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曹 祎, 高 志, 石 怡, 李 芬, 宋 辉, 张 倩, 赵 雅, 陈 凌, 李 晓, 陈 维. [Study on methods measuring mechanical properties of arterial wall by macroscopic indentation]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2024; 41:469-475. [PMID: 38932532 PMCID: PMC11208641 DOI: 10.7507/1001-5515.202310062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/08/2024] [Indexed: 06/28/2024]
Abstract
Accurately evaluating the local biomechanics of arterial wall is crucial for diagnosing and treating arterial diseases. Indentation measurement can be used to evaluate the local mechanical properties of the artery. However, the effects of the indenter's geometric structure and the analysis theory on measurement results remain uncertain. In this paper, four kinds of indenters were used to measure the pulmonary aorta, the proximal thoracic aorta and the distal thoracic aorta in pigs, and the arterial elastic modulus was calculated by Sneddon and Sirghi theory to explore the influence of the indenter geometry and analysis theory on the measured elastic modulus. The results showed that the arterial elastic modulus measured by cylindrical indenter was lower than that measured by spherical indenter. In addition, compared with the calculated results of Sirghi theory, the Sneddon theory, which does not take adhesion forces in account, resulted in slightly larger elastic modulus values. In conclusion, this study provides parametric support for effective measurement of arterial local mechanical properties by millimeter indentation technique.
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Affiliation(s)
- 祎凡 曹
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 志鹏 高
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 怡柯 石
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 芬 李
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
- 太原理工大学 机械与运载工程学院 (太原 030024)College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 辉 宋
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
- 太原理工大学 机械与运载工程学院 (太原 030024)College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 倩倩 张
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 雅威 赵
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 凌峰 陈
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 晓娜 李
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
| | - 维毅 陈
- 太原理工大学 生物医学工程学院 (太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China
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Xie X, Sauer F, Grosser S, Lippoldt J, Warmt E, Das A, Bi D, Fuhs T, Käs JA. Effect of non-linear strain stiffening in eDAH and unjamming. SOFT MATTER 2024; 20:1996-2007. [PMID: 38323652 PMCID: PMC10900305 DOI: 10.1039/d3sm00630a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/02/2024] [Indexed: 02/08/2024]
Abstract
In cell clusters, the prominent factors at play encompass contractility-based enhanced tissue surface tension and cell unjamming transition. The former effect pertains to the boundary effect, while the latter constitutes a bulk effect. Both effects share outcomes of inducing significant elongation in cells. This elongation is so substantial that it surpasses the limits of linear elasticity, thereby giving rise to additional effects. To investigate these effects, we employ atomic force microscopy (AFM) to analyze how the mechanical properties of individual cells change under such considerable elongation. Our selection of cell lines includes MCF-10A, chosen for its pronounced demonstration of the extended differential adhesion hypothesis (eDAH), and MDA-MB-436, selected due to its manifestation of cell unjamming behavior. In the AFM analyses, we observe a common trend in both cases: as elongation increases, both cell lines exhibit strain stiffening. Notably, this effect is more prominent in MCF-10A compared to MDA-MB-436. Subsequently, we employ AFM on a dynamic range of 1-200 Hz to probe the mechanical characteristics of cell spheroids, focusing on both surface and bulk mechanics. Our findings align with the results from single cell investigations. Specifically, MCF-10A cells, characterized by strong contractile tissue tension, exhibit the greatest stiffness on their surface. Conversely, MDA-MB-436 cells, which experience significant elongation, showcase their highest stiffness within the bulk region. Consequently, the concept of single cell strain stiffening emerges as a crucial element in understanding the mechanics of multicellular spheroids (MCSs), even in the case of MDA-MB-436 cells, which are comparatively softer in nature.
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Affiliation(s)
- Xiaofan Xie
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Frank Sauer
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Steffen Grosser
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Jürgen Lippoldt
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Enrico Warmt
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Amit Das
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Dapeng Bi
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Thomas Fuhs
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
| | - Josef A Käs
- Soft Matter Physics Division, Peter Debye Institute for Soft Matter Physics, University of Leipzig, Germany.
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Arce FT, Younger S, Gaber AA, Mascarenhas JB, Rodriguez M, Dudek SM, Garcia JGN. Lamellipodia dynamics and microrheology in endothelial cell paracellular gap closure. Biophys J 2023; 122:4730-4747. [PMID: 37978804 PMCID: PMC10754712 DOI: 10.1016/j.bpj.2023.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 05/06/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
Vascular endothelial cells (ECs) form a semipermeable barrier separating vascular contents from the interstitium, thereby regulating the movement of water and molecular solutes across small intercellular gaps, which are continuously forming and closing. Under inflammatory conditions, however, larger EC gaps form resulting in increased vascular leakiness to circulating fluid, proteins, and cells, which results in organ edema and dysfunction responsible for key pathophysiologic findings in numerous inflammatory disorders. In this study, we extend our earlier work examining the biophysical properties of EC gap formation and now address the role of lamellipodia, thin sheet-like membrane projections from the leading edge, in modulating EC spatial-specific contractile properties and gap closure. Micropillars, fabricated by soft lithography, were utilized to form reproducible paracellular gaps in human lung ECs. Using time-lapse imaging via optical microscopy, rates of EC gap closure and motility were measured with and without EC stimulation with the barrier-enhancing sphingolipid, sphingosine-1-phosphate. Peripheral ruffle formation was ubiquitous during gap closure. Kymographs were generated to quantitatively compare the lamellipodia dynamics of sphingosine-1-phosphate-stimulated and -unstimulated ECs. Utilizing atomic force microscopy, we characterized the viscoelastic behavior of EC lamellipodia. Our results indicate decreased stiffness and increased liquid-like behavior of expanding lamellipodia compared with regions away from the cellular edge (lamella and cell body) during EC gap closure, results in sync with the rapid kinetics of protrusion/retraction motion. We hypothesize this dissipative EC behavior during gap closure is linked to actomyosin cytoskeletal rearrangement and decreased cross-linking during lamellipodia expansion. In summary, these studies of the kinetic and mechanical properties of EC lamellipodia and ruffles at gap boundaries yield insights into the mechanisms of vascular barrier restoration and potentially a model system for examining the druggability of lamellipodial protein targets to enhance vascular barrier integrity.
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Affiliation(s)
- Fernando Teran Arce
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida.
| | - Scott Younger
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona
| | - Amir A Gaber
- Department of Medicine, University of Arizona, Tucson, Arizona
| | | | - Marisela Rodriguez
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida; Department of Medicine, University of Arizona, Tucson, Arizona
| | - Steven M Dudek
- Department of Medicine, The University of Illinois at Chicago, Chicago, Illinois
| | - Joe G N Garcia
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida.
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Beltrán-Partida E, Valdez-Salas B, García-López Portillo M, Gutierrez-Perez C, Castillo-Uribe S, Salvador-Carlos J, Alcocer-Cañez J, Cheng N. Atherosclerotic-Derived Endothelial Cell Response Conducted by Titanium Oxide Nanotubes. MATERIALS (BASEL, SWITZERLAND) 2023; 16:794. [PMID: 36676534 PMCID: PMC9865858 DOI: 10.3390/ma16020794] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/04/2023] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
Atherosclerosis lesions are described as the formation of an occlusive wall-vessel plaque that can exacerbate infarctions, strokes, and even death. Furthermore, atherosclerosis damages the endothelium integrity, avoiding proper regeneration after stent implantation. Therefore, we investigate the beneficial effects of TiO2 nanotubes (NTs) in promoting the initial response of detrimental human atherosclerotic-derived endothelial cells (AThEC). We synthesized and characterized NTs on Ti6Al4V by anodization. We isolated AThEC and tested the adhesion long-lasting proliferation activity, and the modulation of focal adhesions conducted on the materials. Moreover, ultrastructural cell-surface contact at the nanoscale and membrane roughness were evaluated to explain the results. Our findings depicted improved filopodia and focal adhesions stimulated by the NTs. Similarly, the NTs harbored long-lasting proliferative metabolism after 5 days, explained by overcoming cell-contact interactions at the nanoscale. Furthermore, the senescent activity detected in the AThEC could be mitigated by the modified membrane roughness and cellular stretch orchestrated by the NTs. Importantly, the NTs stimulate the initial endothelial anchorage and metabolic recovery required to regenerate the endothelial monolayer. Despite the dysfunctional status of the AThEC, our study brings new evidence for the potential application of nano-configured biomaterials for innovation in stent technologies.
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Affiliation(s)
- Ernesto Beltrán-Partida
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - Benjamín Valdez-Salas
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - Martha García-López Portillo
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - Claudia Gutierrez-Perez
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - Sandra Castillo-Uribe
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - Jorge Salvador-Carlos
- Laboratorio de Biología Molecular y Cáncer, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Mexicali C.P. 21040, Baja California, Mexico
| | - José Alcocer-Cañez
- Coordinación Clínica de Cirugía, Hospital General de Zona No. 30, Instituto Mexicano del Seguro Social (IMSS), Av. Lerdo de Tejada s/n, Mexicali C.P. 21100, Baja California, Mexico
| | - Nelson Cheng
- Magna International Pte Ltd., 10 H Enterprise Road, Singapore 629834, Singapore
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Xie L, Sun Z, Brown NJ, Glinskii OV, Meininger GA, Glinsky VV. Changes in dynamics of tumor/endothelial cell adhesive interactions depending on endothelial cell growth state and elastic properties. PLoS One 2022; 17:e0269552. [PMID: 35666755 PMCID: PMC9170101 DOI: 10.1371/journal.pone.0269552] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 05/23/2022] [Indexed: 11/18/2022] Open
Abstract
Cancer cell adhesion to the endothelium is a crucial process in hematogenous metastasis, but how the integrity of the endothelial barrier and endothelial cell (EC) mechanical properties influence the adhesion between metastatic cancer cells and the endothelium remain unclear. In the present study, we have measured the adhesion between single cancer cells and two types of ECs at various growth states and their mechanical properties (elasticity) using atomic force microscopy single cell force spectroscopy. We demonstrated that the EC stiffness increased and adhesion with cancer cells decreased, as ECs grew from a single cell to a confluent state and developed cell-cell contacts, but this was reversed when confluent cells returned to a single state in a scratch assay. Our results suggest that the integrity of the endothelial barrier is an important factor in reducing the ability of the metastatic tumor cells to adhere to the vascular endothelium, extravasate and lodge in the vasculature of a distant organ where secondary metastatic tumors would develop.
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Affiliation(s)
- Leike Xie
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Zhe Sun
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
| | - Nicola J. Brown
- Microcirculation Research Group, Department of Oncology and Metabolism, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, United Kingdom
| | - Olga V. Glinskii
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri, United States of America
| | - Gerald A. Meininger
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America
| | - Vladislav V. Glinsky
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, United States of America
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri, United States of America
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Ko PL, Wang CK, Hsu HH, Lee TA, Tung YC. Revealing anisotropic elasticity of endothelium under fluid shear stress. Acta Biomater 2022; 145:316-328. [PMID: 35367381 DOI: 10.1016/j.actbio.2022.03.040] [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: 11/16/2021] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 11/26/2022]
Abstract
Endothelium lining interior surface of blood vessels experiences various physical stimulations in vivo. Its physical properties, especially elasticity, play important roles in regulating the physiological functions of vascular systems. In this paper, an integrated approach is developed to characterize the anisotropic elasticity of the endothelium under physiological-level fluid shear stress. A pressure sensor-embedded microfluidic device is developed to provide fluid shear stress on the perfusion-cultured endothelium and to measure transverse in-plane elasticities in the directions parallel and perpendicular to the flow direction. Biological atomic force microscopy (Bio-AFM) is further exploited to measure the vertical elasticity of the endothelium in its out-of-plane direction. The results show that the transverse elasticity of the endothelium in the direction parallel to the perfusion culture flow direction is about 70% higher than that in the direction perpendicular to the flow direction. Moreover, the transverse elasticities of the endothelium are estimated to be approximately 120 times larger than the vertical one. The results indicate the effects of fluid shear stress on the transverse elasticity anisotropy of the endothelium, and the difference between the elasticities in transverse and vertical directions. The quantitative measurement of the endothelium anisotropic elasticity in different directions at the tissue level under the fluid shear stress provides biologists insightful information for the advanced vascular system studies from biophysical and biomaterial viewpoints. STATEMENT OF SIGNIFICANCE: In this paper, we take advantage an integrated approach combining microfluidic devices and biological atomic force microscopy (Bio-AFM) to characterize anisotropic elasticities of endothelia with and without fluidic shear stress application. The microfluidic devices are exploited to conduct perfusion cell culture of the endothelial cells, and to estimate the in-plane elasticities of the endothelium in the direction parallel and perpendicular to the shear stress. In addition, the Bio-AFM is utilized for characterization of the endothelium morphology and vertical elasticity. The measurement results demonstrate the very first anisotropic elasticity quantification of the endothelia. Furthermore, the study provides insightful information bridging the microscopic sing cell and macroscopic organ level studies, which can greatly help to advance vascular system research from material perspective.
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Zhou H, Xue Y, Dong L, Wang C. Biomaterial-based physical regulation of macrophage behaviour. J Mater Chem B 2021; 9:3608-3621. [PMID: 33908577 DOI: 10.1039/d1tb00107h] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Macrophages play a critical role in regulating immune reactions induced by implanted biomaterials. They are highly plastic and in response to diverse stimuli in the microenvironment can exhibit a spectrum of phenotypes and functions. In addition to biochemical signals, the physical properties of biomaterials are becoming increasingly appreciated for their significant impact on macrophage behaviour, and the underlying mechanisms deserve more in-depth investigations. This review first summarises the effects of key physical cues - including stiffness, topography, physical confinement and applied force - on macrophage behaviour. Then, it reviews the current knowledge of cellular sensing and transduction of physical cues into intracellular signals. Finally, it discusses the major challenges in understanding mechanical regulation that could provide insights for biomaterial design.
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Affiliation(s)
- Huiqun Zhou
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China.
| | - Yizebang Xue
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China. and Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Lei Dong
- State Key Laboratory of Pharmaceutical Biotechnology, Medical School & School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Chunming Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China.
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Huang D, Ding Q, Chen S, Lü S, Zhang Y, Long M. E-selectin negatively regulates polymorphonuclear neutrophil transmigration through altered endothelial junction integrity. FASEB J 2021; 35:e21521. [PMID: 33811691 DOI: 10.1096/fj.202000662rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 01/28/2021] [Accepted: 02/26/2021] [Indexed: 11/11/2022]
Abstract
Transendothelial migration (TEM) of neutrophils under blood flow is critical in the inflammatory cascade. However, the role of endothelial plasticity in this process is not fully understood. Therefore, we used an in vitro model to test the dynamics of human polymorphonuclear neutrophil (PMN) TEM across lipopolysaccharide-treated human umbilical vein endothelial cell (HUVEC) monolayers. Interestingly, shRNA-E-selectin knockdown in HUVECs destabilized endothelial junctional integrity by reducing actin branching and increasing stress fiber at cell-cell junctions. This process is accomplished by downregulating the activation of cortactin and Arp2/3, which in turn alters the adhesive function of VE-cadherin, enhancing PMN transmigration. Meanwhile, redundant P-selectins possess overlapping functions in E-selectin-mediated neutrophil adhesion, and transmigration. These results demonstrate, to our knowledge, for the first time, that E-selectins negatively regulate neutrophil transmigration through alterations in endothelial plasticity. Furthermore, it improves our understanding of the mechanisms underlying actin remodeling, and junctional integrity, in endothelial cells mediating leukocyte TEM.
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Affiliation(s)
- Dandan Huang
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Qihan Ding
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Shenbao Chen
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Shouqin Lü
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yan Zhang
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Mian Long
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China.,Lead Contact, Beijing, China
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Migliorini E, Cavalcanti-Adam EA, Uva AE, Fiorentino M, Gattullo M, Manghisi VM, Vaiani L, Boccaccio A. Nanoindentation of mesenchymal stem cells using atomic force microscopy: effect of adhesive cell-substrate structures. NANOTECHNOLOGY 2021; 32:215706. [PMID: 33596559 DOI: 10.1088/1361-6528/abe748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
The procedure commonly adopted to characterize cell materials using atomic force microscopy neglects the stress state induced in the cell by the adhesion structures that anchor it to the substrate. In several studies, the cell is considered as made from a single material and no specific information is provided regarding the mechanical properties of subcellular components. Here we present an optimization algorithm to determine separately the material properties of subcellular components of mesenchymal stem cells subjected to nanoindentation measurements. We assess how these properties change if the adhesion structures at the cell-substrate interface are considered or not in the algorithm. In particular, among the adhesion structures, the focal adhesions and the stress fibers were simulated. We found that neglecting the adhesion structures leads to underestimate the cell mechanical properties thus making errors up to 15%. This result leads us to conclude that the action of adhesion structures should be taken into account in nanoindentation measurements especially for cells that include a large number of adhesions to the substrate.
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Affiliation(s)
| | - Elisabetta Ada Cavalcanti-Adam
- Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany
- Heidelberg University, D-69120 Heidelberg, Germany
| | - Antonio Emmanuele Uva
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
| | - Michele Fiorentino
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
| | - Michele Gattullo
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
| | - Vito Modesto Manghisi
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
| | - Lorenzo Vaiani
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
| | - Antonio Boccaccio
- Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Bari, Italy
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Zhu JJ, Jiang ZT, Liu C, Xi YF, Wang J, Yang FF, Yao WJ, Pang W, Han LL, Zhang YH, Sun AQ, Zhou J. VAMP3 and SNAP23 as Potential Targets for Preventing the Disturbed Flow-Accelerated Thrombus Formation. Front Cell Dev Biol 2020; 8:576826. [PMID: 33224946 PMCID: PMC7674309 DOI: 10.3389/fcell.2020.576826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 10/05/2020] [Indexed: 01/21/2023] Open
Abstract
Disturbed blood flow has been recognized to promote platelet aggregation and thrombosis via increasing accumulation of von Willebrand factor (VWF) at the arterial post-stenotic sites. The mechanism underlying the disturbed-flow regulated endothelial VWF production remains elusive. Here we described a mouse model, in which the left external carotid artery (LECA) is ligated to generate disturbed flow in the common carotid artery. Ligation of LECA increased VWF accumulation in the plasma. Carotid arterial thrombosis was induced by ferric chloride (FeCl3) application and the time to occlusion in the ligated vessels was reduced in comparison with the unligated vessels. In vitro, endothelial cells were subjected to oscillatory shear (OS, 0.5 ± 4 dynes/cm2) or pulsatile shear (PS, 12 ± 4 dynes/cm2). OS promoted VWF secretion as well as the cell conditioned media-induced platelet aggregation by regulating the intracellular localization of vesicle-associated membrane protein 3 (VAMP3) and synaptosomal-associated protein 23 (SNAP23). Disruption of vimentin intermediate filaments abolished the OS-induced translocation of SNAP23 to the cell membrane. Knockdown of VAMP3 and SNAP23 reduced the endothelial secretion of VWF. Systemic inhibition of VAMP3 and SNAP23 by treatment of mice with rapamycin significantly ameliorated the FeCl3-induced thrombogenesis, whereas intraluminal overexpression of VAMP3 and SNAP23 aggravated it. Our findings demonstrate VAMP3 and SNAP23 as potential targets for preventing the disturbed flow-accelerated thrombus formation.
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Affiliation(s)
- Juan-Juan Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.,National Health Commission of the People's Republic of China Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing, China.,Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China
| | - Zhi-Tong Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.,National Health Commission of the People's Republic of China Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing, China
| | - Chen Liu
- Department of Clinical Laboratory, Peking University People's Hospital, Beijing, China
| | - Yi-Feng Xi
- School of Biological Science and Medical Engineering, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
| | - Jin Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.,National Health Commission of the People's Republic of China Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing, China
| | - Fang-Fang Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.,National Health Commission of the People's Republic of China Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing, China
| | - Wei-Juan Yao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Wei Pang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Li-Li Han
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yong-He Zhang
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China
| | - An-Qiang Sun
- School of Biological Science and Medical Engineering, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
| | - Jing Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China.,National Health Commission of the People's Republic of China Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing, China
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11
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Grexa I, Fekete T, Molnár J, Molnár K, Vizsnyiczai G, Ormos P, Kelemen L. Single-Cell Elasticity Measurement with an Optically Actuated Microrobot. MICROMACHINES 2020; 11:mi11090882. [PMID: 32972024 PMCID: PMC7570390 DOI: 10.3390/mi11090882] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/15/2020] [Accepted: 09/20/2020] [Indexed: 02/07/2023]
Abstract
A cell elasticity measurement method is introduced that uses polymer microtools actuated by holographic optical tweezers. The microtools were prepared with two-photon polymerization. Their shape enables the approach of the cells in any lateral direction. In the presented case, endothelial cells grown on vertical polymer walls were probed by the tools in a lateral direction. The use of specially shaped microtools prevents the target cells from photodamage that may arise during optical trapping. The position of the tools was recorded simply with video microscopy and analyzed with image processing methods. We critically compare the resulting Young’s modulus values to those in the literature obtained by other methods. The application of optical tweezers extends the force range available for cell indentations measurements down to the fN regime. Our approach demonstrates a feasible alternative to the usual vertical indentation experiments.
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Affiliation(s)
- István Grexa
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
- Doctoral School of Interdisciplinary Medicine, University of Szeged, Korányi fasor 10, 6720 Szeged, Hungary
| | - Tamás Fekete
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
- Doctoral School of Multidisciplinary Medicine, Dóm tér 9, Hungary University of Szeged, 6720 Szeged, Hungary
| | - Judit Molnár
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
| | - Kinga Molnár
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
- Doctoral School of Theoretical Medicine, University of Szeged, Korányi fasor 10, 6720 Szeged, Hungary
| | - Gaszton Vizsnyiczai
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
| | - Pál Ormos
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
| | - Lóránd Kelemen
- Biological Research Centre, Temesvári krt. 62, 6726 Szeged, Hungary; (I.G.); (T.F.); (J.M.); (K.M.); (G.V.); (P.O.)
- Correspondence: ; Tel.: +36-62-599-600 (ext. 419)
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12
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Gao Q, Dai Z, Zhang S, Fang Y, Yung KKL, Lo PK, Lai KWC. Interaction of Sp1 and APP promoter elucidates a mechanism for Pb 2+ caused neurodegeneration. Arch Biochem Biophys 2020; 681:108265. [PMID: 31945313 DOI: 10.1016/j.abb.2020.108265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 12/31/2022]
Abstract
A ubiquitously expressed transcription factor, specificity protein 1 (Sp1), interacts with the amyloid precursor protein (APP) promoter and likely mediates APP expression. Promoter-interaction strengths variably regulate the level of APP expression. Here, we examined the interactions of finger 3 of Sp1 (Sp1-f3) with a DNA fragment containing the APP promoter in different ionic solutions using atomic force microscope (AFM) spectroscopy. Sp1-f3 molecules immobilized on an Si substrate were bound to the APP promoter, which was linked to the AFM tips via covalent bonds. The interactions were strongly influenced by Pb2+, considering that substituting Zn2+ with Pb2+ increased the binding affinity of Sp1 for the APP promoter. The results revealed that the enhanced interaction force facilitated APP expression and that APP overexpression could confer a high-risk for disease incidence. An increased interaction force between Sp1-f3 and the APP promoter in Pb2+ solutions was consistent with a lower binding free energy, as determined by computer-assisted analysis. The impact of Pb2+ on cell morphology and related mechanical properties were also detected by AFM. The overexpression of APP caused by the enhanced interaction force triggered actin reorganization and further resulted in an increased Young's modulus and viscosity. The correlation with single-force measurements revealed that altered cellular activities could result from alternation of Sp1-APP promoter interaction. Our AFM findings offer a new approach in understanding Pb2+ associated neurodegeneration.
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Affiliation(s)
- Qi Gao
- Department of Biomedical Engineering, Centre for Robotics and Automation, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Ziwen Dai
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China
| | - Shiqing Zhang
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong SAR, China
| | - Yuqiang Fang
- School of Mechanical Science and Engineering, Jilin University, Changchun, 130025, China
| | - Ken Kin Lam Yung
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong SAR, China.
| | - Pik Kwan Lo
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China.
| | - King Wai Chiu Lai
- Department of Biomedical Engineering, Centre for Robotics and Automation, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
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13
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Chambers L, Dorrance AM. Regulation of ion channels in the microcirculation by mineralocorticoid receptor activation. CURRENT TOPICS IN MEMBRANES 2020; 85:151-185. [PMID: 32402638 DOI: 10.1016/bs.ctm.2020.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The mineralocorticoid receptor (MR) has classically been studied in the renal epithelium for its role in regulating sodium and water balance and, subsequently, blood pressure. However, the MR also plays a critical role in the microvasculature by regulating ion channel expression and function. Activation of the MR by its endogenous agonist aldosterone results in translocation of the MR into the nucleus, where it can act as a transcription factor. Although most of the actions of the aldosterone can be attributed to its genomic activity though MR activation, it can also act by nongenomic mechanisms. Activation of this ubiquitous receptor increases the expression of epithelial sodium channels (ENaC) in both the endothelium and smooth muscle cells of peripheral and cerebral vessels. MR activation also regulates activity of calcium channels, calcium-activated potassium channels, and various transient receptor potential (TRP) channels. Modification of these ion channels results in a myriad of negative consequences, including impaired endothelium-dependent vasodilation, alterations in generation of myogenic tone, and increased inflammation and oxidative stress. Taken together, these studies demonstrate the importance of studying the impact of the MR on ion channel function in the vasculature. While research in this area has made advances in recent years, there are still many large gaps in knowledge that need to be filled. Crucial future directions of study include defining the molecular mechanisms involved in this interaction, as well as elucidating the potential sex differences that may exist, as these areas of understanding are currently lacking.
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Affiliation(s)
- Laura Chambers
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States.
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14
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Delgadillo LF, Marsh GA, Waugh RE. Endothelial Glycocalyx Layer Properties and Its Ability to Limit Leukocyte Adhesion. Biophys J 2020; 118:1564-1575. [PMID: 32135082 DOI: 10.1016/j.bpj.2020.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/20/2019] [Accepted: 02/06/2020] [Indexed: 12/11/2022] Open
Abstract
The endothelial glycocalyx layer (EGL), which consists of long proteoglycans protruding from the endothelium, acts as a regulator of inflammation by preventing leukocyte engagement with adhesion molecules on the endothelial surface. The amount of resistance to adhesive events the EGL provides is the result of two properties: EGL thickness and stiffness. To determine these, we used an atomic force microscope to indent the surfaces of cultured endothelial cells with a glass bead and evaluated two different approaches for interpreting the resulting force-indentation curves. In one, we treat the EGL as a molecular brush, and in the other, we treat it as a thin elastic layer on an elastic half-space. The latter approach proved more robust in our hands and yielded a thickness of 110 nm and a modulus of 0.025 kPa. Neither value showed significant dependence on indentation rate. The brush model indicated a larger layer thickness (∼350 nm) but tended to result in larger uncertainties in the fitted parameters. The modulus of the endothelial cell was determined to be 3.0-6.5 kPa (1.5-2.5 kPa for the brush model), with a significant increase in modulus with increasing indentation rates. For forces and leukocyte properties in the physiological range, a model of a leukocyte interacting with the endothelium predicts that the number of molecules within bonding range should decrease by an order of magnitude because of the presence of a 110-nm-thick layer and even further for a glycocalyx with larger thickness. Consistent with these predictions, neutrophil adhesion increased for endothelial cells with reduced EGL thickness because they were grown in the absence of fluid shear stress. These studies establish a framework for understanding how glycocalyx layers with different thickness and stiffness limit adhesive events under homeostatic conditions and how glycocalyx damage or removal will increase leukocyte adhesion potential during inflammation.
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Affiliation(s)
- Luis F Delgadillo
- Department of Biomedical Engineering, University of Rochester, Rochester, New York
| | - Graham A Marsh
- Department of Biomedical Engineering, University of Rochester, Rochester, New York
| | - Richard E Waugh
- Department of Biomedical Engineering, University of Rochester, Rochester, New York.
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15
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Efremov YM, Velay-Lizancos M, Weaver CJ, Athamneh AI, Zavattieri PD, Suter DM, Raman A. Anisotropy vs isotropy in living cell indentation with AFM. Sci Rep 2019; 9:5757. [PMID: 30962474 PMCID: PMC6453879 DOI: 10.1038/s41598-019-42077-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/18/2019] [Indexed: 12/30/2022] Open
Abstract
The measurement of local mechanical properties of living cells by nano/micro indentation relies on the foundational assumption of locally isotropic cellular deformation. As a consequence of assumed isotropy, the cell membrane and underlying cytoskeleton are expected to locally deform axisymmetrically when indented by a spherical tip. Here, we directly observe the local geometry of deformation of membrane and cytoskeleton of different living adherent cells during nanoindentation with the integrated Atomic Force (AFM) and spinning disk confocal (SDC) microscope. We show that the presence of the perinuclear actin cap (apical stress fibers), such as those encountered in cells subject to physiological forces, causes a strongly non-axisymmetric membrane deformation during indentation reflecting local mechanical anisotropy. In contrast, axisymmetric membrane deformation reflecting mechanical isotropy was found in cells without actin cap: cancerous cells MDA-MB-231, which naturally lack the actin cap, and NIH 3T3 cells in which the actin cap is disrupted by latrunculin A. Careful studies were undertaken to quantify the effect of the live cell fluorescent stains on the measured mechanical properties. Using finite element computations and the numerical analysis, we explored the capability of one of the simplest anisotropic models – transverse isotropy model with three local mechanical parameters (longitudinal and transverse modulus and planar shear modulus) – to capture the observed non-axisymmetric deformation. These results help identifying which cell types are likely to exhibit non-isotropic properties, how to measure and quantify cellular deformation during AFM indentation using live cell stains and SDC, and suggest modelling guidelines to recover quantitative estimates of the mechanical properties of living cells.
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Affiliation(s)
- Yuri M Efremov
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA.,Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA
| | | | - Cory J Weaver
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,University of South Carolina, Department of Biological Sciences, Jones PSC Building, 712 Main Street, room 517, Columbia, SC, 29208, USA
| | - Ahmad I Athamneh
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA.,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Pablo D Zavattieri
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Daniel M Suter
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA. .,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA. .,Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA. .,Purdue Institute for Integrative Neuroscience, West Lafayette, Indiana, USA.
| | - Arvind Raman
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA. .,Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA.
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16
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Fels J, Kusche-Vihrog K. Endothelial Nanomechanics in the Context of Endothelial (Dys)function and Inflammation. Antioxid Redox Signal 2019; 30:945-959. [PMID: 29433330 PMCID: PMC6354603 DOI: 10.1089/ars.2017.7327] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
SIGNIFICANCE Stiffness of endothelial cells is closely linked to the function of the vasculature as it regulates the release of vasoactive substances such as nitric oxide (NO) and reactive oxygen species. The outer layer of endothelial cells, consisting of the glycocalyx above and the cortical zone beneath the plasma membrane, is a vulnerable compartment able to adapt its nanomechanical properties to any changes of forces exerted by the adjacent blood stream. Sustained stiffening of this layer contributes to the development of endothelial dysfunction and vascular pathologies. Recent Advances: The development of specific techniques to quantify the mechanical properties of cells enables the detailed investigation of the mechanistic link between structure and function of cells. CRITICAL ISSUES Challenging the mechanical stiffness of cells, for instance, by inflammatory mediators can lead to the development of endothelial dysfunction. Prevention of sustained stiffening of the outer layer of endothelial cells in turn improves endothelial function. FUTURE DIRECTIONS The mechanical properties of cells can be used as critical marker and test system for the proper function of the vascular system. Pharmacological substances, which are able to improve endothelial nanomechanics and function, could take a new importance in the prevention and treatment of vascular diseases. Thus, detailed knowledge acquisition about the structure/function relationship of endothelial cells and the underlying signaling pathways should be promoted.
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Affiliation(s)
- Johannes Fels
- 1 Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany
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17
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Vahabikashi A, Park CY, Perkumas K, Zhang Z, Deurloo EK, Wu H, Weitz DA, Stamer WD, Goldman RD, Fredberg JJ, Johnson M. Probe Sensitivity to Cortical versus Intracellular Cytoskeletal Network Stiffness. Biophys J 2019; 116:518-529. [PMID: 30685055 DOI: 10.1016/j.bpj.2018.12.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 12/04/2018] [Accepted: 12/20/2018] [Indexed: 11/19/2022] Open
Abstract
In development, wound healing, and pathology, cell biomechanical properties are increasingly recognized as being of central importance. To measure these properties, experimental probes of various types have been developed, but how each probe reflects the properties of heterogeneous cell regions has remained obscure. To better understand differences attributable to the probe technology, as well as to define the relative sensitivity of each probe to different cellular structures, here we took a comprehensive approach. We studied two cell types-Schlemm's canal endothelial cells and mouse embryonic fibroblasts (MEFs)-using four different probe technologies: 1) atomic force microscopy (AFM) with sharp tip, 2) AFM with round tip, 3) optical magnetic twisting cytometry (OMTC), and 4) traction microscopy (TM). Perturbation of Schlemm's canal cells with dexamethasone treatment, α-actinin overexpression, or RhoA overexpression caused increases in traction reported by TM and stiffness reported by sharp-tip AFM as compared to corresponding controls. By contrast, under these same experimental conditions, stiffness reported by round-tip AFM and by OMTC indicated little change. Knockout (KO) of vimentin in MEFs caused a diminution of traction reported by TM, as well as stiffness reported by sharp-tip and round-tip AFM. However, stiffness reported by OMTC in vimentin-KO MEFs was greater than in wild type. Finite-element analysis demonstrated that this paradoxical OMTC result in vimentin-KO MEFs could be attributed to reduced cell thickness. Our results also suggest that vimentin contributes not only to intracellular network stiffness but also cortex stiffness. Taken together, this evidence suggests that AFM sharp tip and TM emphasize properties of the actin-rich shell of the cell, whereas round-tip AFM and OMTC emphasize those of the noncortical intracellular network.
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Affiliation(s)
- Amir Vahabikashi
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Chan Young Park
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Kristin Perkumas
- Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Zhiguo Zhang
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Emily K Deurloo
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Huayin Wu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - David A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts; Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts; Department of Physics, Harvard University, Cambridge, Massachusetts
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina; Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Jeffrey J Fredberg
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Mark Johnson
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois; Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Department of Mechanical Engineering, Northwestern University, Evanston, Illinois.
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18
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Maase M, Rygula A, Pacia MZ, Proniewski B, Mateuszuk L, Sternak M, Kaczor A, Chlopicki S, Kusche-Vihrog K. Combined Raman- and AFM-based detection of biochemical and nanomechanical features of endothelial dysfunction in aorta isolated from ApoE/LDLR-/- mice. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2018; 16:97-105. [PMID: 30550804 DOI: 10.1016/j.nano.2018.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/09/2018] [Accepted: 11/20/2018] [Indexed: 01/08/2023]
Abstract
Endothelial dysfunction is recognized as a critical condition in the development of cardiovascular disorders. This multifactorial process involves changes in the biochemical and mechanical properties of endothelial cells leading to disturbed release of vasoprotective mediators. Hypercholesterolemia and increased stiffness of the endothelial cortex are independently shown to result in reduced release of nitric oxide and thus endothelial dysfunction. However, direct evidence linking these parameters to each other is missing. Here, a novel method combining Raman spectroscopy for biochemical analysis and Atomic Force Microscopy (AFM) for analyzing the endothelial nanomechanics was established. Using this dual approach, the same areas of native ex vivo aortas were investigated, either derived from mice with endothelial dysfunction (ApoE/LDLR-/-) or wild type mice. In particular an increased intracellular lipid content and elevated cortical stiffness/elasticity were shown in ApoE/LDLR-/- aortas, demonstrating a direct link between endothelial dysfunction, the biochemical composition and the nanomechanical properties of endothelial cells.
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Affiliation(s)
- Martina Maase
- Institute of Physiology II, University of Münster, Robert-Koch Str. 27b, 48149 Münster, Germany
| | - Anna Rygula
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland
| | - Marta Z Pacia
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland; Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Bartosz Proniewski
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland
| | - Lukasz Mateuszuk
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland
| | - Magdalena Sternak
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland
| | - Agnieszka Kaczor
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland; Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Stefan Chlopicki
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland; Chair of Pharmacology, Jagiellonian University, Grzegorzecka 16, 31-531 Krakow, Poland.
| | - Kristina Kusche-Vihrog
- Institute of Physiology II, University of Münster, Robert-Koch Str. 27b, 48149 Münster, Germany; Institute of Physiology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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19
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Basoli F, Giannitelli SM, Gori M, Mozetic P, Bonfanti A, Trombetta M, Rainer A. Biomechanical Characterization at the Cell Scale: Present and Prospects. Front Physiol 2018; 9:1449. [PMID: 30498449 PMCID: PMC6249385 DOI: 10.3389/fphys.2018.01449] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
The rapidly growing field of mechanobiology demands for robust and reproducible characterization of cell mechanical properties. Recent achievements in understanding the mechanical regulation of cell fate largely rely on technological platforms capable of probing the mechanical response of living cells and their physico–chemical interaction with the microenvironment. Besides the established family of atomic force microscopy (AFM) based methods, other approaches include optical, magnetic, and acoustic tweezers, as well as sensing substrates that take advantage of biomaterials chemistry and microfabrication techniques. In this review, we introduce the available methods with an emphasis on the most recent advances, and we discuss the challenges associated with their implementation.
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Affiliation(s)
- Francesco Basoli
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | | | - Manuele Gori
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Pamela Mozetic
- Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital, Brno, Czechia
| | - Alessandra Bonfanti
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Marcella Trombetta
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alberto Rainer
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy.,Institute for Photonics and Nanotechnologies, National Research Council, Rome, Italy
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20
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Shashar M, Hod T, Chernichovski T, Angel A, Kazan S, Grupper A, Naveh S, Kliuk-Ben Bassat O, Weinstein T, Schwartz IF. Mineralocorticoid receptor blockade improves arginine transport and nitric oxide generation through modulation of cationic amino acid transporter-1 in endothelial cells. Nitric Oxide 2018; 80:24-31. [PMID: 30056252 DOI: 10.1016/j.niox.2018.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/12/2018] [Accepted: 07/25/2018] [Indexed: 11/27/2022]
Abstract
Blockade of the mineralocorticoid receptor (MCR) has been shown to improve endothelial function far beyond blood pressure control. In the current studies we have looked at the effect of MCR antagonists on cationic amino acid transporter-1 (CAT-1), a major modulator of endothelial nitric oxide (NO) generation. Using radio-labeled arginine, {[3H] l-arginine} uptake was determined in human umbilical vein endothelial cells (HUVEC) following incubation with either spironolactone or eplerenone with or without silencing of MCR. Western blotting for CAT-1, PKCα and their phosphorylated forms were performed. NO generation was measured by using Griess reaction assay. Both Spironolactone and eplerenone significantly increased endothelial arginine transport, an effect which was further augmented by co-incubation with aldosterone, and blunted by either silencing of MCR or co-administration of amiloride. Following MCR blockade, we identified two bands for CAT-1. The addition of tunicamycin (an inhibitor of protein glycosylation) or MCR silencing resulted in disappearance of the extra band and prevented the increase in arginine transport. Only spironolactone decreased CAT-1 phosphorylation through inhibition of PKCα (CAT-1 inhibitor). Subsequently, incubation with either MCR antagonists significantly augmented NO2/NO3 levels (stable NO metabolites) and this was attenuated by silencing of MCR or tunicamycin. GO 6076 (PKCα inhibitor) intensified the increase of NO metabolites only in eplerenone treated cells. In conclusion spironolactone and eplerenone augment arginine transport and NO generation through modulation of CAT-1 in endothelial cells. Both MCR antagonists activate CAT-1 by inducing its glycosylation while only spironolactone inhibits PKCα.
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Affiliation(s)
- Moshe Shashar
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel; Nephrology Section, Sanz Medical Center, Laniado Hospital, Netanya, Israel
| | - Tamar Hod
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Tamara Chernichovski
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Avital Angel
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Shaul Kazan
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Ayelet Grupper
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Sivan Naveh
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Orit Kliuk-Ben Bassat
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Talia Weinstein
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Idit F Schwartz
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel.
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21
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Zapotoczny B, Szafranska K, Owczarczyk K, Kus E, Chlopicki S, Szymonski M. Atomic Force Microscopy Reveals the Dynamic Morphology of Fenestrations in Live Liver Sinusoidal Endothelial Cells. Sci Rep 2017; 7:7994. [PMID: 28801568 PMCID: PMC5554186 DOI: 10.1038/s41598-017-08555-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/13/2017] [Indexed: 12/19/2022] Open
Abstract
Here, we report an atomic force microscopy (AFM)-based imaging method for resolving the fine nanostructures (e.g., fenestrations) in the membranes of live primary murine liver sinusoidal endothelial cells (LSECs). From data on topographical and nanomechanical properties of the selected cell areas collected within 1 min, we traced the dynamic rearrangement of the cell actin cytoskeleton connected with the formation or closing of cell fenestrations, both in non-stimulated LSECs as well as in response to cytochalasin B and antimycin A. In conclusion, AFM-based imaging permitted the near real-time measurements of dynamic changes in fenestrations in live LSECs.
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Affiliation(s)
- B Zapotoczny
- Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Krakow, Poland.
| | - K Szafranska
- Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Krakow, Poland.,Jagiellonian Centre for Experimental Therapeutics, JCET, Jagiellonian University, Krakow, Poland
| | - K Owczarczyk
- Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Krakow, Poland
| | - E Kus
- Jagiellonian Centre for Experimental Therapeutics, JCET, Jagiellonian University, Krakow, Poland
| | - S Chlopicki
- Jagiellonian Centre for Experimental Therapeutics, JCET, Jagiellonian University, Krakow, Poland.,Chair of Pharmacology, Jagiellonian University, Medical College, Krakow, Poland
| | - M Szymonski
- Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Krakow, Poland
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22
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Dey SK, Singh RK, Chattoraj S, Saha S, Das A, Bhattacharyya K, Sengupta K, Sen S, Jana SS. Differential role of nonmuscle myosin II isoforms during blebbing of MCF-7 cells. Mol Biol Cell 2017; 28:1034-1042. [PMID: 28251924 PMCID: PMC5391180 DOI: 10.1091/mbc.e16-07-0524] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/26/2017] [Accepted: 02/21/2017] [Indexed: 11/21/2022] Open
Abstract
One molecular cue that regulates cellular protrusions such as blebbing and lamellipodia in tumor cells has been less explored than other environmental factors. NM II-A induces blebbing and NM II-C1 induces lamellipodia in tumor cells. NM-II isoforms can change the protrusive activity of a tumor cell. Bleb formation has been correlated with nonmuscle myosin II (NM-II) activity. Whether three isoforms of NM-II (NM-IIA, -IIB and -IIC) have the same or differential roles in bleb formation is not well understood. Here we report that ectopically expressed, GFP-tagged NM-II isoforms exhibit different types of membrane protrusions, such as multiple blebs, lamellipodia, combinations of both, or absence of any such protrusions in MCF-7 cells. Quantification suggests that 50% of NM-IIA-GFP–, 29% of NM-IIB-GFP–, and 19% of NM-IIC1-GFP–expressing MCF-7 cells show multiple bleb formation, compared with 36% of cells expressing GFP alone. Of interest, NM-IIB has an almost 50% lower rate of dissociation from actin filament than NM-IIA and –IIC1 as determined by FRET analysis both at cell and bleb cortices. We induced bleb formation by disruption of the cortex and found that all three NM-II-GFP isoforms can reappear and form filaments but to different degrees in the growing bleb. NM-IIB-GFP can form filaments in blebs in 41% of NM-IIB-GFP–expressing cells, whereas filaments form in only 12 and 3% of cells expressing NM-IIA-GFP and NM-IIC1-GFP, respectively. These studies suggest that NM-II isoforms have differential roles in the bleb life cycle.
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Affiliation(s)
- Sumit K Dey
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Raman K Singh
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Shyamtanu Chattoraj
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Shekhar Saha
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Alakesh Das
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Kaushik Sengupta
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - Shamik Sen
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
| | - Siddhartha S Jana
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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23
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Jokhadar ŠZ, Derganc J. Structural Rearrangements in CHO Cells After Disruption of Individual Cytoskeletal Elements and Plasma Membrane. Cell Biochem Biophys 2016; 71:1605-13. [PMID: 25395197 DOI: 10.1007/s12013-014-0383-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cellular structural integrity is provided primarily by the cytoskeleton, which comprises microtubules, actin filaments, and intermediate filaments. The plasma membrane has been also recognized as a mediator of physical forces, yet its contribution to the structural integrity of the cell as a whole is less clear. In order to investigate the relationship between the plasma membrane and the cytoskeleton, we selectively disrupted the plasma membrane and each of the cytoskeletal elements in Chinese hamster ovary cells and assessed subsequent changes in cellular structural integrity. Confocal microscopy was used to visualize cytoskeletal rearrangements, and optical tweezers were utilized to quantify membrane tether extraction. We found that cholesterol depletion from the plasma membrane resulted in rearrangements of all cytoskeletal elements. Conversely, the state of the plasma membrane, as assessed by tether extraction, was affected by disruption of any of the cytoskeletal elements, including microtubules and intermediate filaments, which are located mainly in the cell interior. The results demonstrate that, besides the cytoskeleton, the plasma membrane is an important contributor to cellular integrity, possibly by acting as an essential framework for cytoskeletal anchoring. In agreement with the tensegrity model of cell mechanics, our results support the notion of the cell as a prestressed structure.
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Affiliation(s)
- Špela Zemljič Jokhadar
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
| | - Jure Derganc
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
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24
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Kreplak L. Introduction to Atomic Force Microscopy (AFM) in Biology. ACTA ACUST UNITED AC 2016; 85:17.7.1-17.7.21. [PMID: 27479503 DOI: 10.1002/cpps.14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The atomic force microscope (AFM) has the unique capability of imaging biological samples with molecular resolution in buffer solution over a wide range of time scales from milliseconds to hours. In addition to providing topographical images of surfaces with nanometer- to angstrom-scale resolution, forces between single molecules and mechanical properties of biological samples can be investigated from the nano-scale to the micro-scale. Importantly, the measurements are made in buffer solutions, allowing biological samples to "stay alive" within a physiological-like environment while temporal changes in structure are measured-e.g., before and after addition of chemical reagents. These qualities distinguish AFM from conventional imaging techniques of comparable resolution, e.g., electron microscopy (EM). This unit provides an introduction to AFM on biological systems and describes specific examples of AFM on proteins, cells, and tissues. The physical principles of the technique and methodological aspects of its practical use and applications are also described. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Laurent Kreplak
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, Canada
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25
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Elasto-mechanical properties of living cells. Biochem Biophys Rep 2016; 7:303-308. [PMID: 28955919 PMCID: PMC5613353 DOI: 10.1016/j.bbrep.2016.06.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/21/2016] [Accepted: 06/21/2016] [Indexed: 11/22/2022] Open
Abstract
The possibility to directly measure the elasticity of living cell has emerged only in the last few decades. In the present study the elastic properties of two cell lines were followed. Both types are widely used as cell barrier models (e.g. blood-brain barrier). During time resolved measurement of the living cell elasticity a continuous quasi-periodic oscillation of the elastic modulus was observed. Fast Fourier transformation of the signals revealed that a very limited number of three to five Fourier terms fitted the signal in the case of human cerebral endothelial cells. In the case of canine kidney epithelial cells more than 8 Fourier terms did not result a good fit. Calculating the correlation between nucleus and periphery of the signals revealed a higher correlation factor for the endothelial cells compared to the epithelial cells.
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26
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Kronlage C, Schäfer-Herte M, Böning D, Oberleithner H, Fels J. Feeling for Filaments: Quantification of the Cortical Actin Web in Live Vascular Endothelium. Biophys J 2016; 109:687-98. [PMID: 26287621 PMCID: PMC4547164 DOI: 10.1016/j.bpj.2015.06.066] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 06/07/2015] [Accepted: 06/24/2015] [Indexed: 12/27/2022] Open
Abstract
Contact-mode atomic force microscopy (AFM) has been shown to reveal cortical actin structures. Using live endothelial cells, we visualized cortical actin dynamics simultaneously by AFM and confocal fluorescence microscopy. We present a method that quantifies dynamic changes in the mechanical ultrastructure of the cortical actin web. We argue that the commonly used, so-called error signal imaging in AFM allows a qualitative, but not quantitative, analysis of cortical actin dynamics. The approach we used comprises fast force-curve-based topography imaging and subsequent image processing that enhances local height differences. Dynamic changes in the organization of the cytoskeleton network can be observed and quantified by surface roughness calculations and automated morphometrics. Upon treatment with low concentrations of the actin-destabilizing agent cytochalasin D, the cortical cytoskeleton network is thinned out and the average mesh size increases. In contrast, jasplakinolide, a drug that enhances actin polymerization, consolidates the cytoskeleton network and reduces the average mesh area. In conclusion, cortical actin dynamics can be quantified in live cells. To our knowledge, this opens a new pathway for conducting quantitative structure-function analyses of the endothelial actin web just beneath the apical plasma membrane.
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Affiliation(s)
| | - Marco Schäfer-Herte
- Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany
| | - Daniel Böning
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | | | - Johannes Fels
- Institute of Physiology II, University of Münster, Münster, Germany; Institute of Cell Dynamics and Imaging, University of Münster, Münster, Germany.
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27
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Birukova AA, Shah AS, Tian Y, Moldobaeva N, Birukov KG. Dual role of vinculin in barrier-disruptive and barrier-enhancing endothelial cell responses. Cell Signal 2016; 28:541-51. [PMID: 26923917 DOI: 10.1016/j.cellsig.2016.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 02/15/2016] [Accepted: 02/21/2016] [Indexed: 01/31/2023]
Abstract
Endothelial cell (EC) barrier disruption induced by edemagenic agonists such as thrombin is a result of increased actomyosin contraction and enforcement of focal adhesions (FA) anchoring contracting stress fibers, which leads to cell retraction and force-induced disruption of cell junctions. In turn, EC barrier enhancement by oxidized phospholipids (OxPAPC) and other agonists is a result of increased tethering forces due to enforcement of the peripheral actin rim and enhancement of cell-cell adherens junction (AJ) complexes promoting EC barrier integrity. This study tested participation of the mechanosensitive adaptor, vinculin, which couples FA and AJ to actin cytoskeleton, in control of the EC permeability response to barrier disruptive (thrombin) and barrier enhancing (OxPAPC) stimulation. OxPAPC and thrombin induced different patterns of FA remodeling. Knockdown of vinculin attenuated both, OxPAPC-induced decrease and thrombin-induced increase in EC permeability. Thrombin stimulated the vinculin association with FA protein talin and suppressed the interaction with AJ protein, VE-cadherin. In contrast, OxPAPC stimulated the vinculin association with VE-cadherin. Thrombin and OxPAPC induced different levels of myosin light chain (MLC) phosphorylation and caused different patterns of intracellular phospho-MLC distribution. Thrombin-induced talin-vinculin and OxPAPC-induced VE-cadherin-vinculin association were abolished by myosin inhibitor blebbistatin. Expression of the vinculin mutant unable to interact with actin attenuated EC permeability changes and MLC phosphorylation caused by both, thrombin and OxPAPC. These data suggest that the specific vinculin interaction with FA or AJ in different contexts of agonist stimulation is defined by development of regional actyomyosin-based tension and participates in both, the barrier-disruptive and barrier-enhancing endothelial responses.
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Affiliation(s)
- Anna A Birukova
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Alok S Shah
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Yufeng Tian
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Nurgul Moldobaeva
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Konstantin G Birukov
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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28
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Guillou L, Babataheri A, Puech PH, Barakat AI, Husson J. Dynamic monitoring of cell mechanical properties using profile microindentation. Sci Rep 2016; 6:21529. [PMID: 26857265 PMCID: PMC4746699 DOI: 10.1038/srep21529] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/25/2016] [Indexed: 11/09/2022] Open
Abstract
We have developed a simple and relatively inexpensive system to visualize adherent cells in profile while measuring their mechanical properties using microindentation. The setup allows simultaneous control of cell microenvironment by introducing a micropipette for the delivery of soluble factors or other cell types. We validate this technique against atomic force microscopy measurements and, as a proof of concept, measure the viscoelastic properties of vascular endothelial cells in terms of an apparent stiffness and a dimensionless parameter that describes stress relaxation. Furthermore, we use this technique to monitor the time evolution of these mechanical properties as the cells' actin is depolymerized using cytochalasin-D.
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Affiliation(s)
- L Guillou
- Hydrodynamics Laboratory (LadHyX), Department of Mechanics, Ecole Polytechnique, 91128 Palaiseau, France
| | - A Babataheri
- Hydrodynamics Laboratory (LadHyX), Department of Mechanics, Ecole Polytechnique, 91128 Palaiseau, France
| | - P-H Puech
- Aix Marseille University, LAI UM 61, Marseille, F-13288, France.,Inserm, UMR_S 1067, Marseille, F-13288, France.,CNRS, UMR 7333, Marseille, F-13288, France
| | - A I Barakat
- Hydrodynamics Laboratory (LadHyX), Department of Mechanics, Ecole Polytechnique, 91128 Palaiseau, France
| | - J Husson
- Hydrodynamics Laboratory (LadHyX), Department of Mechanics, Ecole Polytechnique, 91128 Palaiseau, France
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29
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Yellol J, Pérez SA, Yellol G, Zajac J, Donaire A, Vigueras G, Novohradsky V, Janiak C, Brabec V, Ruiz J. Highly potent extranuclear-targeted luminescent iridium(iii) antitumor agents containing benzimidazole-based ligands with a handle for functionalization. Chem Commun (Camb) 2016; 52:14165-14168. [DOI: 10.1039/c6cc07909a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This discovery could open the door to a new large family of multifunctional bioconjugated drugs.
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Affiliation(s)
- Jyoti Yellol
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
| | - Sergio A. Pérez
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
| | - Gorakh Yellol
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
| | - Juraj Zajac
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- 612 65 Brno
- Czech Republic
- Department of Biophysics
| | - Antonio Donaire
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
| | - Gloria Vigueras
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
| | - Vojtech Novohradsky
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- 612 65 Brno
- Czech Republic
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie
- Heinrich-Heine-Universität Düsseldorf
- D-40225 Düsseldorf
- Germany
| | - Viktor Brabec
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- 612 65 Brno
- Czech Republic
- Department of Biophysics
| | - José Ruiz
- Departamento de Química Inorgánica and Regional Campus of International Excellence “Campus Mare Nostrum”
- Universidad de Murcia, and Biomedical Research Institute of Murcia (IMIB-Arrixaca)
- E-30071 Murcia
- Spain
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30
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Guo M, Kim P, Li G, Elowsky C, Alfano J. A Bacterial Effector Co-opts Calmodulin to Target the Plant Microtubule Network. Cell Host Microbe 2016; 19:67-78. [DOI: 10.1016/j.chom.2015.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 11/03/2015] [Accepted: 12/21/2015] [Indexed: 12/21/2022]
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31
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Kilpatrick JI, Revenko I, Rodriguez BJ. Nanomechanics of Cells and Biomaterials Studied by Atomic Force Microscopy. Adv Healthc Mater 2015. [PMID: 26200464 DOI: 10.1002/adhm.201500229] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The behavior and mechanical properties of cells are strongly dependent on the biochemical and biomechanical properties of their microenvironment. Thus, understanding the mechanical properties of cells, extracellular matrices, and biomaterials is key to understanding cell function and to develop new materials with tailored mechanical properties for tissue engineering and regenerative medicine applications. Atomic force microscopy (AFM) has emerged as an indispensable technique for measuring the mechanical properties of biomaterials and cells with high spatial resolution and force sensitivity within physiologically relevant environments and timescales in the kPa to GPa elastic modulus range. The growing interest in this field of bionanomechanics has been accompanied by an expanding array of models to describe the complexity of indentation of hierarchical biological samples. Furthermore, the integration of AFM with optical microscopy techniques has further opened the door to a wide range of mechanotransduction studies. In recent years, new multidimensional and multiharmonic AFM approaches for mapping mechanical properties have been developed, which allow the rapid determination of, for example, cell elasticity. This Progress Report provides an introduction and practical guide to making AFM-based nanomechanical measurements of cells and surfaces for tissue engineering applications.
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Affiliation(s)
- Jason I. Kilpatrick
- Conway Institute of Biomolecular and Biomedical Research; University College Dublin; Belfield Dublin 4 Ireland
| | - Irène Revenko
- Asylum Research an Oxford Instruments Company; 6310 Hollister Avenue Santa Barbara CA 93117 USA
| | - Brian J. Rodriguez
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin; Belfield, Dublin 4, Ireland; School of Physics; University College Dublin; Belfield Dublin 4 Ireland
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32
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A Parallel-Plate Flow Chamber for Mechanical Characterization of Endothelial Cells Exposed to Laminar Shear Stress. Cell Mol Bioeng 2015; 9:127-138. [PMID: 28989541 DOI: 10.1007/s12195-015-0424-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Shear stresses induced by laminar fluid flow are essential to properly recapitulate the physiological microenvironment experienced by endothelial cells (ECs). ECs respond to these stresses via mechanotransduction by modulating their phenotype and biomechanical characteristics, which can be characterized by Atomic Force Microscopy (AFM). Parallel Plate Flow Chambers (PPFCs) apply unidirectional laminar fluid flow to EC monolayers in vitro. Since ECs in sealed PPFCs are inaccessible to AFM probes, cone-and-plate viscometers (CPs) are commonly used to apply shear stress. This paper presents a comparison of the efficacies of both methods. Computational Fluid Dynamic simulation and validation testing using EC responses as a metric have indicated limitations in the use of CPs to apply laminar shear stress. Monolayers subjected to laminar fluid flow in a PPFC respond by increasing cortical stiffness, elongating, and aligning filamentous actin in the direction of fluid flow to a greater extent than CP devices. Limitations using CP devices to provide laminar flow across an EC monolayer suggest they are better suited when studying EC response for disturbed flow conditions. PPFC platforms allow for exposure of ECs to laminar fluid flow conditions, recapitulating cellular biomechanical behaviors, whereas CP platforms allow for mechanical characterization of ECs under secondary flow.
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33
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A Review of Cell Adhesion Studies for Biomedical and Biological Applications. Int J Mol Sci 2015; 16:18149-84. [PMID: 26251901 PMCID: PMC4581240 DOI: 10.3390/ijms160818149] [Citation(s) in RCA: 511] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 06/21/2015] [Accepted: 06/24/2015] [Indexed: 01/13/2023] Open
Abstract
Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events.
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34
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Morgan JT, Raghunathan VK, Chang YR, Murphy CJ, Russell P. The intrinsic stiffness of human trabecular meshwork cells increases with senescence. Oncotarget 2015; 6:15362-74. [PMID: 25915531 PMCID: PMC4558157 DOI: 10.18632/oncotarget.3798] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 03/20/2015] [Indexed: 12/26/2022] Open
Abstract
Dysfunction of the human trabecular meshwork (HTM) plays a central role in the age-associated disease glaucoma, a leading cause of irreversible blindness. The etiology remains poorly understood but cellular senescence, increased stiffness of the tissue, and the expression of Wnt antagonists such as secreted frizzled related protein-1 (SFRP1) have been implicated. However, it is not known if senescence is causally linked to either stiffness or SFRP1 expression. In this study, we utilized in vitro HTM senescence to determine the effect on cellular stiffening and SFRP1 expression. Stiffness of cultured cells was measured using atomic force microscopy and the morphology of the cytoskeleton was determined using immunofluorescent analysis. SFRP1 expression was measured using qPCR and immunofluorescent analysis. Senescent cell stiffness increased 1.88±0.14 or 2.57±0.14 fold in the presence or absence of serum, respectively. This was accompanied by increased vimentin expression, stress fiber formation, and SFRP1 expression. In aggregate, these data demonstrate that senescence may be a causal factor in HTM stiffening and elevated SFRP1 expression, and contribute towards disease progression. These findings provide insight into the etiology of glaucoma and, more broadly, suggest a causal link between senescence and altered tissue biomechanics in aging-associated diseases.
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Affiliation(s)
- Joshua T. Morgan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Vijay Krishna Raghunathan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Yow-Ren Chang
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
- Department of Ophthalmology &; Vision Science, School of Medicine, University of California, Davis, CA, USA
| | - Paul Russell
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
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Huveneers S, Daemen MJAP, Hordijk PL. Between Rho(k) and a hard place: the relation between vessel wall stiffness, endothelial contractility, and cardiovascular disease. Circ Res 2015; 116:895-908. [PMID: 25722443 DOI: 10.1161/circresaha.116.305720] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vascular stiffness is a mechanical property of the vessel wall that affects blood pressure, permeability, and inflammation. As a result, vascular stiffness is a key driver of (chronic) human disorders, including pulmonary arterial hypertension, kidney disease, and atherosclerosis. Responses of the endothelium to stiffening involve integration of mechanical cues from various sources, including the extracellular matrix, smooth muscle cells, and the forces that derive from shear stress of blood. This response in turn affects endothelial cell contractility, which is an important property that regulates endothelial stiffness, permeability, and leukocyte-vessel wall interactions. Moreover, endothelial stiffening reduces nitric oxide production, which promotes smooth muscle cell contraction and vasoconstriction. In fact, vessel wall stiffening, and microcirculatory endothelial dysfunction, precedes hypertension and thus underlies the development of vascular disease. Here, we review the cross talk among vessel wall stiffening, endothelial contractility, and vascular disease, which is controlled by Rho-driven actomyosin contractility and cellular mechanotransduction. In addition to discussing the various inputs and relevant molecular events in the endothelium, we address which actomyosin-regulated changes at cell adhesion complexes are genetically associated with human cardiovascular disease. Finally, we discuss recent findings that broaden therapeutic options for targeting this important mechanical signaling pathway in vascular pathogenesis.
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Affiliation(s)
- Stephan Huveneers
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Mat J A P Daemen
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Peter L Hordijk
- From the Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Swammerdam Institute for Life Sciences (S.H., P.L.H.) and Department of Pathology (M.J.A.P.D.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Yoshida A, Sakai N, Uekusa Y, Deguchi K, Gilmore JL, Kumeta M, Ito S, Takeyasu K. Probing in vivo dynamics of mitochondria and cortical actin networks using high-speed atomic force/fluorescence microscopy. Genes Cells 2014; 20:85-94. [PMID: 25440894 DOI: 10.1111/gtc.12204] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/06/2014] [Indexed: 12/12/2022]
Abstract
The dynamics of the cell membrane and submembrane structures are closely linked, facilitating various cellular activities. Although cell surface research and cortical actin studies have shown independent mechanisms for the cell membrane and the actin network, it has been difficult to obtain a comprehensive understanding of the dynamics of these structures in live cells. Here, we used a combined atomic force/optical microscope system to analyze membrane-based cellular events at nanometer-scale resolution in live cells. Imaging the COS-7 cell surface showed detailed structural properties of membrane invagination events corresponding to endocytosis and exocytosis. In addition, the movement of mitochondria and the spatiotemporal dynamics of the cortical F-actin network were directly visualized in vivo. Cortical actin microdomains with sizes ranging from 1.7×10(4) to 1.4×10(5) nm2 were dynamically rearranged by newly appearing actin filaments, which sometimes accompanied membrane invaginations, suggesting that these events are integrated with the dynamic regulation of submembrane organizations maintained by actin turnovers. These results provide novel insights into the structural aspects of the entire cell membrane machinery which can be visualized with high temporal and spatial resolution.
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Affiliation(s)
- Aiko Yoshida
- Graduate School of Biostudies, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
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37
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Kusche-Vihrog K, Schmitz B, Brand E. Salt controls endothelial and vascular phenotype. Pflugers Arch 2014; 467:499-512. [DOI: 10.1007/s00424-014-1657-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/11/2014] [Accepted: 11/14/2014] [Indexed: 01/11/2023]
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Glaubitz M, Medvedev N, Pussak D, Hartmann L, Schmidt S, Helm CA, Delcea M. A novel contact model for AFM indentation experiments on soft spherical cell-like particles. SOFT MATTER 2014; 10:6732-6741. [PMID: 25068646 DOI: 10.1039/c4sm00788c] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The use of the simple Hertz model for the analysis of Atomic Force Microscopy (AFM) force-distance curves measured on soft spherical cell-like particles leads to significant underestimations of the objects Young's modulus E. To correct this error, a mixed double contact model (based on the simple Hertz model and the Johnson-Kendall-Roberts (JKR) model) was derived. The model considers two independent particle deformation sites: (i) the upper part of the particle is deformed by the AFM indenter, (ii) the bottom part is deformed by the substrate, which is usually unnoticed. It becomes apparent that for soft particles even small forces between substrate and particle can influence the resulting force-distance curves. For instance we show, that a gravity-induced compression on the particle bottom side can have significant influence on the measurements. To highlight these observations, the deviation of the particle Young's modulus E between the simple Hertz model and our model is calculated. This error strongly depends on the ratio of the three involved radii: (i) the radius of the AFM indenter, (ii) the radius of the particle and (iii) the radius of the substrate as well as on the acting gravity force. Overall, the analysis suggests that for nanoscopic indenters the deviation is negligible, whereas the use of microscopic indenters results in significant errors that can be corrected via the presented model. This is important especially for very soft particles, since larger indenters can achieve higher signal to noise ratios. Furthermore, the applicability of the model was confirmed by indentation experiments on hydrogel microbeads. The mixed double contact model is applicable to a large range of indenter geometries and can be adapted for other contact models.
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Affiliation(s)
- Michael Glaubitz
- ZIK-HIKE - Zentrum für Innovationskompetenz "Humorale Immunreaktionen bei Kardiovaskulären Erkrankungen", Fleischmannstr. 42 - 44, D-17489 Greifswald, Germany.
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Martinelli R, Zeiger AS, Whitfield M, Sciuto TE, Dvorak A, Van Vliet KJ, Greenwood J, Carman CV. Probing the biomechanical contribution of the endothelium to lymphocyte migration: diapedesis by the path of least resistance. J Cell Sci 2014; 127:3720-34. [PMID: 25002404 DOI: 10.1242/jcs.148619] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Immune cell trafficking requires the frequent breaching of the endothelial barrier either directly through individual cells ('transcellular' route) or through the inter-endothelial junctions ('paracellular' route). What determines the loci or route of breaching events is an open question with important implications for overall barrier regulation. We hypothesized that basic biomechanical properties of the endothelium might serve as crucial determinants of this process. By altering junctional integrity, cytoskeletal morphology and, consequently, local endothelial cell stiffness of different vascular beds, we could modify the preferred route of diapedesis. In particular, high barrier function was associated with predominantly transcellular migration, whereas negative modulation of junctional integrity resulted in a switch to paracellular diapedesis. Furthermore, we showed that lymphocytes dynamically probe the underlying endothelium by extending invadosome-like protrusions (ILPs) into its surface that deform the nuclear lamina, distort actin filaments and ultimately breach the barrier. Fluorescence imaging and pharmacologic depletion of F-actin demonstrated that lymphocyte barrier breaching efficiency was inversely correlated with local endothelial F-actin density and stiffness. Taken together, these data support the hypothesis that lymphocytes are guided by the mechanical 'path of least resistance' as they transverse the endothelium, a process we term 'tenertaxis'.
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Affiliation(s)
- Roberta Martinelli
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA Department of Cell Biology, Institute of Ophthalmology, UCL, 11-43 Bath Street, London EC1V 9EL, UK
| | - Adam S Zeiger
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew Whitfield
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tracey E Sciuto
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Ann Dvorak
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Krystyn J Van Vliet
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - John Greenwood
- Department of Cell Biology, Institute of Ophthalmology, UCL, 11-43 Bath Street, London EC1V 9EL, UK
| | - Christopher V Carman
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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Lamers ML, Padilha DM, Bernardi L, da Silveira HE, Fossati ACM. X-ray irradiation alters the actin cytoskeleton in murine lacrimal glands. Acta Odontol Scand 2014; 72:386-91. [PMID: 24125038 DOI: 10.3109/00016357.2013.847488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the effects of X radiation on the distribution of filamentous actin (F-actin) in the mouse exorbital lacrimal gland. MATERIALS AND METHODS Mice were divided into groups that received no radiation (n = 6) or one single exposure of 36 mGy of X radiation (n = 12). The animals were sacrificed after 4, 8 or 24 h. The lacrimal glands were stained with Hematoxylin/Eosin or Rhodamine-phalloidin and the filamentous actin arrangement was analyzed by confocal microscopy. RESULTS After 4 h of X-ray exposure there was an apparent increase in acini area and a decrease in the cortical F-actin content in secretory cells. This effect decreased gradually over time, returning to values close to the control after 24 h. CONCLUSION This study shows that a 36 mGy diagnostic X-ray dose affected reversibly the mouse exorbital lacrimal gland, suggesting that radiation used in diagnosis may induce changes on cell morphology due to actin remodeling.
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Affiliation(s)
- Marcelo Lazzaron Lamers
- Morphological Sciences Department, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul , Brazil
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41
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A computational mechanics approach to assess the link between cell morphology and forces during confined migration. Biomech Model Mechanobiol 2014; 14:143-57. [PMID: 24895016 DOI: 10.1007/s10237-014-0595-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 05/12/2014] [Indexed: 12/20/2022]
Abstract
Confined migration plays a fundamental role during several biological phenomena such as embryogenesis, immunity and tumorogenesis. Here, we propose a two-dimensional mechanical model to simulate the migration of a HeLa cell through a micro-channel. As in our previous works, the cell is modelled as a continuum and a standard Maxwell model is used to describe the mechanical behaviour of both the cytoplasm (including active strains) and the nucleus. The cell cyclically protrudes and contracts and develops viscous forces to adhere to the substrate. The micro-channel is represented by two rigid walls, and it exerts an additional viscous force on the cell boundaries. We test four channels whose dimensions in terms of width are i) larger than the cell diameter, ii) sub-cellular, ii) sub-nuclear and iv) much smaller than the nucleus diameter. The main objective of the work is to assess the necessary conditions for the cell to enter into the channel and migrate through it. Therefore, we evaluate both the evolution of the cell morphology and the cell-channel and cell-substrate surface forces, and we show that there exists a link between the two, which is the essential parameter determining whether the cell is permeative, invasive or penetrating.
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42
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Grimm KB, Oberleithner H, Fels J. Fixed endothelial cells exhibit physiologically relevant nanomechanics of the cortical actin web. NANOTECHNOLOGY 2014; 25:215101. [PMID: 24786855 DOI: 10.1088/0957-4484/25/21/215101] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
It has been unknown whether cells retain their mechanical properties after fixation. Therefore, this study was designed to compare the stiffness properties of the cell cortex (the 50-100 nm thick zone below the plasma membrane) before and after fixation. Atomic force microscopy was used to acquire force indentation curves from which the nanomechanical cell properties were derived. Cells were pretreated with different concentrations of actin destabilizing agent cytochalasin D, which results in a gradual softening of the cell cortex. Then cells were studied 'alive' or 'fixed'. We show that the cortical stiffness of fixed endothelial cells still reports functional properties of the actin web qualitatively comparable to those of living cells. Myosin motor protein activity, tested by blebbistatin inhibition, can only be detected, in terms of cortical mechanics, in living but not in fixed cells. We conclude that fixation interferes with motor proteins while maintaining a functional cortical actin web. Thus, fixation of cells opens up the prospect of differentially studying the actions of cellular myosin and actin.
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Affiliation(s)
- Kai Bodo Grimm
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
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43
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Stroka KM, Jiang H, Chen SH, Tong Z, Wirtz D, Sun SX, Konstantopoulos K. Water permeation drives tumor cell migration in confined microenvironments. Cell 2014; 157:611-23. [PMID: 24726433 DOI: 10.1016/j.cell.2014.02.052] [Citation(s) in RCA: 329] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 09/10/2013] [Accepted: 02/02/2014] [Indexed: 11/28/2022]
Abstract
Cell migration is a critical process for diverse (patho)physiological phenomena. Intriguingly, cell migration through physically confined spaces can persist even when typical hallmarks of 2D planar migration, such as actin polymerization and myosin II-mediated contractility, are inhibited. Here, we present an integrated experimental and theoretical approach ("Osmotic Engine Model") and demonstrate that directed water permeation is a major mechanism of cell migration in confined microenvironments. Using microfluidic and imaging techniques along with mathematical modeling, we show that tumor cells confined in a narrow channel establish a polarized distribution of Na+/H+ pumps and aquaporins in the cell membrane, which creates a net inflow of water and ions at the cell leading edge and a net outflow of water and ions at the trailing edge, leading to net cell displacement. Collectively, this study presents an alternate mechanism of cell migration in confinement that depends on cell-volume regulation via water permeation.
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Affiliation(s)
- Kimberly M Stroka
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA; Johns Hopkins Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Hongyuan Jiang
- Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA; CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei, Anhui 230026, PRC
| | - Shih-Hsun Chen
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ziqiu Tong
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA; Johns Hopkins Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Denis Wirtz
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA; Johns Hopkins Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sean X Sun
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA; Johns Hopkins Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Konstantinos Konstantopoulos
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218, USA; Johns Hopkins Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA.
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Ando T, Uchihashi T, Scheuring S. Filming biomolecular processes by high-speed atomic force microscopy. Chem Rev 2014; 114:3120-88. [PMID: 24476364 PMCID: PMC4076042 DOI: 10.1021/cr4003837] [Citation(s) in RCA: 234] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Toshio Ando
- Department of Physics, and Bio-AFM Frontier
Research Center, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
- CREST,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi 332-0012, Japan
| | - Takayuki Uchihashi
- Department of Physics, and Bio-AFM Frontier
Research Center, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
- CREST,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi 332-0012, Japan
| | - Simon Scheuring
- U1006
INSERM/Aix-Marseille Université, Parc Scientifique et Technologique
de Luminy Bâtiment Inserm TPR2 bloc 5, 163 avenue de Luminy, 13288 Marseille Cedex 9, France
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Schnittler H, Taha M, Schnittler MO, Taha AA, Lindemann N, Seebach J. Actin filament dynamics and endothelial cell junctions: the Ying and Yang between stabilization and motion. Cell Tissue Res 2014; 355:529-43. [PMID: 24643678 DOI: 10.1007/s00441-014-1856-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/24/2014] [Indexed: 12/17/2022]
Abstract
The vascular endothelium is a cellular interface between the blood and the interstitial space of tissue, which controls the exchange of fluid, solutes and cells by both transcellular and paracellular means. To accomplish the demands on barrier function, the regulation of the endothelium requires quick and adaptive mechanisms. This is, among others, accomplished by actin dynamics that interdependently interact with both the VE-cadherin/catenin complex, the main components of the adherens type junctions in endothelium and the membrane cytoskeleton. Actin filaments in endothelium are components of super-structured protein assemblies that control a variety of dynamic processes such as endo- and exocytosis, shape change, cell-substrate along with cell-cell adhesion and cell motion. In endothelium, actin filaments are components of: (1) contractile actin bundles appearing as stress fibers and junction-associated circumferential actin filaments, (2) actin networks accompanied by endocytotic ruffles, lamellipodia at leading edges of migrating cells and junction-associated intermittent lamellipodia (JAIL) that dynamically maintain junction integrity, (3) cortical actin and (4) the membrane cytoskeleton. All these structures, most probably interact with cell junctions and cell-substrate adhesion sites. Due to the rapid growth in information, we aim to provide a bird's eye view focusing on actin filaments in endothelium and its functional relevance for entire cell and junction integrity, rather than discussing the detailed molecular mechanism for control of actin dynamics.
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Affiliation(s)
- Hans Schnittler
- Institute of Anatomy and Vascular Biology, Westfälische Wilhelms-Universität Münster, Vesaliusweg 2-4, 48149, Münster, Germany,
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46
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Microtubules mediate changes in membrane cortical elasticity during contractile activation. Exp Cell Res 2014; 322:21-9. [DOI: 10.1016/j.yexcr.2013.12.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 12/17/2013] [Accepted: 12/31/2013] [Indexed: 12/20/2022]
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Unal M, Alapan Y, Jia H, Varga AG, Angelino K, Aslan M, Sayin I, Han C, Jiang Y, Zhang Z, Gurkan UA. Micro and Nano-Scale Technologies for Cell Mechanics. Nanobiomedicine (Rij) 2014; 1:5. [PMID: 30023016 PMCID: PMC6029242 DOI: 10.5772/59379] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/18/2014] [Indexed: 01/09/2023] Open
Abstract
Cell mechanics is a multidisciplinary field that bridges cell biology, fundamental mechanics, and micro and nanotechnology, which synergize to help us better understand the intricacies and the complex nature of cells in their native environment. With recent advances in nanotechnology, microfabrication methods and micro-electro-mechanical-systems (MEMS), we are now well situated to tap into the complex micro world of cells. The field that brings biology and MEMS together is known as Biological MEMS (BioMEMS). BioMEMS take advantage of systematic design and fabrication methods to create platforms that allow us to study cells like never before. These new technologies have been rapidly advancing the study of cell mechanics. This review article provides a succinct overview of cell mechanics and comprehensively surveys micro and nano-scale technologies that have been specifically developed for and are relevant to the mechanics of cells. Here we focus on micro and nano-scale technologies, and their applications in biology and medicine, including imaging, single cell analysis, cancer cell mechanics, organ-on-a-chip systems, pathogen detection, implantable devices, neuroscience and neurophysiology. We also provide a perspective on the future directions and challenges of technologies that relate to the mechanics of cells.
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Affiliation(s)
- Mustafa Unal
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, USA
| | - Yunus Alapan
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, USA
- Case Biomanufacturing and Microfabrication Laboratory, Case Western Reserve University, Cleveland, USA
| | - Hao Jia
- Department of Biology, Case Western Reserve University, Cleveland, USA
| | - Adrienn G. Varga
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, USA
| | - Keith Angelino
- Department of Civil Engineering, Case Western Reserve University, Cleveland, USA
| | - Mahmut Aslan
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, USA
- Case Biomanufacturing and Microfabrication Laboratory, Case Western Reserve University, Cleveland, USA
| | - Ismail Sayin
- Case Biomanufacturing and Microfabrication Laboratory, Case Western Reserve University, Cleveland, USA
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, USA
| | - Chanjuan Han
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, USA
| | - Yanxia Jiang
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, USA
| | - Zhehao Zhang
- Department of Civil Engineering, Case Western Reserve University, Cleveland, USA
| | - Umut A. Gurkan
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, USA
- Case Biomanufacturing and Microfabrication Laboratory, Case Western Reserve University, Cleveland, USA
- Department of Orthopaedics, Case Western Reserve University, Cleveland, USA
- Advanced Platform Technology Center, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, USA
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48
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Zhdanov VP. Physical aspects of the initial phase of endocytosis. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:064701. [PMID: 24483591 DOI: 10.1103/physreve.88.064701] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Indexed: 06/03/2023]
Abstract
The endocytotic mechanism of entry of virions into cells includes wrapping of a virion by the host membrane with subsequent formation of a vesicle covering a virion. The energy along this pathway depends on the ligand-receptor interaction and deformation of the cell membrane and underlying actin cytoskeleton. The available models describe the cytoskeleton deformation by using the conventional continuum theory of elasticity and predict that this factor often controls the repulsive part of the virion-cell interaction. This approach is, however, debatable because the size of virions is smaller than or comparable to the length scale characterizing the cytoskeleton structure. The author shows that the continuum theory appreciably (up to one order of magnitude) overestimates the cytoskeleton-deformation energy and that the scale of this energy is comparable to that of cell membrane bending.
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Affiliation(s)
- Vladimir P Zhdanov
- Division of Biological Physics, Department of Applied Physics, Chalmers University of Technology, S-41296 Göteborg, Sweden and Boreskov Institute of Catalysis, Russian Academy of Sciences, Novosibirsk 630090, Russia
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49
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Arce FT, Meckes B, Camp SM, Garcia JGN, Dudek SM, Lal R. Heterogeneous elastic response of human lung microvascular endothelial cells to barrier modulating stimuli. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2013; 9:875-84. [PMID: 23523769 PMCID: PMC3762941 DOI: 10.1016/j.nano.2013.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/08/2013] [Accepted: 03/11/2013] [Indexed: 11/15/2022]
Abstract
In this study we employ atomic force microscopy, supported by finite element analysis and fluorescence microscopy, to characterize the elastic properties accompanying cytoskeletal structural rearrangements of lung microvascular endothelial cells in response to barrier altering stimuli. Statistical analysis of elasticity data obtained from multiple cells demonstrates a heterogeneous cellular elastic response to barrier-enhancing and barrier-disrupting agents; sphingosine 1-phosphate (S1P) and thrombin, respectively. A small but detectable (10%) increase in the average elastic modulus of all cells is observed for S1P, which is accompanied by a corresponding significant decrease in cell thickness. Variable effects of thrombin on these parameters were observed. To account for possible substrate effects in our elasticity analysis, we analyzed only the low-force sections of the force-displacement curves and utilized a finite-thickness correction to the Hertzian model. Our finite element analysis results substantiate this approach. The heterogeneous elastic behavior correlates with differential cytoskeletal rearrangements observed with fluorescence microscopy. FROM THE CLINICAL EDITOR This team of investigators employed atomic force microscopy coupled with finite element analysis and fluorescence microscopy to characterize the elastic properties accompanying cytoskeletal structural rearrangements of lung microvascular endothelial cells in response to barrier altering stimuli, demonstrating the validity of their approach.
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Affiliation(s)
- Fernando Terán Arce
- Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA; Bioengineering Departments, University of California San Diego, La Jolla, California, USA.
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50
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Kusche-Vihrog K, Jeggle P, Oberleithner H. The role of ENaC in vascular endothelium. Pflugers Arch 2013; 466:851-9. [PMID: 24046153 DOI: 10.1007/s00424-013-1356-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/09/2013] [Accepted: 09/09/2013] [Indexed: 12/31/2022]
Abstract
Once upon a time, the expression of the epithelial sodium channel (ENaC) was mainly assigned to the kidneys, colon and sweat glands where it was considered to be the main determinant of sodium homeostasis. Recent, though indirect, evidence for the possible existence of ENaC in a non-epithelial tissue was derived from the observation that the vascular endothelium is a target for aldosterone. Inhibitory actions of the intracellular aldosterone receptors by spironolactone and, more directly, by ENaC blockers such as amiloride supported this view. Shortly after, direct data on the expression of ENaC in vascular endothelium could be demonstrated. There, endothelial ENaC (EnNaC) could be defined as a major regulator of cellular mechanics which is a critical parameter in differentiating between vascular function and dysfunction. Foremost, the mechanical stiffness of the endothelial cell cortex, a layer 50-200 nm beneath the plasma membrane, has been shown to play a crucial role as it controls the production of the endothelium-derived vasodilator nitric oxide (NO) which directly affects the tone of the vascular smooth muscle cells. In contrast to soft endothelial cells, stiff endothelial cells release reduced amounts of NO, the hallmark of endothelial dysfunction. Thus, the combination of endothelial stiffness and myogenic tone might increase the peripheral vascular resistance. An elevation of arterial blood pressure is supposed to be the consequence of such functional changes. In this review, EnNaC is discussed as an aldosterone-regulated plasma membrane protein of the vascular endothelium that could significantly contribute to maintaining of an appropriate arterial blood pressure but, if overexpressed, could participate in the pathogenesis of arterial hypertension.
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Affiliation(s)
- Kristina Kusche-Vihrog
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany,
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