scholarly journals High stretchability, strength and toughness of living cells enabled by hyperelastic vimentin network

2018 ◽  
Author(s):  
Jiliang Hu ◽  
Yiwei Li ◽  
Yukun Hao ◽  
Tianqi Zheng ◽  
German Alberto Parada ◽  
...  
Keyword(s):  
Intermediate Filaments ◽  
Actin Filaments ◽  
Cancer Metastasis ◽  
Structural Integrity ◽  
Large Deformations ◽  
Normal Development ◽  
Living Cells ◽  
Cellular Migration ◽  
Physiological Processes ◽  
Small Deformations

AbstractIn many normal and abnormal physiological processes, including cellular migration during normal development and invasion in cancer metastasis, cells are required to withstand severe deformations. The structural integrity of eukaryotic cells under small deformations has been known to depend on the cytoskeleton including actin filaments (F-actin), microtubules and intermediate filaments (IFs). However, it remains unclear how cells resist severe deformations since both F-actin and microtubules fluidize or disassemble under moderate strains. Here, we demonstrate that vimentin intermediate filaments (VIFs), a marker of mesenchymal cells, dominate cytoplasmic mechanics at large deformations. Our results show that cytoskeletal VIFs form a stretchable, hyperelastic network. This network works synergistically with other dissipative cytoplasmic components, substantially enhancing the strength, stretchability, resilience and toughness of the living cytoplasm.

scholarly journals High stretchability, strength, and toughness of living cells enabled by hyperelastic vimentin intermediate filaments

2019 ◽  
Vol 116 (35) ◽  
pp. 17175-17180 ◽  
Author(s):  
Jiliang Hu ◽  
Yiwei Li ◽  
Yukun Hao ◽  
Tianqi Zheng ◽  
Satish K. Gupta ◽  
...  
Keyword(s):  
Intermediate Filaments ◽  
Actin Filaments ◽  
Cancer Metastasis ◽  
Structural Integrity ◽  
Large Deformations ◽  
Normal Development ◽  
Large Family ◽  
Living Cells ◽  
Cellular Migration ◽  
Small Deformations

In many developmental and pathological processes, including cellular migration during normal development and invasion in cancer metastasis, cells are required to withstand severe deformations. The structural integrity of eukaryotic cells under small deformations has been known to depend on the cytoskeleton including actin filaments (F-actin), microtubules (MT), and intermediate filaments (IFs). However, it remains unclear how cells resist severe deformations since both F-actin and microtubules yield or disassemble under moderate strains. Using vimentin containing IFs (VIFs) as a model for studying the large family of IF proteins, we demonstrate that they dominate cytoplasmic mechanics and maintain cell viability at large deformations. Our results show that cytoskeletal VIFs form a stretchable, hyperelastic network in living cells. This network works synergistically with other cytoplasmic components, substantially enhancing the strength, stretchability, resilience, and toughness of cells. Moreover, we find the hyperelastic VIF network, together with other quickly recoverable cytoskeletal components, forms a mechanically robust structure which can mechanically recover after damage.

Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

1995 ◽  
Vol 53 ◽  
pp. 902-903
Author(s):  
J. R. Kuhn ◽  
M. Poenie
Keyword(s):  
Mitotic Spindle ◽  
Actin Filaments ◽  
Cell Shape ◽  
Dynamic Structure ◽  
Living Cells ◽  
Cytoskeletal Proteins ◽  
Polarization Microscopy ◽  
Video Enhancement ◽  
Ultrastructural Studies ◽  
Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

scholarly journals Specification of Actin Filament Function and Molecular Composition by Tropomyosin Isoforms

2003 ◽  
Vol 14 (3) ◽  
pp. 1002-1016 ◽  
Author(s):  
Nicole S. Bryce ◽  
Galina Schevzov ◽  
Vicki Ferguson ◽  
Justin M. Percival ◽  
Jim J.-C. Lin ◽  
...  
Keyword(s):  
Cell Size ◽  
Functional Properties ◽  
Actin Filament ◽  
Actin Filaments ◽  
Myosin Ii ◽  
Molecular Composition ◽  
Cellular Migration ◽  
Stress Fibers ◽  
Human Homologue ◽  
Tropomyosin Isoforms

The specific functions of greater than 40 vertebrate nonmuscle tropomyosins (Tms) are poorly understood. In this article we have tested the ability of two Tm isoforms, TmBr3 and the human homologue of Tm5 (hTM5NM1), to regulate actin filament function. We found that these Tms can differentially alter actin filament organization, cell size, and shape. hTm5NM1was able to recruit myosin II into stress fibers, which resulted in decreased lamellipodia and cellular migration. In contrast, TmBr3 transfection induced lamellipodial formation, increased cellular migration, and reduced stress fibers. Based on coimmunoprecipitation and colocalization studies, TmBr3 appeared to be associated with actin-depolymerizing factor/cofilin (ADF)-bound actin filaments. Additionally, the Tms can specifically regulate the incorporation of other Tms into actin filaments, suggesting that selective dimerization may also be involved in the control of actin filament organization. We conclude that Tm isoforms can be used to specify the functional properties and molecular composition of actin filaments and that spatial segregation of isoforms may lead to localized specialization of actin filament function.

Visualization of intermediate filaments in living cells using fluorescently labeled desmin

1989 ◽  
Vol 12 (3) ◽  
pp. 127-138 ◽  
Author(s):  
B. Mittal ◽  
J. M. Sanger ◽  
J. W. Sanger
Keyword(s):  
Intermediate Filaments ◽  
Living Cells

scholarly journals In Vitro and in Vivo Imaging of Nitroxyl with Copper Fluorescent Probe in Living Cells and Zebrafish

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2551 ◽  
Author(s):  
Sathyadevi Palanisamy ◽  
Yu-Liang Wang ◽  
Yu-Jen Chen ◽  
Chiao-Yun Chen ◽  
Fu-Te Tsai ◽  
...  
Keyword(s):  
Critical Role ◽  
Model Organism ◽  
Living Cells ◽  
Biological Species ◽  
Zebrafish Model ◽  
Physiological Processes ◽  
Collective Data ◽  
Angeli's Salt

Nitroxyl (HNO) plays a critical role in many physiological processes which includes vasorelaxation in heart failure, neuroregulation, and myocardial contractility. Powerful imaging tools are required to obtain information for understanding the mechanisms involved in these in vivo processes. In order to develop a rapid and high sensitive probe for HNO detection in living cells and the zebrafish model organism, 2-((2-(benzothiazole-2yl)benzylidene) amino)benzoic acid (AbTCA) as a ligand, and its corresponding copper(II) complex Cu(II)-AbTCA were synthesized. The reaction results of Cu(II)-AbTCA with Angeli’s salt showed that Cu(II)-AbTCA could detect HNO quantitatively in a range of 40–360 µM with a detection limit of 9.05 µM. Furthermore, Cu(II)-AbTCA is more selective towards HNO over other biological species including thiols, reactive nitrogen, and reactive oxygen species. Importantly, Cu(II)-AbTCA was successfully applied to detect HNO in living cells and zebrafish. The collective data reveals that Cu(II)-AbTCA could be used as a potential probe for HNO detection in living systems.

scholarly journals Deimination, Intermediate Filaments and Associated Proteins

2020 ◽  
Vol 21 (22) ◽  
pp. 8746
Author(s):  
Julie Briot ◽  
Michel Simon ◽  
Marie-Claire Méchin
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Cell Differentiation ◽  
Intermediate Filaments ◽  
Cross Linking ◽  
Post Translational Modification ◽  
Innate And Adaptive Immunity ◽  
Calcium Dependent ◽  
Physiological Processes ◽  
Associated Proteins

Deimination (or citrullination) is a post-translational modification catalyzed by a calcium-dependent enzyme family of five peptidylarginine deiminases (PADs). Deimination is involved in physiological processes (cell differentiation, embryogenesis, innate and adaptive immunity, etc.) and in autoimmune diseases (rheumatoid arthritis, multiple sclerosis and lupus), cancers and neurodegenerative diseases. Intermediate filaments (IF) and associated proteins (IFAP) are major substrates of PADs. Here, we focus on the effects of deimination on the polymerization and solubility properties of IF proteins and on the proteolysis and cross-linking of IFAP, to finally expose some features of interest and some limitations of citrullinomes.

scholarly journals Particle Finite Element Simulation of Chip Formation in Cutting Processes

2017 ◽  
Vol 869 ◽  
pp. 50-61
Author(s):  
Matthias Sabel ◽  
Christian Sator ◽  
Ralf Müller ◽  
Benjamin Kirsch
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Large Deformations ◽  
Element Formulation ◽  
Particle Finite Element Method ◽  
Element Simulation ◽  
Modeling Techniques ◽  
Cutting Processes ◽  
The Impact ◽  
Cutting Simulations

The formation of chips in cutting processes is characterised by large deformations and large configurational changes and therefore challenges established modeling techniques. To overcome these difficulties, the particle finite element method (PFEM) combines the benefits of discrete modeling techniques with methods based on continuum mechanics. In this work an outline of the PFEM, as well as an explanation of the finite element formulation are provided. The impact of the boundary detection on the structural integrity is studied. The numerical examples include a tensile test as well as cutting simulations. The paper is concluded by a comparison of cutting forces with analytical results.

scholarly journals Have necrohormones a role in embryogenesis?

2014 ◽  
Vol 65 (1-2) ◽  
pp. 7-9 ◽  
Author(s):  
P. R. Bell
Keyword(s):  
Cell Death ◽  
Somatic Embryogenesis ◽  
Programmed Cell Death ◽  
Picea Abies ◽  
Recent Work ◽  
Normal Development ◽  
Living Cells ◽  
Embryogenic Cultures ◽  
Conflicting Evidence ◽  
Apomictic Reproduction

The recognition of apoptosis (programmed cell death) as an accompaniment of normal development, the products released by the protoplasts undergoing self-destruction being utilized by adjacent living cells, stimulates renewed interest in Haberlandt's concept of "necrohormones" playing a role in apomictic reproduction. Recent work on somatic embryogenesis in carrot shows that regular death of certain cells in embryogenic cultures satifies the criteria of apoptosis. Similar observations have been made with embryogenic cultures of <em>Picea abies</em>. Haberlandt's claim that cell death induced by injury adjacent to an ovule in <em>Oenothera</em> could lead to parthenogenesis, despite conflicting evidence from later experimenters, is worthy of reexamination.

scholarly journals Three-Dimensional In Vitro Hydro- and Cryogel-Based Cell-Culture Models for the Study of Breast-Cancer Metastasis to Bone

Cancers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 292 ◽  
Author(s):  
Laura Bray ◽  
Constanze Secker ◽  
Berline Murekatete ◽  
Jana Sievers ◽  
Marcus Binner ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Metastasis ◽  
Cell Function ◽  
Three Dimensional ◽  
Breast Cancer Metastasis ◽  
In Vitro Models ◽  
Cellular Migration ◽  
Breast Tumor Tissue ◽  
Culture Models

Bone is the most common site for breast-cancer invasion and metastasis, and it causes severe morbidity and mortality. A greater understanding of the mechanisms leading to bone-specific metastasis could improve therapeutic strategies and thus improve patient survival. While three-dimensional in vitro culture models provide valuable tools to investigate distinct heterocellular and environmental interactions, sophisticated organ-specific metastasis models are lacking. Previous models used to investigate breast-to-bone metastasis have relied on 2.5D or singular-scaffold methods, constraining the in situ mimicry of in vitro models. Glycosaminoglycan-based gels have demonstrated outstanding potential for tumor-engineering applications. Here, we developed advanced biphasic in vitro microenvironments that mimic breast-tumor tissue (MCF-7 and MDA-MB-231 in a hydrogel) spatially separated with a mineralized bone construct (human primary osteoblasts in a cryogel). These models allow distinct advantages over former models due to the ability to observe and manipulate cellular migration towards a bone construct. The gels allow for the binding of adhesion-mediating peptides and controlled release of signaling molecules. Moreover, mechanical and architectural properties can be tuned to manipulate cell function. These results demonstrate the utility of these biomimetic microenvironment models to investigate heterotypic cell–cell and cell–matrix communications in cancer migration to bone.

Sign in / Sign up

Export Citation Format

Share Document