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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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2
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Bhattacharya S, Ettela A, Haydak J, Hobson CM, Stern A, Yoo M, Chew TL, Gusella GL, Gallagher EJ, Hone JC, Azeloglu EU. A high-throughput microfabricated platform for rapid quantification of metastatic potential. SCIENCE ADVANCES 2024; 10:eadk0015. [PMID: 39151003 PMCID: PMC11328906 DOI: 10.1126/sciadv.adk0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 07/12/2024] [Indexed: 08/18/2024]
Abstract
Assays that measure morphology, proliferation, motility, deformability, and migration are used to study the invasiveness of cancer cells. However, native invasive potential of cells may be hidden from these contextual metrics because they depend on culture conditions. We created a micropatterned chip that mimics the native environmental conditions, quantifies the invasive potential of tumor cells, and improves our understanding of the malignancy signatures. Unlike conventional assays, which rely on indirect measurements of metastatic potential, our method uses three-dimensional microchannels to measure the basal native invasiveness without chemoattractants or microfluidics. No change in cell death or proliferation is observed on our chips. Using six cancer cell lines, we show that our system is more sensitive than other motility-based assays, measures of nuclear deformability, or cell morphometrics. In addition to quantifying metastatic potential, our platform can distinguish between motility and invasiveness, help study molecular mechanisms of invasion, and screen for targeted therapeutics.
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Affiliation(s)
- Smiti Bhattacharya
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Abora Ettela
- Division of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jonathan Haydak
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chad M Hobson
- Advanced Imaging Center, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Alan Stern
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Miran Yoo
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Teng-Leong Chew
- Advanced Imaging Center, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - G Luca Gusella
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Emily J Gallagher
- Division of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Tisch Cancer Institute at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - James C Hone
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Evren U Azeloglu
- Barbara T. Murphy Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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3
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Wang B, Dong J, Yang F, Ju T, Wang J, Qu K, Wang Y, Tian Y, Wang Z. Determining the degree of chromosomal instability in breast cancer cells by atomic force microscopy. Analyst 2024; 149:1988-1997. [PMID: 38420857 DOI: 10.1039/d3an01815f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Chromosomal instability (CIN) is a source of genetic variation and is highly linked to the malignance of cancer. Determining the degree of CIN is necessary for understanding the role that it plays in tumor development. There is currently a lack of research on high-resolution characterization of CIN and the relationship between CIN and cell mechanics. Here, a method to determine CIN of breast cancer cells by high resolution imaging with atomic force microscopy (AFM) is explored. The numerical and structural changes of chromosomes in human breast cells (MCF-10A), moderately malignant breast cells (MCF-7) and highly malignant breast cells (MDA-MB-231) were observed and analyzed by AFM. Meanwhile, the nuclei, cytoskeleton and cell mechanics of the three kinds of cells were also investigated. The results showed the differences in CIN between the benign and cancer cells. Also, the degree of structural CIN increased with enhanced malignancy of cancer cells. This was also demonstrated by calculating the probability of micronucleus formation in these three kinds of cells. Meanwhile, we found that the area of the nucleus was related to the number of chromosomes in the nucleus. In addition, reduced or even aggregated actin fibers led to decreased elasticities in MCF-7 and MDA-MB-231 cells. It was found that the rearrangement of actin fibers would affect the nucleus, and then lead to wrong mitosis and CIN. Using AFM to detect chromosomal changes in cells with different malignancy degrees provides a new detection method for the study of cell carcinogenesis with a perspective for targeted therapy of cancer.
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Affiliation(s)
- Bowei Wang
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Jianjun Dong
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Fan Yang
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Tuoyu Ju
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Junxi Wang
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Kaige Qu
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Ying Wang
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
| | - Yanling Tian
- School of Engineering, University of Warwick, Coventry CV4 7AL, UK
| | - Zuobin Wang
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
- Centre for Opto/Bio-Nano Measurement and Manufacturing, Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 528437, China
- JR3CN & IRAC, University of Bedfordshire, Luton LU1 3JU, UK
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Chai XX, Liu J, Yu TY, Zhang G, Sun WJ, Zhou Y, Ren L, Cao HL, Yin DC, Zhang CY. Recent progress of mechanosensitive mechanism on breast cancer. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 185:1-16. [PMID: 37793504 DOI: 10.1016/j.pbiomolbio.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/10/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023]
Abstract
The mechanical environment is important for tumorigenesis and progression. Tumor cells can sense mechanical signals by mechanosensitive receptors, and these mechanical signals can be converted to biochemical signals to regulate cell behaviors, such as cell differentiation, proliferation, migration, apoptosis, and drug resistance. Here, we summarized the effects of the mechanical microenvironment on breast cancer cell activity, and mechanotransduction mechanism from cellular microenvironment to cell membrane, and finally to the nucleus, and also relative mechanosensitive proteins, ion channels, and signaling pathways were elaborated, therefore the mechanical signal could be transduced to biochemical or molecular signal. Meanwhile, the mechanical models commonly used for biomechanics study in vitro and some quantitative descriptions were listed. It provided an essential theoretical basis for the occurrence and development of mechanosensitive breast cancer, and also some potential drug targets were proposed to treat such disease.
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Affiliation(s)
- Xiao-Xia Chai
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Jie Liu
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Tong-Yao Yu
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Ge Zhang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Wen-Jun Sun
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Yan Zhou
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China
| | - Li Ren
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China; Key Laboratory of Flexible Electronics of Zhejiang Province, Ningbo Institute of Northwestern Polytechnical University, Ningbo, 315103, Zhejiang, PR China
| | - Hui-Ling Cao
- Xi'an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, School of Pharmacy, Xi'an Medical University, Xi'an, 710021, Shaanxi, PR China.
| | - Da-Chuan Yin
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China.
| | - Chen-Yan Zhang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, PR China.
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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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Liu S, Li Y, Hong Y, Wang M, Zhang H, Ma J, Qu K, Huang G, Lu TJ. Mechanotherapy in oncology: Targeting nuclear mechanics and mechanotransduction. Adv Drug Deliv Rev 2023; 194:114722. [PMID: 36738968 DOI: 10.1016/j.addr.2023.114722] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 12/23/2022] [Accepted: 01/28/2023] [Indexed: 02/05/2023]
Abstract
Mechanotherapy is proposed as a new option for cancer treatment. Increasing evidence suggests that characteristic differences are present in the nuclear mechanics and mechanotransduction of cancer cells compared with those of normal cells. Recent advances in understanding nuclear mechanics and mechanotransduction provide not only further insights into the process of malignant transformation but also useful references for developing new therapeutic approaches. Herein, we present an overview of the alterations of nuclear mechanics and mechanotransduction in cancer cells and highlight their implications in cancer mechanotherapy.
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Affiliation(s)
- Shaobao Liu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China; MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures, Nanjing University of Aeronautics, Nanjing 210016, PR China
| | - Yuan Li
- MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Yuan Hong
- MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China; National Science Foundation Science and Technology Center for Engineering Mechanobiology, Washington University, St. Louis, MO 63130, USA
| | - Ming Wang
- MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Hao Zhang
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China; MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures, Nanjing University of Aeronautics, Nanjing 210016, PR China
| | - Jinlu Ma
- Department of Radiation Oncology, the First Affiliated Hospital, Xian Jiaotong University, Xi'an 710061, PR China
| | - Kai Qu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, Xian Jiaotong University, Xi'an 710061, PR China
| | - Guoyou Huang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072, PR China.
| | - Tian Jian Lu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China; MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures, Nanjing University of Aeronautics, Nanjing 210016, PR China.
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7
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Lee JI, Ahn TG, Choi JH. Effects of Iron on Efficacy of Photodynamic Therapy Using Photolon in a Mouse Model of CT26 Colon Cancer. J NIPPON MED SCH 2023; 90:41-49. [PMID: 36908127 DOI: 10.1272/jnms.jnms.2023_90-108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
BACKGROUND Photodynamic therapy (PDT) -a minimally invasive anti-cancer therapy-is undergoing experimental studies to increase its anti-cancer effects. This study investigated the influence of iron on the anti-cancer effects of PDT. METHODS PDT was performed in a cancer-bearing mouse model, which was created by using a murine colon carcinoma (CT26) cell line after administration of Photolon and iron. Tumor volume and the results of TdT-mediated dUTP-biotin nick end labeling (TUNEL), 8-OHdG, and TBARS assays were used to measure anti-cancer effect. RESULTS On day 14, tumor volume had increased by 49% in the PDT group and decreased by 72% in the iron+PDT group. The percentage of TUNEL-positive cells in tumor tissues was 45% in the PDT group and 69% in the iron+PDT group, suggesting that the proportion of TUNEL-positive cells had increased in the iron+PDT group. The 8-OHdG content in tumor tissues was 33% higher in the iron+PDT group than in the PDT group. The TBARS content in tumor tissues was 46% higher in the iron+PDT group than in the PDT group. CONCLUSIONS Iron enhances the anti-cancer effect of PDT using Photolon, most likely by increasing oxidative damage.
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Affiliation(s)
- Jung In Lee
- Department of Internal Medicine, Chosun University College of Medicine
| | - Tae-Gyu Ahn
- Department of Obstetrics and Gynecology, Chosun University College of Medicine
| | - Ji Hyun Choi
- Department of Obstetrics and Gynecology, Chosun University College of Medicine
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9
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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: 2.0] [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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Rodríguez-Ibarra C, Medina-Reyes EI, Déciga-Alcaraz A, Delgado-Buenrostro NL, Quezada-Maldonado EM, Ispanixtlahuatl-Meráz O, Ganem-Rondero A, Flores-Flores JO, Vázquez-Zapién GJ, Mata-Miranda MM, López-Marure R, Pedraza-Chaverri J, García-Cuéllar CM, Sánchez-Pérez Y, Chirino YI. Food grade titanium dioxide accumulation leads to cellular alterations in colon cells after removal of a 24-hour exposure. Toxicology 2022; 478:153280. [PMID: 35973603 DOI: 10.1016/j.tox.2022.153280] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/26/2022] [Accepted: 07/30/2022] [Indexed: 10/15/2022]
Abstract
Titanium dioxide food grade (E171) is one of the most used food additives containing nanoparticles. Recently, the European Food Safety Authority indicated that E171 could no longer be considered safe as a food additive due to the possibility of it being genotoxic and there is evidence that E171 administration exacerbates colon tumor formation in murine models. However, less is known about the effects of E171 accumulation once the exposure stopped, then we hypothesized that toxic effects could be detected even after E171 removal. Therefore, we investigated the effects of E171 exposure after being removed from colon cell cultures. Human colon cancer cell line (HCT116) was exposed to 0, 1, 10 and 50 μg/cm2 of E171. Our results showed that in the absence of cytotoxicity, E171 was accumulated in the cells after 24 of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization. After the removal of E171, colon cells were cultured for 48 h more hours to analyze the ability to restore the previously detected alterations. As we hypothesized, the removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.
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Affiliation(s)
- Carolina Rodríguez-Ibarra
- Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla de Baz CP 54090, Estado de México, Mexico
| | - Estefany I Medina-Reyes
- Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla de Baz CP 54090, Estado de México, Mexico
| | - Alejandro Déciga-Alcaraz
- Atmospheric Organic Aerosol Chemical Speciation Group, Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, AP 70228, Ciudad de México 04510, Mexico
| | - Norma Laura Delgado-Buenrostro
- Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla de Baz CP 54090, Estado de México, Mexico
| | - Ericka Marel Quezada-Maldonado
- Subdirección de Investigación Básica, Instituto Nacional de Cancerología, San Fernando No. 22, CP 14080 Ciudad de México, Tlalpan, Mexico
| | - Octavio Ispanixtlahuatl-Meráz
- Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla de Baz CP 54090, Estado de México, Mexico
| | - Adriana Ganem-Rondero
- División de Estudios de Posgrado (Tecnología Farmacéutica), Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Av. 1° de Mayo s/n, Cuautitlán Izcalli CP 54740, Estado de México, Mexico
| | - José Ocotlán Flores-Flores
- Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, CP 04510 Ciudad de México, Mexico
| | - Gustavo J Vázquez-Zapién
- Laboratorio de Embriología, Escuela Militar de Medicina, Centro Militar de Ciencias de la Salud, Secretaría de la Defensa Nacional, Cerrada de Palomas S/N, Lomas de San Isidro, Alcaldía Miguel Hidalgo, CP 11200 Ciudad de México, Mexico
| | - Mónica M Mata-Miranda
- Laboratorio de Biología Celular y Tisular, Escuela Militar de Medicina, Centro Militar de Ciencias de la Salud, Secretaría de la Defensa Nacional, Cerrada de Palomas S/N, Lomas de San Isidro, Alcaldía Miguel Hidalgo, CP 11200 Ciudad de México, Mexico
| | - Rebeca López-Marure
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, Mexico
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, CP 04510 Ciudad de México, Mexico
| | - Claudia M García-Cuéllar
- Subdirección de Investigación Básica, Instituto Nacional de Cancerología, San Fernando No. 22, CP 14080 Ciudad de México, Tlalpan, Mexico
| | - Yesennia Sánchez-Pérez
- Subdirección de Investigación Básica, Instituto Nacional de Cancerología, San Fernando No. 22, CP 14080 Ciudad de México, Tlalpan, Mexico
| | - Yolanda I Chirino
- Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla de Baz CP 54090, Estado de México, Mexico.
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11
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Currey ML, Kandula V, Biggs R, Marko JF, Stephens AD. A Versatile Micromanipulation Apparatus for Biophysical Assays of the Cell Nucleus. Cell Mol Bioeng 2022; 15:303-312. [PMID: 36119136 PMCID: PMC9474788 DOI: 10.1007/s12195-022-00734-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/08/2022] [Indexed: 12/02/2022] Open
Abstract
Intro Force measurements of the nucleus, the strongest organelle, have propelled the field of mechanobiology to understand the basic mechanical components of the nucleus and how these components properly support nuclear morphology and function. Micromanipulation force measurement provides separation of the relative roles of nuclear mechanical components chromatin and lamin A. Methods To provide access to this technique, we have developed a universal micromanipulation apparatus for inverted microscopes. We outline how to engineer and utilize this apparatus through dual micromanipulators, fashion and calibrate micropipettes, and flow systems to isolate a nucleus and provide force vs. extensions measurements. This force measurement approach provides the unique ability to measure the separate contributions of chromatin at short extensions and lamin A strain stiffening at long extensions. We then investigated the apparatus' controllable and programmable micromanipulators through compression, isolation, and extension in conjunction with fluorescence to develop new assays for nuclear mechanobiology. Results Using this methodology, we provide the first rebuilding of the micromanipulation setup outside of its lab of origin and recapitulate many key findings including spring constant of the nucleus and strain stiffening across many cell types. Furthermore, we have developed new micromanipulation-based techniques to compress nuclei inducing nuclear deformation and/or rupture, track nuclear shape post-isolation, and fluorescence imaging during micromanipulation force measurements. Conclusion We provide the workflow to build and use a micromanipulation apparatus with any inverted microscope to perform nucleus isolation, force measurements, and various other biophysical techniques. Supplementary Information The online version contains supplementary material available at 10.1007/s12195-022-00734-y.
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Affiliation(s)
| | - Viswajit Kandula
- Department of Molecular Biosciences and Department of Physics & Astronomy, Northwestern University, Evanston, USA
- Feinberg School of Medicine, Northwestern University, Chicago, USA
| | - Ronald Biggs
- Department of Molecular Biosciences and Department of Physics & Astronomy, Northwestern University, Evanston, USA
| | - John F. Marko
- Department of Molecular Biosciences and Department of Physics & Astronomy, Northwestern University, Evanston, USA
| | - Andrew D. Stephens
- Biology Department, University of Massachusetts Amherst, Amherst, USA
- Molecular and Cellular Biosciences, University of Massachusetts Amherst, Amherst, USA
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12
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Katiyar A, Zhang J, Antani JD, Yu Y, Scott KL, Lele PP, Reinhart‐King CA, Sniadecki NJ, Roux KJ, Dickinson RB, Lele TP. The Nucleus Bypasses Obstacles by Deforming Like a Drop with Surface Tension Mediated by Lamin A/C. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201248. [PMID: 35712768 PMCID: PMC9376816 DOI: 10.1002/advs.202201248] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Migrating cells must deform their stiff cell nucleus to move through pores and fibers in tissue. Lamin A/C is known to hinder cell migration by limiting nuclear deformation and passage through confining channels, but its role in nuclear deformation and passage through fibrous environments is less clear. Cell and nuclear migration through discrete, closely spaced, slender obstacles which mimic the mechanical properties of collagen fibers are studied. Nuclei bypass slender obstacles while preserving their overall morphology by deforming around them with deep local invaginations of little resisting force. The obstacles do not impede the nuclear trajectory and do not cause rupture of the nuclear envelope. Nuclei likewise deform around single collagen fibers in cells migrating in 3D collagen gels. In contrast to its limiting role in nuclear passage through confining channels, lamin A/C facilitates nuclear deformation and passage through fibrous environments; nuclei in lamin-null (Lmna-/- ) cells lose their overall morphology and become entangled on the obstacles. Analogous to surface tension-mediated deformation of a liquid drop, lamin A/C imparts a surface tension on the nucleus that allows nuclear invaginations with little mechanical resistance, preventing nuclear entanglement and allowing nuclear passage through fibrous environments.
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Affiliation(s)
- Aditya Katiyar
- Department of Biomedical EngineeringTexas A&M University101 Bizzell St.College StationTX77843USA
| | - Jian Zhang
- Department of Biomedical EngineeringVanderbilt University2301 Vanderbilt PlaceNashvilleTN37235USA
| | - Jyot D. Antani
- Artie McFerrin Department of Chemical EngineeringTexas A&M University3122 TAMUCollege StationTX77843USA
| | - Yifan Yu
- Department of Chemical EngineeringUniversity of Florida1030 Center DriveGainesvilleFL32611USA
| | - Kelsey L. Scott
- Enabling Technologies GroupSanford Research2301 East 60th St NSioux FallsSD57104USA
| | - Pushkar P. Lele
- Artie McFerrin Department of Chemical EngineeringTexas A&M University3122 TAMUCollege StationTX77843USA
| | - Cynthia A. Reinhart‐King
- Department of Biomedical EngineeringVanderbilt University2301 Vanderbilt PlaceNashvilleTN37235USA
| | - Nathan J. Sniadecki
- Department of Mechanical EngineeringDepartment of Lab Medicine and PathologyInstitute for Stem Cell and Regenerative MedicineCenter for Cardiac BiologyUniversity of WashingtonStevens Way, Box 352600SeattleWA98195USA
| | - Kyle J. Roux
- Enabling Technologies GroupSanford Research2301 East 60th St NSioux FallsSD57104USA
- Department of PediatricsSanford School of MedicineUniversity of South Dakota414 E Clark StVermillionSD57069USA
| | - Richard B. Dickinson
- Department of Chemical EngineeringUniversity of Florida1030 Center DriveGainesvilleFL32611USA
| | - Tanmay P. Lele
- Department of Biomedical EngineeringTexas A&M University101 Bizzell St.College StationTX77843USA
- Artie McFerrin Department of Chemical EngineeringTexas A&M University3122 TAMUCollege StationTX77843USA
- Department of Translational Medical SciencesTexas A&M University2121 W Holcombe St.HoustonTX77030USA
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13
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Atanasova KR, Chakraborty S, Ratnayake R, Khare KD, Luesch H, Lele TP. An epigenetic small molecule screen to target abnormal nuclear morphology in human cells. Mol Biol Cell 2022; 33:ar45. [PMID: 35323046 PMCID: PMC9265153 DOI: 10.1091/mbc.e21-10-0528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Irregular nuclear shapes are a hallmark of human cancers. Recent studies suggest that alterations to chromatin regulators may cause irregular nuclear morphologies. Here we screened an epigenetic small molecule library consisting of 145 compounds against chromatin regulators, for their ability to revert abnormal nuclear shapes that were induced by gene knockdown in non-cancerous MCF10A human mammary breast epithelial cells. We leveraged a previously validated quantitative Fourier approach to quantify the elliptical Fourier coefficient (EFC ratio) as a measure of nuclear irregularities, which allowed us to perform rigorous statistical analyses of screening data. Top hit compounds fell into three major mode of action categories, targeting three separate epigenetic modulation routes: 1) Histone deacetylase (HDAC) inhibitors; 2) Bromodomain and extra-terminal domain (BET) protein inhibitors; and 3) Methyl-transferase inhibitors. Some of the top hit compounds were also efficacious in reverting nuclear irregularities in MDA-MB-231 triple negative breast cancer cells and in PANC-1 pancreatic cancer cells in a cell type dependent manner. Regularization of nuclear shapes was compound-specific, cell-type specific, and dependent on the specific molecular perturbation that induced nuclear irregularities. Our approach of targeting nuclear abnormalities may be potentially useful in screening new types of cancer therapies targeted toward chromatin structure.
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Affiliation(s)
- Kalina R Atanasova
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville FL 32610, USA
| | - Saptarshi Chakraborty
- Department of Biostatistics, State University of New York at Buffalo, Buffalo NY 14214, USA
| | - Ranjala Ratnayake
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville FL 32610, USA
| | - Kshitij D Khare
- Department of Statistics, University of Florida, Gainesville FL 32611, USA
| | - Hendrik Luesch
- Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville FL 32610, USA
| | - Tanmay P Lele
- Department of Biomedical Engineering, Department of Chemical Engineering, and Department of Translational Medical Sciences, Texas A&M University, College Station TX 77843, USA
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14
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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: 6.0] [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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15
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Singh I, Lele TP. Nuclear Morphological Abnormalities in Cancer: A Search for Unifying Mechanisms. Results Probl Cell Differ 2022; 70:443-467. [PMID: 36348118 PMCID: PMC9722227 DOI: 10.1007/978-3-031-06573-6_16] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Irregularities in nuclear shape and/or alterations to nuclear size are a hallmark of malignancy in a broad range of cancer types. Though these abnormalities are commonly used for diagnostic purposes and are often used to assess cancer progression in the clinic, the mechanisms through which they occur are not well understood. Nuclear size alterations in cancer could potentially arise from aneuploidy, changes in osmotic coupling with the cytoplasm, and perturbations to nucleocytoplasmic transport. Nuclear shape changes may occur due to alterations to cell-generated mechanical stresses and/or alterations to nuclear structural components, which balance those stresses, such as the nuclear lamina and chromatin. A better understanding of the mechanisms underlying abnormal nuclear morphology and size may allow the development of new therapeutics to target nuclear aberrations in cancer.
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Affiliation(s)
- Ishita Singh
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Tanmay P. Lele
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA,Department of Chemical Engineering, University of Florida, Gainesville, FL, USA,Department of Translational Medical Sciences, Texas A&M University, Houston, TX, USA
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16
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Hobson CM, Falvo MR, Superfine R. A survey of physical methods for studying nuclear mechanics and mechanobiology. APL Bioeng 2021; 5:041508. [PMID: 34849443 PMCID: PMC8604565 DOI: 10.1063/5.0068126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/20/2021] [Indexed: 12/23/2022] Open
Abstract
It is increasingly appreciated that the cell nucleus is not only a home for DNA but also a complex material that resists physical deformations and dynamically responds to external mechanical cues. The molecules that confer mechanical properties to nuclei certainly contribute to laminopathies and possibly contribute to cellular mechanotransduction and physical processes in cancer such as metastasis. Studying nuclear mechanics and the downstream biochemical consequences or their modulation requires a suite of complex assays for applying, measuring, and visualizing mechanical forces across diverse length, time, and force scales. Here, we review the current methods in nuclear mechanics and mechanobiology, placing specific emphasis on each of their unique advantages and limitations. Furthermore, we explore important considerations in selecting a new methodology as are demonstrated by recent examples from the literature. We conclude by providing an outlook on the development of new methods and the judicious use of the current techniques for continued exploration into the role of nuclear mechanobiology.
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Affiliation(s)
| | - Michael R. Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Richard Superfine
- Department of Applied Physical Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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17
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Nuclear Dynamics and Chromatin Structure: Implications for Pancreatic Cancer. Cells 2021; 10:cells10102624. [PMID: 34685604 PMCID: PMC8534098 DOI: 10.3390/cells10102624] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 12/14/2022] Open
Abstract
Changes in nuclear shape have been extensively associated with the dynamics and functionality of cancer cells. In most normal cells, nuclei have a regular ellipsoid shape and minimal variation in nuclear size; however, an irregular nuclear contour and abnormal nuclear size is often observed in cancer, including pancreatic cancer. Furthermore, alterations in nuclear morphology have become the 'gold standard' for tumor staging and grading. Beyond the utility of altered nuclear morphology as a diagnostic tool in cancer, the implications of altered nuclear structure for the biology and behavior of cancer cells are profound as changes in nuclear morphology could impact cellular responses to physical strain, adaptation during migration, chromatin organization, and gene expression. Here, we aim to highlight and discuss the factors that regulate nuclear dynamics and their implications for pancreatic cancer biology.
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18
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Mukherjee A, Barai A, Singh RK, Yan W, Sen S. Nuclear plasticity increases susceptibility to damage during confined migration. PLoS Comput Biol 2020; 16:e1008300. [PMID: 33035221 PMCID: PMC7577492 DOI: 10.1371/journal.pcbi.1008300] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 10/21/2020] [Accepted: 09/01/2020] [Indexed: 01/07/2023] Open
Abstract
Large nuclear deformations during migration through confined spaces have been associated with nuclear membrane rupture and DNA damage. However, the stresses associated with nuclear damage remain unclear. Here, using a quasi-static plane strain finite element model, we map evolution of nuclear shape and stresses during confined migration of a cell through a deformable matrix. Plastic deformation of the nucleus observed for a cell with stiff nucleus transiting through a stiffer matrix lowered nuclear stresses, but also led to kinking of the nuclear membrane. In line with model predictions, transwell migration experiments with fibrosarcoma cells showed that while nuclear softening increased invasiveness, nuclear stiffening led to plastic deformation and higher levels of DNA damage. In addition to highlighting the advantage of nuclear softening during confined migration, our results suggest that plastic deformations of the nucleus during transit through stiff tissues may lead to bending-induced nuclear membrane disruption and subsequent DNA damage. Stiffness of the nucleus is known to impede migration of cells through dense matrices. Nuclear translocation through small pores is achieved by active deformation of the nucleus by the cytoskeleton. However, stresses on the nucleus during confined migration may lead to nuclear damage, as observed experimentally. However, the factors contributing to nuclear damage remain incompletely understood. Here we show that plastic or permanent nuclear deformation which is necessary for successful migration through small pores in stiff matrices, also leads to bending of the nuclear membrane. We propose that this bending precedes nuclear blebs which are experimentally observed.
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Affiliation(s)
- Abhishek Mukherjee
- IITB-Monash Research Academy, IIT Bombay, Mumbai, India
- Dept. of Mechanical Engineering, IIT Bombay, Mumbai, India
- Dept. of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia
| | - Amlan Barai
- Dept. of Biosciences & Bioengineering, IIT Bombay, Mumbai, India
| | | | - Wenyi Yan
- Dept. of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia
- * E-mail: (WY); (SS)
| | - Shamik Sen
- Dept. of Biosciences & Bioengineering, IIT Bombay, Mumbai, India
- * E-mail: (WY); (SS)
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19
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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: 0.8] [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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20
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Hobson CM, Kern M, O'Brien ET, Stephens AD, Falvo MR, Superfine R. Correlating nuclear morphology and external force with combined atomic force microscopy and light sheet imaging separates roles of chromatin and lamin A/C in nuclear mechanics. Mol Biol Cell 2020; 31:1788-1801. [PMID: 32267206 DOI: 10.1101/2020.02.10.942581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023] Open
Abstract
Nuclei are often under external stress, be it during migration through tight constrictions or compressive pressure by the actin cap, and the mechanical properties of nuclei govern their subsequent deformations. Both altered mechanical properties of nuclei and abnormal nuclear morphologies are hallmarks of a variety of disease states. Little work, however, has been done to link specific changes in nuclear shape to external forces. Here, we utilize a combined atomic force microscope and light sheet microscope to show SKOV3 nuclei exhibit a two-regime force response that correlates with changes in nuclear volume and surface area, allowing us to develop an empirical model of nuclear deformation. Our technique further decouples the roles of chromatin and lamin A/C in compression, showing they separately resist changes in nuclear volume and surface area, respectively; this insight was not previously accessible by Hertzian analysis. A two-material finite element model supports our conclusions. We also observed that chromatin decompaction leads to lower nuclear curvature under compression, which is important for maintaining nuclear compartmentalization and function. The demonstrated link between specific types of nuclear morphological change and applied force will allow researchers to better understand the stress on nuclei throughout various biological processes.
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Affiliation(s)
- Chad M Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Megan Kern
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - E Timothy O'Brien
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew D Stephens
- Biology Department, The University of Massachusetts at Amherst, Amherst, MA 01003, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Michael R Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Richard Superfine
- Department of Applied Physical Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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21
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Hobson CM, Kern M, O’Brien ET, Stephens AD, Falvo MR, Superfine R. Correlating nuclear morphology and external force with combined atomic force microscopy and light sheet imaging separates roles of chromatin and lamin A/C in nuclear mechanics. Mol Biol Cell 2020; 31:1788-1801. [PMID: 32267206 PMCID: PMC7521857 DOI: 10.1091/mbc.e20-01-0073] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/23/2020] [Accepted: 03/31/2020] [Indexed: 12/31/2022] Open
Abstract
Nuclei are often under external stress, be it during migration through tight constrictions or compressive pressure by the actin cap, and the mechanical properties of nuclei govern their subsequent deformations. Both altered mechanical properties of nuclei and abnormal nuclear morphologies are hallmarks of a variety of disease states. Little work, however, has been done to link specific changes in nuclear shape to external forces. Here, we utilize a combined atomic force microscope and light sheet microscope to show SKOV3 nuclei exhibit a two-regime force response that correlates with changes in nuclear volume and surface area, allowing us to develop an empirical model of nuclear deformation. Our technique further decouples the roles of chromatin and lamin A/C in compression, showing they separately resist changes in nuclear volume and surface area, respectively; this insight was not previously accessible by Hertzian analysis. A two-material finite element model supports our conclusions. We also observed that chromatin decompaction leads to lower nuclear curvature under compression, which is important for maintaining nuclear compartmentalization and function. The demonstrated link between specific types of nuclear morphological change and applied force will allow researchers to better understand the stress on nuclei throughout various biological processes.
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Affiliation(s)
- Chad M. Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Megan Kern
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - E. Timothy O’Brien
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew D. Stephens
- Biology Department, The University of Massachusetts at Amherst, Amherst, MA 01003, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Michael R. Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Richard Superfine
- Department of Applied Physical Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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22
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Hobson CM, Stephens AD. Modeling of Cell Nuclear Mechanics: Classes, Components, and Applications. Cells 2020; 9:E1623. [PMID: 32640571 PMCID: PMC7408412 DOI: 10.3390/cells9071623] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/25/2020] [Accepted: 07/02/2020] [Indexed: 12/22/2022] Open
Abstract
Cell nuclei are paramount for both cellular function and mechanical stability. These two roles of nuclei are intertwined as altered mechanical properties of nuclei are associated with altered cell behavior and disease. To further understand the mechanical properties of cell nuclei and guide future experiments, many investigators have turned to mechanical modeling. Here, we provide a comprehensive review of mechanical modeling of cell nuclei with an emphasis on the role of the nuclear lamina in hopes of spurring future growth of this field. The goal of this review is to provide an introduction to mechanical modeling techniques, highlight current applications to nuclear mechanics, and give insight into future directions of mechanical modeling. There are three main classes of mechanical models-schematic, continuum mechanics, and molecular dynamics-which provide unique advantages and limitations. Current experimental understanding of the roles of the cytoskeleton, the nuclear lamina, and the chromatin in nuclear mechanics provide the basis for how each component is subsequently treated in mechanical models. Modeling allows us to interpret assay-specific experimental results for key parameters and quantitatively predict emergent behaviors. This is specifically powerful when emergent phenomena, such as lamin-based strain stiffening, can be deduced from complimentary experimental techniques. Modeling differences in force application, geometry, or composition can additionally clarify seemingly conflicting experimental results. Using these approaches, mechanical models have informed our understanding of relevant biological processes such as migration, nuclear blebbing, nuclear rupture, and cell spreading and detachment. There remain many aspects of nuclear mechanics for which additional mechanical modeling could provide immediate insight. Although mechanical modeling of cell nuclei has been employed for over a decade, there are still relatively few models for any given biological phenomenon. This implies that an influx of research into this realm of the field has the potential to dramatically shape both future experiments and our current understanding of nuclear mechanics, function, and disease.
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Affiliation(s)
- Chad M. Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Andrew D. Stephens
- Biology Department, The University of Massachusetts at Amherst, Amherst, MA 01003, USA
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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: 5.3] [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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Moure A, Gomez H. Dual role of the nucleus in cell migration on planar substrates. Biomech Model Mechanobiol 2020; 19:1491-1508. [PMID: 31907682 DOI: 10.1007/s10237-019-01283-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/21/2019] [Indexed: 01/09/2023]
Abstract
Cell migration is essential to sustain life. There have been significant advances in the understanding of the mechanisms that control cell crawling, but the role of the nucleus remains poorly understood. The nucleus exerts a tight control of cell migration in 3D environments, but its influence in 2D migration on planar substrates remains unclear. Here, we study the role of the cell nucleus in 2D cell migration using a computational model of fish keratocytes. Our results indicate that the apparently minor role played by the nucleus emerges from two antagonist effects: While the nucleus modifies the spatial distributions of actin and myosin in a way that reduces cell velocity (e.g., the nucleus displaces myosin to the sides and front of the cell), its mechanical connection with the cytoskeleton alters the intracellular stresses promoting cell migration. Overall, the favorable effect of the nucleus-cytoskeleton connection prevails, which may explain why regular cells usually move faster than enucleated cells.
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Affiliation(s)
- Adrian Moure
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
| | - Hector Gomez
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.,Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA.,Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47906, USA
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25
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Song Y, Soto J, Chen B, Yang L, Li S. Cell engineering: Biophysical regulation of the nucleus. Biomaterials 2020; 234:119743. [PMID: 31962231 DOI: 10.1016/j.biomaterials.2019.119743] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/02/2019] [Accepted: 12/25/2019] [Indexed: 12/12/2022]
Abstract
Cells live in a complex and dynamic microenvironment, and a variety of microenvironmental cues can regulate cell behavior. In addition to biochemical signals, biophysical cues can induce not only immediate intracellular responses, but also long-term effects on phenotypic changes such as stem cell differentiation, immune cell activation and somatic cell reprogramming. Cells respond to mechanical stimuli via an outside-in and inside-out feedback loop, and the cell nucleus plays an important role in this process. The mechanical properties of the nucleus can directly or indirectly modulate mechanotransduction, and the physical coupling of the cell nucleus with the cytoskeleton can affect chromatin structure and regulate the epigenetic state, gene expression and cell function. In this review, we will highlight the recent progress in nuclear biomechanics and mechanobiology in the context of cell engineering, tissue remodeling and disease development.
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Affiliation(s)
- Yang Song
- Department of Bioengineering, University of California, Los Angeles, CA, USA; School of Bioengineering, Chongqing University, Chongqing, 400044, China
| | - Jennifer Soto
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Binru Chen
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Li Yang
- School of Bioengineering, Chongqing University, Chongqing, 400044, China
| | - Song Li
- Department of Bioengineering, University of California, Los Angeles, CA, USA; Department of Medicine, University of California, Los Angeles, CA, USA.
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26
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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: 17] [Impact Index Per Article: 3.4] [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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27
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Characterization of 3D matrix conditions for cancer cell migration with elasticity/porosity-independent tunable microfiber gels. Polym J 2019. [DOI: 10.1038/s41428-019-0283-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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28
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Smetana K, Klamová H, Mikulenková D. To the approximate size of the nuclear region occupied by nucleolar bodies during cell differentiation and maturation using the human leukemic granulocytic lineage as a convenient model. Physiol Res 2019; 68:633-638. [PMID: 31177792 DOI: 10.33549/physiolres.934045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The present study was undertaken to estimate the approximate size of nuclear regions occupied by nucleolar bodies during the cell differentiation and maturation. The differentiation and maturation of human leukemic granulocytic cells in patients suffering from the chronic phase of the chronic granulocytic leukemia (CML) represented a convenient model for such study because of the large number of cells for the diameter measurements at the single cell level. Early and advanced differentiation or maturation stages of these cells are well defined and nucleolar bodies and nuclear outlines are easily seen by simple cytochemical methods for the visualization of RNA and silver stained proteins in smear preparations. During the cell differentiation and maturation, the estimated size of the nuclear region occupied by nucleolar bodies decreased in both untreated and treated patients with the anti-leukemic therapy. However, the size reduction of nucleolar bodies in differentiated and mature cells was larger than that of the nucleus. In addition, the results also indicated that the nuclear region occupied by nucleolar bodies was characteristic for each differentiation and maturation stage of the granulocytic cell lineage and was not substantially influenced by the anti-leukemic therapy of CML patients.
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Affiliation(s)
- K Smetana
- Institute of Hematology and Blood Transfusion, Prague, Czech Republic.
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29
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Stephens AD, Liu PZ, Kandula V, Chen H, Almassalha LM, Herman C, Backman V, O’Halloran T, Adam SA, Goldman RD, Banigan EJ, Marko JF. Physicochemical mechanotransduction alters nuclear shape and mechanics via heterochromatin formation. Mol Biol Cell 2019; 30:2320-2330. [PMID: 31365328 PMCID: PMC6743459 DOI: 10.1091/mbc.e19-05-0286] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 06/11/2019] [Indexed: 12/12/2022] Open
Abstract
The nucleus houses, organizes, and protects chromatin to ensure genome integrity and proper gene expression, but how the nucleus adapts mechanically to changes in the extracellular environment is poorly understood. Recent studies have revealed that extracellular physical stresses induce chromatin compaction via mechanotransductive processes. We report that increased extracellular multivalent cations lead to increased heterochromatin levels through activation of mechanosensitive ion channels (MSCs), without large-scale cell stretching. In cells with perturbed chromatin or lamins, this increase in heterochromatin suppresses nuclear blebbing associated with nuclear rupture and DNA damage. Through micromanipulation force measurements, we show that this increase in heterochromatin increases chromatin-based nuclear rigidity, which protects nuclear morphology and function. In addition, transduction of elevated extracellular cations rescues nuclear morphology in model and patient cells of human diseases, including progeria and the breast cancer model cell line MDA-MB-231. We conclude that nuclear mechanics, morphology, and function can be modulated by cell sensing of the extracellular environment through MSCs and consequent changes to histone modification state and chromatin-based nuclear rigidity.
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Affiliation(s)
- Andrew D. Stephens
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Patrick Z. Liu
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Viswajit Kandula
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Haimei Chen
- Department of Chemistry, Northwestern University, Evanston, IL 60208
| | - Luay M. Almassalha
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208
| | - Cameron Herman
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208
| | - Thomas O’Halloran
- Department of Chemistry, Northwestern University, Evanston, IL 60208
| | - Stephen A. Adam
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Robert D. Goldman
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Edward J. Banigan
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - John F. Marko
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
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30
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Stephens AD, Banigan EJ, Marko JF. Chromatin's physical properties shape the nucleus and its functions. Curr Opin Cell Biol 2019; 58:76-84. [PMID: 30889417 PMCID: PMC6692209 DOI: 10.1016/j.ceb.2019.02.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 12/13/2022]
Abstract
The cell nucleus encloses, organizes, and protects the genome. Chromatin maintains nuclear mechanical stability and shape in coordination with lamins and the cytoskeleton. Abnormal nuclear shape is a diagnostic marker for human diseases, and it can cause nuclear dysfunction. Chromatin mechanics underlies this link, as alterations to chromatin and its physical properties can disrupt or rescue nuclear shape. The cell can regulate nuclear shape through mechanotransduction pathways that sense and respond to extracellular cues, thus modulating chromatin compaction and rigidity. These findings reveal how chromatin's physical properties can regulate cellular function and drive abnormal nuclear morphology and dysfunction in disease.
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Affiliation(s)
- Andrew D Stephens
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, United States.
| | - Edward J Banigan
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - John F Marko
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, United States; Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, United States.
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31
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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: 6] [Impact Index Per Article: 1.2] [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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32
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Balakrishnan S, Mathad SS, Sharma G, Raju SR, Reddy UB, Das S, Ananthasuresh GK. A Nondimensional Model Reveals Alterations in Nuclear Mechanics upon Hepatitis C Virus Replication. Biophys J 2019; 116:1328-1339. [PMID: 30879645 DOI: 10.1016/j.bpj.2019.02.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/31/2019] [Accepted: 02/07/2019] [Indexed: 02/05/2023] Open
Abstract
Morphology of the nucleus is an important regulator of gene expression. Nuclear morphology is in turn a function of the forces acting on it and the mechanical properties of the nuclear envelope. Here, we present a two-parameter, nondimensional mechanical model of the nucleus that reveals a relationship among nuclear shape parameters, such as projected area, surface area, and volume. Our model fits the morphology of individual nuclei and predicts the ratio between forces and modulus in each nucleus. We analyzed the changes in nuclear morphology of liver cells due to hepatitis C virus (HCV) infection using this model. The model predicted a decrease in the elastic modulus of the nuclear envelope and an increase in the pre-tension in cortical actin as the causes for the change in nuclear morphology. These predictions were validated biomechanically by showing that liver cells expressing HCV proteins possessed enhanced cellular stiffness and reduced nuclear stiffness. Concomitantly, cells expressing HCV proteins showed downregulation of lamin-A,C and upregulation of β-actin, corroborating the predictions of the model. Our modeling assumptions are broadly applicable to adherent, monolayer cell cultures, making the model amenable to investigate changes in nuclear mechanics due to other stimuli by merely measuring nuclear morphology. Toward this, we present two techniques, graphical and numerical, to use our model for predicting physical changes in the nucleus.
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Affiliation(s)
- Sreenath Balakrishnan
- BioSystems Science and Engineering, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Suma S Mathad
- Mechanical Engineering, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Geetika Sharma
- Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Shilpa R Raju
- Mechanical Engineering, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Uma B Reddy
- Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Saumitra Das
- BioSystems Science and Engineering, Indian Institute of Science, Bengaluru, Karnataka, India; Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka, India.
| | - G K Ananthasuresh
- BioSystems Science and Engineering, Indian Institute of Science, Bengaluru, Karnataka, India; Mechanical Engineering, Indian Institute of Science, Bengaluru, Karnataka, India.
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33
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Lee G, Han SB, Lee JH, Kim HW, Kim DH. Cancer Mechanobiology: Microenvironmental Sensing and Metastasis. ACS Biomater Sci Eng 2019; 5:3735-3752. [PMID: 33405888 DOI: 10.1021/acsbiomaterials.8b01230] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cellular microenvironment plays an important role in regulating cancer progress. Cancer can physically and chemically remodel its surrounding extracellular matrix (ECM). Critical cellular behaviors such as recognition of matrix geometry and rigidity, cell polarization and motility, cytoskeletal reorganization, and proliferation can be changed as a consequence of these ECM alternations. Here, we present an overview of cancer mechanobiology in detail, focusing on cancer microenvironmental sensing of exogenous cues and quantification of cancer-substrate interactions. In addition, mechanics of metastasis classified with tumor progression will be discussed. The mechanism underlying cancer mechanosensation and tumor progression may provide new insights into therapeutic strategies to alleviate cancer malignancy.
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Affiliation(s)
- GeonHui Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
| | - Seong-Beom Han
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
| | - Jung-Hwan Lee
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 31116, South Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan 31116, South Korea
| | - Hae-Won Kim
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 31116, South Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan 31116, South Korea.,Department of Nanobiomedical Science and BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, South Korea
| | - Dong-Hwee Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
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34
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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: 12.7] [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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35
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Sierra-López F, Baylón-Pacheco L, Espíritu-Gordillo P, Lagunes-Guillén A, Chávez-Munguía B, Rosales-Encina JL. Influence of Micropatterned Grill Lines on Entamoeba histolytica Trophozoites Morphology and Migration. Front Cell Infect Microbiol 2018; 8:295. [PMID: 30197879 PMCID: PMC6117912 DOI: 10.3389/fcimb.2018.00295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 08/02/2018] [Indexed: 12/28/2022] Open
Abstract
Entamoeba histolytica, the causal agent of human amoebiasis, has two morphologically different phases: a resistant cyst and a trophozoite responsible for the invasion of the host tissues such as the colonic mucosa and the intestinal epithelium. During in vitro migration, trophozoites usually produce protuberances such as pseudopods and rarely filopodia, structures that have been observed in the interaction of trophozoites with human colonic epithelial tissue. To study the different membrane projections produced by the trophozoites, including pseudopods, filopodia, uropods, blebs, and others, we designed an induction system using erythrocyte extract or fibronectin (FN) in micropatterned grill lines (each micro-line containing multiple micro-portions of FN or erythrocyte extract) on which the trophozoites were placed in culture for migration assays. Using light, confocal, and scanning electron microscopy, we established that E. histolytica trophozoites frequently produce short and long filopodia, large retractile uropods in the rear, pseudopods, blebs, and others structures, also showing continuous migration periods. The present study provides a simple migration method to induce trophozoites to generate abundant membrane protrusion structures that are rarely obtained in normal or induced cultures, such as long filopodia; this method will allow a–better understanding of the interactions of trophozoites with FN and cell debris. E. histolytica trophozoites motility plays an important role in invasive amoebiasis. It has been proposed that both physical forces and chemical signals are involved in the trophozoite motility and migration. However, the in vivo molecules that drive the chemotactic migration remain to be determined. We propose the present assay to study host molecules that guide chemotactic behavior because the method is highly reproducible, and a live image of cell movement and migration can be quantified.
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Affiliation(s)
- Francisco Sierra-López
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Lidia Baylón-Pacheco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Patricia Espíritu-Gordillo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Anel Lagunes-Guillén
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Bibiana Chávez-Munguía
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - José L Rosales-Encina
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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36
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Stephens AD, Liu PZ, Banigan EJ, Almassalha LM, Backman V, Adam SA, Goldman RD, Marko JF. Chromatin histone modifications and rigidity affect nuclear morphology independent of lamins. Mol Biol Cell 2018; 29:220-233. [PMID: 29142071 PMCID: PMC5909933 DOI: 10.1091/mbc.e17-06-0410] [Citation(s) in RCA: 211] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/17/2017] [Accepted: 11/08/2017] [Indexed: 01/29/2023] Open
Abstract
Nuclear shape and architecture influence gene localization, mechanotransduction, transcription, and cell function. Abnormal nuclear morphology and protrusions termed "blebs" are diagnostic markers for many human afflictions including heart disease, aging, progeria, and cancer. Nuclear blebs are associated with both lamin and chromatin alterations. A number of prior studies suggest that lamins dictate nuclear morphology, but the contributions of altered chromatin compaction remain unclear. We show that chromatin histone modification state dictates nuclear rigidity, and modulating it is sufficient to both induce and suppress nuclear blebs. Treatment of mammalian cells with histone deacetylase inhibitors to increase euchromatin or histone methyltransferase inhibitors to decrease heterochromatin results in a softer nucleus and nuclear blebbing, without perturbing lamins. Conversely, treatment with histone demethylase inhibitors increases heterochromatin and chromatin nuclear rigidity, which results in reduced nuclear blebbing in lamin B1 null nuclei. Notably, increased heterochromatin also rescues nuclear morphology in a model cell line for the accelerated aging disease Hutchinson-Gilford progeria syndrome caused by mutant lamin A, as well as cells from patients with the disease. Thus, chromatin histone modification state is a major determinant of nuclear blebbing and morphology via its contribution to nuclear rigidity.
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Affiliation(s)
- Andrew D Stephens
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Patrick Z Liu
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Edward J Banigan
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Luay M Almassalha
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208
| | - Stephen A Adam
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - John F Marko
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208.,Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
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