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Zhu Y, Zhang M, Sun Q, Wang X, Li X, Li Q. Advanced Mechanical Testing Technologies at the Cellular Level: The Mechanisms and Application in Tissue Engineering. Polymers (Basel) 2023; 15:3255. [PMID: 37571149 PMCID: PMC10422338 DOI: 10.3390/polym15153255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
Mechanics, as a key physical factor which affects cell function and tissue regeneration, is attracting the attention of researchers in the fields of biomaterials, biomechanics, and tissue engineering. The macroscopic mechanical properties of tissue engineering scaffolds have been studied and optimized based on different applications. However, the mechanical properties of the overall scaffold materials are not enough to reveal the mechanical mechanism of the cell-matrix interaction. Hence, the mechanical detection of cell mechanics and cellular-scale microenvironments has become crucial for unraveling the mechanisms which underly cell activities and which are affected by physical factors. This review mainly focuses on the advanced technologies and applications of cell-scale mechanical detection. It summarizes the techniques used in micromechanical performance analysis, including atomic force microscope (AFM), optical tweezer (OT), magnetic tweezer (MT), and traction force microscope (TFM), and analyzes their testing mechanisms. In addition, the application of mechanical testing techniques to cell mechanics and tissue engineering scaffolds, such as hydrogels and porous scaffolds, is summarized and discussed. Finally, it highlights the challenges and prospects of this field. This review is believed to provide valuable insights into micromechanics in tissue engineering.
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Affiliation(s)
- Yingxuan Zhu
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Mengqi Zhang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Qingqing Sun
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaofeng Wang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaomeng Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Qian Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
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2
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Wubshet NH, Liu AP. Methods to mechanically perturb and characterize GUV-based minimal cell models. Comput Struct Biotechnol J 2022; 21:550-562. [PMID: 36659916 PMCID: PMC9816913 DOI: 10.1016/j.csbj.2022.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Cells shield organelles and the cytosol via an active boundary predominantly made of phospholipids and membrane proteins, yet allowing communication between the intracellular and extracellular environment. Micron-sized liposome compartments commonly known as giant unilamellar vesicles (GUVs) are used to model the cell membrane and encapsulate biological materials and processes in a cell-like confinement. In the field of bottom-up synthetic biology, many have utilized GUVs as substrates to study various biological processes such as protein-lipid interactions, cytoskeletal assembly, and dynamics of protein synthesis. Like cells, it is ideal that GUVs are also mechanically durable and able to stay intact when the inner and outer environment changes. As a result, studies have demonstrated approaches to tune the mechanical properties of GUVs by modulating membrane composition and lumenal material property. In this context, there have been many different methods developed to test the mechanical properties of GUVs. In this review, we will survey various perturbation techniques employed to mechanically characterize GUVs.
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Affiliation(s)
- Nadab H. Wubshet
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Allen P. Liu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
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3
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Bashir KMI, Lee S, Jung DH, Basu SK, Cho MG, Wierschem A. Narrow-Gap Rheometry: A Novel Method for Measuring Cell Mechanics. Cells 2022; 11:cells11132010. [PMID: 35805094 PMCID: PMC9265971 DOI: 10.3390/cells11132010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 12/18/2022] Open
Abstract
The viscoelastic properties of a cell cytoskeleton contain abundant information about the state of a cell. Cells show a response to a specific environment or an administered drug through changes in their viscoelastic properties. Studies of single cells have shown that chemical agents that interact with the cytoskeleton can alter mechanical cell properties and suppress mitosis. This envisions using rheological measurements as a non-specific tool for drug development, the pharmacological screening of new drug agents, and to optimize dosage. Although there exists a number of sophisticated methods for studying mechanical properties of single cells, studying concentration dependencies is difficult and cumbersome with these methods: large cell-to-cell variations demand high repetition rates to obtain statistically significant data. Furthermore, method-induced changes in the cell mechanics cannot be excluded when working in a nonlinear viscoelastic range. To address these issues, we not only compared narrow-gap rheometry with commonly used single cell techniques, such as atomic force microscopy and microfluidic-based approaches, but we also compared existing cell monolayer studies used to estimate cell mechanical properties. This review provides insight for whether and how narrow-gap rheometer could be used as an efficient drug screening tool, which could further improve our current understanding of the mechanical issues present in the treatment of human diseases.
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Affiliation(s)
- Khawaja Muhammad Imran Bashir
- German Engineering Research and Development Center, LSTME-Busan Branch, Busan 46742, Korea; (K.M.I.B.); (S.L.); (D.H.J.); (M.-G.C.)
| | - Suhyang Lee
- German Engineering Research and Development Center, LSTME-Busan Branch, Busan 46742, Korea; (K.M.I.B.); (S.L.); (D.H.J.); (M.-G.C.)
- Institute of Fluid Mechanics, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany;
| | - Dong Hee Jung
- German Engineering Research and Development Center, LSTME-Busan Branch, Busan 46742, Korea; (K.M.I.B.); (S.L.); (D.H.J.); (M.-G.C.)
- Division of Energy and Bioengineering, Dongseo University, Busan 47011, Korea
| | - Santanu Kumar Basu
- Institute of Fluid Mechanics, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany;
| | - Man-Gi Cho
- German Engineering Research and Development Center, LSTME-Busan Branch, Busan 46742, Korea; (K.M.I.B.); (S.L.); (D.H.J.); (M.-G.C.)
- Division of Energy and Bioengineering, Dongseo University, Busan 47011, Korea
| | - Andreas Wierschem
- German Engineering Research and Development Center, LSTME-Busan Branch, Busan 46742, Korea; (K.M.I.B.); (S.L.); (D.H.J.); (M.-G.C.)
- Institute of Fluid Mechanics, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany;
- Correspondence: ; Tel.: +49-9131-85-29566
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4
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Mierke CT, Hayn A, Fischer T. PINCH1 Promotes Fibroblast Migration in Extracellular Matrices and Influences Their Mechanophenotype. Front Cell Dev Biol 2022; 10:869563. [PMID: 35652097 PMCID: PMC9149598 DOI: 10.3389/fcell.2022.869563] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/15/2022] [Indexed: 11/13/2022] Open
Abstract
Cell migration performs a critical function in numerous physiological processes, including tissue homeostasis or wound healing after tissue injury, as well as pathological processes that include malignant progression of cancer. The efficiency of cell migration and invasion appears to be based on the mechano-phenotype of the cytoskeleton. The properties of the cytoskeleton depend on internal cytoskeletal and external environmental factors. A reason for this are connections between the cell and its local matrix microenvironment, which are established by cell-matrix adhesion receptors. Upon activation, focal adhesion proteins such as PINCH1 are recruited to sites where focal adhesions form. PINCH1 specifically couples through interactions with ILK, which binds to cell matrix receptors and the actomyosin cytoskeleton. However, the role of PINCH1 in cell mechanics regulating cellular motility in 3D collagen matrices is still unclear. PINCH1 is thought to facilitate 3D motility by regulating cellular mechanical properties, such as stiffness. In this study, PINCH1 wild-type and knock-out cells were examined for their ability to migrate in dense extracellular 3D matrices. Indeed, PINCH1 wild-type cells migrated more numerously and deeper in 3D matrices, compared to knock-out cells. Moreover, cellular deformability was determined, e.g., elastic modulus (stiffness). PINCH1 knock-out cells are more deformable (compliable) than PINCH1 wild-type cells. Migration of both PINCH1−/− cells and PINCH1fl/fl cells was decreased by Latrunculin A inhibition of actin polymerization, suggesting that actin cytoskeletal differences are not responsible for the discrepancy in invasiveness of the two cell types. However, the mechanical phenotype of PINCH1−/− cells may be reflected by Latrunculin A treatment of PINCH1fl/fl cells, as they exhibit resembling deformability to untreated PINCH1−/− cells. Moreover, an apparent mismatch exists between the elongation of the long axis and the contraction of the short axis between PINCH1fl/fl cells and PINCH1−/− cells following Latrunculin A treatment. There is evidence of this indicating a shift in the proxy values for Poisson’s ratio in PINCH1−/− cells compared with PINCH1fl/fl cells. This is probably attributable to modifications in cytoskeletal architecture. The non-muscle myosin II inhibitor Blebbistatin also reduced the cell invasiveness in 3D extracellular matrices but instead caused a stiffening of the cells. Finally, PINCH1 is apparently essential for providing cellular mechanical stiffness through the actin cytoskeleton, which regulates 3D motility.
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Peltanová B, Holcová Polanská H, Raudenská M, Balvan J, Navrátil J, Vičar T, Gumulec J, Čechová B, Kräter M, Guck J, Kalfeřt D, Grega M, Plzák J, Betka J, Masařík M. mRNA Subtype of Cancer-Associated Fibroblasts Significantly Affects Key Characteristics of Head and Neck Cancer Cells. Cancers (Basel) 2022; 14:2286. [PMID: 35565415 PMCID: PMC9102192 DOI: 10.3390/cancers14092286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 12/10/2022] Open
Abstract
Head and neck squamous cell carcinomas (HNSCC) belong among severe and highly complex malignant diseases showing a high level of heterogeneity and consequently also a variance in therapeutic response, regardless of clinical stage. Our study implies that the progression of HNSCC may be supported by cancer-associated fibroblasts (CAFs) in the tumour microenvironment (TME) and the heterogeneity of this disease may lie in the level of cooperation between CAFs and epithelial cancer cells, as communication between CAFs and epithelial cancer cells seems to be a key factor for the sustained growth of the tumour mass. In this study, we investigated how CAFs derived from tumours of different mRNA subtypes influence the proliferation of cancer cells and their metabolic and biomechanical reprogramming. We also investigated the clinicopathological significance of the expression of these metabolism-related genes in tissue samples of HNSCC patients to identify a possible gene signature typical for HNSCC progression. We found that the right kind of cooperation between cancer cells and CAFs is needed for tumour growth and progression, and only specific mRNA subtypes can support the growth of primary cancer cells or metastases. Specifically, during coculture, cancer cell colony supporting effect and effect of CAFs on cell stiffness of cancer cells are driven by the mRNA subtype of the tumour from which the CAFs are derived. The degree of colony-forming support is reflected in cancer cell glycolysis levels and lactate shuttle-related transporters.
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Affiliation(s)
- Barbora Peltanová
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
| | - Hana Holcová Polanská
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
| | - Martina Raudenská
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300 Brno, Czech Republic
| | - Jan Balvan
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
| | - Jiří Navrátil
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
| | - Tomáš Vičar
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
| | - Jaromír Gumulec
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
| | - Barbora Čechová
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
| | - Martin Kräter
- Max Planck Institute for the Science of Light, Staudtstraße 2, 91058 Erlangen, Germany; (M.K.); (J.G.)
| | - Jochen Guck
- Max Planck Institute for the Science of Light, Staudtstraße 2, 91058 Erlangen, Germany; (M.K.); (J.G.)
| | - David Kalfeřt
- Department of Otorhinolaryngology and Head and Neck Surgery, First Faculty of Medicine, University Hospital Motol, Charles University, V Uvalu 84, 15006 Prague, Czech Republic; (D.K.); (J.P.); (J.B.)
| | - Marek Grega
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, University Hospital Motol, Charles University, V Uvalu 84, 15006 Prague, Czech Republic;
| | - Jan Plzák
- Department of Otorhinolaryngology and Head and Neck Surgery, First Faculty of Medicine, University Hospital Motol, Charles University, V Uvalu 84, 15006 Prague, Czech Republic; (D.K.); (J.P.); (J.B.)
| | - Jan Betka
- Department of Otorhinolaryngology and Head and Neck Surgery, First Faculty of Medicine, University Hospital Motol, Charles University, V Uvalu 84, 15006 Prague, Czech Republic; (D.K.); (J.P.); (J.B.)
| | - Michal Masařík
- Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic; (B.P.); (H.H.P.); (M.R.); (J.B.); (J.N.); (J.G.); (B.Č.)
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic;
- BIOCEV, First Faculty of Medicine, Charles University, Prumyslova 595, 25250 Vestec, Czech Republic
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6
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Automated estimation of cancer cell deformability with machine learning and acoustic trapping. Sci Rep 2022; 12:6891. [PMID: 35477742 PMCID: PMC9046201 DOI: 10.1038/s41598-022-10882-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/13/2022] [Indexed: 11/28/2022] Open
Abstract
Cell deformability is a useful feature for diagnosing various diseases (e.g., the invasiveness of cancer cells). Existing methods commonly inflict pressure on cells and observe changes in cell areas, diameters, or thickness according to the degree of pressure. Then, the Young’s moduli (i.e., a measure of deformability) of cells are estimated based on the assumption that the degrees of the changes are inversely proportional to Young’s moduli. However, manual measurements of the physical changes in cells are labor-intensive, and the subjectivity of the operators can intervene during this step, thereby causing considerable uncertainty. Further, because the shapes of cells are nonuniform, we cannot ensure the assumption for linear correlations of physical changes in cells with their deformability. Therefore, this study aims at measuring non-linear elastic moduli of live cells (degrees of cell deformability) automatically by employing conventional neural networks (CNN) and multilayer perceptrons (MLP) while preserving (or enhancing) the accuracy of the manual methods. First, we obtain photomicrographs of cells on multiple pressure levels using single-beam acoustic tweezers, and then, we suggest an image preprocessing method for emphasizing changes in cell areas on the photomicrographs. The CNN model is trained to measure the ratios of the cell area change at each pressure level. Then, we apply the multilayer perceptron (MLP) to learn the correlations of the cell area change ratios according to the pressure levels with cell deformability. The accuracy of the CNN was evaluated using two types of breast cancer cells: MDA-MB-231 (invasive) and MCF-7 (noninvasive). The MLP was assessed using five different beads (Young’s moduli from 0.214 to 9.235 kPa), which provides standardized reference data of the non-linear elastic moduli of live cells. Finally, we validated the practicality of the proposed system by examining whether the non-linear elastic moduli estimated by the proposed system can distinguish invasive breast cancer cells from noninvasive ones.
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Pires RH, Dau TH, Manu E, Shree N, Otto O. Switching in the expression pattern of actin isoforms marks the onset of contractility and distinct mechanodynamic behavior during cardiomyocyte differentiation. Physiol Rep 2022; 10:e15171. [PMID: 35166060 PMCID: PMC8844573 DOI: 10.14814/phy2.15171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 11/22/2021] [Accepted: 12/12/2021] [Indexed: 04/16/2023] Open
Abstract
Differentiation of cardiac progenitor cells (CPC) into cardiomyocytes is a fundamental step in cardiogenesis, which is marked by changes in gene expression responsible for remodeling of the cytoskeleton and in altering the mechanical properties of cells. Here we have induced the differentiation of CPC derived from human pluripotent stem cells into immature cardiomyocytes (iCM) which we compare with more differentiated cardiomyocytes (mCM). Using atomic force microscopy and real-time deformability cytometry, we describe the mechanodynamic changes that occur during the differentiation process and link our findings to protein expression data of cytoskeletal proteins. Increased levels of cardiac-specific markers as well as evolution of cytoskeletal morphology and contractility parameters correlated with the expected extent of cell differentiation that was accompanied by hypertrophic growth of cells. These changes were associated with switching in the balance of the different actin isoforms where β-actin is predominantly found in CPC, smooth muscle α-actin is dominant in iCM cells and sarcomeric α-actin is found in significantly higher levels in mCM. We link these cytoskeletal changes to differences in mechano-dynamic behavior of cells that translate to changes in Young's modulus that depend on the cell adherence. Our results demonstrate that the intracellular balance of actin isoform expression can be used as a sensitive ruler to determine the stage of differentiation during early phases of cardiomyocyte differentiation that correlates with an increased expression of sarcomeric proteins and is accompanied by changes in cellular elasticity.
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Affiliation(s)
- Ricardo H. Pires
- ZIK‐HIKE ‐ Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären ErkrankungenUniversität GreifswaldGreifswaldGermany
- DZHK ‐ Deutsches Zentrum für HerzkreislaufforschungGreifswaldGermany
| | - Tung H. Dau
- ZIK‐HIKE ‐ Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären ErkrankungenUniversität GreifswaldGreifswaldGermany
- FLI ‐ Friedrich‐Loeffler‐InstitutGreifswaldInsel RiemsGermany
| | - Emmanuel Manu
- ZIK‐HIKE ‐ Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären ErkrankungenUniversität GreifswaldGreifswaldGermany
- DZHK ‐ Deutsches Zentrum für HerzkreislaufforschungGreifswaldGermany
| | - Nithya Shree
- ZIK‐HIKE ‐ Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären ErkrankungenUniversität GreifswaldGreifswaldGermany
| | - Oliver Otto
- ZIK‐HIKE ‐ Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären ErkrankungenUniversität GreifswaldGreifswaldGermany
- DZHK ‐ Deutsches Zentrum für HerzkreislaufforschungGreifswaldGermany
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Choi G, Tang Z, Guan W. Microfluidic high-throughput single-cell mechanotyping: Devices and
applications. NANOTECHNOLOGY AND PRECISION ENGINEERING 2021. [DOI: 10.1063/10.0006042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Gihoon Choi
- Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802,
USA
| | - Zifan Tang
- Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802,
USA
| | - Weihua Guan
- Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802,
USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802,
USA
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9
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Hobson CM, Falvo MR, Superfine R. A survey of physical methods for studying nuclear mechanics and mechanobiology. APL Bioeng 2021; 5:041508. [PMID: 34849443 PMCID: PMC8604565 DOI: 10.1063/5.0068126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/20/2021] [Indexed: 12/23/2022] Open
Abstract
It is increasingly appreciated that the cell nucleus is not only a home for DNA but also a complex material that resists physical deformations and dynamically responds to external mechanical cues. The molecules that confer mechanical properties to nuclei certainly contribute to laminopathies and possibly contribute to cellular mechanotransduction and physical processes in cancer such as metastasis. Studying nuclear mechanics and the downstream biochemical consequences or their modulation requires a suite of complex assays for applying, measuring, and visualizing mechanical forces across diverse length, time, and force scales. Here, we review the current methods in nuclear mechanics and mechanobiology, placing specific emphasis on each of their unique advantages and limitations. Furthermore, we explore important considerations in selecting a new methodology as are demonstrated by recent examples from the literature. We conclude by providing an outlook on the development of new methods and the judicious use of the current techniques for continued exploration into the role of nuclear mechanobiology.
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Affiliation(s)
| | - Michael R. Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Richard Superfine
- Department of Applied Physical Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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10
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Mierke CT. The Pertinent Role of Cell and Matrix Mechanics in Cell Adhesion and Migration. Front Cell Dev Biol 2021; 9:720494. [PMID: 34722504 PMCID: PMC8548417 DOI: 10.3389/fcell.2021.720494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/20/2021] [Indexed: 01/17/2023] Open
Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
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11
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Lou L, Lopez KO, Nautiyal P, Agarwal A. Integrated Perspective of Scaffold Designing and Multiscale Mechanics in Cardiac Bioengineering. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Lihua Lou
- Department of Mechanical and Materials Engineering Florida International University Miami FL 33174 USA
| | - Kazue Orikasa Lopez
- Department of Mechanical and Materials Engineering Florida International University Miami FL 33174 USA
| | - Pranjal Nautiyal
- Mechanical Engineering and Applied Mechanics University of Pennsylvania Philadelphia PA 19104 USA
| | - Arvind Agarwal
- Plasma Forming Laboratory Advanced Materials Engineering Research Institute (AMERI) Mechanical and Materials Engineering College of Engineering and Computing Florida International University Miami FL 33174 USA
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12
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The Mechanical Fingerprint of Circulating Tumor Cells (CTCs) in Breast Cancer Patients. Cancers (Basel) 2021; 13:cancers13051119. [PMID: 33807790 PMCID: PMC7961579 DOI: 10.3390/cancers13051119] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/17/2021] [Accepted: 02/26/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Detection of circulating tumor cells (CTCs) in the blood of cancer patients is a challenging issue, since they adapt to the biochemical and physical landscape of the bloodstream. We approached the issue of CTC identification on a biophysical level. For the first time, we recorded the mechanical deformation profiles of potential CTCs, which were isolated from the blood of breast cancer patients, at the force regime of the deforming blood flow. Mechanical fingerprints of CTCs were significantly different from healthy white blood cells. We used machine learning to further evaluate the differences and identify discrimination criteria. Our results suggest that mechanical characterization of CTCs at low forces is a promising path towards CTC detection. Abstract Circulating tumor cells (CTCs) are a potential predictive surrogate marker for disease monitoring. Due to the sparse knowledge about their phenotype and its changes during cancer progression and treatment response, CTC isolation remains challenging. Here we focused on the mechanical characterization of circulating non-hematopoietic cells from breast cancer patients to evaluate its utility for CTC detection. For proof of premise, we used healthy peripheral blood mononuclear cells (PBMCs), human MDA-MB 231 breast cancer cells and human HL-60 leukemia cells to create a CTC model system. For translational experiments CD45 negative cells—possible CTCs—were isolated from blood samples of patients with mamma carcinoma. Cells were mechanically characterized in the optical stretcher (OS). Active and passive cell mechanical data were related with physiological descriptors by a random forest (RF) classifier to identify cell type specific properties. Cancer cells were well distinguishable from PBMC in cell line tests. Analysis of clinical samples revealed that in PBMC the elliptic deformation was significantly increased compared to non-hematopoietic cells. Interestingly, non-hematopoietic cells showed significantly higher shape restoration. Based on Kelvin–Voigt modeling, the RF algorithm revealed that elliptic deformation and shape restoration were crucial parameters and that the OS discriminated non-hematopoietic cells from PBMC with an accuracy of 0.69, a sensitivity of 0.74, and specificity of 0.63. The CD45 negative cell population in the blood of breast cancer patients is mechanically distinguishable from healthy PBMC. Together with cell morphology, the mechanical fingerprint might be an appropriate tool for marker-free CTC detection.
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Hayn A, Fischer T, Mierke CT. Inhomogeneities in 3D Collagen Matrices Impact Matrix Mechanics and Cancer Cell Migration. Front Cell Dev Biol 2020; 8:593879. [PMID: 33251219 PMCID: PMC7674772 DOI: 10.3389/fcell.2020.593879] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/08/2020] [Indexed: 12/20/2022] Open
Abstract
Cell motility under physiological and pathological conditions including malignant progression of cancer and subsequent metastasis are founded on environmental confinements. During the last two decades, three-dimensional cell migration has been studied mostly by utilizing biomimetic extracellular matrix models. In the majority of these studies, the in vitro collagen scaffolds are usually assumed to be homogenous, as they consist commonly of one specific type of collagen, such as collagen type I, isolated from one species. These collagen matrices should resemble in vivo extracellular matrix scaffolds physiologically, however, mechanical phenotype and functional reliability have been addressed poorly due to certain limitations based on the assumption of homogeneity. How local variations of extracellular matrix structure impact matrix mechanics and cell migration is largely unknown. Here, we hypothesize that local inhomogeneities alter cell movement due to alterations in matrix mechanics, as they frequently occur in in vivo tissue scaffolds and were even changed in diseased tissues. To analyze the effect of structural inhomogeneities on cell migration, we used a mixture of rat tail and bovine dermal collagen type I as well as pure rat and pure bovine collagens at four different concentrations to assess three-dimensional scaffold inhomogeneities. Collagen type I from rat self-assembled to elongated fibrils, whereas bovine collagen tended to build node-shaped inhomogeneous scaffolds. We have shown that the elastic modulus determined with atomic force microscopy in combination with pore size analysis using confocal laser scanning microscopy revealed distinct inhomogeneities within collagen matrices. We hypothesized that elastic modulus and pore size govern cancer cell invasion in three-dimensional collagen matrices. In fact, invasiveness of three breast cancer cell types is altered due to matrix-type and concentration indicating that these two factors are crucial for cellular invasiveness. Our findings revealed that local matrix scaffold inhomogeneity is another crucial parameter to explain differences in cell migration, which not solely depended on pore size and stiffness of the collagen matrices. With these three distinct biophysical parameters, characterizing structure and mechanics of the studied collagen matrices, we were able to explain differences in the invasion behavior of the studied cancer cell lines in dependence of the used collagen model.
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Affiliation(s)
- Alexander Hayn
- Biological Physics Division, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig, Germany
| | - Tony Fischer
- Biological Physics Division, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig, Germany
| | - Claudia Tanja Mierke
- Biological Physics Division, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig, Germany
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Mierke CT. Mechanical Cues Affect Migration and Invasion of Cells From Three Different Directions. Front Cell Dev Biol 2020; 8:583226. [PMID: 33043017 PMCID: PMC7527720 DOI: 10.3389/fcell.2020.583226] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 08/24/2020] [Indexed: 12/20/2022] Open
Abstract
Cell migration and invasion is a key driving factor for providing essential cellular functions under physiological conditions or the malignant progression of tumors following downward the metastatic cascade. Although there has been plentiful of molecules identified to support the migration and invasion of cells, the mechanical aspects have not yet been explored in a combined and systematic manner. In addition, the cellular environment has been classically and frequently assumed to be homogeneous for reasons of simplicity. However, motility assays have led to various models for migration covering only some aspects and supporting factors that in some cases also include mechanical factors. Instead of specific models, in this review, a more or less holistic model for cell motility in 3D is envisioned covering all these different aspects with a special emphasis on the mechanical cues from a biophysical perspective. After introducing the mechanical aspects of cell migration and invasion and presenting the heterogeneity of extracellular matrices, the three distinct directions of cell motility focusing on the mechanical aspects are presented. These three different directions are as follows: firstly, the commonly used invasion tests using structural and structure-based mechanical environmental signals; secondly, the mechano-invasion assay, in which cells are studied by mechanical forces to migrate and invade; and thirdly, cell mechanics, including cytoskeletal and nuclear mechanics, to influence cell migration and invasion. Since the interaction between the cell and the microenvironment is bi-directional in these assays, these should be accounted in migration and invasion approaches focusing on the mechanical aspects. Beyond this, there is also the interaction between the cytoskeleton of the cell and its other compartments, such as the cell nucleus. In specific, a three-element approach is presented for addressing the effect of mechanics on cell migration and invasion by including the effect of the mechano-phenotype of the cytoskeleton, nucleus and the cell's microenvironment into the analysis. In precise terms, the combination of these three research approaches including experimental techniques seems to be promising for revealing bi-directional impacts of mechanical alterations of the cellular microenvironment on cells and internal mechanical fluctuations or changes of cells on the surroundings. Finally, different approaches are discussed and thereby a model for the broad impact of mechanics on cell migration and invasion is evolved.
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Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
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Fischer T, Hayn A, Mierke CT. Effect of Nuclear Stiffness on Cell Mechanics and Migration of Human Breast Cancer Cells. Front Cell Dev Biol 2020; 8:393. [PMID: 32548118 PMCID: PMC7272586 DOI: 10.3389/fcell.2020.00393] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 04/29/2020] [Indexed: 12/18/2022] Open
Abstract
The migration and invasion of cancer cells through 3D confined extracellular matrices is coupled to cell mechanics and the mechanics of the extracellular matrix. Cell mechanics is mainly determined by both the mechanics of the largest organelle in the cell, the nucleus, and the cytoskeletal architecture of the cell. Hence, cytoskeletal and nuclear mechanics are the major contributors to cell mechanics. Among other factors, steric hindrances of the extracellular matrix confinement are supposed to affect nuclear mechanics and thus also influence cell mechanics. Therefore, we propose that the percentage of invasive cells and their invasion depths into loose and dense 3D extracellular matrices is regulated by both nuclear and cytoskeletal mechanics. In order to investigate the effect of both nuclear and cytoskeletal mechanics on the overall cell mechanics, we firstly altered nuclear mechanics by the chromatin de-condensing reagent Trichostatin A (TSA) and secondly altered cytoskeletal mechanics by addition of actin polymerization inhibitor Latrunculin A and the myosin inhibitor Blebbistatin. In fact, we found that TSA-treated MDA-MB-231 human breast cancer cells increased their invasion depth in dense 3D extracellular matrices, whereas the invasion depths in loose matrices were decreased. Similarly, the invasion depths of TSA-treated MCF-7 human breast cancer cells in dense matrices were significantly increased compared to loose matrices, where the invasion depths were decreased. These results are also valid in the presence of a matrix-metalloproteinase inhibitor GM6001. Using atomic force microscopy (AFM), we found that the nuclear stiffnesses of both MDA-MB-231 and MCF-7 breast cancer cells were pronouncedly higher than their cytoskeletal stiffness, whereas the stiffness of the nucleus of human mammary epithelial cells was decreased compared to their cytoskeleton. TSA treatment reduced cytoskeletal and nuclear stiffness of MCF-7 cells, as expected. However, a softening of the nucleus by TSA treatment may induce a stiffening of the cytoskeleton of MDA-MB-231 cells and subsequently an apparent stiffening of the nucleus. Inhibiting actin polymerization using Latrunculin A revealed a softer nucleus of MDA-MB-231 cells under TSA treatment. This indicates that the actin-dependent cytoskeletal stiffness seems to be influenced by the TSA-induced nuclear stiffness changes. Finally, the combined treatment with TSA and Latrunculin A further justifies the hypothesis of apparent nuclear stiffening, indicating that cytoskeletal mechanics seem to be regulated by nuclear mechanics.
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Affiliation(s)
- Tony Fischer
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
| | - Alexander Hayn
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
| | - Claudia Tanja Mierke
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
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Mierke CT, Puder S, Aermes C, Fischer T, Kunschmann T. Effect of PAK Inhibition on Cell Mechanics Depends on Rac1. Front Cell Dev Biol 2020; 8:13. [PMID: 32047750 PMCID: PMC6997127 DOI: 10.3389/fcell.2020.00013] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/10/2020] [Indexed: 12/24/2022] Open
Abstract
Besides biochemical and molecular regulation, the migration and invasion of cells is controlled by the environmental mechanics and cellular mechanics. Hence, the mechanical phenotype of cells, such as fibroblasts, seems to be crucial for the migratory capacity in confined 3D extracellular matrices. Recently, we have shown that the migratory and invasive capacity of mouse embryonic fibroblasts depends on the expression of the Rho-GTPase Rac1, similarly it has been demonstrated that the Rho-GTPase Cdc42 affects cell motility. The p21-activated kinase (PAK) is an effector down-stream target of both Rho-GTPases Rac1 and Cdc42, and it can activate via the LIM kinase-1 its down-stream target cofilin and subsequently support the cell migration and invasion through the polymerization of actin filaments. Since Rac1 deficient cells become mechanically softer than controls, we investigated the effect of group I PAKs and PAK1 inhibition on cell mechanics in the presence and absence of Rac1. Therefore, we determined whether mouse embryonic fibroblasts, in which Rac1 was knocked-out, and control cells, displayed cell mechanical alterations after treatment with group I PAKs or PAK1 inhibitors using a magnetic tweezer (adhesive cell state) and an optical cell stretcher (non-adhesive cell state). In fact, we found that group I PAKs and Pak1 inhibition decreased the stiffness and the Young’s modulus of fibroblasts in the presence of Rac1 independent of their adhesive state. However, in the absence of Rac1 the effect was abolished in the adhesive cell state for both inhibitors and in their non-adhesive state, the effect was abolished for the FRAX597 inhibitor, but not for the IPA3 inhibitor. The migration and invasion were additionally reduced by both PAK inhibitors in the presence of Rac1. In the absence of Rac1, only FRAX597 inhibitor reduced their invasiveness, whereas IPA3 had no effect. These findings indicate that group I PAKs and PAK1 inhibition is solely possible in the presence of Rac1 highlighting Rac1/PAK I (PAK1, 2, and 3) as major players in cell mechanics.
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Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
| | - Stefanie Puder
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
| | - Christian Aermes
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
| | - Tony Fischer
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
| | - Tom Kunschmann
- Faculty of Physics and Earth Science, Peter Debye Institute of Soft Matter Physics, Biological Physics Division, University of Leipzig, Leipzig, Germany
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