1
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Pourali P, Svoboda M, Neuhöferová E, Dzmitruk V, Benson V. Accumulation and toxicity of biologically produced gold nanoparticles in different types of specialized mammalian cells. Biotechnol Appl Biochem 2024; 71:766-778. [PMID: 38480514 DOI: 10.1002/bab.2575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/17/2024] [Indexed: 08/09/2024]
Abstract
The biologically produced gold nanoparticles (AuNPs) are novel carriers with promising use in targeted tumor therapy. Still, there are no studies regarding the efficacy of nanoparticle internalization by cancer and noncancer cells. In this study, AuNPs were produced by Fusarium oxysporum and analyzed by spectrophotometry, transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and Zetasizer. Obtained AuNPs were about 15 nm in size with a zeta potential of -35.8 mV. The AuNPs were added to cancer cells (4T1), noncancer cells (NIH/3T3), and macrophages (RAW264.7). The viability decreased in 4T1 (77 ± 3.74%) in contrast to NIH/3T3 and RAW264.7 cells (89 ± 4.9% and 90 ± 3.5%, respectively). The 4T1 cancer cells also showed the highest uptake and accumulation of Au (∼80% of AuNPs was internalized) as determined by graphite furnace atomic absorption spectroscopy. The lowest amount of AuNPs was internalized by the NIH/3T3 cells (∼30%). The NIH/3T3 cells exhibited prominent reorganization of F-actin filaments as examined by confocal microscopy. In RAW264.7, we analyzed the release of proinflammatory cytokines by flow cytometry and we found the AuNP interaction triggered transient secretion of tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In summary, we proved the biologically produced AuNPs entered all the tested cell types and triggered cell-specific responses. High AuNP uptake by tumor cells was related to decreased cell viability, while low nanoparticle uptake by fibroblasts triggered F-actin reorganization without remarkable toxicity. Thus, the biologically produced AuNPs hold promising potential as cancer drug carriers and likely require proper surface functionalization to shield phagocytizing cells.
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Affiliation(s)
- Parastoo Pourali
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Milan Svoboda
- Institute of Analytical Chemistry, Czech Academy of Sciences, Brno, Czech Republic
| | - Eva Neuhöferová
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Volha Dzmitruk
- Center of Molecular Structure, Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czech Republic
| | - Veronika Benson
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Health Studies, Technical University of Liberec, Liberec, Czech Republic
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2
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Jaddivada S, Gundiah N. Physical biology of cell-substrate interactions under cyclic stretch. Biomech Model Mechanobiol 2024; 23:433-451. [PMID: 38010479 DOI: 10.1007/s10237-023-01783-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/14/2023] [Indexed: 11/29/2023]
Abstract
Mechanosensitive focal adhesion (FA) complexes mediate dynamic interactions between cells and substrates and regulate cellular function. Integrins in FA complexes link substrate ligands to stress fibers (SFs) and aid load transfer and traction generation. We developed a one-dimensional, multi-scale, stochastic finite element model of a fibroblast on a substrate that includes calcium signaling, SF remodeling, and FA dynamics. We linked stochastic dynamics, describing the formation and clustering of integrins to substrate ligands via motor-clutches, to a continuum level SF contractility model at various locations along the cell length. We quantified changes in cellular responses with substrate stiffness, ligand density, and cyclic stretch. Results show that tractions and integrin recruitments varied along the cell length; tractions were maximum at lamellar regions and reduced to zero at the cell center. Optimal substrate stiffness, based on maximum tractions exerted by the cell, shifted toward stiffer substrates at high ligand densities. Mean tractions varied biphasically with substrate stiffness and peaked at the optimal substrate stiffness. Cytosolic calcium increased monotonically with substrate stiffness and accumulated near lamellipodial regions. Cyclic stretch increased the cytosolic calcium, integrin concentrations, and tractions at lamellipodial and intermediate regions on compliant substrates. The optimal substrate stiffness under stretch shifted toward compliant substrates for a given ligand density. Stretch also caused cell deadhesions beyond a critical substrate stiffness. FA's destabilized on stiff substrates under cyclic stretch. An increase in substrate stiffness and cyclic stretch resulted in higher fibroblast contractility. These results show that chemomechanical coupling is essential in mechanosensing responses underlying cell-substrate interactions.
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Affiliation(s)
- Siddhartha Jaddivada
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Namrata Gundiah
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 560012, India.
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3
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Jiang S, Alisafaei F, Huang YY, Hong Y, Peng X, Qu C, Puapatanakul P, Jain S, Miner JH, Genin GM, Suleiman HY. An ex vivo culture model of kidney podocyte injury reveals mechanosensitive, synaptopodin-templating, sarcomere-like structures. SCIENCE ADVANCES 2022; 8:eabn6027. [PMID: 36044576 PMCID: PMC9432837 DOI: 10.1126/sciadv.abn6027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Chronic kidney diseases are widespread and incurable. The biophysical mechanisms underlying them are unclear, in part because material systems for reconstituting the microenvironment of relevant kidney cells are limited. A critical question is how kidney podocytes (glomerular epithelial cells) regenerate foot processes of the filtration apparatus following injury. Recently identified sarcomere-like structures (SLSs) with periodically spaced myosin IIA and synaptopodin appear in injured podocytes in vivo. We hypothesized that SLSs template synaptopodin in the initial stages of recovery in response to microenvironmental stimuli and tested this hypothesis by developing an ex vivo culture system that allows control of the podocyte microenvironment. Results supported our hypothesis. SLSs in podocytes that migrated from isolated kidney glomeruli presented periodic synaptopodin-positive clusters that nucleated peripheral, foot process-like extensions. SLSs were mechanoresponsive to actomyosin inhibitors and substrate stiffness. Results suggest SLSs as mechanobiological mediators of podocyte recovery and as potential targets for therapeutic intervention.
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Affiliation(s)
- Shumeng Jiang
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Farid Alisafaei
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Yin-Yuan Huang
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Yuan Hong
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Xiangjun Peng
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Chengqing Qu
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Pongpratch Puapatanakul
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sanjay Jain
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Guy M. Genin
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Hani Y. Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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4
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Qu C, Roth R, Puapatanakul P, Loitman C, Hammad D, Genin GM, Miner JH, Suleiman HY. Three-Dimensional Visualization of the Podocyte Actin Network Using Integrated Membrane Extraction, Electron Microscopy, and Machine Learning. J Am Soc Nephrol 2022; 33:155-173. [PMID: 34758982 PMCID: PMC8763187 DOI: 10.1681/asn.2021020182] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 10/19/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Actin stress fibers are abundant in cultured cells, but little is known about them in vivo. In podocytes, much evidence suggests that mechanobiologic mechanisms underlie podocyte shape and adhesion in health and in injury, with structural changes to actin stress fibers potentially responsible for pathologic changes to cell morphology. However, this hypothesis is difficult to rigorously test in vivo due to challenges with visualization. A technology to image the actin cytoskeleton at high resolution is needed to better understand the role of structures such as actin stress fibers in podocytes. METHODS We developed the first visualization technique capable of resolving the three-dimensional cytoskeletal network in mouse podocytes in detail, while definitively identifying the proteins that comprise this network. This technique integrates membrane extraction, focused ion-beam scanning electron microscopy, and machine learning image segmentation. RESULTS Using isolated mouse glomeruli from healthy animals, we observed actin cables and intermediate filaments linking the interdigitated podocyte foot processes to newly described contractile actin structures, located at the periphery of the podocyte cell body. Actin cables within foot processes formed a continuous, mesh-like, electron-dense sheet that incorporated the slit diaphragms. CONCLUSIONS Our new technique revealed, for the first time, the detailed three-dimensional organization of actin networks in healthy podocytes. In addition to being consistent with the gel compression hypothesis, which posits that foot processes connected by slit diaphragms act together to counterbalance the hydrodynamic forces across the glomerular filtration barrier, our data provide insight into how podocytes respond to mechanical cues from their surrounding environment.
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Affiliation(s)
- Chengqing Qu
- Department of Mechanical Engineering, National Science Foundation Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri
| | - Robyn Roth
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | | | - Charles Loitman
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Dina Hammad
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Guy M. Genin
- Department of Mechanical Engineering, National Science Foundation Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri
| | - Jeffrey H. Miner
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri,Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y. Suleiman
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
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5
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Zhang C, Zhu H, Ren X, Gao B, Cheng B, Liu S, Sha B, Li Z, Zhang Z, Lv Y, Wang H, Guo H, Lu TJ, Xu F, Genin GM, Lin M. Mechanics-driven nuclear localization of YAP can be reversed by N-cadherin ligation in mesenchymal stem cells. Nat Commun 2021; 12:6229. [PMID: 34711824 PMCID: PMC8553821 DOI: 10.1038/s41467-021-26454-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 10/01/2021] [Indexed: 12/30/2022] Open
Abstract
Mesenchymal stem cells adopt differentiation pathways based upon cumulative effects of mechanosensing. A cell's mechanical microenvironment changes substantially over the course of development, beginning from the early stages in which cells are typically surrounded by other cells and continuing through later stages in which cells are typically surrounded by extracellular matrix. How cells erase the memory of some of these mechanical microenvironments while locking in memory of others is unknown. Here, we develop a material and culture system for modifying and measuring the degree to which cells retain cumulative effects of mechanosensing. Using this system, we discover that effects of the RGD adhesive motif of fibronectin (representative of extracellular matrix), known to impart what is often termed "mechanical memory" in mesenchymal stem cells via nuclear YAP localization, are erased by the HAVDI adhesive motif of the N-cadherin (representative of cell-cell contacts). These effects can be explained by a motor clutch model that relates cellular traction force, nuclear deformation, and resulting nuclear YAP re-localization. Results demonstrate that controlled storage and removal of proteins associated with mechanical memory in mesenchymal stem cells is possible through defined and programmable material systems.
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Affiliation(s)
- Cheng Zhang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Hongyuan Zhu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Xinru Ren
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Bin Gao
- Department of Endocrinology, Second Affiliated Hospital of Air Force Military Medical University, Xi'an, 710038, People's Republic of China
| | - Bo Cheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Shaobao Liu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Baoyong Sha
- School of Basic Medical Science, Xi'an Medical University, Xi'an, 710021, People's Republic of China
| | - Zhaoqing Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Zheng Zhang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Yi Lv
- National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, The First Affiliated Hospital of Xi'an Jiaotong University, Xian, People's Republic of China
| | - Haohua Wang
- National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, The First Affiliated Hospital of Xi'an Jiaotong University, Xian, People's Republic of China
| | - Hui Guo
- Department of Medical Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China
| | - Tian Jian Lu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
- MOE Key Laboratory of Multifunctional Materials and Structures, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Guy M Genin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
- Department of Mechanical Engineering & Materials Science, Washington University in St. Louis, St. Louis, 63130, MO, USA
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, 63130, MO, USA
| | - Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China.
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China.
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6
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Shakiba D, Alisafaei F, Savadipour A, Rowe RA, Liu Z, Pryse KM, Shenoy VB, Elson EL, Genin GM. The Balance between Actomyosin Contractility and Microtubule Polymerization Regulates Hierarchical Protrusions That Govern Efficient Fibroblast-Collagen Interactions. ACS NANO 2020; 14:7868-7879. [PMID: 32286054 DOI: 10.1021/acsnano.9b09941] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Fibroblasts undergo a critical transformation from an initially inactive state to a morphologically different and contractile state after several hours of being embedded within a physiologically relevant three-dimensional (3D) fibrous collagen-based extracellular matrix (ECM). However, little is known about the critical mechanisms by which fibroblasts adapt themselves and their microenvironment in the earliest stage of cell-matrix interaction. Here, we identified the mechanisms by which fibroblasts interact with their 3D collagen fibrous matrices in the early stages of cell-matrix interaction and showed that fibroblasts use energetically efficient hierarchical micro/nano-scaled protrusions in these stages as the primary means for the transformation and adaptation. We found that actomyosin contractility in these protrusions in the early stages of cell-matrix interaction restricts the growth of microtubules by applying compressive forces on them. Our results show that actomyosin contractility and microtubules work in concert in the early stages of cell-matrix interaction to adapt fibroblasts and their microenvironment to one another. These early stage interactions result in responses to disruption of the microtubule network and/or actomyosin contractility that are opposite to well-known responses to late-stage disruption and reveal insight into the ways that cells adapt themselves and their ECM recursively.
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Affiliation(s)
- Delaram Shakiba
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Farid Alisafaei
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Alireza Savadipour
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Roger A Rowe
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Zhangao Liu
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Kenneth M Pryse
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Vivek B Shenoy
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Elliot L Elson
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Guy M Genin
- NSF Science and Technology Center for Engineering Mechanobiology and Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130 United States
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7
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Skamrahl M, Colin-York H, Barbieri L, Fritzsche M. Simultaneous Quantification of the Interplay Between Molecular Turnover and Cell Mechanics by AFM-FRAP. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1902202. [PMID: 31419037 PMCID: PMC7612032 DOI: 10.1002/smll.201902202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/22/2019] [Indexed: 06/02/2023]
Abstract
Quantifying the adaptive mechanical behavior of living cells is essential for the understanding of their inner working and function. Yet, despite the establishment of quantitative methodologies correlating independent measurements of cell mechanics and its underlying molecular kinetics, explicit evidence and knowledge of the sensitivity of the feedback mechanisms of cells controlling their adaptive mechanics behavior remains elusive. Here, a combination of atomic force microscopy and fluorescence recovery after photobleaching is introduced offering simultaneous quantification and direct correlation of molecule kinetics and mechanics in living cells. Systematic application of this optomechanical atomic force microscopy-fluorescence recovery after photobleaching platform reveals changes in the actin turnover and filament lengths of ventral actin stress fibers in response to constant mechanical force at the apical actin cortex with a dynamic range from 0.1 to 10 nN, highlighting a direct relationship of active mechanosensation and adaptation of the cellular actin cytoskeleton. Simultaneous quantification of the relationship between molecule kinetics and cell mechanics may thus open-up unprecedented insights into adaptive mechanobiological mechanisms of cells.
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Affiliation(s)
- Mark Skamrahl
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford. OX3 9DS, United Kingdom
| | - Huw Colin-York
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford. OX3 9DS, United Kingdom
| | - Liliana Barbieri
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford. OX3 9DS, United Kingdom
| | - Marco Fritzsche
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford. OX3 9DS, United Kingdom
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
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8
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Liu S, Tao R, Wang M, Tian J, Genin GM, Lu TJ, Xu F. Regulation of Cell Behavior by Hydrostatic Pressure. APPLIED MECHANICS REVIEWS 2019; 71:0408031-4080313. [PMID: 31700195 PMCID: PMC6808007 DOI: 10.1115/1.4043947] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 05/18/2019] [Indexed: 06/10/2023]
Abstract
Hydrostatic pressure (HP) regulates diverse cell behaviors including differentiation, migration, apoptosis, and proliferation. Abnormal HP is associated with pathologies including glaucoma and hypertensive fibrotic remodeling. In this review, recent advances in quantifying and predicting how cells respond to HP across several tissue systems are presented, including tissues of the brain, eye, vasculature and bladder, as well as articular cartilage. Finally, some promising directions on the study of cell behaviors regulated by HP are proposed.
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Affiliation(s)
- Shaobao Liu
- State Key Laboratory of Mechanics andControl of Mechanical Structures,
Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China
- The Key Laboratory of Biomedical InformationEngineering of Ministry of Education,
School of Life Science and Technology,
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
| | - Ru Tao
- The Key Laboratory of Biomedical InformationEngineering of Ministry of Education,
School of Life Science and Technology,
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
| | - Ming Wang
- The Key Laboratory of Biomedical InformationEngineering of Ministry of Education,
School of Life Science and Technology,
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
| | - Jin Tian
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
- State Key Laboratory for Strength andVibration of Mechanical Structures,
Xi'an Jiaotong University,
Xi'an 710049, China
| | - Guy M. Genin
- The Key Laboratory of Biomedical Information
Engineering of Ministry of Education,
School of Life Science and Technology,
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Mechanical Engineering &
Materials Science,
National Science Foundation Science and
Technology Center for Engineering Mechanobiology,
Washington University,
St. Louis, MO 63130
| | - Tian Jian Lu
- State Key Laboratory of Mechanics andControl of Mechanical Structures,
Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China
- Department of Structural Engineering & Mechanics,
Nanjing Center for Multifunctional LightweightMaterials and Structures,
Nanjing University of Aeronautics and Astronautics,
Nanjing 21006, China;
State Key Laboratory for Strength andVibration of Mechanical Structures,
Xi'an Jiaotong University,
Xi'an 710049, China
| | - Feng Xu
- The Key Laboratory of Biomedical InformationEngineering of Ministry of Education,
School of Life Science and Technology,
Xi'an Jiaotong University,
Xi'an 710049, China
- Department of Biomedical Engineering,Bioinspired Engineering and Biomechanics Center (BEBC),
Xi'an Jiaotong University,
Xi'an 710049, China
e-mail:
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9
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Babaei B, Velasquez-Mao AJ, Pryse KM, McConnaughey WB, Elson EL, Genin GM. Energy dissipation in quasi-linear viscoelastic tissues, cells, and extracellular matrix. J Mech Behav Biomed Mater 2018; 84:198-207. [PMID: 29793157 PMCID: PMC5995675 DOI: 10.1016/j.jmbbm.2018.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/01/2018] [Accepted: 05/07/2018] [Indexed: 11/16/2022]
Abstract
Characterizing how a tissue's constituents give rise to its viscoelasticity is important for uncovering how hidden timescales underlie multiscale biomechanics. These constituents are viscoelastic in nature, and their mechanics must typically be assessed from the uniaxial behavior of a tissue. Confounding the challenge is that tissue viscoelasticity is typically associated with nonlinear elastic responses. Here, we experimentally assessed how fibroblasts and extracellular matrix (ECM) within engineered tissue constructs give rise to the nonlinear viscoelastic responses of a tissue. We applied a constant strain rate, "triangular-wave" loading and interpreted responses using the Fung quasi-linear viscoelastic (QLV) material model. Although the Fung QLV model has several well-known weaknesses, it was well suited to the behaviors of the tissue constructs, cells, and ECM tested. Cells showed relatively high damping over certain loading frequency ranges. Analysis revealed that, even in cases where the Fung QLV model provided an excellent fit to data, the the time constant derived from the model was not in general a material parameter. Results have implications for design of protocols for the mechanical characterization of biological materials, and for the mechanobiology of cells within viscoelastic tissues.
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Affiliation(s)
- Behzad Babaei
- Neuroscience Research Australia, Randwick, Australia
| | - A J Velasquez-Mao
- UC Berkeley and UC San Francisco Graduate Program in Bioengineering, San Francisco, CA, USA
| | - Kenneth M Pryse
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - William B McConnaughey
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Elliot L Elson
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Guy M Genin
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA.
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10
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Cheng B, Lin M, Huang G, Li Y, Ji B, Genin GM, Deshpande VS, Lu TJ, Xu F. Cellular mechanosensing of the biophysical microenvironment: A review of mathematical models of biophysical regulation of cell responses. Phys Life Rev 2017; 22-23:88-119. [PMID: 28688729 PMCID: PMC5712490 DOI: 10.1016/j.plrev.2017.06.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 12/11/2022]
Abstract
Cells in vivo reside within complex microenvironments composed of both biochemical and biophysical cues. The dynamic feedback between cells and their microenvironments hinges upon biophysical cues that regulate critical cellular behaviors. Understanding this regulation from sensing to reaction to feedback is therefore critical, and a large effort is afoot to identify and mathematically model the fundamental mechanobiological mechanisms underlying this regulation. This review provides a critical perspective on recent progress in mathematical models for the responses of cells to the biophysical cues in their microenvironments, including dynamic strain, osmotic shock, fluid shear stress, mechanical force, matrix rigidity, porosity, and matrix shape. The review highlights key successes and failings of existing models, and discusses future opportunities and challenges in the field.
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Affiliation(s)
- Bo Cheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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
| | - Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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
| | - Guoyou Huang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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
| | - Yuhui Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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
| | - Baohua Ji
- Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing, China
| | - Guy M Genin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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; Department of Mechanical Engineering & Materials Science, and NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis 63130, MO, USA
| | - Vikram S Deshpande
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
| | - Tian Jian Lu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, 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.
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11
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Huang G, Li F, Zhao X, Ma Y, Li Y, Lin M, Jin G, Lu TJ, Genin GM, Xu F. Functional and Biomimetic Materials for Engineering of the Three-Dimensional Cell Microenvironment. Chem Rev 2017; 117:12764-12850. [PMID: 28991456 PMCID: PMC6494624 DOI: 10.1021/acs.chemrev.7b00094] [Citation(s) in RCA: 469] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cell microenvironment has emerged as a key determinant of cell behavior and function in development, physiology, and pathophysiology. The extracellular matrix (ECM) within the cell microenvironment serves not only as a structural foundation for cells but also as a source of three-dimensional (3D) biochemical and biophysical cues that trigger and regulate cell behaviors. Increasing evidence suggests that the 3D character of the microenvironment is required for development of many critical cell responses observed in vivo, fueling a surge in the development of functional and biomimetic materials for engineering the 3D cell microenvironment. Progress in the design of such materials has improved control of cell behaviors in 3D and advanced the fields of tissue regeneration, in vitro tissue models, large-scale cell differentiation, immunotherapy, and gene therapy. However, the field is still in its infancy, and discoveries about the nature of cell-microenvironment interactions continue to overturn much early progress in the field. Key challenges continue to be dissecting the roles of chemistry, structure, mechanics, and electrophysiology in the cell microenvironment, and understanding and harnessing the roles of periodicity and drift in these factors. This review encapsulates where recent advances appear to leave the ever-shifting state of the art, and it highlights areas in which substantial potential and uncertainty remain.
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Affiliation(s)
- Guoyou Huang
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
| | - Fei Li
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
- Department of Chemistry, School of Science,
Xi’an Jiaotong University, Xi’an 710049, People’s Republic
of China
| | - Xin Zhao
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
- Interdisciplinary Division of Biomedical
Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong,
People’s Republic of China
| | - Yufei Ma
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
| | - Yuhui Li
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
| | - Min Lin
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
| | - Guorui Jin
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
| | - Tian Jian Lu
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
- MOE Key Laboratory for Multifunctional Materials
and Structures, Xi’an Jiaotong University, Xi’an 710049,
People’s Republic of China
| | - Guy M. Genin
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
- Department of Mechanical Engineering &
Materials Science, Washington University in St. Louis, St. Louis 63130, MO,
USA
- NSF Science and Technology Center for
Engineering MechanoBiology, Washington University in St. Louis, St. Louis 63130,
MO, USA
| | - Feng Xu
- MOE Key Laboratory of Biomedical Information
Engineering, School of Life Science and Technology, Xi’an Jiaotong
University, Xi’an 710049, People’s Republic of China
- Bioinspired Engineering and Biomechanics Center
(BEBC), Xi’an Jiaotong University, Xi’an 710049, People’s
Republic of China
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12
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Sheets K, Wang J, Zhao W, Kapania R, Nain AS. Nanonet Force Microscopy for Measuring Cell Forces. Biophys J 2017; 111:197-207. [PMID: 27410747 DOI: 10.1016/j.bpj.2016.05.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/11/2016] [Accepted: 05/16/2016] [Indexed: 01/03/2023] Open
Abstract
The influence of physical forces exerted by or felt by cells on cell shape, migration, and cytoskeleton arrangement is now widely acknowledged and hypothesized to occur due to modulation of cellular inside-out forces in response to changes in the external fibrous environment (outside-in). Our previous work using the non-electrospinning Spinneret-based Tunable Engineered Parameters' suspended fibers has revealed that cells are able to sense and respond to changes in fiber curvature and structural stiffness as evidenced by alterations to focal adhesion cluster lengths. Here, we present the development and application of a suspended nanonet platform for measuring C2C12 mouse myoblast forces attached to fibers of three diameters (250, 400, and 800 nm) representing a wide range of structural stiffness (3-50 nN/μm). The nanonet force microscopy platform measures cell adhesion forces in response to symmetric and asymmetric external perturbation in single and cyclic modes. We find that contractility-based, inside-out forces are evenly distributed at the edges of the cell, and that forces are dependent on fiber structural stiffness. Additionally, external perturbation in symmetric and asymmetric modes biases cell-fiber failure location without affecting the outside-in forces of cell-fiber adhesion. We then extend the platform to measure forces of (1) cell-cell junctions, (2) single cells undergoing cyclic perturbation in the presence of drugs, and (3) cancerous single-cells transitioning from a blebbing to a pseudopodial morphology.
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Affiliation(s)
- Kevin Sheets
- Departments of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, Virginia
| | - Ji Wang
- Departments of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, Virginia
| | - Wei Zhao
- Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, Virginia
| | - Rakesh Kapania
- Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, Virginia
| | - Amrinder S Nain
- Departments of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, Virginia; Mechanical Engineering, Virginia Tech, Blacksburg, Virginia.
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13
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Spencer TM, Blumenstein RF, Pryse KM, Lee SL, Glaubke DA, Carlson BE, Elson EL, Genin GM. Fibroblasts Slow Conduction Velocity in a Reconstituted Tissue Model of Fibrotic Cardiomyopathy. ACS Biomater Sci Eng 2016; 3:3022-3028. [PMID: 31119190 DOI: 10.1021/acsbiomaterials.6b00576] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Myocardial function deteriorates over the course of fibrotic cardiomyopathy, due to electrophysiological and mechanical effects of myofibroblasts that are not completely understood. Although a range of experimental model systems and associated theoretical treatments exist at the levels of isolated cardiomyocytes and planar co-cultures of myofibroblasts and cardiomyocytes, interactions between these cell types at the tissue level are less clear. We studied these interactions through an engineered heart tissue (EHT) model of fibrotic myocardium and a mathematical model of the effects of cellular composition on EHT impulse conduction velocity. The EHT model allowed for modulation of cardiomyocyte and myofibroblast volume fractions, and observation of cell behavior in a three-dimensional environment that is more similar to native heart tissue than is planar cell culture. The cardiomyocyte and myofibroblast volume fractions determined the retardation of impulse conduction (spread of the action potential) in EHTs as measured by changes of the fluorescence of the Ca2+ probe, Fluo-2. Interpretation through our model showed retardation far in excess of predictions by homogenization theory, with conduction ceasing far below the fibroblast volume fraction associated with steric percolation. Results point to an important multiscale structural role of myofibroblasts in attenuating impulse conduction in fibrotic cardiomyopathy.
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Affiliation(s)
- Teresa M Spencer
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Ryan F Blumenstein
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Kenneth M Pryse
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA.,Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Drive, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sheng-Lin Lee
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - David A Glaubke
- Department of Biomedical Engineering, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Brian E Carlson
- Department of Molecular and Integrative Physiology, NCRC B10 A126, 2800 Plymouth Rd., University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Elliot L Elson
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA.,Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Drive, Washington University School of Medicine, St. Louis, MO 63110, USA.,Department of Biomedical Engineering, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Guy M Genin
- Department of Mechanical Engineering and Materials Science, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA.,NSF Center for Engineering MechanoBiology, 1 Brookings Drive, Washington University in St. Louis, St. Louis, MO 63130 USA
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14
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Remodeling by fibroblasts alters the rate-dependent mechanical properties of collagen. Acta Biomater 2016; 37:28-37. [PMID: 27015891 DOI: 10.1016/j.actbio.2016.03.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 03/18/2016] [Accepted: 03/21/2016] [Indexed: 12/18/2022]
Abstract
UNLABELLED The ways that fibroblasts remodel their environment are central to wound healing, development of musculoskeletal tissues, and progression of pathologies such as fibrosis. However, the changes that fibroblasts make to the material around them and the mechanical consequences of these changes have proven difficult to quantify, especially in realistic, viscoelastic three-dimensional culture environments, leaving a critical need for quantitative data. Here, we observed the mechanisms and quantified the mechanical effects of fibroblast remodeling in engineered tissue constructs (ETCs) comprised of reconstituted rat tail (type I) collagen and human fibroblast cells. To study the effects of remodeling on tissue mechanics, stress-relaxation tests were performed on ETCs cultured for 24, 48, and 72h. ETCs were treated with deoxycholate and tested again to assess the ECM response. Viscoelastic relaxation spectra were obtained using the generalized Maxwell model. Cells exhibited viscoelastic damping at two finite time constants over which the ECM showed little damping, approximately 0.2s and 10-30s. Different finite time constants in the range of 1-7000s were attributed to ECM relaxation. Cells remodeled the ECM to produce a relaxation time constant on the order of 7000s, and to merge relaxation finite time constants in the 0.5-2s range into a single time content in the 1s range. Results shed light on hierarchical deformation mechanisms in tissues, and on pathologies related to collagen relaxation such as diastolic dysfunction. STATEMENT OF SIGNIFICANCE As fibroblasts proliferate within and remodel a tissue, they change the tissue mechanically. Quantifying these changes is critical for understanding wound healing and the development of pathologies such as cardiac fibrosis. Here, we characterize for the first time the spectrum of viscoelastic (rate-dependent) changes arising from the remodeling of reconstituted collagen by fibroblasts. The method also provides estimates of the viscoelastic spectra of fibroblasts within a three-dimensional culture environment. Results are of particular interest because of the ways that fibroblasts alter the mechanical response of collagen at loading frequencies associated with cardiac contraction in humans.
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15
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The concentration of stress at the rotator cuff tendon-to-bone attachment site is conserved across species. J Mech Behav Biomed Mater 2016; 62:24-32. [PMID: 27161959 DOI: 10.1016/j.jmbbm.2016.04.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/13/2016] [Accepted: 04/15/2016] [Indexed: 01/03/2023]
Abstract
The tendon-to-bone attachment site integrates two distinct tissues via a gradual transition in composition, mechanical properties, and structure. Outcomes of surgical repair are poor, in part because surgical repair does not recreate the natural attachment, and in part because the mechanical features that are most critical to mechanical and physiological functions have not been identified. We employed allometric analysis to resolve a paradox about how the architecture of the rotator cuff contributes to load transfer: whereas published data suggest that the mean muscle stresses expected at the tendon-to-bone attachment are conserved across species, data also show that the relative dimensions of key anatomical features vary dramatically, suggesting that the amplification of stresses at the interface between tendon and bone should also vary widely. However, a mechanical model that enabled a sensitivity analysis revealed that the degree of stress concentration was in fact highly conserved across species: the factors that most affected stress amplification were most highly conserved across species, while those that had a lower effect showed broad variation across a range of relative insensitivity. Results highlight how micromechanical factors can influence structure-function relationships and cross-species scaling over several orders of magnitude in animal size, and provide guidance on physiological features to emphasize in surgical and tissue engineered repair of the rotator cuff.
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16
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Li Y, Huang G, Li M, Wang L, Elson EL, Lu TJ, Genin GM, Xu F. An approach to quantifying 3D responses of cells to extreme strain. Sci Rep 2016; 6:19550. [PMID: 26887698 PMCID: PMC4757889 DOI: 10.1038/srep19550] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/18/2015] [Indexed: 12/25/2022] Open
Abstract
The tissues of hollow organs can routinely stretch up to 2.5 times their length. Although significant pathology can arise if relatively large stretches are sustained, the responses of cells are not known at these levels of sustained strain. A key challenge is presenting cells with a realistic and well-defined three-dimensional (3D) culture environment that can sustain such strains. Here, we describe an in vitro system called microscale, magnetically-actuated synthetic tissues (micro-MASTs) to quantify these responses for cells within a 3D hydrogel matrix. Cellular strain-threshold and saturation behaviors were observed in hydrogel matrix, including strain-dependent proliferation, spreading, polarization, and differentiation, and matrix adhesion retained at strains sufficient for apoptosis. More broadly, the system shows promise for defining and controlling the effects of mechanical environment upon a broad range of cells.
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Affiliation(s)
- Yuhui Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.,Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guoyou Huang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.,Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
| | - Moxiao Li
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
| | - Lin Wang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.,Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China.,Department of Biochemistry and Molecular Biophysics, Saint Louis, Missouri 63110, USA
| | - Elliot L Elson
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China.,Department of Biochemistry and Molecular Biophysics, Saint Louis, Missouri 63110, USA.,Department of Mechanical Engineering and Materials Science, Washington University, Saint Louis, Missouri 63130, USA
| | - Tian Jian Lu
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guy M Genin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.,Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China.,Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri 63110, USA.,Department of Mechanical Engineering and Materials Science, Washington University, Saint Louis, Missouri 63130, USA
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.,Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
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17
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Elson EL, Genin GM. Tissue constructs: platforms for basic research and drug discovery. Interface Focus 2016; 6:20150095. [PMID: 26855763 DOI: 10.1098/rsfs.2015.0095] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The functions, form and mechanical properties of cells are inextricably linked to their extracellular environment. Cells from solid tissues change fundamentally when, isolated from this environment, they are cultured on rigid two-dimensional substrata. These changes limit the significance of mechanical measurements on cells in two-dimensional culture and motivate the development of constructs with cells embedded in three-dimensional matrices that mimic the natural tissue. While measurements of cell mechanics are difficult in natural tissues, they have proven effective in engineered tissue constructs, especially constructs that emphasize specific cell types and their functions, e.g. engineered heart tissues. Tissue constructs developed as models of disease also have been useful as platforms for drug discovery. Underlying the use of tissue constructs as platforms for basic research and drug discovery is integration of multiscale biomaterials measurement and computational modelling to dissect the distinguishable mechanical responses separately of cells and extracellular matrix from measurements on tissue constructs and to quantify the effects of drug treatment on these responses. These methods and their application are the main subjects of this review.
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Affiliation(s)
- Elliot L Elson
- Department of Biochemistry and Molecular Biophysics , Washington University School of Medicine , St Louis, MO 63110 , USA
| | - Guy M Genin
- Department of Mechanical Engineering and Materials Science , Washington University , St Louis, MO 63130 , USA
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18
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Cooperative contractility: The role of stress fibres in the regulation of cell-cell junctions. J Biomech 2015; 48:520-8. [DOI: 10.1016/j.jbiomech.2014.11.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 11/13/2014] [Accepted: 11/19/2014] [Indexed: 01/13/2023]
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19
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Genin GM. Nanoscopic injury with macroscopic consequences: tau proteins as mediators of diffuse axonal injury. Biophys J 2014; 106:1551-2. [PMID: 24739151 DOI: 10.1016/j.bpj.2014.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/06/2014] [Indexed: 11/18/2022] Open
Affiliation(s)
- Guy M Genin
- Department of Mechanical Engineering and Materials Science, and Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri.
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20
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Genin GM, Elson EL. Mechanically guided cell migration: less of a stretch than ever. Biophys J 2014; 106:776-7. [PMID: 24559979 DOI: 10.1016/j.bpj.2014.01.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/08/2014] [Accepted: 01/10/2014] [Indexed: 11/17/2022] Open
Affiliation(s)
- Guy M Genin
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri; Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri.
| | - Elliot L Elson
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
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