1
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Alberici Delsin LE, Plutoni C, Clouvel A, Keil S, Marpeaux L, Elouassouli L, Khavari A, Ehrlicher AJ, Emery G. MAP4K4 regulates forces at cell-cell and cell-matrix adhesions to promote collective cell migration. Life Sci Alliance 2023; 6:e202302196. [PMID: 37369604 PMCID: PMC10300198 DOI: 10.26508/lsa.202302196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/12/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Collective cell migration is not only important for development and tissue homeostasis but can also promote cancer metastasis. To migrate collectively, cells need to coordinate cellular extensions and retractions, adhesion sites dynamics, and forces generation and transmission. Nevertheless, the regulatory mechanisms coordinating these processes remain elusive. Using A431 carcinoma cells, we identify the kinase MAP4K4 as a central regulator of collective migration. We show that MAP4K4 inactivation blocks the migration of clusters, whereas its overexpression decreases cluster cohesion. MAP4K4 regulates protrusion and retraction dynamics, remodels the actomyosin cytoskeleton, and controls the stability of both cell-cell and cell-substrate adhesion. MAP4K4 promotes focal adhesion disassembly through the phosphorylation of the actin and plasma membrane crosslinker moesin but disassembles adherens junctions through a moesin-independent mechanism. By analyzing traction and intercellular forces, we found that MAP4K4 loss of function leads to a tensional disequilibrium throughout the cell cluster, increasing the traction forces and the tension loading at the cell-cell adhesions. Together, our results indicate that MAP4K4 activity is a key regulator of biomechanical forces at adhesion sites, promoting collective migration.
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Affiliation(s)
- Lara Elis Alberici Delsin
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
| | - Cédric Plutoni
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
| | - Anna Clouvel
- Department of Bioengineering, McGill University, Montreal, Canada
| | - Sarah Keil
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
| | - Léa Marpeaux
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
| | - Lina Elouassouli
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
| | - Adele Khavari
- Department of Bioengineering, McGill University, Montreal, Canada
| | | | - Gregory Emery
- Vesicular Trafficking and Cell Signalling Research Unit, Institute for Research in Immunology and Cancer https://ror.org/0161xgx34 (IRIC), Université de Montréal, Montréal, Canada
- Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, Canada
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2
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Ayad NM, Lakins JN, Ghagre A, Ehrlicher AJ, Weaver VM. Tissue tension permits β-catenin phosphorylation to drive mesoderm specification in human embryonic stem cells. bioRxiv 2023:2023.07.14.549074. [PMID: 37503095 PMCID: PMC10370032 DOI: 10.1101/2023.07.14.549074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The role of morphogenetic forces in cell fate specification is an area of intense interest. Our prior studies suggested that the development of high cell-cell tension in human embryonic stem cells (hESC) colonies permits the Src-mediated phosphorylation of junctional β-catenin that accelerates its release to potentiate Wnt-dependent signaling critical for initiating mesoderm specification. Using an ectopically expressed nonphosphorylatable mutant of β-catenin (Y654F), we now provide direct evidence that impeding tension-dependent Src-mediated β-catenin phosphorylation impedes the expression of Brachyury (T) and the epithelial-to-mesenchymal transition (EMT) necessary for mesoderm specification. Addition of exogenous Wnt3a or inhibiting GSK3β activity rescued mesoderm expression, emphasizing the importance of force dependent Wnt signaling in regulating mechanomorphogenesis. Our work provides a framework for understanding tension-dependent β-catenin/Wnt signaling in the self-organization of tissues during developmental processes including gastrulation.
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Affiliation(s)
- Nadia M.E. Ayad
- Graduate Program in Bioengineering, University of California, San Francisco and University of California Berkeley, San Francisco, CA 94143, USA; Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Johnathon N. Lakins
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ajinkya Ghagre
- Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Allen J. Ehrlicher
- Department of Bioengineering, Department of Anatomy and Cell Biology, Department of Biomedical Engineering, Department of Mechanical Engineering, Centre for Structural Biology, Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Valerie M. Weaver
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; UCSF Comprehensive Cancer Center, Helen Diller Family Cancer Research Center, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Bioengineering and Therapeutic Sciences, Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA 94143, USA
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3
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Koushki N, Ghagre A, Srivastava LK, Molter C, Ehrlicher AJ. Nuclear compression regulates YAP spatiotemporal fluctuations in living cells. Proc Natl Acad Sci U S A 2023; 120:e2301285120. [PMID: 37399392 PMCID: PMC10334804 DOI: 10.1073/pnas.2301285120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/04/2023] [Indexed: 07/05/2023] Open
Abstract
Yes-associated protein (YAP) is a key mechanotransduction protein in diverse physiological and pathological processes; however, a ubiquitous YAP activity regulatory mechanism in living cells has remained elusive. Here, we show that YAP nuclear translocation is highly dynamic during cell movement and is driven by nuclear compression arising from cell contractile work. We resolve the mechanistic role of cytoskeletal contractility in nuclear compression by manipulation of nuclear mechanics. Disrupting the linker of nucleoskeleton and cytoskeleton complex reduces nuclear compression for a given contractility and correspondingly decreases YAP localization. Conversely, decreasing nuclear stiffness via silencing of lamin A/C increases nuclear compression and YAP nuclear localization. Finally, using osmotic pressure, we demonstrated that nuclear compression even without active myosin or filamentous actin regulates YAP localization. The relationship between nuclear compression and YAP localization captures a universal mechanism for YAP regulation with broad implications in health and biology.
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Affiliation(s)
- Newsha Koushki
- Department of Bioengineering, McGill University, Montreal, QCH3A 0E9, Canada
| | - Ajinkya Ghagre
- Department of Bioengineering, McGill University, Montreal, QCH3A 0E9, Canada
| | | | - Clayton Molter
- Department of Bioengineering, McGill University, Montreal, QCH3A 0E9, Canada
| | - Allen J. Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QCH3A 0E9, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QCH3A 0C7, Canada
- Department of Biomedical Engineering, McGill University, Montreal, QCH3A 2B4, Canada
- Department of Mechanical Engineering, McGill University, Montreal, QCH3A 0C3, Canada
- Centre for Structural Biology, McGill University, Montreal, QCH3G 0B1, Canada
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QCH3A 1A3, Canada
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4
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Hastie C, Tirgar Bahnamiri P, Sepúlveda MR, Bub G, Wiseman PW, Ehrlicher AJ. A novel approach for quantifying active viscoelastic cellular mechanics using cardiomyocyte contractility. Biophys J 2023; 122:406a. [PMID: 36784068 DOI: 10.1016/j.bpj.2022.11.2208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
| | | | | | - Gil Bub
- Physiology, McGill University, Montreal, QC, Canada
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5
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Kishore Srivastava L, Ghagre A, Ehrlicher AJ. Nuclear stiffness regulates cellular senescence via YAP dependent mechanotransduction. Biophys J 2023; 122:88a. [PMID: 36785064 DOI: 10.1016/j.bpj.2022.11.678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
| | - Ajinkya Ghagre
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QC, Canada
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6
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Tirgar P, Romero Sepúlveda JM, Hastie C, Tao Y, Bub G, Ehrlicher AJ. Substrate stiffness induces a chronic adaptation in contractile work and electrophysiology of cardiomyocytes. Biophys J 2023; 122:87a. [PMID: 36785061 DOI: 10.1016/j.bpj.2022.11.671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Pouria Tirgar
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | | | - Cameron Hastie
- Department of Physics, McGill University, Montreal, QC, Canada
| | - Yuanyuan Tao
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Gil Bub
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QC, Canada
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7
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Molter CW, Muszynski EF, Tao Y, Trivedi T, Clouvel A, Ehrlicher AJ. Prostate cancer cells of increasing metastatic potential exhibit diverse contractile forces, cell stiffness, and motility in a microenvironment stiffness-dependent manner. Front Cell Dev Biol 2022; 10:932510. [PMID: 36200037 PMCID: PMC9527313 DOI: 10.3389/fcell.2022.932510] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
During metastasis, all cancer types must migrate through crowded multicellular environments. Simultaneously, cancers appear to change their biophysical properties. Indeed, cell softening and increased contractility are emerging as seemingly ubiquitous biomarkers of metastatic progression which may facilitate metastasis. Cell stiffness and contractility are also influenced by the microenvironment. Stiffer matrices resembling the tumor microenvironment cause metastatic cells to contract more strongly, further promoting contractile tumorigenic phenotypes. Prostate cancer (PCa), however, appears to deviate from these common cancer biophysics trends; aggressive metastatic PCa cells appear stiffer, rather than softer, to their lowly metastatic PCa counterparts. Although metastatic PCa cells have been reported to be more contractile than healthy cells, how cell contractility changes with increasing PCa metastatic potential has remained unknown. Here, we characterize the biophysical changes of PCa cells of various metastatic potential as a function of microenvironment stiffness. Using a panel of progressively increasing metastatic potential cell lines (22RV1, LNCaP, DU145, and PC3), we quantified their contractility using traction force microscopy (TFM), and measured their cortical stiffness using optical magnetic twisting cytometry (OMTC) and their motility using time-lapse microscopy. We found that PCa contractility, cell stiffness, and motility do not universally scale with metastatic potential. Rather, PCa cells of various metastatic efficiencies exhibit unique biophysical responses that are differentially influenced by substrate stiffness. Despite this biophysical diversity, this work concludes that mechanical microenvironment is a key determinant in the biophysical response of PCa with variable metastatic potentials. The mechanics-oriented focus and methodology of the study is unique and complementary to conventional biochemical and genetic strategies typically used to understand this disease, and thus may usher in new perspectives and approaches.
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Affiliation(s)
- Clayton W. Molter
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Eliana F. Muszynski
- Department of Bioengineering, McGill University, Montreal, QC, Canada
- Department of Neuroscience, McGill University, Montreal, QC, Canada
| | - Yuanyuan Tao
- Department of Bioengineering, McGill University, Montreal, QC, Canada
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, Canada
| | - Tanisha Trivedi
- Department of Bioengineering, McGill University, Montreal, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Anna Clouvel
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Allen J. Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Rosalind and Morris Goodman Cancer Research Institute, McGill University, Montreal, QC, Canada
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
- Department of Mechanical Engineering, McGill University, Montreal, QC, Canada
- *Correspondence: Allen J. Ehrlicher,
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8
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Sutton AA, Molter CW, Amini A, Idicula J, Furman M, Tirgar P, Tao Y, Ghagre A, Koushki N, Khavari A, Ehrlicher AJ. Cell monolayer deformation microscopy reveals mechanical fragility of cell monolayers following EMT. Biophys J 2022; 121:629-643. [PMID: 34999131 PMCID: PMC8873957 DOI: 10.1016/j.bpj.2022.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/26/2021] [Accepted: 01/05/2022] [Indexed: 11/24/2022] Open
Abstract
Tissue and cell mechanics are crucial factors in maintaining homeostasis and in development, with aberrant mechanics contributing to many diseases. During the epithelial-to-mesenchymal transition (EMT), a highly conserved cellular program in organismal development and cancer metastasis, cells gain the ability to detach from their original location and autonomously migrate. While a great deal of biochemical and biophysical changes at the single-cell level have been revealed, how the physical properties of multicellular assemblies change during EMT, and how this may affect disease progression, is unknown. Here we introduce cell monolayer deformation microscopy (CMDM), a new methodology to measure the planar mechanical properties of cell monolayers by locally applying strain and measuring their resistance to deformation. We employ this new method to characterize epithelial multicellular mechanics at early and late stages of EMT, finding the epithelial monolayers to be relatively compliant, ductile, and mechanically homogeneous. By comparison, the transformed mesenchymal monolayers, while much stiffer, were also more brittle, mechanically heterogeneous, displayed more viscoelastic creep, and showed sharp yield points at significantly lower strains. Here, CMDM measurements identify specific biophysical functional states of EMT and offer insight into how cell aggregates fragment under mechanical stress. This mechanical fingerprinting of multicellular assemblies using new quantitative metrics may also offer new diagnostic applications in healthcare to characterize multicellular mechanical changes in disease.
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Affiliation(s)
- Amy A. Sutton
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Clayton W. Molter
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Ali Amini
- Department of Mechanical Engineering, McGill University, Montreal, Quebec, Canada
| | - Johanan Idicula
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Max Furman
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Pouria Tirgar
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Yuanyuan Tao
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Ajinkya Ghagre
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Newsha Koushki
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Adele Khavari
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Allen J. Ehrlicher
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada,Department of Mechanical Engineering, McGill University, Montreal, Quebec, Canada,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada,Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada,Centre for Structural Biology, McGill University, Montreal, Quebec, Canada,Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada,Corresponding author
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9
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Bergeron-Sandoval LP, Kumar S, Heris HK, Chang CLA, Cornell CE, Keller SL, François P, Hendricks AG, Ehrlicher AJ, Pappu RV, Michnick SW. Endocytic proteins with prion-like domains form viscoelastic condensates that enable membrane remodeling. Proc Natl Acad Sci U S A 2021; 118:e2113789118. [PMID: 34887356 PMCID: PMC8685726 DOI: 10.1073/pnas.2113789118] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2021] [Indexed: 11/18/2022] Open
Abstract
Membrane invagination and vesicle formation are key steps in endocytosis and cellular trafficking. Here, we show that endocytic coat proteins with prion-like domains (PLDs) form hemispherical puncta in the budding yeast, Saccharomyces cerevisiae These puncta have the hallmarks of biomolecular condensates and organize proteins at the membrane for actin-dependent endocytosis. They also enable membrane remodeling to drive actin-independent endocytosis. The puncta, which we refer to as endocytic condensates, form and dissolve reversibly in response to changes in temperature and solution conditions. We find that endocytic condensates are organized around dynamic protein-protein interaction networks, which involve interactions among PLDs with high glutamine contents. The endocytic coat protein Sla1 is at the hub of the protein-protein interaction network. Using active rheology, we inferred the material properties of endocytic condensates. These experiments show that endocytic condensates are akin to viscoelastic materials. We use these characterizations to estimate the interfacial tension between endocytic condensates and their surroundings. We then adapt the physics of contact mechanics, specifically modifications of Hertz theory, to develop a quantitative framework for describing how interfacial tensions among condensates, the membrane, and the cytosol can deform the plasma membrane to enable actin-independent endocytosis.
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Affiliation(s)
| | - Sandeep Kumar
- Département de Biochimie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | | | - Catherine L A Chang
- Department of Chemistry, University of Washington, Seattle, Seattle, WA 98195-1700
| | - Caitlin E Cornell
- Department of Chemistry, University of Washington, Seattle, Seattle, WA 98195-1700
| | - Sarah L Keller
- Department of Chemistry, University of Washington, Seattle, Seattle, WA 98195-1700
| | - Paul François
- Ernest Rutherford Physics Building, McGill University, Montreal, QC H3A 2T8, Canada
| | - Adam G Hendricks
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO 63130;
| | - Stephen W Michnick
- Département de Biochimie, Université de Montréal, Montréal, QC H3C 3J7, Canada;
- Centre Robert-Cedergren, Bio-Informatique et Génomique, Université de Montréal, Montréal, QC H3C 3J7, Canada
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10
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Kort-Mascort J, Bao G, Elkashty O, Flores-Torres S, Munguia-Lopez JG, Jiang T, Ehrlicher AJ, Mongeau L, Tran SD, Kinsella JM. Decellularized Extracellular Matrix Composite Hydrogel Bioinks for the Development of 3D Bioprinted Head and Neck in Vitro Tumor Models. ACS Biomater Sci Eng 2021; 7:5288-5300. [PMID: 34661396 DOI: 10.1021/acsbiomaterials.1c00812] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Reinforced extracellular matrix (ECM)-based hydrogels recapitulate several mechanical and biochemical features found in the tumor microenvironment (TME) in vivo. While these gels retain several critical structural and bioactive molecules that promote cell-matrix interactivity, their mechanical properties tend toward the viscous regime limiting their ability to retain ordered structural characteristics when considered as architectured scaffolds. To overcome this limitation characteristic of pure ECM hydrogels, we present a composite material containing alginate, a seaweed-derived polysaccharide, and gelatin, denatured collagen, as rheological modifiers which impart mechanical integrity to the biologically active decellularized ECM (dECM). After an optimization process, the reinforced gel proposed is mechanically stable and bioprintable and has a stiffness within the expected physiological values. Our hydrogel's elastic modulus has no significant difference when compared to tumors induced in preclinical xenograft head and neck squamous cell carcinoma (HNSCC) mouse models. The bioprinted cell-laden model is highly reproducible and allows proliferation and reorganization of HNSCC cells while maintaining cell viability above 90% for periods of nearly 3 weeks. Cells encapsulated in our bioink produce spheroids of at least 3000 μm2 of cross-sectional area by day 15 of culture and are positive for cytokeratin in immunofluorescence quantification, a common marker of HNSCC model validation in 2D and 3D models. We use this in vitro model system to evaluate the standard-of-care small molecule therapeutics used to treat HNSCC clinically and report a 4-fold increase in the IC50 of cisplatin and an 80-fold increase for 5-fluorouracil compared to monolayer cultures. Our work suggests that fabricating in vitro models using reinforced dECM provides a physiologically relevant system to evaluate malignant neoplastic phenomena in vitro due to the physical and biological features replicated from the source tissue microenvironment.
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Affiliation(s)
- Jacqueline Kort-Mascort
- Department of Bioengineering, McGill University, McConnell Engineering Building, 3480 University, Room 350, Montreal, Quebec H3A 0E9, Canada
| | - Guangyu Bao
- Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, Room 270, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Osama Elkashty
- Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec H3A 0C7, Canada.,Oral Pathology Department, Faculty of Dentistry, Mansoura University, Mansoura 29R6+Q3F, Egypt
| | - Salvador Flores-Torres
- Department of Bioengineering, McGill University, McConnell Engineering Building, 3480 University, Room 350, Montreal, Quebec H3A 0E9, Canada
| | - Jose G Munguia-Lopez
- Department of Bioengineering, McGill University, McConnell Engineering Building, 3480 University, Room 350, Montreal, Quebec H3A 0E9, Canada.,Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec H3A 0C7, Canada
| | - Tao Jiang
- Department of Intelligent Machinery and Instrument, College of Intelligence Science and Technology, National University of Defense Technology Changsha, No. 109 Deya Road, Kaifu District, Changsha, Hunan 410073, China
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, McConnell Engineering Building, 3480 University, Room 350, Montreal, Quebec H3A 0E9, Canada.,Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, Room 270, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Luc Mongeau
- Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, Room 270, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Simon D Tran
- Faculty of Dentistry, McGill University, 3640 rue University, Montreal, Quebec H3A 0C7, Canada
| | - Joseph M Kinsella
- Department of Bioengineering, McGill University, McConnell Engineering Building, 3480 University, Room 350, Montreal, Quebec H3A 0E9, Canada
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11
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Amini A, Khavari A, Barthelat F, Ehrlicher AJ. Centrifugation and index matching yield a strong and transparent bioinspired nacreous composite. Science 2021; 373:1229-1234. [PMID: 34516787 DOI: 10.1126/science.abf0277] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Ali Amini
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0C3, Canada.,Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada
| | - Adele Khavari
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0C3, Canada.,Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Francois Barthelat
- Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada.,Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, Quebec H3A 0C3, Canada.,Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada.,Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Department of Biomedical Engineering, McGill University, Montreal, Quebec H3A 2B4, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada.,Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
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12
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Srivastava LK, Ju Z, Ghagre A, Ehrlicher AJ. Spatial distribution of lamin A/C determines nuclear stiffness and stress-mediated deformation. J Cell Sci 2021; 134:268336. [PMID: 34028539 PMCID: PMC8186481 DOI: 10.1242/jcs.248559] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 04/14/2021] [Indexed: 01/05/2023] Open
Abstract
While diverse cellular components have been identified as mechanotransduction elements, the deformation of the nucleus itself is a critical mechanosensory mechanism, implying that nuclear stiffness is essential in determining responses to intracellular and extracellular stresses. Although the nuclear membrane protein lamin A/C is known to contribute to nuclear stiffness, bulk moduli of nuclei have not been reported for various levels of lamin A/C. Here, we measure the nuclear bulk moduli as a function of lamin A/C expression and applied osmotic stress, revealing a linear dependence within the range of 2-4 MPa. We also find that the nuclear compression is anisotropic, with the vertical axis of the nucleus being more compliant than the minor and major axes in the substrate plane. We then related the spatial distribution of lamin A/C with submicron 3D nuclear envelope deformation, revealing that local areas of the nuclear envelope with higher density of lamin A/C have correspondingly lower local deformations. These findings describe the complex dispersion of nuclear deformations as a function of lamin A/C expression and distribution, implicating a lamin A/C role in mechanotransduction. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - Zhaoping Ju
- Department of Anatomy and Cell Biology, McGill University, Montreal H3A 0C7, Canada
| | - Ajinkya Ghagre
- Department of Bioengineering, McGill University, Montreal H3A 0E9
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal H3A 0E9.,Department of Anatomy and Cell Biology, McGill University, Montreal H3A 0C7, Canada.,Department of Biomedical Engineering, McGill University, Montreal H3A 2B4, Canada.,Department of Mechanical Engineering, McGill University, Montreal H3A 0C3.,Centre for Structural Biology, McGill University, Montreal H3G 0B1, Canada.,Goodman Cancer Research Centre, McGill University, Montreal H3A 1A3, Canada
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13
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Bergeron-Sandoval LP, Ehrlicher AJ. Dynamic FLNa and FilGAP Binding Is Required for Contractile Mechanotransduction Response to Shear-Stress. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Sutton AA, Ehrlicher AJ, Molter CW, Amini A, Idicula J, Furman M, Tirgar Bahnamiri P, Tao Y, Ghagre A, Koushki N, Khavari A. Cell Monolayer Deformation Microscopy - A New Method to Measure the Rheology of Cell Monolayers Reveals Mechanical Fragility of the Cell Network in the Epithelial to Mesenchymal Transition. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Srivastava LK, Ju Z, Ghagre A, Ehrlicher AJ. Spatial Distribution of Lamin a Determines Nuclear Stiffness and Stress-Mediated Deformation. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Chaubet L, Chaudhary AR, Heris HK, Ehrlicher AJ, Hendricks AG. Dynamic actin cross-linking governs the cytoplasm's transition to fluid-like behavior. Mol Biol Cell 2020; 31:1744-1752. [PMID: 32579489 PMCID: PMC7521843 DOI: 10.1091/mbc.e19-09-0504] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 06/05/2020] [Accepted: 06/16/2020] [Indexed: 12/21/2022] Open
Abstract
Cells precisely control their mechanical properties to organize and differentiate into tissues. The architecture and connectivity of cytoskeletal filaments change in response to mechanical and biochemical cues, allowing the cell to rapidly tune its mechanics from highly cross-linked, elastic networks to weakly cross-linked viscous networks. While the role of actin cross-linking in controlling actin network mechanics is well-characterized in purified actin networks, its mechanical role in the cytoplasm of living cells remains unknown. Here, we probe the frequency-dependent intracellular viscoelastic properties of living cells using multifrequency excitation and in situ optical trap calibration. At long timescales in the intracellular environment, we observe that the cytoskeleton becomes fluid-like. The mechanics are well-captured by a model in which actin filaments are dynamically connected by a single dominant cross-linker. A disease-causing point mutation (K255E) of the actin cross-linker α-actinin 4 (ACTN4) causes its binding kinetics to be insensitive to tension. Under normal conditions, the viscoelastic properties of wild-type (WT) and K255E+/- cells are similar. However, when tension is reduced through myosin II inhibition, WT cells relax 3× faster to the fluid-like regime while K255E+/- cells are not affected. These results indicate that dynamic actin cross-linking enables the cytoplasm to flow at long timescales.
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Affiliation(s)
- Loïc Chaubet
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
| | | | - Hossein K. Heris
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
| | - Allen J. Ehrlicher
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
| | - Adam G. Hendricks
- Department of Bioengineering, McGill University, Montreal, QC H3A 0C3, Canada
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17
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Koushki N, Ehrlicher AJ. YAP Activity Directly Scales with Nuclear Deformation and Lamin a Distribution. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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18
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Chaubet L, Khadivi Heris H, Ehrlicher AJ, Hendricks AG. Dynamic Crosslinking of the Actin Cytoskeleton Governs Cell Mechanics. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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19
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Jiang T, Munguia-Lopez JG, Gu K, Bavoux MM, Flores-Torres S, Kort-Mascort J, Grant J, Vijayakumar S, De Leon-Rodriguez A, Ehrlicher AJ, Kinsella JM. Engineering bioprintable alginate/gelatin composite hydrogels with tunable mechanical and cell adhesive properties to modulate tumor spheroid growth kinetics. Biofabrication 2019; 12:015024. [DOI: 10.1088/1758-5090/ab3a5c] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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20
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Ram-Mohan S, Bai Y, Schaible N, Ehrlicher AJ, Cook DP, Suki B, Stoltz DA, Solway J, Ai X, Krishnan R. Tissue traction microscopy to quantify muscle contraction within precision-cut lung slices. Am J Physiol Lung Cell Mol Physiol 2019; 318:L323-L330. [PMID: 31774304 DOI: 10.1152/ajplung.00297.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In asthma, acute bronchospasm is driven by contractile forces of airway smooth muscle (ASM). These forces can be imaged in the cultured ASM cell or assessed in the muscle strip and the tracheal/bronchial ring, but in each case, the ASM is studied in isolation from the native airway milieu. Here, we introduce a novel platform called tissue traction microscopy (TTM) to measure ASM contractile force within porcine and human precision-cut lung slices (PCLS). Compared with the conventional measurements of lumen area changes in PCLS, TTM measurements of ASM force changes are 1) more sensitive to bronchoconstrictor stimuli, 2) less variable across airways, and 3) provide spatial information. Notably, within every human airway, TTM measurements revealed local regions of high ASM contraction that we call "stress hotspots". As an acute response to cyclic stretch, these hotspots promptly decreased but eventually recovered in magnitude, spatial location, and orientation, consistent with local ASM fluidization and resolidification. By enabling direct and precise measurements of ASM force, TTM should accelerate preclinical studies of airway reactivity.
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Affiliation(s)
- Sumati Ram-Mohan
- Center for Vascular Biology Research, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Yan Bai
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Niccole Schaible
- Center for Vascular Biology Research, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Daniel P Cook
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa
| | - Bela Suki
- Biomedical Engineering Department, Boston University, Boston, Massachusetts
| | - David A Stoltz
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa
| | - Julian Solway
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Xingbin Ai
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Ramaswamy Krishnan
- Center for Vascular Biology Research, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
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21
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Yoshie H, Koushki N, Kaviani R, Tabatabaei M, Rajendran K, Dang Q, Husain A, Yao S, Li C, Sullivan JK, Saint-Geniez M, Krishnan R, Ehrlicher AJ. Traction Force Screening Enabled by Compliant PDMS Elastomers. Biophys J 2019; 114:2194-2199. [PMID: 29742412 DOI: 10.1016/j.bpj.2018.02.045] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 02/01/2018] [Accepted: 02/28/2018] [Indexed: 01/01/2023] Open
Abstract
Actomyosin contractility is an essential element of many aspects of cellular biology and manifests as traction forces that cells exert on their surroundings. The central role of these forces makes them a novel principal therapeutic target in diverse diseases. This requires accurate and higher-capacity measurements of traction forces; however, existing methods are largely low throughput, limiting their utility in broader applications. To address this need, we employ Fourier-transform traction force microscopy in a parallelized 96-well format, which we refer to as contractile force screening. Critically, rather than the frequently employed hydrogel polyacrylamide, we fabricate these plates using polydimethylsiloxane rubber. Key to this approach is that the polydimethylsiloxane used is very compliant, with a lower-bound Young's modulus of ∼0.4 kPa. We subdivide these monolithic substrates spatially into biochemically independent wells, creating a uniform multiwell platform for traction force screening. We demonstrate the utility and versatility of this platform by quantifying the compound and dose-dependent contractility responses of human airway smooth muscle cells and retinal pigment epithelial cells. By directly quantifying the endpoint of therapeutic intent, airway-smooth-muscle contractile force, this approach fills an important methodological void in current screening approaches for bronchodilator drug discovery, and, more generally, in measuring contractile response for a broad range of cell types and pathologies.
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Affiliation(s)
- Haruka Yoshie
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Newsha Koushki
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Rosa Kaviani
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Mohammad Tabatabaei
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada; Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | | | - Quynh Dang
- Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Amjad Husain
- Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Sean Yao
- Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Chuck Li
- Amgen Inc., Thousand Oaks, California
| | | | - Magali Saint-Geniez
- Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts
| | | | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada.
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22
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Yoshie H, Koushki N, Molter C, Siegel PM, Krishnan R, Ehrlicher AJ. High Throughput Traction Force Microscopy Using PDMS Reveals Dose-Dependent Effects of Transforming Growth Factor-β on the Epithelial-to-Mesenchymal Transition. J Vis Exp 2019. [PMID: 31205302 DOI: 10.3791/59364] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cellular contractility is essential in diverse aspects of biology, driving processes that range from motility and division, to tissue contraction and mechanical stability, and represents a core element of multi-cellular animal life. In adherent cells, acto-myosin contraction is seen in traction forces that cells exert on their substrate. Dysregulation of cellular contractility appears in a myriad of pathologies, making contractility a promising target in diverse diagnostic approaches using biophysics as a metric. Moreover, novel therapeutic strategies can be based on correcting the apparent malfunction of cell contractility. These applications, however, require direct quantification of these forces. We have developed silicone elastomer-based traction force microscopy (TFM) in a parallelized multi-well format. Our use of a silicone rubber, specifically polydimethylsiloxane (PDMS), rather than the commonly employed hydrogel polyacrylamide (PAA) enables us to make robust and inert substrates with indefinite shelf-lives requiring no specialized storage conditions. Unlike pillar-PDMS based approaches that have a modulus in the GPa range, the PDMS used here is very compliant, ranging from approximately 0.4 kPa to 100 kPa. We create a high-throughput platform for TFM by partitioning these large monolithic substrates spatially into biochemically independent wells, creating a multi-well platform for traction force screening that is compatible with existing multi-well systems. In this manuscript, we use this multi-well traction force system to examine the Epithelial to Mesenchymal Transition (EMT); we induce EMT in NMuMG cells by exposing them to TGF-β, and to quantify the biophysical changes during EMT. We measure the contractility as a function of concentration and duration of TGF-β exposure. Our findings here demonstrate the utility of parallelized TFM in the context of disease biophysics.
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Affiliation(s)
| | | | | | - Peter M Siegel
- Goodman Cancer Research Centre, McGill University; Department of Medicine, McGill University
| | | | - Allen J Ehrlicher
- Department of Bioengineering, McGill University; Goodman Cancer Research Centre, McGill University;
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23
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24
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Michnick S, Bergeron-Sandoval LP, Pappu R, François P, Hendricks AG, Ehrlicher AJ, Khadivi Heris H. A Protein Condensate Drives Actin-Independent Endocytosis. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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25
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26
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Khavari A, Nydén M, Weitz DA, Ehrlicher AJ. Composite alginate gels for tunable cellular microenvironment mechanics. Sci Rep 2016; 6:30854. [PMID: 27484403 PMCID: PMC4971458 DOI: 10.1038/srep30854] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/08/2016] [Indexed: 01/06/2023] Open
Abstract
The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation.
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Affiliation(s)
- Adele Khavari
- Applied Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.,SUMO Biomaterials VINN Excellence Center, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Magnus Nydén
- Applied Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.,UCL Australia, 220 Victoria Square, Adelaide, SA 5000 Australia
| | - David A Weitz
- Department of Bioengineering, McGill University, Montreal Canada H3A 0C3
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal Canada H3A 0C3.,School of Engineering and Applied Sciences, Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.,Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, United States.,Harvard Medical School, Boston, Massachusetts 02115, United States
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27
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Bender M, Thon JN, Ehrlicher AJ, Wu S, Mazutis L, Deschmann E, Sola-Visner M, Italiano JE, Hartwig JH. Microtubule sliding drives proplatelet elongation and is dependent on cytoplasmic dynein. Blood 2015; 125:860-8. [PMID: 25411426 PMCID: PMC4311231 DOI: 10.1182/blood-2014-09-600858] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 11/08/2014] [Indexed: 01/04/2023] Open
Abstract
Bone marrow megakaryocytes produce platelets by extending long cytoplasmic protrusions, designated proplatelets, into sinusoidal blood vessels. Although microtubules are known to regulate platelet production, the underlying mechanism of proplatelet elongation has yet to be resolved. Here we report that proplatelet formation is a process that can be divided into repetitive phases (extension, pause, and retraction), as revealed by differential interference contrast and fluorescence loss after photoconversion time-lapse microscopy. Furthermore, we show that microtubule sliding drives proplatelet elongation and is dependent on cytoplasmic dynein under static and physiological shear stress by using fluorescence recovery after photobleaching in proplatelets with fluorescence-tagged β1-tubulin. A refined understanding of the specific mechanisms regulating platelet production will yield strategies to treat patients with thrombocythemia or thrombocytopenia.
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Affiliation(s)
| | - Jonathan N Thon
- Hematology Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Platelet BioGenesis, Chestnut Hill, MA
| | - Allen J Ehrlicher
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA; Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Stephen Wu
- Hematology Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Linas Mazutis
- Platelet BioGenesis, Chestnut Hill, MA; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA; Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
| | - Emoke Deschmann
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Neonatology, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Martha Sola-Visner
- Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Joseph E Italiano
- Hematology Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Platelet BioGenesis, Chestnut Hill, MA; Department of Surgery, Vascular Biology Program, Boston Children's Hospital, Boston, MA; and
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28
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Guo M, Ehrlicher AJ, Jensen MH, Renz M, Moore JR, Goldman RD, Lippincott-Schwartz J, Mackintosh FC, Weitz DA. Probing the stochastic, motor-driven properties of the cytoplasm using force spectrum microscopy. Cell 2014; 158:822-832. [PMID: 25126787 PMCID: PMC4183065 DOI: 10.1016/j.cell.2014.06.051] [Citation(s) in RCA: 323] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/28/2014] [Accepted: 06/29/2014] [Indexed: 01/17/2023]
Abstract
Molecular motors in cells typically produce highly directed motion; however, the aggregate, incoherent effect of all active processes also creates randomly fluctuating forces, which drive diffusive-like, nonthermal motion. Here, we introduce force-spectrum-microscopy (FSM) to directly quantify random forces within the cytoplasm of cells and thereby probe stochastic motor activity. This technique combines measurements of the random motion of probe particles with independent micromechanical measurements of the cytoplasm to quantify the spectrum of force fluctuations. Using FSM, we show that force fluctuations substantially enhance intracellular movement of small and large components. The fluctuations are three times larger in malignant cells than in their benign counterparts. We further demonstrate that vimentin acts globally to anchor organelles against randomly fluctuating forces in the cytoplasm, with no effect on their magnitude. Thus, FSM has broad applications for understanding the cytoplasm and its intracellular processes in relation to cell physiology in healthy and diseased states.
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Affiliation(s)
- Ming Guo
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Allen J Ehrlicher
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Mikkel H Jensen
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Department of Physiology and Biophysics, Boston University, Boston, MA 02118, USA
| | - Malte Renz
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeffrey R Moore
- Department of Physiology and Biophysics, Boston University, Boston, MA 02118, USA
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jennifer Lippincott-Schwartz
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - David A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Department of Physics, Harvard University, Cambridge, MA 02138, USA.
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29
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Guo M, Ehrlicher AJ, Mahammad S, Fabich H, Jensen MH, Moore JR, Fredberg JJ, Goldman RD, Weitz DA. The role of vimentin intermediate filaments in cortical and cytoplasmic mechanics. Biophys J 2014; 105:1562-8. [PMID: 24094397 DOI: 10.1016/j.bpj.2013.08.037] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 12/20/2022] Open
Abstract
The mechanical properties of a cell determine many aspects of its behavior, and these mechanics are largely determined by the cytoskeleton. Although the contribution of actin filaments and microtubules to the mechanics of cells has been investigated in great detail, relatively little is known about the contribution of the third major cytoskeletal component, intermediate filaments (IFs). To determine the role of vimentin IF (VIF) in modulating intracellular and cortical mechanics, we carried out studies using mouse embryonic fibroblasts (mEFs) derived from wild-type or vimentin(-/-) mice. The VIFs contribute little to cortical stiffness but are critical for regulating intracellular mechanics. Active microrheology measurements using optical tweezers in living cells reveal that the presence of VIFs doubles the value of the cytoplasmic shear modulus to ∼10 Pa. The higher levels of cytoplasmic stiffness appear to stabilize organelles in the cell, as measured by tracking endogenous vesicle movement. These studies show that VIFs both increase the mechanical integrity of cells and localize intracellular components.
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Affiliation(s)
- Ming Guo
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
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30
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Koziej D, Floryan C, Sperling RA, Ehrlicher AJ, Issadore D, Westervelt R, Weitz DA. Microwave dielectric heating of non-aqueous droplets in a microfluidic device for nanoparticle synthesis. Nanoscale 2013; 5:5468-75. [PMID: 23670701 DOI: 10.1039/c3nr00500c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We describe a microfluidic device with an integrated microwave heater specifically designed to dielectrically heat non-aqueous droplets using time-varying electrical fields with the frequency range between 700 and 900 MHz. The precise control of frequency, power, temperature and duration of the applied field opens up new vistas for experiments not attainable by conventional microwave heating. We use a non-contact temperature measurement system based on fluorescence to directly determine the temperature inside a single droplet. The maximum temperature achieved of the droplets is 50 °C in 15 ms which represents an increase of about 25 °C above the base temperature of the continuous phase. In addition we use an infrared camera to monitor the thermal characteristics of the device allowing us to ensure that heating is exclusively due to the dielectric heating and not due to other effects like non-dielectric losses due to electrode or contact imperfection. This is crucial for illustrating the potential of dielectric heating of benzyl alcohol droplets for the synthesis of metal oxides. We demonstrate the utility of this technology for metal oxide nanoparticle synthesis, achieving crystallization of tungsten oxide nanoparticles and remarkable microstructure, with a reaction time of 64 ms, a substantial improvement over conventional heating methods.
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Affiliation(s)
- Dorota Koziej
- School of Engineering and Applied Sciences, Department of Physics, Harvard University, Cambridge, MA 02138, USA.
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31
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Rossow T, Heyman JA, Ehrlicher AJ, Langhoff A, Weitz DA, Haag R, Seiffert S. Controlled synthesis of cell-laden microgels by radical-free gelation in droplet microfluidics. J Am Chem Soc 2012; 134:4983-9. [PMID: 22356466 DOI: 10.1021/ja300460p] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Micrometer-sized hydrogel particles that contain living cells can be fabricated with exquisite control through the use of droplet-based microfluidics and bioinert polymers such as polyethyleneglycol (PEG) and hyperbranched polyglycerol (hPG). However, in existing techniques, the microgel gelation is often achieved through harmful reactions with free radicals. This is detrimental for the viability of the encapsulated cells. To overcome this limitation, we present a technique that combines droplet microfluidic templating with bio-orthogonal thiol-ene click reactions to fabricate monodisperse, cell-laden microgel particles. The gelation of these microgels is achieved via the nucleophilic Michael addition of dithiolated PEG macro-cross-linkers to acrylated hPG building blocks and does not require any initiator. We systematically vary the microgel properties through the use of PEG linkers with different molecular weights along with different concentrations of macromonomers to investigate the influence of these parameters on the viability and proliferation of encapsulated yeast cells. We also demonstrate the encapsulation of mammalian cells including fibroblasts and lymphoblasts.
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Affiliation(s)
- Torsten Rossow
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, D-14195 Berlin, Germany
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32
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Ehrlicher AJ, Nakamura F, Hartwig JH, Weitz DA, Stossel TP. Mechanical Strain in Actin Networks Regulates FilGAP and Integrin Binding to Filamin A. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.1905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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33
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Ehrlicher AJ, Nakamura F, Hartwig JH, Weitz DA, Stossel TP. Mechanical strain in actin networks regulates FilGAP and integrin binding to filamin A. Nature 2011; 478:260-3. [PMID: 21926999 PMCID: PMC3204864 DOI: 10.1038/nature10430] [Citation(s) in RCA: 265] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 08/05/2011] [Indexed: 12/14/2022]
Affiliation(s)
- A J Ehrlicher
- Translational Medicine Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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