1
|
Basu A, Paul MK, Weiss S. The actin cytoskeleton: Morphological changes in pre- and fully developed lung cancer. BIOPHYSICS REVIEWS 2022; 3:041304. [PMID: 38505516 PMCID: PMC10903407 DOI: 10.1063/5.0096188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 12/09/2022] [Indexed: 03/21/2024]
Abstract
Actin, a primary component of the cell cytoskeleton can have multiple isoforms, each of which can have specific properties uniquely suited for their purpose. These monomers are then bound together to form polymeric filaments utilizing adenosine triphosphate hydrolysis as a source of energy. Proteins, such as Arp2/3, VASP, formin, profilin, and cofilin, serve important roles in the polymerization process. These filaments can further be linked to form stress fibers by proteins called actin-binding proteins, such as α-actinin, myosin, fascin, filamin, zyxin, and epsin. These stress fibers are responsible for mechanotransduction, maintaining cell shape, cell motility, and intracellular cargo transport. Cancer metastasis, specifically epithelial mesenchymal transition (EMT), which is one of the key steps of the process, is accompanied by the formation of thick stress fibers through the Rho-associated protein kinase, MAPK/ERK, and Wnt pathways. Recently, with the advent of "field cancerization," pre-malignant cells have also been demonstrated to possess stress fibers and related cytoskeletal features. Analytical methods ranging from western blot and RNA-sequencing to cryo-EM and fluorescent imaging have been employed to understand the structure and dynamics of actin and related proteins including polymerization/depolymerization. More recent methods involve quantifying properties of the actin cytoskeleton from fluorescent images and utilizing them to study biological processes, such as EMT. These image analysis approaches exploit the fact that filaments have a unique structure (curvilinear) compared to the noise or other artifacts to separate them. Line segments are extracted from these filament images that have assigned lengths and orientations. Coupling such methods with statistical analysis has resulted in development of a new reporter for EMT in lung cancer cells as well as their drug responses.
Collapse
Affiliation(s)
| | | | - Shimon Weiss
- Author to whom correspondence should be addressed:
| |
Collapse
|
2
|
Chagnon-Lessard S, Godin M, Pelling AE. Time dependence of cellular responses to dynamic and complex strain fields. Integr Biol (Camb) 2019; 11:4-15. [PMID: 30778578 DOI: 10.1093/intbio/zyy002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/08/2018] [Indexed: 11/13/2022]
Abstract
Exposing cells to an unconventional sequence of physical cues can reveal subtleties of cellular sensing and response mechanisms. We investigated the mechanoresponse of cyclically stretched fibroblasts under a spatially non-uniform strain field which was subjected to repeated changes in stretching directions over 55 h. A polydimethylsiloxane microfluidic stretcher array optimized for complex staining procedures and imaging was developed to generate biologically relevant strain and strain gradient amplitudes. We demonstrated that cells can successfully reorient themselves repeatedly, as the main cyclical stretching direction is consecutively switched between two perpendicular directions every 11 h. Importantly, from one reorientation to the next, the extent to which cells reorient themselves perpendicularly to the local strain direction progressively decreases, while their tendency to align perpendicularly to the strain gradient direction increases. We demonstrate that these results are consistent with our finding that cellular responses to strains and strain gradients occur on two distinct time scales, the latter being slower. Overall, our results reveal the absence of major irreversible cellular changes that compromise the ability to sense and reorient to changing strain directions under the conditions of this experiment. On the other hand, we show how the history of strain field dynamics can influence the cellular realignment behavior, due to the interplay of complex time-dependent responses.
Collapse
Affiliation(s)
| | - Michel Godin
- Department of Physics, STEM Building 150 Louis Pasteur, Ottawa, Canada.,Department of Mechanical Engineering, Site Building, 800 King Edward Avenue, University of Ottawa, ON, Canada.,Ottawa-Carleton Institute for Biomedical Engineering, Ottawa, ON, Canada
| | - Andrew E Pelling
- Department of Physics, STEM Building 150 Louis Pasteur, Ottawa, Canada.,Department of Biology, Gendron Hall, 30 Marie Curie, University of Ottawa, Ottawa, ON, Canada.,Institute for Science Society and Policy, Simard Hall, 60 University, University of Ottawa, Ottawa, ON, Canada.,SymbioticA, School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, Australia
| |
Collapse
|
3
|
Okimura C, Sakumura Y, Shimabukuro K, Iwadate Y. Sensing of substratum rigidity and directional migration by fast-crawling cells. Phys Rev E 2018; 97:052401. [PMID: 29906928 DOI: 10.1103/physreve.97.052401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 12/24/2022]
Abstract
Living cells sense the mechanical properties of their surrounding environment and respond accordingly. Crawling cells detect the rigidity of their substratum and migrate in certain directions. They can be classified into two categories: slow-moving and fast-moving cell types. Slow-moving cell types, such as fibroblasts, smooth muscle cells, mesenchymal stem cells, etc., move toward rigid areas on the substratum in response to a rigidity gradient. However, there is not much information on rigidity sensing in fast-moving cell types whose size is ∼10 μm and migration velocity is ∼10 μm/min. In this study, we used both isotropic substrata with different rigidities and an anisotropic substratum that is rigid on the x axis but soft on the y axis to demonstrate rigidity sensing by fast-moving Dictyostelium cells and neutrophil-like differentiated HL-60 cells. Dictyostelium cells exerted larger traction forces on a more rigid isotropic substratum. Dictyostelium cells and HL-60 cells migrated in the "soft" direction on the anisotropic substratum, although myosin II-null Dictyostelium cells migrated in random directions, indicating that rigidity sensing of fast-moving cell types differs from that of slow types and is induced by a myosin II-related process.
Collapse
Affiliation(s)
- Chika Okimura
- Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
| | - Yuichi Sakumura
- School of Information Science and Technology, Aichi Prefectural University, Aichi 480-1198, Japan.,Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, 630-0192, Japan
| | - Katsuya Shimabukuro
- Department of Chemical and Biological Engineering, National Institute of Technology, Ube College, Ube 755-8555, Japan
| | - Yoshiaki Iwadate
- Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
| |
Collapse
|
4
|
Chagnon-Lessard S, Jean-Ruel H, Godin M, Pelling AE. Cellular orientation is guided by strain gradients. Integr Biol (Camb) 2018; 9:607-618. [PMID: 28534911 DOI: 10.1039/c7ib00019g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The strain-induced reorientation response of cyclically stretched cells has been well characterized in uniform strain fields. In the present study, we comprehensively analyse the behaviour of human fibroblasts subjected to a highly non-uniform strain field within a polymethylsiloxane microdevice. Our results indicate that the strain gradient amplitude and direction regulate cell reorientation through a coordinated gradient avoidance response. We provide critical evidence that strain gradient is a key physical cue that can guide cell organization. Specifically, our work suggests that cells are able to pinpoint the location under the cell of multiple physical cues and integrate this information (strain and strain gradient amplitudes and directions), resulting in a coordinated response. To gain insight into the underlying mechanosensing processes, we studied focal adhesion reorganization and the effect of modulating myosin-II contractility. The extracted focal adhesion orientation distributions are similar to those obtained for the cell bodies, and their density is increased by the presence of stretching forces. Moreover, it was found that the myosin-II activity promoter calyculin-A has little effect on the cellular response, while the inhibitor blebbistatin suppresses cell and focal adhesion alignment and reduces focal adhesion density. These results confirm that similar internal structures involved in sensing and responding to strain direction and amplitude are also key players in strain gradient mechanosensing and avoidance.
Collapse
Affiliation(s)
- Sophie Chagnon-Lessard
- Department of Physics, Center for Interdisciplinary Nanophysics, University of Ottawa, 598 King Edward, Ottawa, ON K1N 6N5, Canada.
| | | | | | | |
Collapse
|
5
|
Çoban G, Çelebi MS. A novel computational remodelling algorithm for the probabilistic evolution of collagen fibre dispersion in biaxially strained vascular tissue. MATHEMATICAL MEDICINE AND BIOLOGY : A JOURNAL OF THE IMA 2017; 34:433-467. [PMID: 27614761 DOI: 10.1093/imammb/dqw012] [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: 03/27/2015] [Accepted: 08/02/2016] [Indexed: 06/06/2023]
Abstract
In this work, we constructed a novel collagen fibre remodelling algorithm that incorporates the complex nature of random evolution acting on single fibres causing macroscopic fibre dispersion. The proposed framework is different from the existing remodelling algorithms, in that the microscopic random force on cellular scales causing a rotational-type Brownian motion alone is considered as an aspect of vascular tissue remodelling. A continuum mechanical framework for the evolution of local dispersion and how it could be used for modeling the evolution of internal radius of biaxially strained artery structures under constant internal blood pressure are presented. A linear evolution form for the statistical fibre dispersion is employed in the model. The random force component of the evolution, which depends on the mechanical stress stimuli, is described by a single parameter. Although the mathematical form of the proposed model is simple, there is a strong link between the microscopic evolution of collagen dispersion on the cellular level and its effects on the macroscopic visible world through mechanical variables. We believe that the proposed algorithm utilizes a better understanding of the relationship between the evolution rates of mean fibre direction and fibre dispersion. The predictive capability of the algorithm is presented using experimental data. The model has been simulated by solving a single-layered axisymmetric artery (adventitia) deformation problem. The algorithm performed well for estimating the quantitative features of experimental anisotropy, the mean fibre direction vector and the dispersion (κ) measurements under strain-dependent evolution assumptions.
Collapse
Affiliation(s)
- Gürsan Çoban
- Department of Computational Science & Engineering, Informatics Institute, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey
| | - M Serdar Çelebi
- Department of Computational Science & Engineering, Informatics Institute, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey
| |
Collapse
|
6
|
Alioscha-Perez M, Benadiba C, Goossens K, Kasas S, Dietler G, Willaert R, Sahli H. A Robust Actin Filaments Image Analysis Framework. PLoS Comput Biol 2016; 12:e1005063. [PMID: 27551746 PMCID: PMC4995035 DOI: 10.1371/journal.pcbi.1005063] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 07/15/2016] [Indexed: 11/18/2022] Open
Abstract
The cytoskeleton is a highly dynamical protein network that plays a central role in numerous cellular physiological processes, and is traditionally divided into three components according to its chemical composition, i.e. actin, tubulin and intermediate filament cytoskeletons. Understanding the cytoskeleton dynamics is of prime importance to unveil mechanisms involved in cell adaptation to any stress type. Fluorescence imaging of cytoskeleton structures allows analyzing the impact of mechanical stimulation in the cytoskeleton, but it also imposes additional challenges in the image processing stage, such as the presence of imaging-related artifacts and heavy blurring introduced by (high-throughput) automated scans. However, although there exists a considerable number of image-based analytical tools to address the image processing and analysis, most of them are unfit to cope with the aforementioned challenges. Filamentous structures in images can be considered as a piecewise composition of quasi-straight segments (at least in some finer or coarser scale). Based on this observation, we propose a three-steps actin filaments extraction methodology: (i) first the input image is decomposed into a ‘cartoon’ part corresponding to the filament structures in the image, and a noise/texture part, (ii) on the ‘cartoon’ image, we apply a multi-scale line detector coupled with a (iii) quasi-straight filaments merging algorithm for fiber extraction. The proposed robust actin filaments image analysis framework allows extracting individual filaments in the presence of noise, artifacts and heavy blurring. Moreover, it provides numerous parameters such as filaments orientation, position and length, useful for further analysis. Cell image decomposition is relatively under-exploited in biological images processing, and our study shows the benefits it provides when addressing such tasks. Experimental validation was conducted using publicly available datasets, and in osteoblasts grown in two different conditions: static (control) and fluid shear stress. The proposed methodology exhibited higher sensitivity values and similar accuracy compared to state-of-the-art methods. We propose a novel actin filaments cytoskeleton analysis framework that allows extracting quasi-straight individual fibers in a robust manner, and provides their respective position, orientation, and length as output. The proposed framework is defined as a three-steps processing sequence, that can explicitly cope with high-throughput imaging related issues, such as noise/artifacts presence and heavy blurring, and can similarly process artifacts-free and well-focused images.
Collapse
Affiliation(s)
- Mitchel Alioscha-Perez
- Electronics and Informatics Dept (ETRO), AVSP Lab, Vrije Universiteit Brussel, Brussels, Belgium
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- * E-mail: (MAP); (HS)
| | - Carine Benadiba
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Laboratoire de Physique de la Matière Vivante (LPMV), EPFL, Cubotron, Lausanne, Switzerland
| | - Katty Goossens
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Department of Bioengineering Sciences (DBIT), Vrije Universiteit Brussel, Brussels, Belgium
| | - Sandor Kasas
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Laboratoire de Physique de la Matière Vivante (LPMV), EPFL, Cubotron, Lausanne, Switzerland
| | - Giovanni Dietler
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Laboratoire de Physique de la Matière Vivante (LPMV), EPFL, Cubotron, Lausanne, Switzerland
| | - Ronnie Willaert
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Department of Bioengineering Sciences (DBIT), Vrije Universiteit Brussel, Brussels, Belgium
| | - Hichem Sahli
- Electronics and Informatics Dept (ETRO), AVSP Lab, Vrije Universiteit Brussel, Brussels, Belgium
- VUB-EPFL International Joint Research Group (IJRG) NanoBiotechnology and NanoMedicine (NANO), Brussels, Belgium
- Interuniversity Microelectronics Centre (IMEC), Heverlee, Belgium
- * E-mail: (MAP); (HS)
| |
Collapse
|
7
|
Okimura C, Iwadate Y. Hybrid mechanosensing system to generate the polarity needed for migration in fish keratocytes. Cell Adh Migr 2016; 10:406-18. [PMID: 27124267 DOI: 10.1080/19336918.2016.1170268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Crawling cells can generate polarity for migration in response to forces applied from the substratum. Such reaction varies according to cell type: there are both fast- and slow-crawling cells. In response to periodic stretching of the elastic substratum, the intracellular stress fibers in slow-crawling cells, such as fibroblasts, rearrange themselves perpendicular to the direction of stretching, with the result that the shape of the cells extends in that direction; whereas fast-crawling cells, such as neutrophil-like differentiated HL-60 cells and Dictyostelium cells, which have no stress fibers, migrate perpendicular to the stretching direction. Fish epidermal keratocytes are another type of fast-crawling cell. However, they have stress fibers in the cell body, which gives them a typical slow-crawling cell structure. In response to periodic stretching of the elastic substratum, intact keratocytes rearrange their stress fibers perpendicular to the direction of stretching in the same way as fibroblasts and migrate parallel to the stretching direction, while blebbistatin-treated stress fiber-less keratocytes migrate perpendicular to the stretching direction, in the same way as seen in HL-60 cells and Dictyostelium cells. Our results indicate that keratocytes have a hybrid mechanosensing system that comprises elements of both fast- and slow-crawling cells, to generate the polarity needed for migration.
Collapse
Affiliation(s)
- Chika Okimura
- a Faculty of Science , Yamaguchi University , Yamaguchi , Japan
| | | |
Collapse
|
8
|
Okimura C, Ueda K, Sakumura Y, Iwadate Y. Fast-crawling cell types migrate to avoid the direction of periodic substratum stretching. Cell Adh Migr 2016; 10:331-41. [PMID: 26980079 DOI: 10.1080/19336918.2015.1129482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To investigate the relationship between mechanical stimuli from substrata and related cell functions, one of the most useful techniques is the application of mechanical stimuli via periodic stretching of elastic substrata. In response to this stimulus, Dictyostelium discoideum cells migrate in a direction perpendicular to the stretching direction. The origins of directional migration, higher migration velocity in the direction perpendicular to the stretching direction or the higher probability of a switch of migration direction to perpendicular to the stretching direction, however, remain unknown. In this study, we applied periodic stretching stimuli to neutrophil-like differentiated HL-60 cells, which migrate perpendicular to the direction of stretch. Detailed analysis of the trajectories of HL-60 cells and Dictyostelium cells obtained in a previous study revealed that the higher probability of a switch of migration direction to that perpendicular to the direction of stretching was the main cause of such directional migration. This directional migration appears to be a strategy adopted by fast-crawling cells in which they do not migrate faster in the direction they want to go, but migrate to avoid a direction they do not want to go.
Collapse
Affiliation(s)
- Chika Okimura
- a Faculty of Science , Yamaguchi University , Yamaguchi , Japan
| | - Kazuki Ueda
- a Faculty of Science , Yamaguchi University , Yamaguchi , Japan
| | - Yuichi Sakumura
- b School of Information Science and Technology , Aichi Prefectural University , Aichi , Japan.,c Graduate School of Biological Sciences , Nara Institute of Science and Technology , Nara , Japan
| | | |
Collapse
|
9
|
Elosegui-Artola A, Jorge-Peñas A, Moreno-Arotzena O, Oregi A, Lasa M, García-Aznar JM, De Juan-Pardo EM, Aldabe R. Image analysis for the quantitative comparison of stress fibers and focal adhesions. PLoS One 2014; 9:e107393. [PMID: 25269086 PMCID: PMC4182299 DOI: 10.1371/journal.pone.0107393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 08/15/2014] [Indexed: 01/08/2023] Open
Abstract
Actin stress fibers (SFs) detect and transmit forces to the extracellular matrix through focal adhesions (FAs), and molecules in this pathway determine cellular behavior. Here, we designed two different computational tools to quantify actin SFs and the distribution of actin cytoskeletal proteins within a normalized cellular morphology. Moreover, a systematic cell response comparison between the control cells and those with impaired actin cytoskeleton polymerization was performed to demonstrate the reliability of the tools. Indeed, a variety of proteins that were present within the string beginning at the focal adhesions (vinculin) up to the actin SFs contraction (non-muscle myosin II (NMMII)) were analyzed. Finally, the software used allows for the quantification of the SFs based on the relative positions of FAs. Therefore, it provides a better insight into the cell mechanics and broadens the knowledge of the nature of SFs.
Collapse
Affiliation(s)
- Alberto Elosegui-Artola
- Tissue Engineering and Biomaterials Unit, Centro de Estudios e Investigaciones Técnicas and Tecnun, University of Navarra, San Sebastian, Spain
| | - Alvaro Jorge-Peñas
- Tissue Engineering and Biomaterials Unit, Centro de Estudios e Investigaciones Técnicas and Tecnun, University of Navarra, San Sebastian, Spain
| | - Oihana Moreno-Arotzena
- Multiscale in Mechanical and Biological Engineering, Aragón Institute of Engineering Research, Universidad de Zaragoza, Zaragoza, Spain
| | - Amaia Oregi
- Tissue Engineering and Biomaterials Unit, Centro de Estudios e Investigaciones Técnicas and Tecnun, University of Navarra, San Sebastian, Spain
| | - Marta Lasa
- Gene Therapy and Hepatology Area, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - José Manuel García-Aznar
- Multiscale in Mechanical and Biological Engineering, Aragón Institute of Engineering Research, Universidad de Zaragoza, Zaragoza, Spain
| | - Elena M. De Juan-Pardo
- Tissue Engineering and Biomaterials Unit, Centro de Estudios e Investigaciones Técnicas and Tecnun, University of Navarra, San Sebastian, Spain
- * E-mail: (RA); (EMDJ)
| | - Rafael Aldabe
- Gene Therapy and Hepatology Area, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- * E-mail: (RA); (EMDJ)
| |
Collapse
|
10
|
Jiang L, Yang C, Zhao L, Zheng Q. Stress fiber response to mechanics: a free energy dependent statistical model. SOFT MATTER 2014; 10:4603-4608. [PMID: 24763746 DOI: 10.1039/c3sm52914b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An experimental observation has been puzzling scientists for years: cells tend to align perpendicular to cyclic uniaxial strain, but parallel to external static strain. Recent experimental results demonstrate that both the magnitude of the external strain and the cell contractility manipulate the cells' orientation under cyclic uniaxial strain. In light of these reports, we introduce a minimum free energy model to explain the different orientation tendencies of cells subjected to external strain, and elucidate the significant role of cell contractility in this issue. With the present model, we successfully explain a series of well-documented phenomena: (1) cells orient nearly parallel to static uniaxial strain; (2) cell alignment depends on the magnitude of the cyclic uniaxial strain; (3) under cyclic uniaxial stretch, a tensioned contractility results in a strengthened perpendicular alignment of the cells, whereas a contractility relaxation results in a nearly parallel alignment. In addition, this model also successfully describes the functional relationship between cell contractility and substrate stiffness.
Collapse
Affiliation(s)
- Li Jiang
- Institute of Biomechanics and Medical Engineering, Engineering Mechanics Department, School of Aerospace, Tsinghua University, Beijing 100084, China.
| | | | | | | |
Collapse
|
11
|
Planas-Paz L, Lammert E. Mechanosensing in developing lymphatic vessels. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2014; 214:23-40. [PMID: 24276884 DOI: 10.1007/978-3-7091-1646-3_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The lymphatic vasculature is responsible for fluid homeostasis, transport of immune cells, inflammatory molecules, and dietary lipids. It is composed of a network of lymphatic capillaries that drain into collecting lymphatic vessels and ultimately bring fluid back to the blood circulation. Lymphatic endothelial cells (LECs) that line lymphatic capillaries present loose overlapping intercellular junctions and anchoring filaments that support fluid drainage. When interstitial fluid accumulates within tissues, the extracellular matrix (ECM) swells and pulls the anchoring filaments. This results in opening of the LEC junctions and permits interstitial fluid uptake. The absorbed fluid is then transported within collecting lymphatic vessels, which exhibit intraluminal valves that prevent lymph backflow and smooth muscle cells that sequentially contract to propel lymph.Mechanotransduction involves translation of mechanical stimuli into biological responses. LECs have been shown to sense and respond to changes in ECM stiffness, fluid pressure-induced cell stretch, and fluid flow-induced shear stress. How these signals influence LEC function and lymphatic vessel growth can be investigated by using different mechanotransduction assays in vitro and to some extent in vivo.In this chapter, we will focus on the mechanical forces that regulate lymphatic vessel expansion during embryonic development and possibly secondary lymphedema. In mouse embryos, it has been recently shown that the amount of interstitial fluid determines the extent of lymphatic vessel expansion via a mechanosensory complex formed by β1 integrin and vascular endothelial growth factor receptor-3 (VEGFR3). This model might as well apply to secondary lymphedema.
Collapse
Affiliation(s)
- Lara Planas-Paz
- Institute of Metabolic Physiology, Heinrich-Heine University, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | | |
Collapse
|
12
|
Iwadate Y, Okimura C, Sato K, Nakashima Y, Tsujioka M, Minami K. Myosin-II-mediated directional migration of Dictyostelium cells in response to cyclic stretching of substratum. Biophys J 2013; 104:748-58. [PMID: 23442953 DOI: 10.1016/j.bpj.2013.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 01/03/2013] [Accepted: 01/07/2013] [Indexed: 11/29/2022] Open
Abstract
Living cells are constantly subjected to various mechanical stimulations, such as shear flow, osmotic pressure, and hardness of substratum. They must sense the mechanical aspects of their environment and respond appropriately for proper cell function. Cells adhering to substrata must receive and respond to mechanical stimuli from the substrata to decide their shape and/or migrating direction. In response to cyclic stretching of the elastic substratum, intracellular stress fibers in fibroblasts and endothelial, osteosarcoma, and smooth muscle cells are rearranged perpendicular to the stretching direction, and the shape of those cells becomes extended in this new direction. In the case of migrating Dictyostelium cells, cyclic stretching regulates the direction of migration, and not the shape, of the cell. The cells migrate in a direction perpendicular to that of the stretching. However, the molecular mechanisms that induce the directional migration remain unknown. Here, using a microstretching device, we recorded green fluorescent protein (GFP)-myosin-II dynamics in Dictyostelium cells on an elastic substratum under cyclic stretching. Repeated stretching induced myosin II localization equally on both stretching sides in the cells. Although myosin-II-null cells migrated randomly, myosin-II-null cells expressing a variant of myosin II that cannot hydrolyze ATP migrated perpendicular to the stretching. These results indicate that Dictyostelium cells accumulate myosin II at the portion of the cell where a large strain is received and migrate in a direction other than that of the portion where myosin II accumulated. This polarity generation for migration does not require the contraction of actomyosin.
Collapse
Affiliation(s)
- Yoshiaki Iwadate
- Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan.
| | | | | | | | | | | |
Collapse
|
13
|
Charnley M, Anderegg F, Holtackers R, Textor M, Meraldi P. Effect of Cell Shape and Dimensionality on Spindle Orientation and Mitotic Timing. PLoS One 2013; 8:e66918. [PMID: 23825020 PMCID: PMC3688943 DOI: 10.1371/journal.pone.0066918] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/13/2013] [Indexed: 01/13/2023] Open
Abstract
The formation and orientation of the mitotic spindle is a critical feature of mitosis. The morphology of the cell and the spatial distribution and composition of the cells' adhesive microenvironment all contribute to dictate the position of the spindle. However, the impact of the dimensionality of the cells' microenvironment has rarely been studied. In this study we present the use of a microwell platform, where the internal surfaces of the individual wells are coated with fibronectin, enabling the three-dimensional presentation of adhesive ligands to single cells cultured within the microwells. This platform was used to assess the effect of dimensionality and cell shape in a controlled microenvironment. Single HeLa cells cultured in circular microwells exhibited greater tilting of the mitotic spindle, in comparison to cells cultured in square microwells. This correlated with an increase in the time required to align the chromosomes at the metaphase plate due to prolonged activation of the spindle checkpoint in an actin dependent process. The comparison to 2D square patterns revealed that the dimensionality of cell adhesions alone affected both mitotic timings and spindle orientation; in particular the role of actin varied according to the dimensionality of the cells' microenvironment. Together, our data revealed that cell shape and the dimensionality of the cells' adhesive environment impacted on both the orientation of the mitotic spindle and progression through mitosis.
Collapse
Affiliation(s)
- Mirren Charnley
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
- * E-mail:
| | - Fabian Anderegg
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
| | | | - Marcus Textor
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
| | | |
Collapse
|