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Chadha Y, Khurana A, Schmoller KM. Eukaryotic cell size regulation and its implications for cellular function and dysfunction. Physiol Rev 2024; 104:1679-1717. [PMID: 38900644 DOI: 10.1152/physrev.00046.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 05/24/2024] [Accepted: 06/19/2024] [Indexed: 06/22/2024] Open
Abstract
Depending on cell type, environmental inputs, and disease, the cells in the human body can have widely different sizes. In recent years, it has become clear that cell size is a major regulator of cell function. However, we are only beginning to understand how the optimization of cell function determines a given cell's optimal size. Here, we review currently known size control strategies of eukaryotic cells and the intricate link of cell size to intracellular biomolecular scaling, organelle homeostasis, and cell cycle progression. We detail the cell size-dependent regulation of early development and the impact of cell size on cell differentiation. Given the importance of cell size for normal cellular physiology, cell size control must account for changing environmental conditions. We describe how cells sense environmental stimuli, such as nutrient availability, and accordingly adapt their size by regulating cell growth and cell cycle progression. Moreover, we discuss the correlation of pathological states with misregulation of cell size and how for a long time this was considered a downstream consequence of cellular dysfunction. We review newer studies that reveal a reversed causality, with misregulated cell size leading to pathophysiological phenotypes such as senescence and aging. In summary, we highlight the important roles of cell size in cellular function and dysfunction, which could have major implications for both diagnostics and treatment in the clinic.
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Affiliation(s)
- Yagya Chadha
- Institute of Functional Epigenetics, Molecular Targets and Therapeutics Center, Helmholtz Zentrum München, Neuherberg, Germany
| | - Arohi Khurana
- Institute of Functional Epigenetics, Molecular Targets and Therapeutics Center, Helmholtz Zentrum München, Neuherberg, Germany
| | - Kurt M Schmoller
- Institute of Functional Epigenetics, Molecular Targets and Therapeutics Center, Helmholtz Zentrum München, Neuherberg, Germany
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2
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Nieto C, Vargas-García CA, Singh A. A Generalized Adder mechanism for Cell Size Homeostasis: Implications for Stochastic Dynamics of Clonal Proliferation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.13.612972. [PMID: 39345437 PMCID: PMC11429681 DOI: 10.1101/2024.09.13.612972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Measurements of cell size dynamics have revealed phenomeno-logical principles by which individual cells control their size across diverse organisms. One of the emerging paradigms of cell size homeostasis is the adder , where the cell cycle duration is established such that the cell size increase from birth to division is independent of the newborn cell size. We provide a mechanistic formulation of the adder considering that cell size follows any arbitrary non-exponential growth law . Our results show that the main requirement to obtain an adder regardless of the growth law (the time derivative of cell size) is that cell cycle regulators are produced at a rate proportional to the growth law and cell division is triggered when these molecules reach a prescribed threshold level. Among the implications of this generalized adder, we investigate fluctuations in the proliferation of single-cell derived colonies. Considering exponential cell size growth, random fluctuations in clonal size show a transient increase and then eventually decay to zero over time (i.e., clonal populations become asymptotically more similar). In contrast, several forms of non-exponential cell size dynamics (with adder-based cell size control) yield qualitatively different results: clonal size fluctuations monotonically increase over time reaching a non-zero value. These results characterize the interplay between cell size homeostasis at the single-cell level and clonal proliferation at the population level, explaining the broad fluctuations in clonal sizes seen in barcoded human cell lines.
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Affiliation(s)
- César Nieto
- Department of Electrical and Computer Engineering, University of Delaware. Newark, DE 19716, USA
| | | | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware. Newark, DE 19716, USA
- Department of Electrical and Computer Engineering, Biomedical Engineering, Mathematical Sciences, Interdisciplinary Neuroscience Program, University of Delaware, Newark, DE 19716, USA
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3
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Das P, Murthy S, Abbas E, White K, Arya R. The Hox Gene, abdominal A controls timely mitotic entry of neural stem cell and their growth during CNS development in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.04.611161. [PMID: 39282366 PMCID: PMC11398374 DOI: 10.1101/2024.09.04.611161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/20/2024]
Abstract
The size of a cell is important for its function and physiology. Interestingly, size variation can be easily observed in clonally derived embryonic and hematopoietic stem cells. Here, we investigated the regulation of stem cell growth and its association with cell fate. We observed heterogeneous sizes of neuroblasts or neural stem cells (NSCs) in the Drosophila ventral nerve cord (VNC). Specifically, thoracic NSCs were larger than those in the abdominal region of the VNC. Our research uncovered a significant role of the Hox gene abdominal A (abdA) in the regulation of abdominal NSC growth. Developmental expression of AbdA retards their growth and delays mitotic entry compared to thoracic NSCs. The targeted loss of abdA enhanced their growth and caused an earlier entry into mitosis with a faster cycling rate. Furthermore, ectopic expression of abdA reduced the size of thoracic NSCs and delayed their entry into mitosis. We suggest that abdA plays an instructive role in regulating NSC size and exit from quiescence. This study demonstrates for the first time the involvement of abdA in NSC fate determination by regulating their growth, entry into mitosis and proliferation rate, and thus their potential to make appropriate number of progeny for CNS patterning.
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Affiliation(s)
- Papri Das
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi-221005
| | | | - Eshan Abbas
- ADP Road, Christianpatty, Nagaon, Assam- 782003, India
| | - Kristin White
- MGH/Harvard Medical School,CBRC, Bldg 149, 13th St, Charlestown, MA 02129
| | - Richa Arya
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi-221005
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4
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Annecke HTP, Eidelpes R, Feyrer H, Ilgen J, Gürdap CO, Dasgupta R, Petzold K. Optimising in-cell NMR acquisition for nucleic acids. JOURNAL OF BIOMOLECULAR NMR 2024:10.1007/s10858-024-00448-5. [PMID: 39162911 DOI: 10.1007/s10858-024-00448-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 08/08/2024] [Indexed: 08/21/2024]
Abstract
Understanding the structure and function of nucleic acids in their native environment is crucial to structural biology and one focus of in-cell NMR spectroscopy. Many challenges hamper in-cell NMR in human cell lines, e.g. sample decay through cell death and RNA degradation. The resulting low signal intensities and broad line widths limit the use of more complex NMR experiments, reducing the possible structural and dynamic information that can be extracted. Here, we optimize the detection of imino proton signals, indicators of base-pairing and therefore secondary structure, of a double-stranded DNA oligonucleotide in HeLa cells, using selective excitation. We demonstrate the reproducible quantification of in-cell selective longitudinal relaxation times (selT1), which are reduced compared to the in vitro environment, as a result of interactions with the complex cellular environment. By measuring the intracellular selT1, we optimize the existing proton pulse sequences, and shorten measurement time whilst enhancing the signal gained per unit of time. This exemplifies an advantage of selective excitation over conventional methods like jump-return water suppression for in-cell NMR. Furthermore, important experimental controls are discussed, including intracellular quantification, supernatant control measurements, as well as the processing of lowly concentrated in-cell NMR samples. We expect that robust and fast in-cell NMR experiments of nucleic acids will facilitate the study of structure and dynamics and reveal their functional correlation.
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Affiliation(s)
- Henry T P Annecke
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solnavägen 1, 171 65, Stockholm, Sweden
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Husargatan 3, 752 37, Uppsala, Sweden
| | - Reiner Eidelpes
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solnavägen 1, 171 65, Stockholm, Sweden
| | - Hannes Feyrer
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solnavägen 1, 171 65, Stockholm, Sweden
| | - Julian Ilgen
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solnavägen 1, 171 65, Stockholm, Sweden
| | - Cenk Onur Gürdap
- Department of Women's and Children's Health, Karolinska Institutet, 171 65, Solna, Sweden
- Science for Life Laboratory, 171 65, Solna, Sweden
| | - Rubin Dasgupta
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Husargatan 3, 752 37, Uppsala, Sweden
| | - Katja Petzold
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solnavägen 1, 171 65, Stockholm, Sweden.
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Husargatan 3, 752 37, Uppsala, Sweden.
- Science for Life Laboratory, 171 65, Solna, Sweden.
- Center of Excellence for the Chemical Mechanisms of Life, Uppsala University, 752 37, Uppsala, Sweden.
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5
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Lanz MC, Zhang S, Swaffer MP, Ziv I, Götz LH, Kim J, McCarthy F, Jarosz DF, Elias JE, Skotheim JM. Genome dilution by cell growth drives starvation-like proteome remodeling in mammalian and yeast cells. Nat Struct Mol Biol 2024:10.1038/s41594-024-01353-z. [PMID: 39048803 DOI: 10.1038/s41594-024-01353-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 06/12/2024] [Indexed: 07/27/2024]
Abstract
Cell size is tightly controlled in healthy tissues and single-celled organisms, but it remains unclear how cell size influences physiology. Increasing cell size was recently shown to remodel the proteomes of cultured human cells, demonstrating that large and small cells of the same type can be compositionally different. In the present study, we utilize the natural heterogeneity of hepatocyte ploidy and yeast genetics to establish that the ploidy-to-cell size ratio is a highly conserved determinant of proteome composition. In both mammalian and yeast cells, genome dilution by cell growth elicits a starvation-like phenotype, suggesting that growth in large cells is restricted by genome concentration in a manner that mimics a limiting nutrient. Moreover, genome dilution explains some proteomic changes ascribed to yeast aging. Overall, our data indicate that genome concentration drives changes in cell composition independently of external environmental cues.
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Affiliation(s)
- Michael C Lanz
- Department of Biology, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub San Francisco, Stanford University, Stanford, CA, USA.
| | - Shuyuan Zhang
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Inbal Ziv
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA
| | | | - Jacob Kim
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA
| | - Frank McCarthy
- Chan Zuckerberg Biohub San Francisco, Stanford University, Stanford, CA, USA
| | - Daniel F Jarosz
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Joshua E Elias
- Chan Zuckerberg Biohub San Francisco, Stanford University, Stanford, CA, USA
| | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub San Francisco, Stanford University, Stanford, CA, USA.
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6
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Dixon JC, Frick CL, Leveille CL, Garrison P, Lee PA, Mogre SS, Morris B, Nivedita N, Vasan R, Chen J, Fraser CL, Gamlin CR, Harris LK, Hendershott MC, Johnson GT, Klein KN, Oluoch SA, Thirstrup DJ, Sluzewski MF, Wilhelm L, Yang R, Toloudis DM, Viana MP, Theriot JA, Rafelski SM. Colony context and size-dependent compensation mechanisms give rise to variations in nuclear growth trajectories. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601071. [PMID: 38979140 PMCID: PMC11230432 DOI: 10.1101/2024.06.28.601071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
To investigate the fundamental question of how cellular variations arise across spatiotemporal scales in a population of identical healthy cells, we focused on nuclear growth in hiPS cell colonies as a model system. We generated a 3D timelapse dataset of thousands of nuclei over multiple days, and developed open-source tools for image and data analysis and an interactive timelapse viewer for exploring quantitative features of nuclear size and shape. We performed a data-driven analysis of nuclear growth variations across timescales. We found that individual nuclear volume growth trajectories arise from short timescale variations attributable to their spatiotemporal context within the colony. We identified a strikingly time-invariant volume compensation relationship between nuclear growth duration and starting volume across the population. Notably, we discovered that inheritance plays a crucial role in determining these two key nuclear growth features while other growth features are determined by their spatiotemporal context and are not inherited.
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Affiliation(s)
- Julie C. Dixon
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Christopher L. Frick
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Chantelle L. Leveille
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Philip Garrison
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Peyton A. Lee
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Saurabh S. Mogre
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Benjamin Morris
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Nivedita Nivedita
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Ritvik Vasan
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- These authors contributed equally to this work
| | - Jianxu Chen
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
- Present address: Leibniz-Institut fur Analytische Wissenschaften – ISAS – e.V., Dortmund, 44139, Germany
| | - Cameron L. Fraser
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Clare R. Gamlin
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Leigh K. Harris
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | | | - Graham T. Johnson
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Kyle N. Klein
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Sandra A. Oluoch
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Derek J. Thirstrup
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - M. Filip Sluzewski
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Lyndsay Wilhelm
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Ruian Yang
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Daniel M. Toloudis
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Matheus P. Viana
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
| | - Julie A. Theriot
- Department of Biology and Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Susanne M. Rafelski
- Allen Institute for Cell Science, 615 Westlake Ave N, Seattle, WA, 98109, USA
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7
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Scepanovic G, Fernandez-Gonzalez R. Should I shrink or should I grow: cell size changes in tissue morphogenesis. Genome 2024; 67:125-138. [PMID: 38198661 DOI: 10.1139/gen-2023-0091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Cells change shape, move, divide, and die to sculpt tissues. Common to all these cell behaviours are cell size changes, which have recently emerged as key contributors to tissue morphogenesis. Cells can change their mass-the number of macromolecules they contain-or their volume-the space they encompass. Changes in cell mass and volume occur through different molecular mechanisms and at different timescales, slow for changes in mass and rapid for changes in volume. Therefore, changes in cell mass and cell volume, which are often linked, contribute to the development and shaping of tissues in different ways. Here, we review the molecular mechanisms by which cells can control and alter their size, and we discuss how changes in cell mass and volume contribute to tissue morphogenesis. The role that cell size control plays in developing embryos is only starting to be elucidated. Research on the signals that control cell size will illuminate our understanding of the cellular and molecular mechanisms that drive tissue morphogenesis.
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Affiliation(s)
- Gordana Scepanovic
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
- Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Rodrigo Fernandez-Gonzalez
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
- Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada
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8
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Wu W, Ishamuddin SH, Quinn TW, Yerrum S, Zhang Y, Debaize LL, Kao PL, Duquette SM, Murakami MA, Mohseni M, Chow KH, Miettinen TP, Ligon KL, Manalis SR. Measuring single-cell density with high throughput enables dynamic profiling of immune cell and drug response from patient samples. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591092. [PMID: 38712225 PMCID: PMC11071500 DOI: 10.1101/2024.04.25.591092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Cell density, the ratio of cell mass to volume, is an indicator of molecular crowding and therefore a fundamental determinant of cell state and function. However, existing density measurements lack the precision or throughput to quantify subtle differences in cell states, particularly in primary samples. Here we present an approach for measuring the density of 30,000 single cells per hour with a precision of 0.03% (0.0003 g/mL) by integrating fluorescence exclusion microscopy with a suspended microchannel resonator. Applying this approach to human lymphocytes, we discovered that cell density and its variation decrease as cells transition from quiescence to a proliferative state, suggesting that the level of molecular crowding decreases and becomes more regulated upon entry into the cell cycle. Using a pancreatic cancer patient-derived xenograft model, we found that the ex vivo density response of primary tumor cells to drug treatment can predict in vivo tumor growth response. Our method reveals unexpected behavior in molecular crowding during cell state transitions and suggests density as a new biomarker for functional precision medicine.
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Affiliation(s)
- Weida Wu
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 21 Ames St #56-651, Cambridge, MA 02139, USA
| | - Sarah H. Ishamuddin
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
| | - Thomas W. Quinn
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, 21 Burlington Ave, Boston, MA 02215, USA
- Department of Pathology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Smitha Yerrum
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, 21 Burlington Ave, Boston, MA 02215, USA
- Department of Pathology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Ye Zhang
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
| | - Lydie L. Debaize
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Pei-Lun Kao
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, 21 Burlington Ave, Boston, MA 02215, USA
- Department of Pathology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Sarah Marie Duquette
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 21 Ames St #56-651, Cambridge, MA 02139, USA
| | - Mark A. Murakami
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Morvarid Mohseni
- Oncology Discovery, Bristol-Myers Squibb, 250 Water St, Cambridge, MA 02141, USA
| | - Kin-Hoe Chow
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, 21 Burlington Ave, Boston, MA 02215, USA
- Department of Pathology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Teemu P. Miettinen
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
| | - Keith L. Ligon
- Center for Patient-Derived Models, Dana-Farber Cancer Institute, 21 Burlington Ave, Boston, MA 02215, USA
- Department of Pathology, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
- Broad Institute of Harvard and MIT, 415 Main St, Cambridge, MA 02142, USA
- Department of Pathology, Brigham & Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02215, USA
- Department of Pathology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Scott R. Manalis
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main St building 76, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 21 Ames St #56-651, Cambridge, MA 02139, USA
- Broad Institute of Harvard and MIT, 415 Main St, Cambridge, MA 02142, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 33 Massachusetts Ave, Cambridge, MA 02139, USA
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9
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Ni Q, Ge Z, Li Y, Shatkin G, Fu J, Bera K, Yang Y, Wang Y, Sen A, Wu Y, Vasconcelos ACN, Feinberg AP, Konstantopoulos K, Sun SX. Cytoskeletal activation of NHE1 regulates mechanosensitive cell volume adaptation and proliferation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.31.555808. [PMID: 37693593 PMCID: PMC10491192 DOI: 10.1101/2023.08.31.555808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Mammalian cells can rapidly respond to osmotic and hydrostatic pressure imbalances during an environmental change, generating large fluxes of water and ions that alter cell volume within minutes. While the role of ion pump and leak in cell volume regulation has been well-established, the potential contribution of the actomyosin cytoskeleton and its interplay with ion transporters is unclear. We discovered a cell volume regulation system that is controlled by cytoskeletal activation of ion transporters. After a hypotonic shock, normal-like cells (NIH-3T3, MCF-10A, and others) display a slow secondary volume increase (SVI) following the immediate regulatory volume decrease. We show that SVI is initiated by hypotonic stress induced Ca 2+ influx through stretch activated channel Piezo1, which subsequently triggers actomyosin remodeling. The actomyosin network further activates NHE1 through their synergistic linker ezrin, inducing SVI after the initial volume recovery. We find that SVI is absent in cancer cell lines such as HT1080 and MDA-MB-231, where volume regulation is dominated by intrinsic response of ion transporters. A similar cytoskeletal activation of NHE1 can also be achieved by mechanical stretching. On compliant substrates where cytoskeletal contractility is attenuated, SVI generation is abolished. Moreover, cytoskeletal activation of NHE1 during SVI triggers nuclear deformation, leading to a significant, immediate transcriptomic change in 3T3 cells, a phenomenon that is again absent in HT1080 cells. While hypotonic shock hinders ERK-dependent cell growth, cells deficient in SVI are unresponsive to such inhibitory effects. Overall, our findings reveal the critical role of Ca 2+ and actomyosin-mediated mechanosensation in the regulation of ion transport, cell volume, transcriptomics, and cell proliferation.
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10
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Sun T, Xiang Y, Turner F, Bao X. Integrated Experimental and Mathematical Exploration of Modular Tissue Cultures for Developmental Engineering. Int J Mol Sci 2024; 25:2987. [PMID: 38474234 DOI: 10.3390/ijms25052987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/06/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Developmental engineering (DE) involves culturing various cells on modular scaffolds (MSs), yielding modular tissues (MTs) assembled into three-dimensional (3D) tissues, mimicking developmental biology. This study employs an integrated approach, merging experimental and mathematical methods to investigate the biological processes in MT cultivation and assembly. Human dermal fibroblasts (HDFs) were cultured on tissue culture plastics, poly(lactic acid) (PLA) discs with regular open structures, or spherical poly(methyl methacrylate) (PMMA) MSs, respectively. Notably, HDFs exhibited flattened spindle shapes when adhered to solid surfaces, and complex 3D structures when migrating into the structured voids of PLA discs or interstitial spaces between aggregated PMMA MSs, showcasing coordinated colonization of porous scaffolds. Empirical investigations led to power law models simulating density-dependent cell growth on solid surfaces or voids. Concurrently, a modified diffusion model was applied to simulate oxygen diffusion within tissues cultured on solid surfaces or porous structures. These mathematical models were subsequently combined to explore the influences of initial cell seeding density, culture duration, and oxygen diffusion on MT cultivation and assembly. The findings underscored the intricate interplay of factors influencing MT design for tissue assembly. The integrated approach provides insights into mechanistic aspects, informing bioprocess design for manufacturing MTs and 3D tissues in DE.
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Affiliation(s)
- Tao Sun
- Department of Chemical Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Yu Xiang
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Freya Turner
- Department of Chemical Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Xujin Bao
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
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11
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Pennacchio FA, Poli A, Pramotton FM, Lavore S, Rancati I, Cinquanta M, Vorselen D, Prina E, Romano OM, Ferrari A, Piel M, Cosentino Lagomarsino M, Maiuri P. N2FXm, a method for joint nuclear and cytoplasmic volume measurements, unravels the osmo-mechanical regulation of nuclear volume in mammalian cells. Nat Commun 2024; 15:1070. [PMID: 38326317 PMCID: PMC10850064 DOI: 10.1038/s41467-024-45168-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 01/15/2024] [Indexed: 02/09/2024] Open
Abstract
In eukaryotes, cytoplasmic and nuclear volumes are tightly regulated to ensure proper cell homeostasis. However, current methods to measure cytoplasmic and nuclear volumes, including confocal 3D reconstruction, have limitations, such as relying on two-dimensional projections or poor vertical resolution. Here, to overcome these limitations, we describe a method, N2FXm, to jointly measure cytoplasmic and nuclear volumes in single cultured adhering human cells, in real time, and across cell cycles. We find that this method accurately provides joint size over dynamic measurements and at different time resolutions. Moreover, by combining several experimental perturbations and analyzing a mathematical model including osmotic effects and tension, we show that N2FXm can give relevant insights on how mechanical forces exerted by the cytoskeleton on the nuclear envelope can affect the growth of nucleus volume by biasing nuclear import. Our method, by allowing for accurate joint nuclear and cytoplasmic volume dynamic measurements at different time resolutions, highlights the non-constancy of the nucleus/cytoplasm ratio along the cell cycle.
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Affiliation(s)
- Fabrizio A Pennacchio
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
| | - Alessandro Poli
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Francesca Michela Pramotton
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, Zurich, CH-8092, Switzerland
| | - Stefania Lavore
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Ilaria Rancati
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Mario Cinquanta
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Daan Vorselen
- Department of Biology and Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98105, USA
| | - Elisabetta Prina
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Orso Maria Romano
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Aldo Ferrari
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, Zurich, CH-8092, Switzerland
| | - Matthieu Piel
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
- Institut Pierre-Gilles de Gennes, PSL Research University, F-75005, Paris, France
| | - Marco Cosentino Lagomarsino
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
- Dipartimento di Fisica, Università degli Studi di Milano, and I.N.F.N., Via Celoria 16, 20133, Milan, Italy
| | - Paolo Maiuri
- IFOM ETS-The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy.
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Via S. Pansini 5, 80131, Naples, Italy.
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12
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Diehl FF, Sapp KM, Vander Heiden MG. The bidirectional relationship between metabolism and cell cycle control. Trends Cell Biol 2024; 34:136-149. [PMID: 37385879 DOI: 10.1016/j.tcb.2023.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 07/01/2023]
Abstract
The relationship between metabolism and cell cycle progression is complex and bidirectional. Cells must rewire metabolism to meet changing biosynthetic demands across cell cycle phases. In turn, metabolism can influence cell cycle progression through direct regulation of cell cycle proteins, through nutrient-sensing signaling pathways, and through its impact on cell growth, which is linked to cell division. Furthermore, metabolism is a key player in mediating quiescence-proliferation transitions in physiologically important cell types, such as stem cells. How metabolism impacts cell cycle progression, exit, and re-entry, as well as how these processes impact metabolism, is not fully understood. Recent advances uncovering mechanistic links between cell cycle regulators and metabolic processes demonstrate a complex relationship between metabolism and cell cycle control, with many questions remaining.
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Affiliation(s)
- Frances F Diehl
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Koch Institute for Integrative Cancer Research and the Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kiera M Sapp
- Koch Institute for Integrative Cancer Research and the Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research and the Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Dana-Farber Cancer Institute, Boston, MA, USA.
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13
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Huang R, Situ Q, Lei J. Dynamics of cell-type transition mediated by epigenetic modifications. J Theor Biol 2024; 577:111664. [PMID: 37977478 DOI: 10.1016/j.jtbi.2023.111664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 10/20/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023]
Abstract
Maintaining tissue homeostasis requires appropriate regulation of stem cell differentiation. The Waddington landscape posits that gene circuits in a cell form a potential landscape of different cell types, wherein cells follow attractors of the probability landscape to develop into distinct cell types. However, how adult stem cells achieve a delicate balance between self-renewal and differentiation remains unclear. We propose that random inheritance of epigenetic states plays a pivotal role in stem cell differentiation and present a hybrid model of stem cell differentiation induced by epigenetic modifications. Our comprehensive model integrates gene regulation networks, epigenetic state inheritance, and cell regeneration, encompassing multi-scale dynamics ranging from transcription regulation to cell population. Through model simulations, we demonstrate that random inheritance of epigenetic states during cell divisions can spontaneously induce cell differentiation, dedifferentiation, and transdifferentiation. Furthermore, we investigate the influences of interfering with epigenetic modifications and introducing additional transcription factors on the probabilities of dedifferentiation and transdifferentiation, revealing the underlying mechanism of cell reprogramming. This in silico model provides valuable insights into the intricate mechanism governing stem cell differentiation and cell reprogramming and offers a promising path to enhance the field of regenerative medicine.
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Affiliation(s)
- Rongsheng Huang
- School of Science, Jimei University, Xiamen, Fujian, 361021, China
| | - Qiaojun Situ
- Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua University, Beijing, 100084, China
| | - Jinzhi Lei
- School of Mathematical Sciences, Center for Applied Mathematics, Tiangong University, Tianjin, 300387, China.
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14
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Maiti S, Bhattacharya K, Wider D, Hany D, Panasenko O, Bernasconi L, Hulo N, Picard D. Hsf1 and the molecular chaperone Hsp90 support a 'rewiring stress response' leading to an adaptive cell size increase in chronic stress. eLife 2023; 12:RP88658. [PMID: 38059913 DOI: 10.7554/elife.88658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023] Open
Abstract
Cells are exposed to a wide variety of internal and external stresses. Although many studies have focused on cellular responses to acute and severe stresses, little is known about how cellular systems adapt to sublethal chronic stresses. Using mammalian cells in culture, we discovered that they adapt to chronic mild stresses of up to two weeks, notably proteotoxic stresses such as heat, by increasing their size and translation, thereby scaling the amount of total protein. These adaptations render them more resilient to persistent and subsequent stresses. We demonstrate that Hsf1, well known for its role in acute stress responses, is required for the cell size increase, and that the molecular chaperone Hsp90 is essential for coupling the cell size increase to augmented translation. We term this translational reprogramming the 'rewiring stress response', and propose that this protective process of chronic stress adaptation contributes to the increase in size as cells get older, and that its failure promotes aging.
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Affiliation(s)
- Samarpan Maiti
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
| | - Kaushik Bhattacharya
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
| | - Diana Wider
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
| | - Dina Hany
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
- On leave from: Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Pharos University in Alexandria, Alexandria, Egypt
| | - Olesya Panasenko
- BioCode: RNA to Proteins Core Facility, Département de Microbiologie et Médecine Moléculaire, Faculté de Médecine, Université de Genève, Genève, Switzerland
| | - Lilia Bernasconi
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
| | - Nicolas Hulo
- Institute of Genetics and Genomics of Geneva, Université de Genève, Genève, Switzerland
| | - Didier Picard
- Département de Biologie Moléculaire et Cellulaire, Université de Genève, Genève, Switzerland
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15
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Stürmer VS, Stopper S, Binder P, Klemmer A, Lichti NP, Becker NB, Guizetti J. Progeny counter mechanism in malaria parasites is linked to extracellular resources. PLoS Pathog 2023; 19:e1011807. [PMID: 38051755 PMCID: PMC10723702 DOI: 10.1371/journal.ppat.1011807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/15/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023] Open
Abstract
Malaria is caused by the rapid proliferation of Plasmodium parasites in patients and disease severity correlates with the number of infected red blood cells in circulation. Parasite multiplication within red blood cells is called schizogony and occurs through an atypical multinucleated cell division mode. The mechanisms regulating the number of daughter cells produced by a single progenitor are poorly understood. We investigated underlying regulatory principles by quantifying nuclear multiplication dynamics in Plasmodium falciparum and knowlesi using super-resolution time-lapse microscopy. This confirmed that the number of daughter cells was consistent with a model in which a counter mechanism regulates multiplication yet incompatible with a timer mechanism. P. falciparum cell volume at the start of nuclear division correlated with the final number of daughter cells. As schizogony progressed, the nucleocytoplasmic volume ratio, which has been found to be constant in all eukaryotes characterized so far, increased significantly, possibly to accommodate the exponentially multiplying nuclei. Depleting nutrients by dilution of culture medium caused parasites to produce fewer merozoites and reduced proliferation but did not affect cell volume or total nuclear volume at the end of schizogony. Our findings suggest that the counter mechanism implicated in malaria parasite proliferation integrates extracellular resource status to modify progeny number during blood stage infection.
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Affiliation(s)
- Vanessa S. Stürmer
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Sophie Stopper
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Patrick Binder
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anja Klemmer
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Nicolas P. Lichti
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Nils B. Becker
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Julien Guizetti
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
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16
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Johnstone BH, Gu D, Lin CH, Du J, Woods EJ. Identification of a fundamental cryoinjury mechanism in MSCs and its mitigation through cell-cycle synchronization prior to freezing. Cryobiology 2023; 113:104592. [PMID: 37827209 DOI: 10.1016/j.cryobiol.2023.104592] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 10/04/2023] [Accepted: 10/09/2023] [Indexed: 10/14/2023]
Abstract
Clinical development of cellular therapies, including mesenchymal stem/stromal cell (MSC) treatments, has been hindered by ineffective cryopreservation methods that result in substantial loss of post-thaw cell viability and function. Proposed solutions to generate high potency MSC for clinical testing include priming cells with potent cytokines such as interferon gamma (IFNγ) prior to cryopreservation, which has been shown to enhance post-thaw function, or briefly culturing to allow recovery from cryopreservation injury prior to administering to patients. However, both solutions have disadvantages: cryorecovery increases the complexity of manufacturing and distribution logistics, while the pleiotropic effects of IFNγ may have uncharacterized and unintended consequences on MSC function. To determine specific cellular functions impacted by cryoinjury, we first evaluated cell cycle status. It was discovered that S phase MSC are exquisitely sensitive to cryoinjury, demonstrating heightened levels of delayed apoptosis post-thaw and reduced immunomodulatory function. Blocking cell cycle progression at G0/G1 by growth factor deprivation (commonly known as serum starvation) greatly reduced post-thaw dysfunction of MSC by preventing apoptosis induced by double-stranded breaks in labile replicating DNA that form during the cryopreservation and thawing processes. Viability, clonal growth and T cell suppression function were preserved at pre-cryopreservation levels and were no different than cells prior to freezing or frozen after priming with IFNγ. Thus, we have developed a robust and effective strategy to enhance post-thaw recovery of therapeutic MSC.
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Affiliation(s)
| | - Dongsheng Gu
- Ossium Health, Inc., Indianapolis, IN, United States
| | - Chieh-Han Lin
- Ossium Health, Inc., Indianapolis, IN, United States
| | - Jianguang Du
- Ossium Health, Inc., Indianapolis, IN, United States
| | - Erik J Woods
- Ossium Health, Inc., Indianapolis, IN, United States.
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17
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Lanz MC, Fuentes Valenzuela L, Elias JE, Skotheim JM. Cell Size Contributes to Single-Cell Proteome Variation. J Proteome Res 2023; 22:3773-3779. [PMID: 37910793 PMCID: PMC10802137 DOI: 10.1021/acs.jproteome.3c00441] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Accurate measurements of the molecular composition of single cells will be necessary for understanding the relationship between gene expression and function in diverse cell types. One of the most important phenotypes that differs between cells is their size, which was recently shown to be an important determinant of proteome composition in populations of similarly sized cells. We, therefore, sought to test if the effects of the cell size on protein concentrations were also evident in single-cell proteomics data. Using the relative concentrations of a set of reference proteins to estimate a cell's DNA-to-cell volume ratio, we found that differences in the cell size explain a significant amount of cell-to-cell variance in two published single-cell proteome data sets.
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Affiliation(s)
- Michael C Lanz
- Department of Biology, Stanford University, Stanford, California 94305, United States
- Chan Zuckerberg Biohub, Stanford, California 94305, United States
| | | | - Joshua E Elias
- Chan Zuckerberg Biohub, Stanford, California 94305, United States
| | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, California 94305, United States
- Chan Zuckerberg Biohub, Stanford, California 94305, United States
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18
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Stojanovski K, Gheorghe I, Lenart P, Lanjuin A, Mair WB, Towbin BD. Maintenance of appropriate size scaling of the C. elegans pharynx by YAP-1. Nat Commun 2023; 14:7564. [PMID: 37985670 PMCID: PMC10661912 DOI: 10.1038/s41467-023-43230-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023] Open
Abstract
Even slight imbalance between the growth rate of different organs can accumulate to a large deviation from their appropriate size during development. Here, we use live imaging of the pharynx of C. elegans to ask if and how organ size scaling nevertheless remains uniform among individuals. Growth trajectories of hundreds of individuals reveal that pharynxes grow by a near constant volume per larval stage that is independent of their initial size, such that undersized pharynxes catch-up in size during development. Tissue-specific depletion of RAGA-1, an activator of mTOR and growth, shows that maintaining correct pharynx-to-body size proportions involves a bi-directional coupling between pharynx size and body growth. In simulations, this coupling cannot be explained by limitation of food uptake alone, and genetic experiments reveal an involvement of the mechanotransducing transcriptional co-regulator yap-1. Our data suggests that mechanotransduction coordinates pharynx growth with other tissues, ensuring body plan uniformity among individuals.
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Affiliation(s)
| | - Ioana Gheorghe
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Peter Lenart
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Anne Lanjuin
- Department Molecular Metabolism, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - William B Mair
- Department Molecular Metabolism, Harvard TH Chan School of Public Health, Boston, MA, USA
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19
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Lanz MC, Zhang S, Swaffer MP, Hernández Götz L, McCarty F, Ziv I, Jarosz DF, Elias JE, Skotheim JM. Genome dilution by cell growth drives starvation-like proteome remodeling in mammalian and yeast cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.16.562558. [PMID: 37905015 PMCID: PMC10614910 DOI: 10.1101/2023.10.16.562558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Cell size is tightly controlled in healthy tissues and single-celled organisms, but it remains unclear how size influences cell physiology. Increasing cell size was recently shown to remodel the proteomes of cultured human cells, demonstrating that large and small cells of the same type can be biochemically different. Here, we corroborate these results in mouse hepatocytes and extend our analysis using yeast. We find that size-dependent proteome changes are highly conserved and mostly independent of metabolic state. As eukaryotic cells grow larger, the dilution of the genome elicits a starvation-like proteome phenotype, suggesting that growth in large cells is limited by the genome in a manner analogous to a limiting nutrient. We also demonstrate that the proteomes of replicatively-aged yeast are primarily determined by their large size. Overall, our data suggest that genome concentration is a universal determinant of proteome content in growing cells.
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20
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Zhu F, Lu X, Jiang Y, Wang D, Pan L, Jia C, Zhang L, Xie Y, Zhao M, Liu H, Wang M, Wang T, Liu H, Li J. Proteomics reveals the underlying mechanism by which the first uneven division affects embryonic development in pig. Theriogenology 2023; 210:42-52. [PMID: 37473595 DOI: 10.1016/j.theriogenology.2023.07.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023]
Abstract
One of the most typical abnormal cleavage patterns during early embryonic development is uneven division, but the first uneven division of pig zygote is common. Uneven division results in different daughter cell sizes and an uneven distribution of organelles such as lipid droplet, mitochondria, but the developmental capacity of daughter cells and proteomic changes of daughter cells are still unclear. Therefore, the developmental ability and proteomic quantification were investigated on blastomeres from even division (ED) or uneven division (UD) embryos at 2-cell stage in the present study. Firstly, the developmental ability was affected by the blastomeric size, when compared with medium blastomeres (MBs), the large blastomeres (LBs) with the higher cleavage rate but the small blastomeres (SBs) with the lower rate was observed. Subsequently, proteomic analysis was performed on blastomeres of LBs, MBs and SBs, a total of 109 DEPs were detected, which were involved in protein metabolism and processing, energy metabolism and ribosome. In particular, DEPs in LBs vs. SBs were focused on RNA binding and actin cytoskeletal tissue. Two protein-dense networks associated with RNA binding and cytoskeleton were revealed by further protein-protein interaction (PPI) analysis of DEPs in LBs vs. SBs, that DDX1 related to RNA binding and ACTB related to cytoskeleton were confirmed in UD embryos. Therefore, a briefly information of DEPs in blastomeres of 2-cell stage pig embryos was described in the present study, and it further confirmed that the formation of uneven division of the first cell cycle of pig embryos might be controlled by the cytoskeleton; the developmental capacity of daughter cells might be affected by the energy metabolism, RNA binding and ribosome, and further account for the developmental potential of the whole embryo.
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Affiliation(s)
- Fuquan Zhu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Xinyue Lu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Yuan Jiang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Dayu Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Linqing Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Chao Jia
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Lin Zhang
- Jiangsu Yangyu Ecological Agriculture Co., Ltd, Taixing, 225400, China
| | - Yan Xie
- Taixing Animal Husbandry and Veterinary Center, Taixing, 225400, China
| | - Mingyue Zhao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Huijun Liu
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Zhejiang Institute of Microbiology, Hangzhou, 310012, China
| | - Meixia Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Zhejiang Institute of Microbiology, Hangzhou, 310012, China
| | - Tingzhang Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Zhejiang Institute of Microbiology, Hangzhou, 310012, China
| | - Honglin Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China
| | - Juan Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210018, China.
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21
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Williamson D, Tasker-Brown W, Murray JAH, Jones AR, Band LR. Modelling how plant cell-cycle progression leads to cell size regulation. PLoS Comput Biol 2023; 19:e1011503. [PMID: 37862377 PMCID: PMC10653611 DOI: 10.1371/journal.pcbi.1011503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 11/16/2023] [Accepted: 09/07/2023] [Indexed: 10/22/2023] Open
Abstract
Populations of cells typically maintain a consistent size, despite cell division rarely being precisely symmetrical. Therefore, cells must possess a mechanism of "size control", whereby the cell volume at birth affects cell-cycle progression. While size control mechanisms have been elucidated in a number of other organisms, it is not yet clear how this mechanism functions in plants. Here, we present a mathematical model of the key interactions in the plant cell cycle. Model simulations reveal that the network of interactions exhibits limit-cycle solutions, with biological switches underpinning both the G1/S and G2/M cell-cycle transitions. Embedding this network model within growing cells, we test hypotheses as to how cell-cycle progression can depend on cell size. We investigate two different mechanisms at both the G1/S and G2/M transitions: (i) differential expression of cell-cycle activator and inhibitor proteins (with synthesis of inhibitor proteins being independent of cell size), and (ii) equal inheritance of inhibitor proteins after cell division. The model demonstrates that both these mechanisms can lead to larger daughter cells progressing through the cell cycle more rapidly, and can thus contribute to cell-size control. To test how these features enable size homeostasis over multiple generations, we then simulated these mechanisms in a cell-population model with multiple rounds of cell division. These simulations suggested that integration of size-control mechanisms at both G1/S and G2/M provides long-term cell-size homeostasis. We concluded that while both size independence and equal inheritance of inhibitor proteins can reduce variations in cell size across individual cell-cycle phases, combining size-control mechanisms at both G1/S and G2/M is essential to maintain size homeostasis over multiple generations. Thus, our study reveals how features of the cell-cycle network enable cell-cycle progression to depend on cell size, and provides a mechanistic understanding of how plant cell populations maintain consistent size over generations.
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Affiliation(s)
- Daniel Williamson
- Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - William Tasker-Brown
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - James A. H. Murray
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - Angharad R. Jones
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, United Kingdom
| | - Leah R. Band
- Centre for Mathematical Medicine and Biology, School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
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22
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Pincigher L, Valenti F, Bergamini C, Prata C, Fato R, Amorati R, Jin Z, Farruggia G, Fiorentini D, Calonghi N, Zalambani C. Myrcene: A Natural Compound Showing Anticancer Activity in HeLa Cells. Molecules 2023; 28:6728. [PMID: 37764505 PMCID: PMC10537210 DOI: 10.3390/molecules28186728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/14/2023] [Accepted: 09/17/2023] [Indexed: 09/29/2023] Open
Abstract
γ-terpinene, α-terpinene, p-cymene, and myrcene are monoterpenes found in many essential oils extracted from a variety of plants and spices. Myrcene also occurs naturally in plants such as hops, cannabis, lemongrass, and verbena and is used as a flavoring agent in food and beverage manufacturing. In this research, the biological efficacy of γ-terpinene, α-terpinene, p-cymene, and myrcene was studied in human cell lines (HeLa, SH-SY5Y, and HDFa). Cytotoxicity, cell proliferation, cell migration, and morphology assays were performed to obtain detailed information on the anticancer properties. Our results show that myrcene has potential biological activity, especially in HeLa cells. In this cell line, it leads to an arrest of proliferation, a decrease in motility and morphological changes with loss of sphericity and thickness, and DNA damage. In addition, the interaction of γ-terpinene, α-terpinene, p-terpinene, and myrcene with calf thymus DNA (ct-DNA) was studied by UV-visible spectrophotometry. DNA binding experiments show that only myrcene can interact with DNA with an apparent dissociation constant (Kd) of 29 × 10-6 M.
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Affiliation(s)
- Luca Pincigher
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Francesca Valenti
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Christian Bergamini
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Cecilia Prata
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Romana Fato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Via Gobetti 83, 40129 Bologna, Italy; (R.A.); (Z.J.)
| | - Zongxin Jin
- Department of Chemistry “G. Ciamician”, University of Bologna, Via Gobetti 83, 40129 Bologna, Italy; (R.A.); (Z.J.)
| | - Giovanna Farruggia
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
- National Institute of Biostructures and Biosystems, Via delle Medaglie d’Oro 305, 00136 Rome, Italy
| | - Diana Fiorentini
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Natalia Calonghi
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
| | - Chiara Zalambani
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (L.P.); (F.V.); (C.B.); (C.P.); (R.F.); (G.F.); (C.Z.)
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23
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Jafarpour F, Levien E, Amir A. Evolutionary dynamics in non-Markovian models of microbial populations. Phys Rev E 2023; 108:034402. [PMID: 37849168 DOI: 10.1103/physreve.108.034402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 06/07/2023] [Indexed: 10/19/2023]
Abstract
In the past decade, great strides have been made to quantify the dynamics of single-cell growth and division in microbes. In order to make sense of the evolutionary history of these organisms, we must understand how features of single-cell growth and division influence evolutionary dynamics. This requires us to connect processes on the single-cell scale to population dynamics. Here, we consider a model of microbial growth in finite populations which explicitly incorporates the single-cell dynamics. We study the behavior of a mutant population in such a model and ask: can the evolutionary dynamics be coarse-grained so that the forces of natural selection and genetic drift can be expressed in terms of the long-term fitness? We show that it is in fact not possible, as there is no way to define a single fitness parameter (or reproductive rate) that defines the fate of an organism even in a constant environment. This is due to fluctuations in the population averaged division rate. As a result, various details of the single-cell dynamics affect the fate of a new mutant independently from how they affect the long-term growth rate of the mutant population. In particular, we show that in the case of neutral mutations, variability in generation times increases the rate of genetic drift, and in the case of beneficial mutations, variability decreases its fixation probability. Furthermore, we explain the source of the persistent division rate fluctuations and provide analytic solutions for the fixation probability as a multispecies generalization of the Euler-Lotka equation.
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Affiliation(s)
- Farshid Jafarpour
- Institute for Theoretical Physics, Utrecht University, 3584 CC Utrecht, The Netherlands
| | - Ethan Levien
- Mathematics Department, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Ariel Amir
- Department of Complex Systems, Faculty of Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
- John A. Paulson, School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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24
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Devany J, Falk MJ, Holt LJ, Murugan A, Gardel ML. Epithelial tissue confinement inhibits cell growth and leads to volume-reducing divisions. Dev Cell 2023; 58:1462-1476.e8. [PMID: 37339629 PMCID: PMC10528006 DOI: 10.1016/j.devcel.2023.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/12/2023] [Accepted: 05/26/2023] [Indexed: 06/22/2023]
Abstract
Cell proliferation is a central process in tissue development, homeostasis, and disease, yet how proliferation is regulated in the tissue context remains poorly understood. Here, we introduce a quantitative framework to elucidate how tissue growth dynamics regulate cell proliferation. Using MDCK epithelial monolayers, we show that a limiting rate of tissue expansion creates confinement that suppresses cell growth; however, this confinement does not directly affect the cell cycle. This leads to uncoupling between rates of cell growth and division in epithelia and, thereby, reduces cell volume. Division becomes arrested at a minimal cell volume, which is consistent across diverse epithelia in vivo. Here, the nucleus approaches the minimum volume capable of packaging the genome. Loss of cyclin D1-dependent cell-volume regulation results in an abnormally high nuclear-to-cytoplasmic volume ratio and DNA damage. Overall, we demonstrate how epithelial proliferation is regulated by the interplay between tissue confinement and cell-volume regulation.
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Affiliation(s)
- John Devany
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Martin J Falk
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Liam J Holt
- Institute for Systems Genetics, New York University, Grossman School of Medicine, New York, NY 10016, USA
| | - Arvind Murugan
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Margaret L Gardel
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA; Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA.
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25
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Carpenter LC, Pérez-Verdugo F, Banerjee S. Mechanical control of cell proliferation patterns in growing tissues. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550581. [PMID: 37546964 PMCID: PMC10402015 DOI: 10.1101/2023.07.25.550581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Cell proliferation plays a crucial role in regulating tissue homeostasis and development. However, our understanding of how cell proliferation is controlled in densely packed tissues is limited. Here we develop a computational framework to predict the patterns of cell proliferation in growing tissues, connecting single-cell behaviors and cell-cell interactions to tissue-level growth. Our model incorporates probabilistic rules governing cell growth, division, and elimination, while also taking into account their feedback with tissue mechanics. In particular, cell growth is suppressed and apoptosis is enhanced in regions of high cell density. With these rules and model parameters calibrated using experimental data, we predict how tissue confinement influences cell size and proliferation dynamics, and how single-cell physical properties influence the spatiotemporal patterns of tissue growth. Our findings indicate that mechanical feedback between tissue confinement and cell growth leads to enhanced cell proliferation at tissue boundaries, whereas cell growth in the bulk is arrested. By tuning cellular elasticity and contact inhibition of proliferation we can regulate the emergent patterns of cell proliferation, ranging from uniform growth at low contact inhibition to localized growth at higher contact inhibition. Furthermore, mechanical state of the tissue governs the dynamics of tissue growth, with cellular parameters affecting tissue pressure playing a significant role in determining the overall growth rate. Our computational study thus underscores the impact of cell mechanical properties on the spatiotemporal patterns of cell proliferation in growing tissues.
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Affiliation(s)
- Logan C Carpenter
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | | | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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26
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Introini V, Kidiyoor GR, Porcella G, Cicuta P, Cosentino Lagomarsino M. Centripetal nuclear shape fluctuations associate with chromatin condensation in early prophase. Commun Biol 2023; 6:715. [PMID: 37438411 PMCID: PMC10338514 DOI: 10.1038/s42003-023-05074-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/26/2023] [Indexed: 07/14/2023] Open
Abstract
The nucleus plays a central role in several key cellular processes, including chromosome organisation, DNA replication and gene transcription. Recent work suggests an association between nuclear mechanics and cell-cycle progression, but many aspects of this connection remain unexplored. Here, by monitoring nuclear shape fluctuations at different cell cycle stages, we uncover increasing inward fluctuations in late G2 and in early prophase, which are initially transient, but develop into instabilities when approaching the nuclear-envelope breakdown. We demonstrate that such deformations correlate with chromatin condensation by perturbing both the chromatin and the cytoskeletal structures. We propose that the contrasting forces between an extensile stress and centripetal pulling from chromatin condensation could mechanically link chromosome condensation with nuclear-envelope breakdown, two main nuclear processes occurring during mitosis.
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Affiliation(s)
- Viola Introini
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK
| | - Gururaj Rao Kidiyoor
- IFOM, FIRC Institute of Molecular Oncology, Via Adamello 16, Milan, 20139, Italy
| | - Giancarlo Porcella
- IFOM, FIRC Institute of Molecular Oncology, Via Adamello 16, Milan, 20139, Italy
| | - Pietro Cicuta
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Marco Cosentino Lagomarsino
- IFOM, FIRC Institute of Molecular Oncology, Via Adamello 16, Milan, 20139, Italy.
- Dipartimento di Fisica, Università degli Studi di Milano and I.N.F.N., Via Celoria 16, Milan, 20133, Italy.
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27
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Ji X, Lin J. Implications of differential size-scaling of cell-cycle regulators on cell size homeostasis. PLoS Comput Biol 2023; 19:e1011336. [PMID: 37506170 PMCID: PMC10411824 DOI: 10.1371/journal.pcbi.1011336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 08/09/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
Accurate timing of division and size homeostasis is crucial for cells. A potential mechanism for cells to decide the timing of division is the differential scaling of regulatory protein copy numbers with cell size. However, it remains unclear whether such a mechanism can lead to robust growth and division, and how the scaling behaviors of regulatory proteins influence the cell size distribution. Here we study a mathematical model combining gene expression and cell growth, in which the cell-cycle activators scale superlinearly with cell size while the inhibitors scale sublinearly. The cell divides once the ratio of their concentrations reaches a threshold value. We find that the cell can robustly grow and divide within a finite range of the threshold value with the cell size proportional to the ploidy. In a stochastic version of the model, the cell size at division is uncorrelated with that at birth. Also, the more differential the cell-size scaling of the cell-cycle regulators is, the narrower the cell-size distribution is. Intriguingly, our model with multiple regulators rationalizes the observation that after the deletion of a single regulator, the coefficient of variation of cell size remains roughly the same though the average cell size changes significantly. Our work reveals that the differential scaling of cell-cycle regulators provides a robust mechanism of cell size control.
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Affiliation(s)
- Xiangrui Ji
- Yuanpei College, Peking University, Beijing, China
| | - Jie Lin
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
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28
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Hansson KA, Eftestøl E. Scaling of nuclear numbers and their spatial arrangement in skeletal muscle cell size regulation. Mol Biol Cell 2023; 34:pe3. [PMID: 37339435 PMCID: PMC10398882 DOI: 10.1091/mbc.e22-09-0424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 03/29/2023] [Accepted: 04/28/2023] [Indexed: 06/22/2023] Open
Abstract
Many cells display considerable functional plasticity and depend on the regulation of numerous organelles and macromolecules for their maintenance. In large cells, organelles also need to be carefully distributed to supply the cell with essential resources and regulate intracellular activities. Having multiple copies of the largest eukaryotic organelle, the nucleus, epitomizes the importance of scaling gene products to large cytoplasmic volumes in skeletal muscle fibers. Scaling of intracellular constituents within mammalian muscle fibers is, however, poorly understood, but according to the myonuclear domain hypothesis, a single nucleus supports a finite amount of cytoplasm and is thus postulated to act autonomously, causing the nuclear number to be commensurate with fiber volume. In addition, the orderly peripheral distribution of myonuclei is a hallmark of normal cell physiology, as nuclear mispositioning is associated with impaired muscle function. Because underlying structures of complex cell behaviors are commonly formalized by scaling laws and thus emphasize emerging principles of size regulation, the work presented herein offers more of a unified conceptual platform based on principles from physics, chemistry, geometry, and biology to explore cell size-dependent correlations of the largest mammalian cell by means of scaling.
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Affiliation(s)
- Kenth-Arne Hansson
- Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, 2624 Lillehammer, Norway
| | - Einar Eftestøl
- Department of Biosciences, University of Oslo, 0371 Oslo, Norway
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29
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Lengefeld J, Zatulovskiy E. Editorial: Cell size regulation: molecular mechanisms and physiological importance. Front Cell Dev Biol 2023; 11:1219294. [PMID: 37274748 PMCID: PMC10233121 DOI: 10.3389/fcell.2023.1219294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/10/2023] [Indexed: 06/06/2023] Open
Affiliation(s)
- Jette Lengefeld
- Helsinki Institute of Life Science, HiLIFE, Institute of Biotechnology, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Department of Medicine Huddinge, Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden
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30
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Terhorst A, Sandikci A, Whittaker CA, Szórádi T, Holt LJ, Neurohr GE, Amon A. The environmental stress response regulates ribosome content in cell cycle-arrested S. cerevisiae. Front Cell Dev Biol 2023; 11:1118766. [PMID: 37123399 PMCID: PMC10130656 DOI: 10.3389/fcell.2023.1118766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/21/2023] [Indexed: 05/02/2023] Open
Abstract
Prolonged cell cycle arrests occur naturally in differentiated cells and in response to various stresses such as nutrient deprivation or treatment with chemotherapeutic agents. Whether and how cells survive prolonged cell cycle arrests is not clear. Here, we used S. cerevisiae to compare physiological cell cycle arrests and genetically induced arrests in G1-, meta- and anaphase. Prolonged cell cycle arrest led to growth attenuation in all studied conditions, coincided with activation of the Environmental Stress Response (ESR) and with a reduced ribosome content as determined by whole ribosome purification and TMT mass spectrometry. Suppression of the ESR through hyperactivation of the Ras/PKA pathway reduced cell viability during prolonged arrests, demonstrating a cytoprotective role of the ESR. Attenuation of cell growth and activation of stress induced signaling pathways also occur in arrested human cell lines, raising the possibility that the response to prolonged cell cycle arrest is conserved.
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Affiliation(s)
- Allegra Terhorst
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Arzu Sandikci
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Charles A. Whittaker
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Tamás Szórádi
- Institute for Systems Genetics, New York University Langone Health, New York City, NY, United States
| | - Liam J. Holt
- Institute for Systems Genetics, New York University Langone Health, New York City, NY, United States
| | - Gabriel E. Neurohr
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Angelika Amon
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
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31
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Jia C, Grima R. Coupling gene expression dynamics to cell size dynamics and cell cycle events: Exact and approximate solutions of the extended telegraph model. iScience 2023; 26:105746. [PMID: 36619980 PMCID: PMC9813732 DOI: 10.1016/j.isci.2022.105746] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/02/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
The standard model describing the fluctuations of mRNA numbers in single cells is the telegraph model which includes synthesis and degradation of mRNA, and switching of the gene between active and inactive states. While commonly used, this model does not describe how fluctuations are influenced by the cell cycle phase, cellular growth and division, and other crucial aspects of cellular biology. Here, we derive the analytical time-dependent solution of an extended telegraph model that explicitly considers the doubling of gene copy numbers upon DNA replication, dependence of the mRNA synthesis rate on cellular volume, gene dosage compensation, partitioning of molecules during cell division, cell-cycle duration variability, and cell-size control strategies. Based on the time-dependent solution, we obtain the analytical distributions of transcript numbers for lineage and population measurements in steady-state growth and also find a linear relation between the Fano factor of mRNA fluctuations and cell volume fluctuations. We show that generally the lineage and population distributions in steady-state growth cannot be accurately approximated by the steady-state solution of extrinsic noise models, i.e. a telegraph model with parameters drawn from probability distributions. This is because the mRNA lifetime is often not small enough compared to the cell cycle duration to erase the memory of division and replication. Accurate approximations are possible when this memory is weak, e.g. for genes with bursty expression and for which there is sufficient gene dosage compensation when replication occurs.
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Affiliation(s)
- Chen Jia
- Applied and Computational Mathematics Division, Beijing Computational Science Research Center, Beijing 100193, China
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JH, UK
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32
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Chen P, Levy DL. Regulation of organelle size and organization during development. Semin Cell Dev Biol 2023; 133:53-64. [PMID: 35148938 PMCID: PMC9357868 DOI: 10.1016/j.semcdb.2022.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/20/2022] [Accepted: 02/01/2022] [Indexed: 12/11/2022]
Abstract
During early embryogenesis, as cells divide in the developing embryo, the size of intracellular organelles generally decreases to scale with the decrease in overall cell size. Organelle size scaling is thought to be important to establish and maintain proper cellular function, and defective scaling may lead to impaired development and disease. However, how the cell regulates organelle size and organization are largely unanswered questions. In this review, we summarize the process of size scaling at both the cell and organelle levels and discuss recently discovered mechanisms that regulate this process during early embryogenesis. In addition, we describe how some recently developed techniques and Xenopus as an animal model can be used to investigate the underlying mechanisms of size regulation and to uncover the significance of proper organelle size scaling and organization.
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Affiliation(s)
- Pan Chen
- Institute of Biochemistry and Molecular Biology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, China.
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA.
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33
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Han XX, Jin S, Yu LM, Wang M, Hu XY, Hu DY, Ren J, Zhang MH, Huang W, Deng JJ, Chen QQ, Gao Z, He H, Cai C. Interferon-beta inhibits human glioma stem cell growth by modulating immune response and cell cycle related signaling pathways. CELL REGENERATION 2022; 11:23. [PMID: 35778531 PMCID: PMC9249963 DOI: 10.1186/s13619-022-00123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/06/2022] [Indexed: 11/19/2022]
Abstract
Malignant Glioma is characterized by strong self-renewal potential and immature differentiation potential. The main reason is that malignant glioma holds key cluster cells, glioma stem cells (GSCs). GSCs contribute to tumorigenesis, tumor progression, recurrence, and treatment resistance. Interferon-beta (IFN-β) is well known for its anti-proliferative efficacy in diverse cancers. IFN-β also displayed potent antitumor effects in malignant glioma. IFN-β affect both GSCs and Neural stem cells (NSCs) in the treatment of gliomas. However, the functional comparison, similar or different effects of IFN-β on GSCs and NSCs are rarely reported. Here, we studied the similarities and differences of the responses to IFN-β between human GSCs and normal NSCs. We found that IFN-β preferentially inhibited GSCs over NSCs. The cell body and nucleus size of GSCs increased after IFN-β treatment, and the genomic analysis revealed the enrichment of the upregulated immune response, cell adhesion genes and down regulated cell cycle, ribosome pathways. Several typical cyclin genes, including cyclin A2 (CCNA2), cyclin B1 (CCNB1), cyclin B2 (CCNB2), and cyclin D1 (CCND1), were significantly downregulated in GSCs after IFN-β stimulation. We also found that continuous IFN-β stimulation after passage further enhanced the inhibitory effect. Our study revealed how genetic diversity resulted in differential effects in response to IFN-β treatment. These results may contribute to improve the applications of IFN-β in anti-cancer immunotherapy. In addition, these results may also help to design more effective pharmacological strategies to target cancer stem cells while protecting normal neural stem cells.
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34
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Serbanescu D, Ojkic N, Banerjee S. Cellular resource allocation strategies for cell size and shape control in bacteria. FEBS J 2022; 289:7891-7906. [PMID: 34665933 PMCID: PMC9016100 DOI: 10.1111/febs.16234] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/21/2021] [Accepted: 10/18/2021] [Indexed: 01/14/2023]
Abstract
Bacteria are highly adaptive microorganisms that thrive in a wide range of growth conditions via changes in cell morphologies and macromolecular composition. How bacterial morphologies are regulated in diverse environmental conditions is a long-standing question. Regulation of cell size and shape implies control mechanisms that couple the growth and division of bacteria to their cellular environment and macromolecular composition. In the past decade, simple quantitative laws have emerged that connect cell growth to proteomic composition and the nutrient availability. However, the relationships between cell size, shape, and growth physiology remain challenging to disentangle and unifying models are lacking. In this review, we focus on regulatory models of cell size control that reveal the connections between bacterial cell morphology and growth physiology. In particular, we discuss how changes in nutrient conditions and translational perturbations regulate the cell size, growth rate, and proteome composition. Integrating quantitative models with experimental data, we identify the physiological principles of bacterial size regulation, and discuss the optimization strategies of cellular resource allocation for size control.
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Affiliation(s)
- Diana Serbanescu
- Department of Physics and Astronomy, University College London, UK
| | - Nikola Ojkic
- Department of Physics and Astronomy, University College London, UK
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35
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Balachandra S, Sarkar S, Amodeo AA. The Nuclear-to-Cytoplasmic Ratio: Coupling DNA Content to Cell Size, Cell Cycle, and Biosynthetic Capacity. Annu Rev Genet 2022; 56:165-185. [PMID: 35977407 PMCID: PMC10165727 DOI: 10.1146/annurev-genet-080320-030537] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Though cell size varies between different cells and across species, the nuclear-to-cytoplasmic (N/C) ratio is largely maintained across species and within cell types. A cell maintains a relatively constant N/C ratio by coupling DNA content, nuclear size, and cell size. We explore how cells couple cell division and growth to DNA content. In some cases, cells use DNA as a molecular yardstick to control the availability of cell cycle regulators. In other cases, DNA sets a limit for biosynthetic capacity. Developmentally programmed variations in the N/C ratio for a given cell type suggest that a specific N/C ratio is required to respond to given physiological demands. Recent observations connecting decreased N/C ratios with cellular senescence indicate that maintaining the proper N/C ratio is essential for proper cellular functioning. Together, these findings suggest a causative, not simply correlative, role for the N/C ratio in regulating cell growth and cell cycle progression.
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Affiliation(s)
- Shruthi Balachandra
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA; ,
| | - Sharanya Sarkar
- Department of Microbiology and Immunology, Dartmouth College, Hanover, New Hampshire, USA;
| | - Amanda A Amodeo
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA; ,
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36
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Davies DM, van den Handel K, Bharadwaj S, Lengefeld J. Cellular enlargement - A new hallmark of aging? Front Cell Dev Biol 2022; 10:1036602. [PMID: 36438561 PMCID: PMC9688412 DOI: 10.3389/fcell.2022.1036602] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/17/2022] [Indexed: 12/03/2023] Open
Abstract
Years of important research has revealed that cells heavily invest in regulating their size. Nevertheless, it has remained unclear why accurate size control is so important. Our recent study using hematopoietic stem cells (HSCs) in vivo indicates that cellular enlargement is causally associated with aging. Here, we present an overview of these findings and their implications. Furthermore, we performed a broad literature analysis to evaluate the potential of cellular enlargement as a new aging hallmark and to examine its connection to previously described aging hallmarks. Finally, we highlight interesting work presenting a correlation between cell size and age-related diseases. Taken together, we found mounting evidence linking cellular enlargement to aging and age-related diseases. Therefore, we encourage researchers from seemingly unrelated areas to take a fresh look at their data from the perspective of cell size.
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Affiliation(s)
- Daniel M. Davies
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Kim van den Handel
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Soham Bharadwaj
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Jette Lengefeld
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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37
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Liu S, Tan C, Tyers M, Zetterberg A, Kafri R. What programs the size of animal cells? Front Cell Dev Biol 2022; 10:949382. [PMID: 36393871 PMCID: PMC9665425 DOI: 10.3389/fcell.2022.949382] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/07/2022] [Indexed: 01/19/2023] Open
Abstract
The human body is programmed with definite quantities, magnitudes, and proportions. At the microscopic level, such definite sizes manifest in individual cells - different cell types are characterized by distinct cell sizes whereas cells of the same type are highly uniform in size. How do cells in a population maintain uniformity in cell size, and how are changes in target size programmed? A convergence of recent and historical studies suggest - just as a thermostat maintains room temperature - the size of proliferating animal cells is similarly maintained by homeostatic mechanisms. In this review, we first summarize old and new literature on the existence of cell size checkpoints, then discuss additional advances in the study of size homeostasis that involve feedback regulation of cellular growth rate. We further discuss recent progress on the molecules that underlie cell size checkpoints and mechanisms that specify target size setpoints. Lastly, we discuss a less-well explored teleological question: why does cell size matter and what is the functional importance of cell size control?
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Affiliation(s)
- Shixuan Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, United States
| | - Ceryl Tan
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mike Tyers
- Institute for Research in Immunology and Cancer, University of Montréal, Montréal, QC, Canada
| | - Anders Zetterberg
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Ran Kafri
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
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38
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Øvrebø JI, Ma Y, Edgar BA. Cell growth and the cell cycle: New insights about persistent questions. Bioessays 2022; 44:e2200150. [PMID: 36222263 DOI: 10.1002/bies.202200150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 11/08/2022]
Abstract
Before a cell divides into two daughter cells, it typically doubles not only its DNA, but also its mass. Numerous studies in cells ranging from yeast to mammals have shown that cellular growth, stimulated by nutrients and/or growth factor signaling, is a prerequisite for cell cycle progression in most types of cells. The textbook view of growth-regulated cell cycles is that growth signaling activates the transcription of G1 Cyclin genes to induce cell proliferation, and also stimulates anabolic metabolism and cell growth in parallel. However, genetic knockout tests in model organisms indicate that this is not the whole story, and new studies show that additional, "smarter" mechanisms help to coordinate the cell cycle with growth itself. Here we summarize recent advances in this field, and discuss current models in which growth signaling regulates cell proliferation by targeting core cell cycle regulators via non-transcriptional mechanisms.
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Affiliation(s)
- Jan Inge Øvrebø
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Yiqin Ma
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
| | - Bruce A Edgar
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
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39
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Kellogg DR, Levin PA. Nutrient availability as an arbiter of cell size. Trends Cell Biol 2022; 32:908-919. [PMID: 35851491 PMCID: PMC9588502 DOI: 10.1016/j.tcb.2022.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/07/2022] [Accepted: 06/16/2022] [Indexed: 01/21/2023]
Abstract
Pioneering work carried out over 60 years ago discovered that bacterial cell size is proportional to the growth rate set by nutrient availability. This relationship is traditionally referred to as the 'growth law'. Subsequent studies revealed the growth law to hold across all orders of life, a remarkable degree of conservation. However, recent work suggests the relationship between growth rate, nutrients, and cell size is far more complicated and less deterministic than originally thought. Focusing on bacteria and yeast, here we review efforts to understand the molecular mechanisms underlying the relationship between growth rate and cell size.
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Affiliation(s)
- Douglas R Kellogg
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St Louis, MO 63130, USA; Center for Science & Engineering of Living Systems (CSELS), McKelvey School of Engineering, Washington University in St Louis, St Louis, MO 63130, USA.
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40
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Cao C, Wang K, Wang Y, Liu TB, Rivera A, Xue C. Ubiquitin proteolysis of a CDK-related kinase regulates titan cell formation and virulence in the fungal pathogen Cryptococcus neoformans. Nat Commun 2022; 13:6397. [PMID: 36302775 PMCID: PMC9613880 DOI: 10.1038/s41467-022-34151-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 10/17/2022] [Indexed: 12/25/2022] Open
Abstract
Fungal pathogens often undergo morphological switches, including cell size changes, to adapt to the host environment and cause disease. The pathogenic yeast Cryptococcus neoformans forms so-called 'titan cells' during infection. Titan cells are large, polyploid, display alterations in cell wall and capsule, and are more resistant to phagocytosis and various types of stress. Titan cell formation is regulated by the cAMP/PKA signal pathway, which is stimulated by the protein Gpa1. Here, we show that Gpa1 is activated through phosphorylation by a CDK-related kinase (Crk1), which is targeted for degradation by an E3 ubiquitin ligase (Fbp1). Strains overexpressing CRK1 or an allele lacking a PEST domain exhibit increased production of titan cells similarly to the fbp1∆ mutant. Conversely, CRK1 deletion results in reduced titan cell production, indicating that Crk1 stimulates titan cell formation. Crk1 phosphorylates Gpa1, which then localizes to the plasma membrane and activates the cAMP/PKA signal pathway to induce cell enlargement. Furthermore, titan cell-overproducing strains trigger increased Th1 and Th17 cytokine production in CD4+ T cells and show attenuated virulence in a mouse model of systemic cryptococcosis. Overall, our study provides insights into the regulation of titan cell formation and fungal virulence.
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Affiliation(s)
- Chengjun Cao
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Keyi Wang
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Yina Wang
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Tong-Bao Liu
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
- Medical Research Institute, Southwest University, Chongqing, 400715, China
| | - Amariliz Rivera
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Chaoyang Xue
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
- Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ, 08901, USA.
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41
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Liu X, Oh S, Kirschner MW. The uniformity and stability of cellular mass density in mammalian cell culture. Front Cell Dev Biol 2022; 10:1017499. [PMID: 36313562 PMCID: PMC9597509 DOI: 10.3389/fcell.2022.1017499] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/23/2022] [Indexed: 12/04/2022] Open
Abstract
Cell dry mass is principally determined by the sum of biosynthesis and degradation. Measurable change in dry mass occurs on a time scale of hours. By contrast, cell volume can change in minutes by altering the osmotic conditions. How changes in dry mass and volume are coupled is a fundamental question in cell size control. If cell volume were proportional to cell dry mass during growth, the cell would always maintain the same cellular mass density, defined as cell dry mass dividing by cell volume. The accuracy and stability against perturbation of this proportionality has never been stringently tested. Normalized Raman Imaging (NoRI), can measure both protein and lipid dry mass density directly. Using this new technique, we have been able to investigate the stability of mass density in response to pharmaceutical and physiological perturbations in three cultured mammalian cell lines. We find a remarkably narrow mass density distribution within cells, that is, significantly tighter than the variability of mass or volume distribution. The measured mass density is independent of the cell cycle. We find that mass density can be modulated directly by extracellular osmolytes or by disruptions of the cytoskeleton. Yet, mass density is surprisingly resistant to pharmacological perturbations of protein synthesis or protein degradation, suggesting there must be some form of feedback control to maintain the homeostasis of mass density when mass is altered. By contrast, physiological perturbations such as starvation or senescence induce significant shifts in mass density. We have begun to shed light on how and why cell mass density remains fixed against some perturbations and yet is sensitive during transitions in physiological state.
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Affiliation(s)
| | | | - Marc W. Kirschner
- Department of Systems Biology, Harvard Medical School, Boston, MA, United States
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42
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Abstract
The most fundamental feature of cellular form is size, which sets the scale of all cell biological processes. Growth, form, and function are all necessarily linked in cell biology, but we often do not understand the underlying molecular mechanisms nor their specific functions. Here, we review progress toward determining the molecular mechanisms that regulate cell size in yeast, animals, and plants, as well as progress toward understanding the function of cell size regulation. It has become increasingly clear that the mechanism of cell size regulation is deeply intertwined with basic mechanisms of biosynthesis, and how biosynthesis can be scaled (or not) in proportion to cell size. Finally, we highlight recent findings causally linking aberrant cell size regulation to cellular senescence and their implications for cancer therapies.
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Affiliation(s)
- Shicong Xie
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Matthew Swaffer
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, California, USA;
- Chan Zuckerberg Biohub, San Francisco, California, USA
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43
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Concentration fluctuations in growing and dividing cells: Insights into the emergence of concentration homeostasis. PLoS Comput Biol 2022; 18:e1010574. [PMID: 36194626 PMCID: PMC9565450 DOI: 10.1371/journal.pcbi.1010574] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/14/2022] [Accepted: 09/14/2022] [Indexed: 11/19/2022] Open
Abstract
Intracellular reaction rates depend on concentrations and hence their levels are often regulated. However classical models of stochastic gene expression lack a cell size description and cannot be used to predict noise in concentrations. Here, we construct a model of gene product dynamics that includes a description of cell growth, cell division, size-dependent gene expression, gene dosage compensation, and size control mechanisms that can vary with the cell cycle phase. We obtain expressions for the approximate distributions and power spectra of concentration fluctuations which lead to insight into the emergence of concentration homeostasis. We find that (i) the conditions necessary to suppress cell division-induced concentration oscillations are difficult to achieve; (ii) mRNA concentration and number distributions can have different number of modes; (iii) two-layer size control strategies such as sizer-timer or adder-timer are ideal because they maintain constant mean concentrations whilst minimising concentration noise; (iv) accurate concentration homeostasis requires a fine tuning of dosage compensation, replication timing, and size-dependent gene expression; (v) deviations from perfect concentration homeostasis show up as deviations of the concentration distribution from a gamma distribution. Some of these predictions are confirmed using data for E. coli, fission yeast, and budding yeast.
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44
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Molenaar TM, Malik M, Silva J, Liu NQ, Haarhuis JHI, Ambrosi C, Kwesi-Maliepaard EM, van Welsem T, Baubec T, Faller WJ, van Leeuwen F. The histone methyltransferase SETD2 negatively regulates cell size. J Cell Sci 2022; 135:jcs259856. [PMID: 36052643 PMCID: PMC9659392 DOI: 10.1242/jcs.259856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 08/23/2022] [Indexed: 11/20/2022] Open
Abstract
Cell size varies between cell types but is tightly regulated by cell intrinsic and extrinsic mechanisms. Cell size control is important for cell function, and changes in cell size are frequently observed in cancer. Here, we uncover a role for SETD2 in regulating cell size. SETD2 is a lysine methyltransferase and a tumor suppressor protein involved in transcription, RNA processing and DNA repair. At the molecular level, SETD2 is best known for associating with RNA polymerase II through its Set2-Rbp1 interacting (SRI) domain and methylating histone H3 on lysine 36 (H3K36) during transcription. Using multiple independent perturbation strategies, we identify SETD2 as a negative regulator of global protein synthesis rates and cell size. We provide evidence that overexpression of the H3K36 demethylase KDM4A or the oncohistone H3.3K36M also increase cell size. In addition, ectopic overexpression of a decoy SRI domain increased cell size, suggesting that the relevant substrate is engaged by SETD2 via its SRI domain. These data add a central role of SETD2 in regulating cellular physiology and warrant further studies on separating the different functions of SETD2 in cancer development.
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Affiliation(s)
- Thom M. Molenaar
- Division of Gene Regulation, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Muddassir Malik
- Division of Gene Regulation, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Joana Silva
- Division of Oncogenomics, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Ning Qing Liu
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Judith H. I. Haarhuis
- Division of Cell Biology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Christina Ambrosi
- Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland
- Life Science Zurich Graduate School, University of Zurich and ETH Zurich, CH-8057 Zurich, Switzerland
| | | | - Tibor van Welsem
- Division of Gene Regulation, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Tuncay Baubec
- Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland
- Genome Biology and Epigenetics, Institute of Biodynamics and Biocomplexity, Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - William J. Faller
- Division of Oncogenomics, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, 1105AZ Amsterdam, The Netherlands
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45
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Figueroa B, Xu FX, Hu R, Men S, Fu D. Quantitative Imaging of Intracellular Density with Ratiometric Stimulated Raman Scattering Microscopy. J Phys Chem B 2022; 126:7595-7603. [PMID: 36135097 DOI: 10.1021/acs.jpcb.2c04355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell size and density are tightly controlled in mammalian cells. They impact a wide range of physiological functions, including osmoregulation, tissue homeostasis, and growth regulation. Compared to size, density variation for a given cell type is typically much smaller, implying that cell-type-specific density plays an important role in cell function. However, little is known about how cell density affects cell function or how it is regulated. Current tools for intracellular cell density measurements are limited to either suspended cells or cells grown on 2D substrates, neither of which recapitulate the physiology of single cells in intact tissue. While optical measurements have the potential to noninvasively measure cell density in situ, light scattering in multicellular systems prevents direct quantification. Here, we introduce an intracellular density imaging technique based on ratiometric stimulated Raman scattering microscopy (rSRS). It uses intrinsic vibrational information from intracellular macromolecules to quantify dry mass density. Moreover, water is used as an internal standard to correct for aberration and light scattering effects. We demonstrate real-time measurement of intracellular density and show that density is tightly regulated across different cell types and can be used to differentiate cell types as well as cell states. We further demonstrate dynamic imaging of density change in response to osmotic challenge as well as intracellular density imaging of a 3D tumor spheroid. Our technique has the potential for imaging intracellular density in intact tissue and understanding density regulation and its role in tissue homeostasis.
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Affiliation(s)
- Benjamin Figueroa
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Fiona Xi Xu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Ruoqian Hu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Shuaiqian Men
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Dan Fu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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46
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Zatulovskiy E, Lanz MC, Zhang S, McCarthy F, Elias JE, Skotheim JM. Delineation of proteome changes driven by cell size and growth rate. Front Cell Dev Biol 2022; 10:980721. [PMID: 36133920 PMCID: PMC9483106 DOI: 10.3389/fcell.2022.980721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/09/2022] [Indexed: 01/10/2023] Open
Abstract
Increasing cell size drives changes to the proteome, which affects cell physiology. As cell size increases, some proteins become more concentrated while others are diluted. As a result, the state of the cell changes continuously with increasing size. In addition to these proteomic changes, large cells have a lower growth rate (protein synthesis rate per unit volume). That both the cell's proteome and growth rate change with cell size suggests they may be interdependent. To test this, we used quantitative mass spectrometry to measure how the proteome changes in response to the mTOR inhibitor rapamycin, which decreases the cellular growth rate and has only a minimal effect on cell size. We found that large cell size and mTOR inhibition, both of which lower the growth rate of a cell, remodel the proteome in similar ways. This suggests that many of the effects of cell size are mediated by the size-dependent slowdown of the cellular growth rate. For example, the previously reported size-dependent expression of some senescence markers could reflect a cell's declining growth rate rather than its size per se. In contrast, histones and other chromatin components are diluted in large cells independently of the growth rate, likely so that they remain in proportion with the genome. Finally, size-dependent changes to the cell's growth rate and proteome composition are still apparent in cells continually exposed to a saturating dose of rapamycin, which indicates that cell size can affect the proteome independently of mTORC1 signaling. Taken together, our results clarify the dependencies between cell size, growth, mTOR activity, and the proteome remodeling that ultimately controls many aspects of cell physiology.
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Affiliation(s)
| | - Michael C. Lanz
- Department of Biology, Stanford University, Stanford, CA, United States
- Chan Zuckerberg Biohub, Stanford, CA, United States
| | - Shuyuan Zhang
- Department of Biology, Stanford University, Stanford, CA, United States
| | | | | | - Jan M. Skotheim
- Department of Biology, Stanford University, Stanford, CA, United States
- Chan Zuckerberg Biohub, Stanford, CA, United States
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47
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Urbaniak P, Wronski S, Tarasiuk J, Lipinski P, Kotwicka M. A new method to estimate 3D cell parameters from 2D microscopy images. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119286. [PMID: 35598752 DOI: 10.1016/j.bbamcr.2022.119286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/10/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Optical microscopy has been a basic and standard technique in cell biology research for decades. Microscopy techniques function well for thin, optically transparent cultures and allow for the imaging of thicker biological specimens. There is no better method of in vitro cell observation and analysis, hence microscopic techniques are extensively used and constitute an optimal tool for cell culture studies. This paper proposes an original methodology of optical microscopy data processing based on the phase contrast technique during cell culture monitoring. By exploiting images recorded during cell proliferation, a surface reconstruction was performed based on assumption, it can be considered that the local brightness of the image depends on the cells' thickness and thus the obtained results can be interpreted in the form of a surface that represents a three-dimensional structure, which allowed for a quantitative description of the cell evolution. The 3D data obtained enabled the investigation of parameters describing the morphology of the cells and the topology of their proliferation. These parameters included cell sizes in plane but also in the direction perpendicular to it, cell volume changes, their spatial distribution, as well as anisotropy and directivity. The method presented provides data carrying information similar to that obtained using a holographic microscope, e.g. A HoloMonitor (Phase Holographic Imaging PHI Inc.), or from confocal scanning microscopy with the "z-stack" mode. The techniques of bright field or phase contrast cell observation are, however, much cheaper, and widely available when compared to holographic microscopy, for instance. Besides, these also enable monitoring of cell activity over time, i.e. the study and quantitative description of dynamic changes in the cells. The proposed approach uses generally available free tools such as ImageJ software with BoneJ and Particle Analyzer plugins. The methodology is suitable for even a basic microscope, it can be easily implemented as a script, and thus data processing can be significantly shortened, the methodology can be automated, and also applied for data processing in real time.
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Affiliation(s)
- P Urbaniak
- University of Medical Sciences, Department of Cell Biology, Rokietnicka 5D, 60-806 Poznan, Poland
| | - S Wronski
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Kraków, Poland.
| | - J Tarasiuk
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Kraków, Poland
| | - P Lipinski
- Laboratory of Mechanics, Biomechanics, Polymers and Structures (LaBPS), Ecole Nationaled'Ingénieurs de Metz, 1 Route d'ArsLaquenexy, 57078 Metz, France
| | - M Kotwicka
- University of Medical Sciences, Department of Cell Biology, Rokietnicka 5D, 60-806 Poznan, Poland
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48
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Kitaguchi Y, Tei H, Uriu K. Cell size homeostasis under the circadian regulation of cell division in cyanobacteria. J Theor Biol 2022; 553:111260. [PMID: 36057343 DOI: 10.1016/j.jtbi.2022.111260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 06/10/2022] [Accepted: 08/18/2022] [Indexed: 10/31/2022]
Abstract
Bacterial cells maintain their characteristic cell size over many generations. Several rod-shaped bacteria, such as Escherichia coli and the cyanobacteria Synechococcus elongatus, divide after adding a constant length to their length at birth. Through this division control known as the adder mechanism, perturbation in cell length due to physiological fluctuation decays over generations at a rate of 2-1 per cell division. However, previous experiments have shown that the circadian clock in cyanobacteria reduces cell division frequency at a specific time of day under constant light. This circadian gating should modulate the division control by the adder mechanism, but its significance remains unknown. Here we address how the circadian gating affects cell length, doubling time, and cell length stability in cyanobacteria by using mathematical models. We show that a cell subject to circadian gating grows for a long time, and gives birth to elongated daughter cells. These elongated daughter cells grow faster than the previous generation, as elongation speed is proportional to cell length and divide in a short time before the next gating. Hence, the distributions of doubling time and cell length become bimodal, as observed in experimental data. Interestingly, the average doubling time over the population of cells is independent of gating because the extension of doubling time by gating is compensated by its reduction in the subsequent generation. On the other hand, average cell length is increased by gating, suggesting that the circadian clock controls cell length. We then show that the decay rate of perturbation in cell length depends on the ratio of delay in division by the gating τG to the average doubling time τ0 as [Formula: see text] . We estimated τG≈2.5, τ0≈13.6 hours, and τG/τ0≈0.18 from experimental data, indicating that a long doubling time in cyanobacteria maintains the decay rate similar to that of the adder mechanism. Thus, our analysis suggests that the acquisition of the circadian clock during evolution did not impose a constraint on cell size homeostasis in cyanobacteria.
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Affiliation(s)
- Yuta Kitaguchi
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan.
| | - Hajime Tei
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan
| | - Koichiro Uriu
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1129, Japan
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49
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Zhang S, Zatulovskiy E, Arand J, Sage J, Skotheim JM. The cell cycle inhibitor RB is diluted in G1 and contributes to controlling cell size in the mouse liver. Front Cell Dev Biol 2022; 10:965595. [PMID: 36092730 PMCID: PMC9452963 DOI: 10.3389/fcell.2022.965595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/27/2022] [Indexed: 12/14/2022] Open
Abstract
Every type of cell in an animal maintains a specific size, which likely contributes to its ability to perform its physiological functions. While some cell size control mechanisms are beginning to be elucidated through studies of cultured cells, it is unclear if and how such mechanisms control cell size in an animal. For example, it was recently shown that RB, the retinoblastoma protein, was diluted by cell growth in G1 to promote size-dependence of the G1/S transition. However, it remains unclear to what extent the RB-dilution mechanism controls cell size in an animal. We therefore examined the contribution of RB-dilution to cell size control in the mouse liver. Consistent with the RB-dilution model, genetic perturbations decreasing RB protein concentrations through inducible shRNA expression or through liver-specific Rb1 knockout reduced hepatocyte size, while perturbations increasing RB protein concentrations in an Fah -/- mouse model increased hepatocyte size. Moreover, RB concentration reflects cell size in G1 as it is lower in larger G1 hepatocytes. In contrast, concentrations of the cell cycle activators Cyclin D1 and E2f1 were relatively constant. Lastly, loss of Rb1 weakened cell size control, i.e., reduced the inverse correlation between how much cells grew in G1 and how large they were at birth. Taken together, our results show that an RB-dilution mechanism contributes to cell size control in the mouse liver by linking cell growth to the G1/S transition.
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Affiliation(s)
- Shuyuan Zhang
- Department of Biology, Stanford University, Stanford, CA, United States
| | | | - Julia Arand
- Departments of Pediatrics and Genetics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Julien Sage
- Departments of Pediatrics and Genetics, School of Medicine, Stanford University, Stanford, CA, United States
| | - Jan M. Skotheim
- Department of Biology, Stanford University, Stanford, CA, United States
- Chan Zuckerberg Biohub, San Francisco, CA, United States
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50
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Memristive FHN Spiking Neuron Model and Brain-Inspired Threshold Logic Computing. Neurocomputing 2022. [DOI: 10.1016/j.neucom.2022.08.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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