/RUNX activity in mammals.
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26
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Upregulation of the Drosophila Friend of GATA gene U-shaped by JAK/STAT signaling maintains lymph gland prohemocyte potency. Mol Cell Biol 2009; 29:6086-96. [PMID: 19737914 DOI: 10.1128/mcb.00244-09] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies using Drosophila melanogaster have contributed significantly to our understanding of the interaction between stem cells and their protective microenvironments or stem cell niches. During lymph gland hematopoiesis, the Drosophila posterior signaling center functions as a stem cell niche to maintain prohemocyte multipotency through Hedgehog and JAK/STAT signaling. In this study, we provide evidence that the Friend of GATA protein U-shaped is an important regulator of lymph gland prohemocyte potency and differentiation. U-shaped expression was determined to be upregulated in third-instar lymph gland prohemocytes and downregulated in a subpopulation of differentiating blood cells. Genetic analyses indicated that U-shaped maintains the prohemocyte population by blocking differentiation. In addition, activated STAT directly regulated ush expression as evidenced by results from loss- and gain-of-function studies and from analyses of the u-shaped hematopoietic cis-regulatory module. Collectively, these findings identify U-shaped as a downstream effector of the posterior signaling center, establishing a novel link between the stem cell niche and the intrinsic regulation of potency and differentiation. Given the functional conservation of Friend of GATA proteins and the role that GATA factors play during cell fate choice, these factors may regulate essential functions of vertebrate hematopoietic stem cells, including processing signals from the stem cell niche.
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27
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A Drosophila model identifies calpains as modulators of the human leukemogenic fusion protein AML1-ETO. Proc Natl Acad Sci U S A 2009; 106:12043-8. [PMID: 19581587 DOI: 10.1073/pnas.0902449106] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The t(8:21)(q22;q22) translocation is 1 of the most common chromosomal abnormalities linked to acute myeloid leukemia (AML). AML1-ETO, the product of this translocation, fuses the N-terminal portion of the RUNX transcription factor AML1 (also known as RUNX1), including its DNA-binding domain, to the almost entire transcriptional corepressor ETO (also known as MTG8 or RUNX1T1). This fusion protein acts primarily by interfering with endogenous AML1 function during myeloid differentiation, although relatively few genes are known that participate with AML1-ETO during leukemia progression. Here, we assessed the consequences of expressing this chimera in Drosophila blood cells. Reminiscent of what is observed in AML, AML1-ETO specifically inhibited the differentiation of the blood cell lineage whose development depends on the RUNX factor Lozenge (LZ) and induced increased numbers of LZ(+) progenitors. Using an in vivo RNAi-based screen for suppressors of AML1-ETO, we identified calpainB as required for AML1-ETO-induced blood cell disorders in Drosophila. Remarkably, calpain inhibition triggered AML1-ETO degradation and impaired the clonogenic potential of the human t(8;21) leukemic blood cell line Kasumi-1. Therefore Drosophila provides a promising genetically tractable model to investigate the conserved basis of leukemogenesis and to open avenues in AML therapy.
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Braun T, Woollard A. RUNX factors in development: lessons from invertebrate model systems. Blood Cells Mol Dis 2009; 43:43-8. [PMID: 19447650 DOI: 10.1016/j.bcmd.2009.05.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 05/06/2009] [Indexed: 12/20/2022]
Abstract
Runt-related (RUNX) transcription factors are evolutionarily conserved regulators of cell proliferation, differentiation and stem cell maintenance. They are critical for the correct development and function of a variety of human tissues, including during haematopoiesis. RUNX genes regulate various aspects of proliferation control, stem cell maintenance, lineage commitment and regulation of differentiation; disruptions in the correct function of RUNX genes have been associated with human pathologies, most prominently cancer. Because of the high context dependency and partial redundancy of vertebrate RUNX genes, invertebrate model systems have been studied in the hope of finding an ancestral function. Here we review the progress of these studies in three invertebrate systems, the fruit fly Drosophila melanogaster, the sea urchin Strongylocentrotus purpuratus and the nematode Caenorhabditis elegans. All essential aspects of RUNX function in vertebrates have counterparts in invertebrates, confirming the usefulness of these studies in simpler organisms. The fact that not all RUNX functions are conserved in all systems, though, underscores the importance of choosing the right model to ask specific questions.
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Affiliation(s)
- Toby Braun
- Department of Biochemistry, Laboratory of Genes and Development, University of Oxford, Oxford, UK
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Salmonella pathogenesis reveals that BMP signaling regulates blood cell homeostasis and immune responses in Drosophila. Proc Natl Acad Sci U S A 2008; 105:14952-7. [PMID: 18815369 DOI: 10.1073/pnas.0808208105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Intercellular signaling by bone morphogenetic proteins (BMPs) regulates developmental decisions in virtually all animals. Here, we report that Decapentaplegic (Dpp; a Drosophila BMP family member) plays a role in blood cell homeostasis and immune responses by regulating a transcription factor cascade. The cascade begins with Dpp repression of Zfh1, continues with Zfh1 activation of Serpent (Srp; a GATA factor), and terminates with Srp activation of U-shaped (Ush) in hematopoietic cells. Hyperactivation of Zfh1, Srp, and Ush in dpp mutants leads to hyperplasia of plasmatocytes. Salmonella challenge revealed that in dpp mutants the misregulation of this cascade also prevents the generation of lamellocytes. These findings support the hypothesis that Ush participates in a switch between plasmatocyte and lamellocyte fate in a common precursor and further suggests a mechanism for how all blood cell types can arise from a single progenitor. These results also demonstrate that combining Drosophila and Salmonella genetics can provide novel opportunities for advancing our knowledge of hematopoiesis and innate immunity.
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