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Bermudez A, Latham ZD, Ma AJ, Bi D, Hu JK, Lin NYC. Regulation of chromatin modifications through coordination of nucleus size and epithelial cell morphology heterogeneity. Commun Biol 2025; 8:269. [PMID: 39979587 PMCID: PMC11842846 DOI: 10.1038/s42003-025-07677-w] [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: 04/18/2024] [Accepted: 02/05/2025] [Indexed: 02/22/2025] Open
Abstract
Cell morphology heterogeneity is pervasive in epithelial collectives, yet the underlying mechanisms driving such heterogeneity and its consequential biological ramifications remain elusive. Here, we observed a consistent correlation between the epithelial cell morphology and nucleus morphology during crowding, revealing a persistent log-normal probability distribution characterizing both cell and nucleus areas across diverse epithelial model systems. We showed that this morphological diversity arises from asymmetric partitioning during cell division. Next, we provide insights into the impact of nucleus morphology on chromatin modifications. We demonstrated that constraining nucleus leads to downregulation of the euchromatic mark H3K9ac and upregulation of the heterochromatic mark H3K27me3. Furthermore, we showed that nucleus size regulates H3K27me3 levels through histone demethylase UTX. These findings highlight the significance of cell morphology heterogeneity as a driver of chromatin state diversity, shaping functional variability within epithelial tissues.
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Affiliation(s)
- Alexandra Bermudez
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | - Zoe D Latham
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | - Alex J Ma
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | - Dapeng Bi
- Department of Physics, Northeastern University, Boston, MA, USA
| | - Jimmy K Hu
- School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA.
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA.
- Broad Stem Cell Center, University of California Los Angeles, Los Angeles, CA, USA.
| | - Neil Y C Lin
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA.
- Broad Stem Cell Center, University of California Los Angeles, Los Angeles, CA, USA.
- Mechanical and Aerospace Engineering Department, University of California Los Angeles, Los Angeles, CA, USA.
- Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA.
- Institute for Quantitative and Computational Biosciences, University of California Los Angeles, Los Angeles, CA, USA.
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2
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Bermudez A, Latham ZD, Ma AJ, Bi D, Hu JK, Lin NYC. Regulation of Chromatin Modifications through Coordination of Nucleus Size and Epithelial Cell Morphology Heterogeneity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2024.04.18.590164. [PMID: 38712099 PMCID: PMC11071433 DOI: 10.1101/2024.04.18.590164] [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 morphology heterogeneity is pervasive in epithelial collectives, yet the underlying mechanisms driving such heterogeneity and its consequential biological ramifications remain elusive. Here, we observed a consistent correlation between the epithelial cell morphology and nucleus morphology during crowding, revealing a persistent log-normal probability distribution characterizing both cell and nucleus areas across diverse epithelial model systems. We further showed that this morphological diversity arises from asymmetric partitioning during cell division. Moreover, we provide insights into the impact of nucleus morphology on chromatin modifications. We demonstrated that constraining nucleus leads to downregulation of the euchromatic mark H3K9ac and upregulation of the heterochromatic mark H3K27me3. Furthermore, we showed that nucleus size regulates H3K27me3 levels through histone demethylase UTX. These findings highlight the significance of cell morphology heterogeneity as a driver of chromatin state diversity, shaping functional variability within epithelial tissues.
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3
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Wang TC, Dollahon CR, Mishra S, Patel H, Abolghasemzade S, Singh I, Thomazy V, Rosen DG, Sandulache VC, Chakraborty S, Lele TP. Extreme wrinkling of the nuclear lamina is a morphological marker of cancer. NPJ Precis Oncol 2024; 8:276. [PMID: 39623008 PMCID: PMC11612457 DOI: 10.1038/s41698-024-00775-8] [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: 07/20/2024] [Accepted: 11/24/2024] [Indexed: 12/06/2024] Open
Abstract
Nuclear atypia is a hallmark of cancer. A recent model posits that excess surface area, visible as folds/wrinkles in the lamina of a rounded nucleus, allows the nucleus to take on diverse shapes with little mechanical resistance. Whether this model is applicable to normal and cancer nuclei in human tissues is unclear. We image nuclear lamins in patient tissues and find: (a) nuclear laminar wrinkles are present in control and cancer tissue but are obscured in hematoxylin and eosin (H&E) images, (b) nuclei rarely have a smooth lamina, and (c) wrinkled nuclei assume diverse shapes. Deep learning reveals the presence of extreme nuclear laminar wrinkling in cancer tissues, which is confirmed by Fourier analysis. These data support a model in which excess surface area in the nuclear lamina enables nuclear shape diversity in vivo. Extreme laminar wrinkling is a marker of cancer, and imaging the lamina may benefit cancer diagnosis.
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Affiliation(s)
- Ting-Ching Wang
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Christina R Dollahon
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Sneha Mishra
- Department of Computer Science & Engineering, Texas A&M University, College Station, TX, USA
| | - Hailee Patel
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Samere Abolghasemzade
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Ishita Singh
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | | | - Daniel G Rosen
- Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA
| | - Vlad C Sandulache
- Bobby R. Alford Department of Otolaryngology Head and Neck Surgery, Baylor College of Medicine, Houston, TX, USA
- ENT Section, Operative CareLine, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA
| | | | - Tanmay P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.
- Department of Translational Medical Sciences, Texas A&M University, Houston, TX, USA.
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4
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Dickinson RB, Abolghasemzade S, Lele TP. Rethinking nuclear shaping: insights from the nuclear drop model. SOFT MATTER 2024; 20:7558-7565. [PMID: 39105242 PMCID: PMC11446230 DOI: 10.1039/d4sm00683f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
Changes in the nuclear shape caused by cellular shape changes are generally assumed to reflect an elastic deformation from a spherical nuclear shape. Recent evidence, however, suggests that the nuclear lamina, which forms the outer nuclear surface together with the nuclear envelope, possesses more area than that of a sphere of the same volume. This excess area manifests as folds/wrinkles in the nuclear surface in rounded cells and allows facile nuclear flattening during cell spreading without any changes in nuclear volume or surface area. When the lamina becomes smooth and taut, it is inextensible, and supports a surface tension. At this point, it is possible to mathematically calculate the limiting nuclear shape purely based on geometric considerations. In this paper, we provide a commentary on the "nuclear drop model" which seeks to integrate the above features. We outline its testable physical properties and explore its biological implications.
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Affiliation(s)
- Richard B Dickinson
- Department of Chemical Engineering, University of Florida, 1030 Center Drive, Gainesville, FL, 32611, USA.
| | - Samere Abolghasemzade
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX, 77843, USA.
| | - Tanmay P Lele
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX, 77843, USA.
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, 3122 TAMU, College Station, TX, 77843, USA
- Department of Translational Medical Sciences, Texas A&M University, 2121 W Holcombe St., Houston, TX, 77030, USA
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5
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Dickinson RB, Lele TP. A new function for nuclear lamins: providing surface tension to the nuclear drop. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2023; 28:100483. [PMID: 38283102 PMCID: PMC10812902 DOI: 10.1016/j.cobme.2023.100483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
The nuclear lamina, a conserved structure in metazoans, provides mechanical rigidity to the nuclear envelope. A decrease in lamin levels and/or lamin mutations are associated with a host of human diseases. Despite being only about 15 nm thick, perturbation of components of the nuclear lamina dramatically impacts the deformation response of the entire nucleus through mechanisms that are not well understood. Here we discuss evidence for the recently proposed 'nuclear drop' model that explains the role of A-type lamins in nuclear deformation in migrating cells. In this model, the nuclear lamina acts as an inextensible surface, supporting a surface tension when fully unfolded, that balances nuclear interior pressure. Much like a liquid drop surface where the molecularly thin interface governs surface tension and drop shape under external forces, the thin nuclear lamina imparts a surface tension on the nuclear drop to resist nuclear deformation as well as to establish nuclear shape. We discuss implications of the nuclear drop model for the function of this crucially important eukaryotic organelle.
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Affiliation(s)
- Richard B. Dickinson
- Department of Chemical Engineering, University of Florida, 1030 Center Drive, Gainesville, FL, 32611, USA
| | - Tanmay P. Lele
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St., College Station, TX, 77843, USA
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, 3122 TAMU, College Station, TX, 77843, USA
- Department of Translational Medical Sciences, Texas A&M University, 2121 W Holcombe St., Houston, TX, 77030, USA
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6
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Bozuyuk U, Yildiz E, Han M, Demir SO, Sitti M. Size-Dependent Locomotion Ability of Surface Microrollers on Physiologically Relevant Microtopographical Surfaces. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303396. [PMID: 37488686 DOI: 10.1002/smll.202303396] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 07/10/2023] [Indexed: 07/26/2023]
Abstract
Controlled microrobotic navigation inside the body possesses significant potential for various biomedical engineering applications. Successful application requires considering imaging, control, and biocompatibility. Interaction with biological environments is also a crucial factor in ensuring safe application, but can also pose counterintuitive hydrodynamic barriers, limiting the use of microrobots. Surface rolling microrobots or surface microrollers is a robust microrobotic platform with significant potential for various applications; however, conventional spherical microrollers have limited locomotion ability over biological surfaces due to microtopography effects resulting from cell microtopography in the size range of 2-5 µm. Here, the impact of the microtopography effect on spherical microrollers of different sizes (5, 10, 25, and 50 µm) is investigated using computational fluid dynamics simulations and experiments. Simulations revealed that the microtopography effect becomes insignificant for increasing microroller sizes, such as 50 µm. Moreover, it is demonstrated that 50 µm microrollers exhibited smooth locomotion ability on in vitro cell layers and inside blood vessels of a chicken embryo model. These findings offer rational design principles for surface microrollers for their potential practical biomedical applications.
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Affiliation(s)
- Ugur Bozuyuk
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Erdost Yildiz
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Mertcan Han
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Sinan Ozgun Demir
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, 8092, Switzerland
- School of Medicine and School of Engineering, Koç University, Istanbul, 34450, Turkey
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7
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Dickinson RB, Lele TP. Nuclear shapes are geometrically determined by the excess surface area of the nuclear lamina. Front Cell Dev Biol 2023; 11:1058727. [PMID: 37397244 PMCID: PMC10308086 DOI: 10.3389/fcell.2023.1058727] [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: 09/30/2022] [Accepted: 05/30/2023] [Indexed: 07/04/2023] Open
Abstract
Introduction: Nuclei have characteristic shapes dependent on cell type, which are critical for proper cell function, and nuclei lose their distinct shapes in multiple diseases including cancer, laminopathies, and progeria. Nuclear shapes result from deformations of the sub-nuclear components-nuclear lamina and chromatin. How these structures respond to cytoskeletal forces to form the nuclear shape remains unresolved. Although the mechanisms regulating nuclear shape in human tissues are not fully understood, it is known that different nuclear shapes arise from cumulative nuclear deformations post-mitosis, ranging from the rounded morphologies that develop immediately after mitosis to the various nuclear shapes that roughly correspond to cell shape (e.g., elongated nuclei in elongated cells, flat nuclei in flat cells). Methods: We formulated a mathematical model to predict nuclear shapes of cells in various contexts under the geometric constraints of fixed cell volume, nuclear volume and lamina surface area. Nuclear shapes were predicted and compared to experiments for cells in various geometries, including isolated on a flat surface, on patterned rectangles and lines, within a monolayer, isolated in a well, or when the nucleus is impinging against a slender obstacle. Results and Discussion: The close agreement between predicted and experimental shapes demonstrates a simple geometric principle of nuclear shaping: the excess surface area of the nuclear lamina (relative to that of a sphere of the same volume) permits a wide range of highly deformed nuclear shapes under the constraints of constant surface area and constant volume. When the lamina is smooth (tensed), the nuclear shape can be predicted entirely from these geometric constraints alone for a given cell shape. This principle explains why flattened nuclear shapes in fully spread cells are insensitive to the magnitude of the cytoskeletal forces. Also, the surface tension in the nuclear lamina and nuclear pressure can be estimated from the predicted cell and nuclear shapes when the cell cortical tension is known, and the predictions are consistent with measured forces. These results show that excess surface area of the nuclear lamina is the key determinant of nuclear shapes. When the lamina is smooth (tensed), the nuclear shape can be determined purely by the geometric constraints of constant (but excess) nuclear surface area, nuclear volume, and cell volume, for a given cell adhesion footprint, independent of the magnitude of the cytoskeletal forces involved.
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Affiliation(s)
- Richard B. Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, FL, United States
| | - Tanmay P. Lele
- Department of Biomedical Engineering, College of Engineering, Texas A&M University College Station, College Station, TX, United States
- Artie McFerrin Department of Chemical Engineering, College of Engineering, Texas A&M University, College Station, TX, United States
- Department of Translational Medical Sciences, Texas A&M University, College Station, TX, United States
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8
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Jones ML, Dahl KN, Lele TP, Conway DE, Shenoy V, Ghosh S, Szczesny SE. The Elephant in the Cell: Nuclear Mechanics and Mechanobiology. J Biomech Eng 2022; 144:080802. [PMID: 35147160 PMCID: PMC8990742 DOI: 10.1115/1.4053797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/28/2022] [Indexed: 11/08/2022]
Abstract
The 2021 Summer Biomechanics, Bioengineering, and Biotransport Conference (SB3C) featured a workshop titled "The Elephant in the Room: Nuclear Mechanics and Mechanobiology." The goal of this workshop was to provide a perspective from experts in the field on the current understanding of nuclear mechanics and its role in mechanobiology. This paper reviews the major themes and questions discussed during the workshop, including historical context on the initial methods of measuring the mechanical properties of the nucleus and classifying the primary structures dictating nuclear mechanics, physical plasticity of the nucleus, the emerging role of the linker of nucleoskeleton and cytoskeleton (LINC) complex in coupling the nucleus to the cytoplasm and driving the behavior of individual cells and multicellular assemblies, and the computational models currently in use to investigate the mechanisms of gene expression and cell signaling. Ongoing questions and controversies, along with promising future directions, are also discussed.
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Affiliation(s)
| | - Kris Noel Dahl
- Department of Chemical Engineering, Carnegie Mellon University, Doherty Hall, 5000 Forbes Avenue, Pittsburgh, PA 15213; Forensics Department, Thornton Tomasetti, 120 Broadway 15th Floor, New York City, NY 10271
| | - Tanmay P. Lele
- Department of Biomedical Engineering, Texas A&M University, 101 Bizzell Street, College Station, TX 77840; Department of Chemical Engineering, Texas A&M University, 101 Bizzell Street, College Station, TX 77840; Department of Translational Medical Sciences, Texas A&M University, 101 Bizzell Street, College Station, TX 77840
| | - Daniel E. Conway
- Department of Biomedical Engineering, Virginia Commonwealth University, 601 West Main Street, P.O. Box 843068, Richmond, VA 23284
| | - Vivek Shenoy
- Materials Science and Engineering Bioengineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104; Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104; Center for Engineering Mechanobiology, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104
| | - Soham Ghosh
- Department of Mechanical Engineering, School of Biomedical Engineering, Translational Medicine Institute, Colorado State University, 400 Isotope Drive, Fort Collins, CO 80521
| | - Spencer E. Szczesny
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802; Department of Orthopaedics and Rehabilitation, Pennsylvania State University, University Park, PA 16802
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Tomaz D, Pereira PM, Guerra N, Dyson J, Gould K, Henriques R. Nanoscale Colocalization of NK Cell Activating and Inhibitory Receptors Controls Signal Integration. Front Immunol 2022; 13:868496. [PMID: 35720315 PMCID: PMC9198454 DOI: 10.3389/fimmu.2022.868496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
Natural killer (NK) cell responses depend on the balance of signals from inhibitory and activating receptors. However, how the integration of antagonistic signals occurs upon NK cell-target cell interaction is not fully understood. Here we provide evidence that NK cell inhibition via the inhibitory receptor Ly49A is dependent on its relative colocalization at the nanometer scale with the activating receptor NKG2D upon immune synapse (IS) formation. NKG2D and Ly49A signal integration and colocalization were studied using NKG2D-GFP and Ly49A-RFP-expressing primary NK cells, forming ISs with NIH3T3 target cells, with or without the expression of single-chain trimer (SCT) H2-Dd and an extended form of SCT H2-Dd-CD4 MHC-I molecules. Nanoscale colocalization was assessed by Förster resonance energy transfer between NKG2D-GFP and Ly49A-RFP and measured for each synapse. In the presence of their respective cognate ligands, NKG2D and Ly49A colocalize at the nanometer scale, leading to NK cell inhibition. However, increasing the size of the Ly49A ligand reduced the nanoscale colocalization with NKG2D, consequently impairing Ly49A-mediated inhibition. Thus, our data shows that NK cell signal integration is critically dependent on the dimensions of NK cell ligand-receptor pairs by affecting their relative nanometer-scale colocalization at the IS. Our results together suggest that the balance of NK cell signals and NK cell responses is determined by the relative nanoscale colocalization of activating and inhibitory receptors in the immune synapse.
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Affiliation(s)
- David Tomaz
- Department of Immunology, Wright-Fleming Institute, Imperial College London, London, United Kingdom
- Department of Immunology, Hammersmith Hospital, Imperial College London, London, United Kingdom
| | - Pedro Matos Pereira
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Nadia Guerra
- Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Julian Dyson
- Department of Immunology, Hammersmith Hospital, Imperial College London, London, United Kingdom
| | - Keith Gould
- Department of Immunology, Wright-Fleming Institute, Imperial College London, London, United Kingdom
| | - Ricardo Henriques
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Division of Infection and Immunity, University College London, London, United Kingdom
- Optical Cell Biology Lab, Instituto Gulbenkian de Ciência, Oeiras, Portugal
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10
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Deviri D, Safran SA. Balance of osmotic pressures determines the nuclear-to-cytoplasmic volume ratio of the cell. Proc Natl Acad Sci U S A 2022; 119:e2118301119. [PMID: 35580183 PMCID: PMC9173802 DOI: 10.1073/pnas.2118301119] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 04/05/2022] [Indexed: 01/06/2023] Open
Abstract
The volume of the cell nucleus varies across cell types and species and is commonly thought to be determined by the size of the genome and degree of chromatin compaction. However, this notion has been challenged over the years by much experimental evidence. Here, we consider the physical condition of mechanical force balance as a determining condition of the nuclear volume and use quantitative, order-of-magnitude analysis to estimate the forces from different sources of nuclear and cytoplasmic pressure. Our estimates suggest that the dominant pressure within the nucleus and cytoplasm of nonstriated muscle cells originates from the osmotic pressure of proteins and RNA molecules that are localized to the nucleus or cytoplasm by out-of-equilibrium, active nucleocytoplasmic transport rather than from chromatin or its associated ions. This motivates us to formulate a physical model for the ratio of the cell and nuclear volumes in which osmotic pressures of localized proteins determine the relative volumes. In accordance with unexplained observations that are a century old, our model predicts that the ratio of the cell and nuclear volumes is a constant, robust to a wide variety of biochemical and biophysical manipulations, and is changed only if gene expression or nucleocytoplasmic transport is modulated.
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Affiliation(s)
- Dan Deviri
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovet 76100, Israel
| | - Samuel A. Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovet 76100, Israel
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11
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Dickinson RB, Katiyar A, Dubell CR, Lele TP. Viscous shaping of the compliant cell nucleus. APL Bioeng 2022; 6:010901. [PMID: 35028490 PMCID: PMC8730821 DOI: 10.1063/5.0071652] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/01/2021] [Indexed: 01/08/2023] Open
Abstract
The cell nucleus is commonly considered to be a stiff organelle that mechanically resists changes in shape, and this resistance is thought to limit the ability of cells to migrate through pores or spread on surfaces. Generation of stresses on the cell nucleus during migration and nuclear response to these stresses is fundamental to cell migration and mechano-transduction. In this Perspective, we discuss our previous experimental and computational evidence that supports a dynamic model, in which the soft nucleus is irreversibly shaped by viscous stresses generated by the motion of cell boundaries and transmitted through the intervening cytoskeletal network. While the nucleus is commonly modeled as a stiff elastic body, we review how nuclear shape changes on the timescale of migration can be explained by simple geometric constraints of constant nuclear volume and constant surface area of the nuclear lamina. Because the lamina surface area is in excess of that of a sphere of the same volume, these constraints permit dynamic transitions between a wide range of shapes during spreading and migration. The excess surface area allows the nuclear shape changes to mirror those of the cell with little mechanical resistance. Thus, the nucleus can be easily shaped by the moving cell boundaries over a wide range of shape changes and only becomes stiff to more extreme deformations that would require the lamina to stretch or the volume to compress. This model explains how nuclei can easily flatten on surfaces during cell spreading or elongate as cells move through pores until the lamina smooths out and becomes tense.
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Affiliation(s)
- Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, USA
| | - Aditya Katiyar
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Christina R Dubell
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, USA
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12
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Pedersen MW, Antunes C, De Cahsan B, Moreno-Mayar JV, Sikora M, Vinner L, Mann D, Klimov PB, Black S, Michieli CT, Braig HR, Perotti MA. Ancient human genomes and environmental DNA from the cement attaching 2,000 year-old head lice nits. Mol Biol Evol 2021; 39:6481551. [PMID: 34963129 PMCID: PMC8829908 DOI: 10.1093/molbev/msab351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Over the past few decades, there has been a growing demand for genome analysis of ancient human remains. Destructive sampling is increasingly difficult to obtain for ethical reasons, and standard methods of breaking the skull to access the petrous bone or sampling remaining teeth are often forbidden for curatorial reasons. However, most ancient humans carried head lice and their eggs abound in historical hair specimens. Here we show that host DNA is protected by the cement that glues head lice nits to the hair of ancient Argentinian mummies, 1,500–2,000 years old. The genetic affinities deciphered from genome-wide analyses of this DNA inform that this population migrated from north-west Amazonia to the Andes of central-west Argentina; a result confirmed using the mitochondria of the host lice. The cement preserves ancient environmental DNA of the skin, including the earliest recorded case of Merkel cell polyomavirus. We found that the percentage of human DNA obtained from nit cement equals human DNA obtained from the tooth, yield 2-fold compared with a petrous bone, and 4-fold to a bloodmeal of adult lice a millennium younger. In metric studies of sheaths, the length of the cement negatively correlates with the age of the specimens, whereas hair linear distance between nit and scalp informs about the environmental conditions at the time before death. Ectoparasitic lice sheaths can offer an alternative, nondestructive source of high-quality ancient DNA from a variety of host taxa where bones and teeth are not available and reveal complementary details of their history.
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Affiliation(s)
- Mikkel W Pedersen
- GLOBE Institute, Faculty of Health and Medical Science, University of Copenhagen, Denmark
| | - Catia Antunes
- Ecology and Evolutionary Biology Section, School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Binia De Cahsan
- GLOBE Institute, Faculty of Health and Medical Science, University of Copenhagen, Denmark
| | - J Víctor Moreno-Mayar
- GLOBE Institute, Faculty of Health and Medical Science, University of Copenhagen, Denmark
| | - Martin Sikora
- GLOBE Institute, Faculty of Health and Medical Science, University of Copenhagen, Denmark
| | - Lasse Vinner
- GLOBE Institute, Faculty of Health and Medical Science, University of Copenhagen, Denmark
| | - Darren Mann
- Oxford University Museum of Natural History, Oxford, United Kingdom
| | - Pavel B Klimov
- School of Natural Sciences, Bangor University, Bangor, Wales, United Kingdom.,Department of Ecology and Evolutionary Biology, University of Michigan, Museum of Zoology, Ann Arbor, USA
| | - Stuart Black
- Department of Geography and Environmental Science, Wager Building, University of Reading, Reading, United Kingdom
| | - Catalina Teresa Michieli
- Instituto de Investigaciones Arqueológicas y Museo "Prof. Mariano Gambier", Universidad Nacional de San Juan, San Juan, Argentina
| | - Henk R Braig
- School of Natural Sciences, Bangor University, Bangor, Wales, United Kingdom.,Institute and Museum of Natural Sciences, Faculty of Exact, Physical and Natural Sciences, National University of San Juan, San Juan, Argentina
| | - M Alejandra Perotti
- Ecology and Evolutionary Biology Section, School of Biological Sciences, University of Reading, Reading, United Kingdom
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13
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Nyga A, Muñoz JJ, Dercksen S, Fornabaio G, Uroz M, Trepat X, Baum B, Matthews HK, Conte V. Oncogenic RAS instructs morphological transformation of human epithelia via differential tissue mechanics. SCIENCE ADVANCES 2021; 7:eabg6467. [PMID: 34644109 PMCID: PMC8514103 DOI: 10.1126/sciadv.abg6467] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 08/22/2021] [Indexed: 05/05/2023]
Abstract
The loss of epithelial homeostasis and the disruption of normal tissue morphology are hallmarks of tumor development. Here, we ask how the uniform activation oncogene RAS affects the morphology and tissue mechanics in a normal epithelium. We found that inducible induction of HRAS in confined epithelial monolayers on soft substrates drives a morphological transformation of a 2D monolayer into a compact 3D cell aggregate. This transformation was initiated by the loss of monolayer integrity and formation of two distinct cell layers with differential cell-cell junctions, cell-substrate adhesion, and tensional states. Computational modeling revealed how adhesion and active peripheral tension induces inherent mechanical instability in the system, which drives the 2D-to-3D morphological transformation. Consistent with this, removal of epithelial tension through the inhibition of actomyosin contractility halted the process. These findings reveal the mechanisms by which oncogene activation within an epithelium can induce mechanical instability to drive morphological tissue transformation.
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Affiliation(s)
- Agata Nyga
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jose J. Muñoz
- Department of Mathematics, Polytechnic University of Catalonia (UPC), Barcelona, Spain
- Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE), Barcelona, Spain
- Institut de Matemàtiques de la UPC - BarcelonaTech (IMTECH), Barcelona, Spain
| | - Suze Dercksen
- Department of Biomedical Engineering, Eindhoven University of Technology (TU/e), Eindhoven, Netherlands
| | - Giulia Fornabaio
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Department of Physics, University of Barcelona (UB), Barcelona, Spain
| | - Marina Uroz
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA, USA
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
- Department of Biomedicine, University of Barcelona (UB), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Buzz Baum
- MRC Laboratory of Molecular Biology, Cambridge, UK
- MRC Laboratory of Molecular Cell Biology, University College London (UCL), London, UK
| | - Helen K. Matthews
- MRC Laboratory of Molecular Cell Biology, University College London (UCL), London, UK
| | - Vito Conte
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Department of Biomedical Engineering, Eindhoven University of Technology (TU/e), Eindhoven, Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology (TU/e), Eindhoven, Netherlands
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14
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Gómez HF, Dumond MS, Hodel L, Vetter R, Iber D. 3D cell neighbour dynamics in growing pseudostratified epithelia. eLife 2021; 10:e68135. [PMID: 34609280 PMCID: PMC8570695 DOI: 10.7554/elife.68135] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 09/27/2021] [Indexed: 12/29/2022] Open
Abstract
During morphogenesis, epithelial sheets remodel into complex geometries. How cells dynamically organise their contact with neighbouring cells in these tightly packed tissues is poorly understood. We have used light-sheet microscopy of growing mouse embryonic lung explants, three-dimensional cell segmentation, and physical theory to unravel the principles behind 3D cell organisation in growing pseudostratified epithelia. We find that cells have highly irregular 3D shapes and exhibit numerous neighbour intercalations along the apical-basal axis as well as over time. Despite the fluidic nature, the cell packing configurations follow fundamental relationships previously described for apical epithelial layers, that is, Euler's polyhedron formula, Lewis' law, and Aboav-Weaire's law, at all times and across the entire tissue thickness. This arrangement minimises the lateral cell-cell surface energy for a given cross-sectional area variability, generated primarily by the distribution and movement of nuclei. We conclude that the complex 3D cell organisation in growing epithelia emerges from simple physical principles.
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Affiliation(s)
- Harold Fernando Gómez
- Department of Biosystems Science and Engineering (D-BSSE), ETH ZürichBaselSwitzerland
- Swiss Institute of Bioinformatics (SIB)BaselSwitzerland
| | - Mathilde Sabine Dumond
- Department of Biosystems Science and Engineering (D-BSSE), ETH ZürichBaselSwitzerland
- Swiss Institute of Bioinformatics (SIB)BaselSwitzerland
| | - Leonie Hodel
- Department of Biosystems Science and Engineering (D-BSSE), ETH ZürichBaselSwitzerland
| | - Roman Vetter
- Department of Biosystems Science and Engineering (D-BSSE), ETH ZürichBaselSwitzerland
- Swiss Institute of Bioinformatics (SIB)BaselSwitzerland
| | - Dagmar Iber
- Department of Biosystems Science and Engineering (D-BSSE), ETH ZürichBaselSwitzerland
- Swiss Institute of Bioinformatics (SIB)BaselSwitzerland
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15
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Viegas AMD, Postuma I, Bortolussi S, Guidi C, Riback JS, Provenzano L, Marcaccio B, Rossini AE, Ferrari C, Cansolino L, Ferrari M, Portu AM, González SJ. Detailed dosimetry calculation for in-vitro experiments and its impact on clinical BNCT. Phys Med 2021; 89:282-292. [PMID: 34474326 DOI: 10.1016/j.ejmp.2021.08.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/18/2021] [Accepted: 08/21/2021] [Indexed: 10/20/2022] Open
Abstract
PURPOSE Boron Neutron Capture Therapy (BNCT) is a form of hadrontherapy based on the selective damage caused by the products of neutron capture in 10B to tumour cells. BNCT dosimetry strongly depends on the parameters of the dose calculation models derived from radiobiological experiments. This works aims at determining an adequate dosimetry for in-vitro experiments involving irradiation of monolayer-cultured cells with photons and BNCT and assessing its impact on clinical settings. M&M: Dose calculations for rat osteosarcoma UMR-106 and human metastatic melanoma Mel-J cell survival experiments were performed using MCNP, transporting uncharged particles for KERMA determinations, and secondary particles (electrons, protons, 14C, 4He and 7Li) to compute absorbed dose in cultures. Dose-survival curves were modified according to the dose correction factors determined from computational studies. New radiobiological parameters of the photon isoeffective dose models for osteosarcoma and metastatic melanoma tumours were obtained. Dosimetry implications considering cutaneous melanoma patients treated in Argentina with BNCT were assessed and discussed. RESULTS KERMA values for the monolayer-cultured cells overestimate absorbed doses of radiation components of interest in BNCT. Detailed dose calculations for the osteosarcoma irradiation increased the relative biological effectiveness factor RBE1% of the neutron component in more than 30%. The analysis based on melanoma cases reveals that the use of survival curves based on KERMA leads to an underestimation of the tumour doses delivered to patients. CONCLUSIONS Considering detailed dose calculation for in-vitro experiments significantly impact on the prediction of the tumor control in patients. Therefore, proposed methods are clinically relevant.
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Affiliation(s)
- Ana Mailén Dattoli Viegas
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón I, Ciudad Universitaria, C1428EHA Buenos Aires, Argentina; Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina
| | - Ian Postuma
- National Institute of Nuclear Physics (INFN), Unit of Pavia, via A. Bassi 6, 27100 Pavia, Italy
| | - Silva Bortolussi
- National Institute of Nuclear Physics (INFN), Unit of Pavia, via A. Bassi 6, 27100 Pavia, Italy; University of Pavia, Department of Physics, via A. Bassi 6, 27100 Pavia, Italy.
| | - Claretta Guidi
- National Institute of Nuclear Physics (INFN), Unit of Pavia, via A. Bassi 6, 27100 Pavia, Italy; University of Pavia, Department of Physics, via A. Bassi 6, 27100 Pavia, Italy
| | - Jessica Sofía Riback
- Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2270, C, Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucas Provenzano
- Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina
| | - Barbara Marcaccio
- University of Pavia, Department of Physics, via A. Bassi 6, 27100 Pavia, Italy
| | - Andrés Eugenio Rossini
- Laboratorio de Radiopatología, Gerencia de Mediciones y Evaluaciones en protección Radiológica. Autoridad Regulatoria Nuclear (ARN), Av. del Libertador 8250, C1429 BNP Ciudad Autónoma de Buenos Aires, Argentina
| | - Cinzia Ferrari
- National Institute of Nuclear Physics (INFN), Unit of Pavia, via A. Bassi 6, 27100 Pavia, Italy; University of Pavia, Laboratory of Experimental Surgery, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, via Ferrata 9, 27100 Pavia, Italy
| | - Laura Cansolino
- National Institute of Nuclear Physics (INFN), Unit of Pavia, via A. Bassi 6, 27100 Pavia, Italy; University of Pavia, Laboratory of Experimental Surgery, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, via Ferrata 9, 27100 Pavia, Italy
| | | | - Agustina Mariana Portu
- Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2270, C, Ciudad Autónoma de Buenos Aires, Argentina
| | - Sara Josefina González
- Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2270, C, Ciudad Autónoma de Buenos Aires, Argentina
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16
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Module to Support Real-Time Microscopic Imaging of Living Organisms on Ground-Based Microgravity Analogs. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11073122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Since opportunities for spaceflight experiments are scarce, ground-based microgravity simulation devices (MSDs) offer accessible and economical alternatives for gravitational biology studies. Among the MSDs, the random positioning machine (RPM) provides simulated microgravity conditions on the ground by randomizing rotating biological samples in two axes to distribute the Earth’s gravity vector in all directions over time. Real-time microscopy and image acquisition during microgravity simulation are of particular interest to enable the study of how basic cell functions, such as division, migration, and proliferation, progress under altered gravity conditions. However, these capabilities have been difficult to implement due to the constantly moving frames of the RPM as well as mechanical noise. Therefore, we developed an image acquisition module that can be mounted on an RPM to capture live images over time while the specimen is in the simulated microgravity (SMG) environment. This module integrates a digital microscope with a magnification range of 20× to 700×, a high-speed data transmission adaptor for the wireless streaming of time-lapse images, and a backlight illuminator to view the sample under brightfield and darkfield modes. With this module, we successfully demonstrated the real-time imaging of human cells cultured on an RPM in brightfield, lasting up to 80 h, and also visualized them in green fluorescent channel. This module was successful in monitoring cell morphology and in quantifying the rate of cell division, cell migration, and wound healing in SMG. It can be easily modified to study the response of other biological specimens to SMG.
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17
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Lee H, Bonin K, Guthold M. Human mammary epithelial cells in a mature, stratified epithelial layer flatten and stiffen compared to single and confluent cells. Biochim Biophys Acta Gen Subj 2021; 1865:129891. [PMID: 33689830 DOI: 10.1016/j.bbagen.2021.129891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/07/2021] [Accepted: 03/03/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND The epithelium forms a protective barrier against external biological, chemical and physical insults. So far, AFM-based, micro-mechanical measurements have only been performed on single cells and confluent cells, but not yet on cells in mature layers. METHODS Using a combination of atomic force, fluorescence and confocal microscopy, we determined the changes in stiffness, morphology and actin distribution of human mammary epithelial cells (HMECs) as they transition from single cells to confluency to a mature layer. RESULTS Single HMECs have a tall, round (planoconvex) morphology, have actin stress fibers at the base, have diffuse cortical actin, and have a stiffness of 1 kPa. Confluent HMECs start to become flatter, basal actin stress fibers start to disappear, and actin accumulates laterally where cells abut. Overall stiffness is still 1 kPa with two-fold higher stiffness in the abutting regions. As HMECs mature and form multilayered structures, cells on apical surfaces become flatter (apically more level), wider, and seven times stiffer (mean, 7 kPa) than single and confluent cells. The main drivers of these changes are actin filaments, as cells show strong actin accumulation in the regions where cells adjoin, and in the apical regions. CONCLUSIONS HMECs stiffen, flatten and redistribute actin upon transiting from single cells to mature, confluent layers. GENERAL SIGNIFICANCE Our findings advance the understanding of breast ductal morphogenesis and mechanical homeostasis.
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Affiliation(s)
- Hyunsu Lee
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Keith Bonin
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Martin Guthold
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
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18
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Cosgrove BD, Loebel C, Driscoll TP, Tsinman TK, Dai EN, Heo SJ, Dyment NA, Burdick JA, Mauck RL. Nuclear envelope wrinkling predicts mesenchymal progenitor cell mechano-response in 2D and 3D microenvironments. Biomaterials 2021; 270:120662. [PMID: 33540172 PMCID: PMC7936657 DOI: 10.1016/j.biomaterials.2021.120662] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/24/2020] [Accepted: 01/03/2021] [Indexed: 12/21/2022]
Abstract
Exogenous mechanical cues are transmitted from the extracellular matrix to the nuclear envelope (NE), where mechanical stress on the NE mediates shuttling of transcription factors and other signaling cascades that dictate downstream cellular behavior and fate decisions. To systematically study how nuclear morphology can change across various physiologic microenvironmental contexts, we cultured mesenchymal progenitor cells (MSCs) in engineered 2D and 3D hyaluronic acid hydrogel systems. Across multiple contexts we observed highly 'wrinkled' nuclear envelopes, and subsequently developed a quantitative single-cell imaging metric to better evaluate how wrinkles in the nuclear envelope relate to progenitor cell mechanotransduction. We determined that in soft 2D environments the NE is predominately wrinkled, and that increases in cellular mechanosensing (indicated by cellular spreading, adhesion complex growth, and nuclear localization of YAP/TAZ) occurred only in absence of nuclear envelope wrinkling. Conversely, in 3D hydrogel and tissue contexts, we found NE wrinkling occurred along with increased YAP/TAZ nuclear localization. We further determined that these NE wrinkles in 3D were largely generated by actin impingement, and compared to other nuclear morphometrics, the degree of nuclear wrinkling showed the greatest correlation with nuclear YAP/TAZ localization. These findings suggest that the degree of nuclear envelope wrinkling can predict mechanotransduction state in mesenchymal progenitor cells and highlights the differential mechanisms of NE stress generation operative in 2D and 3D microenvironmental contexts.
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Affiliation(s)
- Brian D Cosgrove
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Claudia Loebel
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Tristan P Driscoll
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Tonia K Tsinman
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Eric N Dai
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Su-Jin Heo
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
| | - Nathaniel A Dyment
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA
| | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA
| | - Robert L Mauck
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Bioengineering, University of Pennsylvania Philadelphia, PA, 19104, USA; Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, 19104, USA.
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19
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Zakarial Ansar FH, Latifah SY, Wan Kamal WHB, Khong KC, Ng Y, Foong JN, Gopalsamy B, Ng WK, How CW, Ong YS, Abdullah R, Aziz MY. Pharmacokinetics and Biodistribution of Thymoquinone-loaded Nanostructured Lipid Carrier After Oral and Intravenous Administration into Rats. Int J Nanomedicine 2020; 15:7703-7717. [PMID: 33116496 PMCID: PMC7553255 DOI: 10.2147/ijn.s262395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/27/2020] [Indexed: 12/28/2022] Open
Abstract
Background Thymoquinone (TQ), an active compound isolated from Nigella sativa, has been proven to exhibit various biological properties such as antioxidant. Although oral delivery of TQ is valuable, it is limited by poor oral bioavailability and low solubility. Recently, TQ-loaded nanostructured lipid carrier (TQ-NLC) was formulated with the aim of overcoming the limitations. TQ-NLC was successfully synthesized by the high-pressure homogenization method with remarkable physiochemical properties whereby the particle size is less than 100 nm, improved encapsulation efficiency and is stable up to 24 months of storage. Nevertheless, the pharmacokinetics and biodistribution of TQ-NLC have not been studied. This study determined the bioavailability of oral and intravenous administration of thymoquinone-loaded nanostructured lipid carrier (TQ-NLC) in rats and its distribution to organs. Materials and Methods TQ-NLC was radiolabeled with technetium-99m before the administration to the rats. The biodistribution and pharmacokinetics parameters were then evaluated at various time points. The rats were imaged at time intervals and the percentage of the injected dose/gram (%ID/g) in blood and each organ was analyzed. Results Oral administration of TQ-NLC exhibited greater relative bioavailability compared to intravenous administration. It is postulated that the movement of TQ-NLC through the intestinal lymphatic system bypasses the first metabolism and therefore enhances the relative bioavailability. However, oral administration has a slower absorption rate compared to intravenous administration where the AUC0-∞ was 4.539 times lower than the latter. Conclusion TQ-NLC had better absorption when administered intravenously compared to oral administration. However, oral administration showed greater bioavailability compared to the intravenous route. This study provides the pharmacokinetics and biodistribution profile of TQ-NLC in vivo which is useful to assist researchers in clinical use.
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Affiliation(s)
- Fatin Hannani Zakarial Ansar
- Laboratory of Molecular Medicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Saiful Yazan Latifah
- Laboratory of Molecular Medicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.,Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Wan Hamirul Bahrin Wan Kamal
- Laboratory of Preclinical Study, Block 24, Medical Technology Division, Malaysian Nuclear Agency, Kajang, Selangor, Malaysia
| | - Khei Choong Khong
- Laboratory of Preclinical Study, Block 24, Medical Technology Division, Malaysian Nuclear Agency, Kajang, Selangor, Malaysia
| | - Yen Ng
- Laboratory of Preclinical Study, Block 24, Medical Technology Division, Malaysian Nuclear Agency, Kajang, Selangor, Malaysia
| | - Jia Ning Foong
- Laboratory of Molecular Medicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Banulata Gopalsamy
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Wei Keat Ng
- Laboratory of Molecular Medicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Chee Wun How
- Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Yong Sze Ong
- Laboratory of Molecular Medicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Rasedee Abdullah
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.,Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Mohd Yusmaidie Aziz
- Advanced Medical and Dental Institute, University of Science Malaysia, Kepala Batas, Pulau Pinang, Malaysia
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20
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Katiyar A, Antani JD, McKee BP, Gupta R, Lele PP, Lele TP. A method for direct imaging of x-z cross-sections of fluorescent samples. J Microsc 2020; 281:224-230. [PMID: 33020917 DOI: 10.1111/jmi.12965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/22/2020] [Accepted: 09/30/2020] [Indexed: 01/08/2023]
Abstract
The x-z cross-sectional profiles of fluorescent objects can be distorted in confocal microscopy, in large part due to mismatch between the refractive index of the immersion medium of typical high numerical aperture objectives and the refractive index of the medium in which the sample is present. Here, we introduce a method to mount fluorescent samples parallel to the optical axis. This mounting allows direct imaging of what would normally be an x-z cross-section of the object, in the x-y plane of the microscope. With this approach, the x-y cross-sections of fluorescent beads were seen to have significantly lower shape-distortions as compared to x-z cross-sections reconstructed from confocal z-stacks. We further tested the method for imaging of nuclear and cellular heights in cultured cells, and found that they are significantly flatter than previously reported. This approach allows improved imaging of the x-z cross-section of fluorescent samples. LAY DESCRIPTION: Optical distortions are common in confocal microscopy. In particular, the mismatch between the refractive index of the immersion medium of the microscope objective and the refractive index of the sample medium distorts the shapes of fluorescent objects in the x-z plane of the microscope. Here, we introduced a method to eliminate the shape-distortion in the x-z cross-sections. This was achieved by mounting fluorescent samples on vertical glass slides such that the cross-sections orthogonal to the glass surface could be imaged in the x-y plane of the microscope. Our method successfully improved the imaging of nuclear and cellular heights in cultured cells and revealed that the heights were significantly flatter than previously reported with conventional approaches.
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Affiliation(s)
- A Katiyar
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77840, U.S.A
| | - J D Antani
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, 3122 TAMU, College Station, Texas, 77843, U.S.A
| | - B P McKee
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, 32611, U.S.A
| | - R Gupta
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, 3122 TAMU, College Station, Texas, 77843, U.S.A
| | - P P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, 3122 TAMU, College Station, Texas, 77843, U.S.A
| | - T P Lele
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77840, U.S.A
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21
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Nie Y, Xu X, Wang W, Ma N, Lendlein A. The effects of oscillatory temperature on HaCaT keratinocyte behaviors. Clin Hemorheol Microcirc 2020; 76:317-327. [PMID: 32925012 DOI: 10.3233/ch-209208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Keratinocytes are exposed to a thermal gradient throughout epidermal layers in human skin depending on environmental temperatures. OBJECTIVE Here, the effect of cyclic temperature changes (ΔT) on HaCaT cell behaviors was explored. METHODS HaCaT cells were cultured at constant temperature (37 °C or 25 °C) or under ΔT conditions. The morphology, mechanics, cell cycle progression, proliferation, and lipid synthesis of HaCaT cells were determined. RESULTS ΔT conditions led to the inhomogeneous arrangement of the cytoskeleton in HaCaT cells, which resulted in enlarged size, rounder shape, and increased stiffness. Accumulation in the G2/M phase in the cell cycle, a decreased proliferation rate, and a delayed lipogenesis were detected in HaCaT cells cultured under ΔT conditions. CONCLUSIONS ΔT conditions resulted in the re-arrangement of the cytoskeleton in HaCaT cells, which showed similarity to the temperature-induced disassemble and re-assemble of cytoskeletons in keratinocyte in vivo. The altered cytoskeleton arrangement resulted in the cell enlargement and stiffening, which reflected the changes in cellular functions. The application of oscillatory temperature in the in vitro culture of keratinocytes provides a way to gain more insights into the role of skin in response to environmental stimuli and maintaining its homeostasis in vivo.
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Affiliation(s)
- Yan Nie
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany.,Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Xun Xu
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany
| | - Weiwei Wang
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany
| | - Nan Ma
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Andreas Lendlein
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany.,Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
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22
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Changes in Nuclear Shape and Gene Expression in Response to Simulated Microgravity Are LINC Complex-Dependent. Int J Mol Sci 2020; 21:ijms21186762. [PMID: 32942630 PMCID: PMC7555797 DOI: 10.3390/ijms21186762] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
Microgravity is known to affect the organization of the cytoskeleton, cell and nuclear morphology and to elicit differential expression of genes associated with the cytoskeleton, focal adhesions and the extracellular matrix. Although the nucleus is mechanically connected to the cytoskeleton through the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, the role of this group of proteins in these responses to microgravity has yet to be defined. In our study, we used a simulated microgravity device, a 3-D clinostat (Gravite), to investigate whether the LINC complex mediates cellular responses to the simulated microgravity environment. We show that nuclear shape and differential gene expression are both responsive to simulated microgravity in a LINC-dependent manner and that this response changes with the duration of exposure to simulated microgravity. These LINC-dependent genes likely represent elements normally regulated by the mechanical forces imposed by gravity on Earth.
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23
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Tamashunas AC, Tocco VJ, Matthews J, Zhang Q, Atanasova KR, Paschall L, Pathak S, Ratnayake R, Stephens AD, Luesch H, Licht JD, Lele TP. High-throughput gene screen reveals modulators of nuclear shape. Mol Biol Cell 2020; 31:1392-1402. [PMID: 32320319 PMCID: PMC7353136 DOI: 10.1091/mbc.e19-09-0520] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 03/30/2020] [Accepted: 04/14/2020] [Indexed: 12/11/2022] Open
Abstract
Irregular nuclear shapes characterized by blebs, lobules, micronuclei, or invaginations are hallmarks of many cancers and human pathologies. Despite the correlation between abnormal nuclear shape and human pathologies, the mechanism by which the cancer nucleus becomes misshapen is not fully understood. Motivated by recent evidence that modifying chromatin condensation can change nuclear morphology, we conducted a high-throughput RNAi screen to identify epigenetic regulators that are required to maintain normal nuclear shape in human breast epithelial MCF-10A cells. We silenced 608 genes in parallel using an epigenetics siRNA library and used an unbiased Fourier analysis approach to quantify nuclear contour irregularity from fluorescent images captured on a high-content microscope. Using this quantitative approach, which we validated with confocal microscopy, we significantly expand the list of epigenetic regulators that impact nuclear morphology.
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Affiliation(s)
| | | | - James Matthews
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610
| | | | - Kalina R. Atanasova
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610
| | | | | | - Ranjala Ratnayake
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610
| | - Andrew D. Stephens
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003
| | - Hendrik Luesch
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610
| | - Jonathan D. Licht
- Division of Hematology/Oncology, University of Florida Health Cancer Center, Gainesville, FL 32610
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24
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Tasiopoulos CP, Petronis S, Sahlin H, Hedhammar M. Surface Functionalization of PTFE Membranes Intended for Guided Bone Regeneration Using Recombinant Spider Silk. ACS APPLIED BIO MATERIALS 2019; 3:577-583. [DOI: 10.1021/acsabm.9b00972] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christos Panagiotis Tasiopoulos
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, KTH - Royal Institute of Technology, Stockholm 114 21, Sweden
| | - Sarunas Petronis
- Bioscience and Materials, RISE Research Institutes of Sweden, Borås 501 15, Sweden
| | - Herman Sahlin
- Research Department, Neoss Ltd, Göteborg 413 46, Sweden
| | - My Hedhammar
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, KTH - Royal Institute of Technology, Stockholm 114 21, Sweden
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25
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Katiyar A, Tocco VJ, Li Y, Aggarwal V, Tamashunas AC, Dickinson RB, Lele TP. Nuclear size changes caused by local motion of cell boundaries unfold the nuclear lamina and dilate chromatin and intranuclear bodies. SOFT MATTER 2019; 15:9310-9317. [PMID: 31674621 PMCID: PMC6870954 DOI: 10.1039/c9sm01666j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The mechanisms by which mammalian nuclear shape and size are established in cells, and become abnormal in disease states are not understood. Here, we tracked motile cells that underwent systematic changes in cell morphology as they moved from 1-D to 2-D micro-patterned adhesive domains. Motion of the cell boundaries during cell motility caused a dynamic and systematic change in nuclear volume. Short time scales (∼1 h) distinguished the dilation of the nucleus from the familiar increase that occurs during the cell cycle. Nuclear volume was systematically different between cells cultured in 3-D, 2-D and 1-D environments. Dilation of the nuclear volume was accompanied by dilation of chromatin, a decrease in the number of folds in the nuclear lamina, and an increase in nucleolar volume. Treatment of 2-D cells with non-muscle myosin-II inhibitors decreased cell volume, and proportionately caused a decrease in nuclear volume. These data suggest that nuclear size changes during cell migration may potentially impact gene expression through the modulation of intranuclear structure.
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Affiliation(s)
- Aditya Katiyar
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA
| | - V J Tocco
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Yuan Li
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Varun Aggarwal
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Andrew C Tamashunas
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
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26
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Kent IA, Zhang Q, Katiyar A, Li Y, Pathak S, Dickinson RB, Lele TP. Apical cell protrusions cause vertical deformation of the soft cancer nucleus. J Cell Physiol 2019; 234:20675-20684. [PMID: 31006858 DOI: 10.1002/jcp.28672] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/21/2019] [Indexed: 01/17/2023]
Abstract
Breast cancer nuclei have highly irregular shapes, which are diagnostic and prognostic markers of breast cancer progression. The mechanisms by which irregular cancer nuclear shapes develop are not well understood. Here we report the existence of vertical, apical cell protrusions in cultured MDA-MB-231 breast cancer cells. Once formed, these protrusions persist over time scales of hours and are associated with vertically upward nuclear deformations. They are absent in normal mammary epithelial cells (MCF-10A cells). Microtubule disruption enriched these protrusions preferentially in MDA-MB-231 cells compared with MCF-10A cells, whereas inhibition of nonmuscle myosin II (NMMII) abolished this enrichment. Dynamic confocal imaging of the vertical cell and nuclear shape revealed that the apical cell protrusions form first, and in response, the nucleus deforms and/or subsequently gets vertically extruded into the apical protrusion. Overexpression of lamin A/C in MDA-MB-231 cells reduced nuclear deformation in apical protrusions. These data highlight the role of mechanical stresses generated by moving boundaries, as well as abnormal nuclear mechanics in the development of abnormal nuclear shapes in breast cancer cells.
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Affiliation(s)
- Ian A Kent
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Qiao Zhang
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Aditya Katiyar
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida
| | - Yuan Li
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Shreya Pathak
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
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27
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Zhang Q, Tamashunas AC, Agrawal A, Torbati M, Katiyar A, Dickinson RB, Lammerding J, Lele TP. Local, transient tensile stress on the nuclear membrane causes membrane rupture. Mol Biol Cell 2019; 30:899-906. [PMID: 30566037 PMCID: PMC6589786 DOI: 10.1091/mbc.e18-09-0604] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/03/2018] [Accepted: 12/14/2018] [Indexed: 01/18/2023] Open
Abstract
Cancer cell migration through narrow constrictions generates compressive stresses on the nucleus that deform it and cause rupture of nuclear membranes. Nuclear membrane rupture allows uncontrolled exchange between nuclear and cytoplasmic contents. Local tensile stresses can also cause nuclear deformations, but whether such deformations are accompanied by nuclear membrane rupture is unknown. Here we used a direct force probe to locally deform the nucleus by applying a transient tensile stress to the nuclear membrane. We found that a transient (∼0.2 s) deformation (∼1% projected area strain) in normal mammary epithelial cells (MCF-10A cells) was sufficient to cause rupture of the nuclear membrane. Nuclear membrane rupture scaled with the magnitude of nuclear deformation and the magnitude of applied tensile stress. Comparison of diffusive fluxes of nuclear probes between wild-type and lamin-depleted MCF-10A cells revealed that lamin A/C, but not lamin B2, protects the nuclear membranes against rupture from tensile stress. Our results suggest that transient nuclear deformations typically caused by local tensile stresses are sufficient to cause nuclear membrane rupture.
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Affiliation(s)
- Qiao Zhang
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
| | - Andrew C. Tamashunas
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
| | - Ashutosh Agrawal
- Department of Mechanical Engineering, University of Houston, Houston, TX 77204
| | - Mehdi Torbati
- Department of Mechanical Engineering, University of Houston, Houston, TX 77204
| | - Aditya Katiyar
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611
| | - Richard B. Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
| | - Jan Lammerding
- Weill Institute for Cell and Molecular Biology and Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
| | - Tanmay P. Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
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28
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Jetta D, Gottlieb PA, Verma D, Sachs F, Hua SZ. Shear stress induced nuclear shrinkage through activation of Piezo1 channels in epithelial cells. J Cell Sci 2019; 132:jcs.226076. [DOI: 10.1242/jcs.226076] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/29/2019] [Indexed: 12/30/2022] Open
Abstract
The cell nucleus responds to mechanical cues with changes in size, morphology, and motility. Previous work showed that external forces couple to nuclei through the cytoskeleton network, but we show here that changes in nuclear shape can be driven solely by calcium levels. Fluid shear stress applied to MDCK cells caused the nuclei to shrink through a Ca2+ dependent signaling pathway. Inhibiting mechanosensitive Piezo1 channels with GsMTx4 prevented nuclear shrinkage. Piezo1 knockdown also significantly reduced the nuclear shrinkage. Activation of Piezo1 with the agonist Yoda1 caused similar nucleus shrinkage without shear stress. These results demonstrate that Piezo1 channel is a key element for transmitting shear force input to nuclei. To ascertain the relative contributions of Ca2+ to cytoskeleton perturbation, we examined the F-actin reorganization under shear stress and static conditions, and showed that reorganization of the cytoskeleton is not necessary for nuclear shrinkage. These results emphasize the role of the mechanosensitive channels as primary transducers in force transmission to the nucleus.
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Affiliation(s)
- Deekshitha Jetta
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Philip A. Gottlieb
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
| | - Deepika Verma
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Frederick Sachs
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
| | - Susan Z. Hua
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
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29
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Yao M, Sattler T, Rabbani ZN, Pulliam T, Walker G, Gamcsik MP. Mixing and delivery of multiple controlled oxygen environments to a single multiwell culture plate. Am J Physiol Cell Physiol 2018; 315:C766-C775. [PMID: 30183322 DOI: 10.1152/ajpcell.00276.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Precise oxygen control is critical to evaluating cell growth, molecular content, and stress response in cultured cells. We have designed, fabricated, and characterized a 96-well plate-based device that is capable of delivering eight static or dynamically changing oxygen environments to different rows on a single plate. The device incorporates a gas-mixing tree that combines two input gases to generate the eight gas mixtures that supply each row of the plate with a different gas atmosphere via a removable manifold. Using air and nitrogen as feed gases, a single 96-well plate can culture cells in applied gas atmospheres with Po2 levels ranging from 1 to 135 mmHg. Human cancer cell lines MCF-7, PANC-1, and Caco-2 were grown on a single plate under this range of oxygen levels. Only cells grown in wells exposed to Po2 ≤37 mmHg express the endogenous hypoxia markers hypoxia-inducible factor-1α and carbonic anhydrase IX. This design is amenable to multiwell plate-based molecular assays or drug dose-response studies in static or cycling hypoxia conditions.
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Affiliation(s)
- Ming Yao
- Department of Mechanical and Aerospace Engineering, North Carolina State University , Raleigh, North Carolina
| | - Tyler Sattler
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Zahid N Rabbani
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Thomas Pulliam
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina
| | - Glenn Walker
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Michael P Gamcsik
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
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30
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Lele TP, Dickinson RB, Gundersen GG. Mechanical principles of nuclear shaping and positioning. J Cell Biol 2018; 217:3330-3342. [PMID: 30194270 PMCID: PMC6168261 DOI: 10.1083/jcb.201804052] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/27/2018] [Accepted: 08/24/2018] [Indexed: 12/16/2022] Open
Abstract
Positioning and shaping the nucleus represents a mechanical challenge for the migrating cell because of its large size and resistance to deformation. Cells shape and position the nucleus by transmitting forces from the cytoskeleton onto the nuclear surface. This force transfer can occur through specialized linkages between the nuclear envelope and the cytoskeleton. In response, the nucleus can deform and/or it can move. Nuclear movement will occur when there is a net differential in mechanical force across the nucleus, while nuclear deformation will occur when mechanical forces overcome the mechanical resistance of the various structures that comprise the nucleus. In this perspective, we review current literature on the sources and magnitude of cellular forces exerted on the nucleus, the nuclear envelope proteins involved in transferring cellular forces, and the contribution of different nuclear structural components to the mechanical response of the nucleus to these forces.
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Affiliation(s)
- Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL
- Anatomy and Cell Biology, University of Florida, Gainesville, FL
| | | | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Columbia University, New York, NY
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31
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Armiger TJ, Lampi MC, Reinhart-King CA, Dahl KN. Determining mechanical features of modulated epithelial monolayers using subnuclear particle tracking. J Cell Sci 2018; 131:jcs.216010. [PMID: 29748381 DOI: 10.1242/jcs.216010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/04/2018] [Indexed: 12/29/2022] Open
Abstract
Force generation within cells, mediated by motor proteins along cytoskeletal networks, maintains the function of multicellular structures during homeostasis and when generating collective forces. Here, we describe the use of chromatin dynamics to detect cellular force propagation [a technique termed SINK (sensors from intranuclear kinetics)] and investigate the force response of cells to disruption of the monolayer and changes in substrate stiffness. We find that chromatin dynamics change in a substrate stiffness-dependent manner within epithelial monolayers. We also investigate point defects within monolayers to map the impact on the strain field of a heterogeneous monolayer. We find that cell monolayers behave as a colloidal assembly rather than as a continuum since the data fit an exponential decay; the lateral characteristic length of recovery from the mechanical defect is ∼50 µm for cells with a 10 µm spacing. At distances greater than this characteristic length, cells behave similarly to those in a fully intact monolayer. This work demonstrates the power of SINK to investigate diseases including cancer and atherosclerosis that result from single cells or heterogeneities in monolayers.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Travis J Armiger
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marsha C Lampi
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | | | - Kris Noel Dahl
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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32
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Sfakis L, Kamaldinov T, Khmaladze A, Hosseini ZF, Nelson DA, Larsen M, Castracane J. Mesenchymal Cells Affect Salivary Epithelial Cell Morphology on PGS/PLGA Core/Shell Nanofibers. Int J Mol Sci 2018; 19:ijms19041031. [PMID: 29596382 PMCID: PMC5979364 DOI: 10.3390/ijms19041031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/21/2018] [Accepted: 03/28/2018] [Indexed: 12/15/2022] Open
Abstract
Engineering salivary glands is of interest due to the damaging effects of radiation therapy and the autoimmune disease Sjögren’s syndrome on salivary gland function. One of the current problems in tissue engineering is that in vitro studies often fail to predict in vivo regeneration due to failure of cells to interact with scaffolds and of the single cell types that are typically used for these studies. Although poly (lactic co glycolic acid) (PLGA) nanofiber scaffolds have been used for in vitro growth of epithelial cells, PLGA has low compliance and cells do not penetrate the scaffolds. Using a core-shell electrospinning technique, we incorporated poly (glycerol sebacate) (PGS) into PLGA scaffolds to increase the compliance and decrease hydrophobicity. PGS/PLGA scaffolds promoted epithelial cell penetration into the scaffold and apical localization of tight junction proteins, which is necessary for epithelial cell function. Additionally, co-culture of the salivary epithelial cells with NIH3T3 mesenchymal cells on PGS/PLGA scaffolds facilitated epithelial tissue reorganization and apical localization of tight junction proteins significantly more than in the absence of the mesenchyme. These data demonstrate the applicability of PGS/PLGA nanofibers for epithelial cell self-organization and facilitation of co-culture cell interactions that promote tissue self-organization in vitro.
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Affiliation(s)
- Lauren Sfakis
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA.
| | - Tim Kamaldinov
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA.
| | - Alexander Khmaladze
- Department of Physics, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Zeinab F Hosseini
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Deirdre A Nelson
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Melinda Larsen
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - James Castracane
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY 12203, USA.
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33
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Tocco VJ, Li Y, Christopher KG, Matthews JH, Aggarwal V, Paschall L, Luesch H, Licht JD, Dickinson RB, Lele TP. The nucleus is irreversibly shaped by motion of cell boundaries in cancer and non-cancer cells. J Cell Physiol 2017; 233:1446-1454. [PMID: 28542912 DOI: 10.1002/jcp.26031] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 05/24/2017] [Indexed: 01/01/2023]
Abstract
Actomyosin stress fibers impinge on the nucleus and can exert compressive forces on it. These compressive forces have been proposed to elongate nuclei in fibroblasts, and lead to abnormally shaped nuclei in cancer cells. In these models, the elongated or flattened nuclear shape is proposed to store elastic energy. However, we found that deformed shapes of nuclei are unchanged even after removal of the cell with micro-dissection, both for smooth, elongated nuclei in fibroblasts and abnormally shaped nuclei in breast cancer cells. The lack of shape relaxation implies that the nuclear shape in spread cells does not store any elastic energy, and the cellular stresses that deform the nucleus are dissipative, not static. During cell spreading, the deviation of the nucleus from a convex shape increased in MDA-MB-231 cancer cells, but decreased in MCF-10A cells. Tracking changes of nuclear and cellular shape on micropatterned substrata revealed that fibroblast nuclei deform only during deformations in cell shape and only in the direction of nearby moving cell boundaries. We propose that motion of cell boundaries exert a stress on the nucleus, which allows the nucleus to mimic cell shape. The lack of elastic energy in the nuclear shape suggests that nuclear shape changes in cells occur at constant surface area and volume.
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Affiliation(s)
- Vincent J Tocco
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Yuan Li
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Keith G Christopher
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - James H Matthews
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida
| | - Varun Aggarwal
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Lauren Paschall
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Hendrik Luesch
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida
| | - Jonathan D Licht
- Division of Hematology and Oncology, Department of Medicine, University of Florida Health Cancer Center, Gainesville, Florida
| | - Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, Florida
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, Florida.,Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida
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34
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Duan X, Wan JMF, Mak AFT. Oxidative Stress Alters the Morphological Responses of Myoblasts to Single-Site Membrane Photoporation. Cell Mol Bioeng 2017; 10:313-325. [PMID: 31719866 DOI: 10.1007/s12195-017-0488-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 04/26/2017] [Indexed: 01/19/2023] Open
Abstract
The responses of single cells to plasma membrane damage is critical to cell survival under adverse conditions and to many transfection protocols in genetic engineering. While the post-damage molecular responses have been much studied, the holistic morphological changes of damaged cells have received less attention. Here we document the post-damage morphological changes of the C2C12 myoblast cell bodies and nuclei after femtosecond laser photoporation targeted at the plasma membrane. One adverse environmental condition, namely oxidative stress, was also studied to investigate whether external environmental threats could affect the cellular responses to plasma membrane damage. The 3D characteristics data showed that in normal conditions, the cell bodies underwent significant shrinkage after single-site laser photoporation on the plasma membrane. However for the cells bearing hydrogen peroxide oxidative stress beforehand, the cell bodies showed significant swelling after laser photoporation. The post-damage morphological changes of single cells were more obvious after chronic oxidative exposure than that after acute ones. Interestingly, in both conditions, the 2D projection of nucleus apparently shrank after laser photoporation and distanced itself from the damage site. Our results suggest that the cells may experience significant multi-dimensional biophysical changes after single-site plasma membrane damage. These post-damage responses could be dramatically affected by oxidative stress.
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Affiliation(s)
- Xinxing Duan
- 1Division of Biomedical Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong
- 3Department of Mechanical & Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong
- 4School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Jennifer M F Wan
- 4School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Arthur F T Mak
- 1Division of Biomedical Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong
- 2Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong
- 3Department of Mechanical & Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong
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35
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Allier C, Morel S, Vincent R, Ghenim L, Navarro F, Menneteau M, Bordy T, Hervé L, Cioni O, Gidrol X, Usson Y, Dinten JM. Imaging of dense cell cultures by multiwavelength lens-free video microscopy. Cytometry A 2017; 91:433-442. [DOI: 10.1002/cyto.a.23079] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/27/2017] [Accepted: 02/07/2017] [Indexed: 01/15/2023]
Affiliation(s)
- C. Allier
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - S. Morel
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - R. Vincent
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - L. Ghenim
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA BIG Biologie à Grande Echelle; Grenoble F-38054 France
- INSERM; U1038 Grenoble F-38054 France
- CNRS, FR CNRS 3425; Grenoble F-38000 France
| | - F. Navarro
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - M. Menneteau
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - T. Bordy
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - L. Hervé
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - O. Cioni
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
| | - X. Gidrol
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA BIG Biologie à Grande Echelle; Grenoble F-38054 France
- INSERM; U1038 Grenoble F-38054 France
| | - Y. Usson
- Universite Grenoble Alpes; Grenoble F-38000 France
- TIMC-IMAG; Grenoble F-38000 France
| | - J.-M. Dinten
- Universite Grenoble Alpes; Grenoble F-38000 France
- CEA LETI MlNATEC Campus; Grenoble F-38054 France
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Three-Dimensional Tissue Models and Available Probes for Multi-Parametric Live Cell Microscopy: A Brief Overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1035:49-67. [DOI: 10.1007/978-3-319-67358-5_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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