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Winter CM, Szekely P, Popov V, Belcher H, Carter R, Jones M, Fraser SE, Truong TV, Benfey PN. SHR and SCR coordinate root patterning and growth early in the cell cycle. Nature 2024; 626:611-616. [PMID: 38297119 PMCID: PMC10866714 DOI: 10.1038/s41586-023-06971-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/13/2023] [Indexed: 02/02/2024]
Abstract
Precise control of cell division is essential for proper patterning and growth during the development of multicellular organisms. Coordination of formative divisions that generate new tissue patterns with proliferative divisions that promote growth is poorly understood. SHORTROOT (SHR) and SCARECROW (SCR) are transcription factors that are required for formative divisions in the stem cell niche of Arabidopsis roots1,2. Here we show that levels of SHR and SCR early in the cell cycle determine the orientation of the division plane, resulting in either formative or proliferative cell division. We used 4D quantitative, long-term and frequent (every 15 min for up to 48 h) light sheet and confocal microscopy to probe the dynamics of SHR and SCR in tandem within single cells of living roots. Directly controlling their dynamics with an SHR induction system enabled us to challenge an existing bistable model3 of the SHR-SCR gene-regulatory network and to identify key features that are essential for rescue of formative divisions in shr mutants. SHR and SCR kinetics do not align with the expected behaviour of a bistable system, and only low transient levels, present early in the cell cycle, are required for formative divisions. These results reveal an uncharacterized mechanism by which developmental regulators directly coordinate patterning and growth.
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Affiliation(s)
- Cara M Winter
- Department of Biology, Duke University, Durham, NC, USA.
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA.
| | - Pablo Szekely
- Department of Biology, Duke University, Durham, NC, USA.
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA.
| | | | | | - Raina Carter
- Department of Biology, Duke University, Durham, NC, USA
| | - Matthew Jones
- Translational Imaging Center, Bridge Institute, University of Southern California, Los Angeles, CA, USA
| | - Scott E Fraser
- Translational Imaging Center, Bridge Institute, University of Southern California, Los Angeles, CA, USA
| | - Thai V Truong
- Translational Imaging Center, Bridge Institute, University of Southern California, Los Angeles, CA, USA
| | - Philip N Benfey
- Department of Biology, Duke University, Durham, NC, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
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2
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Ahmed N, Etzrodt M, Dettinger P, Kull T, Loeffler D, Hoppe PS, Chavez JS, Zhang Y, Camargo Ortega G, Hilsenbeck O, Nakajima H, Pietras EM, Schroeder T. Blood stem cell PU.1 upregulation is a consequence of differentiation without fast autoregulation. J Exp Med 2022; 219:e20202490. [PMID: 34817548 PMCID: PMC8624737 DOI: 10.1084/jem.20202490] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 05/07/2021] [Accepted: 09/23/2021] [Indexed: 11/12/2022] Open
Abstract
Transcription factors (TFs) regulate cell fates, and their expression must be tightly regulated. Autoregulation is assumed to regulate many TFs' own expression to control cell fates. Here, we manipulate and quantify the (auto)regulation of PU.1, a TF controlling hematopoietic stem and progenitor cells (HSPCs), and correlate it to their future fates. We generate transgenic mice allowing both inducible activation of PU.1 and noninvasive quantification of endogenous PU.1 protein expression. The quantified HSPC PU.1 dynamics show that PU.1 up-regulation occurs as a consequence of hematopoietic differentiation independently of direct fast autoregulation. In contrast, inflammatory signaling induces fast PU.1 up-regulation, which does not require PU.1 expression or its binding to its own autoregulatory enhancer. However, the increased PU.1 levels induced by inflammatory signaling cannot be sustained via autoregulation after removal of the signaling stimulus. We conclude that PU.1 overexpression induces HSC differentiation before PU.1 up-regulation, only later generating cell types with intrinsically higher PU.1.
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Affiliation(s)
- Nouraiz Ahmed
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Martin Etzrodt
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Philip Dettinger
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Tobias Kull
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Dirk Loeffler
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Philipp S. Hoppe
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - James S. Chavez
- Division of Hematology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Yang Zhang
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Germán Camargo Ortega
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Oliver Hilsenbeck
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
| | - Hideaki Nakajima
- Department of Stem Cell and Immune Regulation, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Eric M. Pietras
- Division of Hematology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Timm Schroeder
- Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland
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3
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A Novel GATA2 Protein Reporter Mouse Reveals Hematopoietic Progenitor Cell Types. Stem Cell Reports 2020; 15:326-339. [PMID: 32649900 PMCID: PMC7419669 DOI: 10.1016/j.stemcr.2020.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 01/05/2023] Open
Abstract
The transcription factor (TF) GATA2 plays a key role in organ development and cell fate control in the central nervous, urogenital, respiratory, and reproductive systems, and in primitive and definitive hematopoiesis. Here, we generate a knockin protein reporter mouse line expressing a GATA2VENUS fusion from the endogenous Gata2 genomic locus, with correct expression and localization of GATA2VENUS in different organs. GATA2VENUS expression is heterogeneous in different hematopoietic stem and progenitor cell populations (HSPCs), identifies functionally distinct subsets, and suggests a novel monocyte and mast cell lineage bifurcation point. GATA2 levels further correlate with proliferation and lineage outcome of hematopoietic progenitors. The GATA2VENUS mouse line improves the identification of specific live cell types during embryonic and adult development and will be crucial for analyzing GATA2 protein dynamics in TF networks. A novel GATA2VENUS fusion mouse line to report GATA2 protein expression VENUS fusion does not alter GATA2 expression or disturb development or homeostasis GATA2 expression identifies functionally distinct HSPC subpopulations GATA2 expression unveils an earlier monocyte-mast cell lineage bifurcation point
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4
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Understanding cell fate control by continuous single-cell quantification. Blood 2019; 133:1406-1414. [PMID: 30728141 DOI: 10.1182/blood-2018-09-835397] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/20/2018] [Indexed: 12/15/2022] Open
Abstract
Cells and the molecular processes underlying their behavior are highly dynamic. Understanding these dynamic biological processes requires noninvasive continuous quantitative single-cell observations, instead of population-based average or single-cell snapshot analysis. Ideally, single-cell dynamics are measured long-term in vivo; however, despite progress in recent years, technical limitations still prevent such studies. On the other hand, in vitro studies have proven to be useful for answering long-standing questions. Although technically still demanding, long-term single-cell imaging and tracking in vitro have become valuable tools to elucidate dynamic molecular processes and mechanisms, especially in rare and heterogeneous populations. Here, we review how continuous quantitative single-cell imaging of hematopoietic cells has been used to solve decades-long controversies. Because aberrant cell fate decisions are at the heart of tissue degeneration and disease, we argue that studying their molecular dynamics using quantitative single-cell imaging will also improve our understanding of these processes and lead to new strategies for therapies.
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5
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Sanada CD, Ooi AT. Single-Cell Dosing and mRNA Sequencing of Suspension and Adherent Cells Using the Polaris TM System. Methods Mol Biol 2019; 1979:185-195. [PMID: 31028639 DOI: 10.1007/978-1-4939-9240-9_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Single-cell functional analysis provides a natural next step in the now widely adopted single-cell mRNA sequencing studies. Functional studies can be designed to study cellular context by using single-cell culture, perturbation, manipulation, or treatment. Here we present a method for a functional study of 48 single cells by single-cell isolation, dosing, and mRNA sequencing with an integrated fluidic circuit (IFC) on the Fluidigm® Polaris™ system. The major procedures required to execute this protocol are (1) cell preparation and staining; (2) priming, single-cell selection, cell dosing, cell staining, and cDNA generation on the Polaris IFC; and (3) preparation and sequencing of single-cell mRNA-seq libraries. The cell preparation and staining steps employ the use of a universal tracking dye to trace all cells that enter the IFC, while additional fluorescence dyes chosen by the user can be used to differentiate cell types in the overall mix. The steps on the Polaris IFC follow standard protocols, which are also described in the Fluidigm user documentation. The library preparation step adds Illumina® Nextera® XT indexes to the cDNA generated on the Polaris IFC. The resulting sequencing libraries can be sequenced on any Illumina sequencing platform.
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Affiliation(s)
| | - Aik T Ooi
- Fluidigm Corporation, South San Francisco, CA, USA
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6
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Lineage marker synchrony in hematopoietic genealogies refutes the PU.1/GATA1 toggle switch paradigm. Nat Commun 2018; 9:2697. [PMID: 30002371 PMCID: PMC6043612 DOI: 10.1038/s41467-018-05037-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 05/25/2018] [Indexed: 01/21/2023] Open
Abstract
Molecular regulation of cell fate decisions underlies health and disease. To identify molecules that are active or regulated during a decision, and not before or after, the decision time point is crucial. However, cell fate markers are usually delayed and the time of decision therefore unknown. Fortunately, dividing cells induce temporal correlations in their progeny, which allow for retrospective inference of the decision time point. We present a computational method to infer decision time points from correlated marker signals in genealogies and apply it to differentiating hematopoietic stem cells. We find that myeloid lineage decisions happen generations before lineage marker onsets. Inferred decision time points are in agreement with data from colony assay experiments. The levels of the myeloid transcription factor PU.1 do not change during, but long after the predicted lineage decision event, indicating that the PU.1/GATA1 toggle switch paradigm cannot explain the initiation of early myeloid lineage choice.
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7
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Hastreiter S, Skylaki S, Loeffler D, Reimann A, Hilsenbeck O, Hoppe PS, Coutu DL, Kokkaliaris KD, Schwarzfischer M, Anastassiadis K, Theis FJ, Schroeder T. Inductive and Selective Effects of GSK3 and MEK Inhibition on Nanog Heterogeneity in Embryonic Stem Cells. Stem Cell Reports 2018; 11:58-69. [PMID: 29779897 PMCID: PMC6066909 DOI: 10.1016/j.stemcr.2018.04.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 11/30/2022] Open
Abstract
Embryonic stem cells (ESCs) display heterogeneous expression of pluripotency factors such as Nanog when cultured with serum and leukemia inhibitory factor (LIF). In contrast, dual inhibition of the signaling kinases GSK3 and MEK (2i) converts ESC cultures into a state with more uniform and high Nanog expression. However, it is so far unclear whether 2i acts through an inductive or selective mechanism. Here, we use continuous time-lapse imaging to quantify the dynamics of death, proliferation, and Nanog expression in mouse ESCs after 2i addition. We show that 2i has a dual effect: it both leads to increased cell death of Nanog low ESCs (selective effect) and induces and maintains high Nanog levels (inductive effect) in single ESCs. Genetic manipulation further showed that presence of NANOG protein is important for cell viability in 2i medium. This demonstrates complex Nanog-dependent effects of 2i treatment on ESC cultures. Continuous long-term single-cell quantification of 2i effects on murine ESCs 2i enriches for a Nanog high population through a selective cell death effect 2i also upregulates Nanog expression and prevents its downregulation The viability of Nanog−/− cells is compromised in 2i
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Affiliation(s)
- Simon Hastreiter
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Stavroula Skylaki
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Dirk Loeffler
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Andreas Reimann
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Oliver Hilsenbeck
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Philipp S Hoppe
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Daniel L Coutu
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Konstantinos D Kokkaliaris
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Michael Schwarzfischer
- Institute of Computational Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | | | - Fabian J Theis
- Institute of Computational Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Mathematics, Technische Universität München, 85748 Garching, Germany
| | - Timm Schroeder
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland; Research Unit Stem Cell Dynamics, Helmholtz Zentrum München, 85764 Neuherberg, Germany.
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