Intermediate Filament Cytoskeletal System: Dynamic and Mechanical Properties

1998 ◽  
Vol 194 (3) ◽  
pp. 361-363 ◽  
Author(s):  
R. D. Goldman ◽  
S. Clement ◽  
S. Khuon ◽  
R. Moir ◽  
A. Trejo-Skalli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intermediate Filament ◽  
System Dynamic ◽  
Cytoskeletal System

scholarly journals The focal adhesion scaffold protein Hic-5 regulates vimentin organization in fibroblasts

2019 ◽  
Vol 30 (25) ◽  
pp. 3037-3056 ◽  
Author(s):  
Rishel B. Vohnoutka ◽  
Anushree C. Gulvady ◽  
Gregory Goreczny ◽  
Kyle Alpha ◽  
Samuel K. Handelman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Actin Cytoskeleton ◽  
Western Blotting ◽  
Focal Adhesion ◽  
Posttranslational Modifications ◽  
Intermediate Filament ◽  
Fluorescence Recovery After Photobleaching ◽  
Scaffold Protein ◽  
Cancer Associated Fibroblasts ◽  
Genetic Ablation

Focal adhesion (FA)-stimulated reorganization of the F-actin cytoskeleton regulates cellular size, shape, and mechanical properties. However, FA cross-talk with the intermediate filament cytoskeleton is poorly understood. Genetic ablation of the FA-associated scaffold protein Hic-5 in mouse cancer-associated fibroblasts (CAFs) promoted a dramatic collapse of the vimentin network, which was rescued following EGFP-Hic-5 expression. Vimentin collapse correlated with a loss of detergent-soluble vimentin filament precursors and decreased vimentin S72/S82 phosphorylation. Additionally, fluorescence recovery after photobleaching analysis indicated impaired vimentin dynamics. Microtubule (MT)-associated EB1 tracking and Western blotting of MT posttranslational modifications indicated no change in MT dynamics that could explain the vimentin collapse. However, pharmacological inhibition of the RhoGTPase Cdc42 in Hic-5 knockout CAFs rescued the vimentin collapse, while pan-formin inhibition with SMIFH2 promoted vimentin collapse in Hic-5 heterozygous CAFs. Our results reveal novel regulation of vimentin organization/dynamics by the FA scaffold protein Hic-5 via modulation of RhoGTPases and downstream formin activity.

Intermediate Filament and Associated Proteins in Heart Purkinje Fibers: A Membrane-Myofibril Anchored Cytoskeletal System

1985 ◽  
Vol 455 (1 Intermediate) ◽  
pp. 213-240 ◽  
Author(s):  
LARS-ERIC THORNELL ◽  
ANDERS ERIKSSON ◽  
BENGT JOHANSSON ◽  
UNO KJÖRELL ◽  
WERNER W. FRANKE ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Purkinje Fibers ◽  
Associated Proteins ◽  
Cytoskeletal System

scholarly journals Tuning intermediate filament mechanics by variation of pH and ion charges

Nanoscale ◽  
2020 ◽  
Vol 12 (28) ◽  
pp. 15236-15245 ◽  
Author(s):  
Anna V. Schepers ◽  
Charlotta Lorenz ◽  
Sarah Köster
Keyword(s):  
Mechanical Properties ◽  
Intermediate Filaments ◽  
Intermediate Filament ◽  
Ion Concentration

The mechanical properties of intermediate filaments depend on pH and ion concentration, providing cells with tools to tune their mechanics.

scholarly journals Tuning Intermediate Filament Mechanics by Variation of pH and Ion Charges

2019 ◽  
Author(s):  
Anna V. Schepers ◽  
Charlotta Lorenz ◽  
Sarah Köster
Keyword(s):  
Mechanical Properties ◽  
Monte Carlo ◽  
Intermediate Filaments ◽  
Intermediate Filament ◽  
Actin Filaments ◽  
Electrostatic Interactions ◽  
Ion Concentration ◽  
Ion Concentrations ◽  
Ph Values ◽  
Internal Forces

The cytoskeleton is formed by three types of filamentous proteins – microtubules, actin filaments, and intermediate filaments (IFs) – and enables cells to withstand external and internal forces. Vimentin is the most abundant IF protein in humans and assembles into 10 nm diameter filaments with remarkable mechanical properties, such as high extensibility and stability. It is, however, unclear to which extent these properties are influenced by the electrostatic environment. Here, we study the mechanical properties of single vimentin filaments by employing optical trapping combined with microfluidics. Force-strain curves, recorded at varying ion concentrations and pH values, reveal that the mechanical properties of single vimentin IFs are influenced by pH and ion concentration. By combination with Monte Carlo simulations, we relate these altered mechanics to electrostatic interactions of subunits within the filaments. We thus suggest possible mechanisms that allow cells to locally tune their stiffness without remodeling the entire cytoskeleton.

scholarly journals Mechanical Properties of Vimentin Intermediate Filament Networks

2014 ◽  
Vol 106 (2) ◽  
pp. 785a
Author(s):  
Huayin Wu ◽  
Mikkel Jensen ◽  
Ming Guo ◽  
David A. Weitz
Keyword(s):  
Mechanical Properties ◽  
Intermediate Filament ◽  
Filament Networks ◽  
Vimentin Intermediate Filament

scholarly journals A flexible network of vimentin intermediate filaments promotes migration of amoeboid cancer cells through confined environments

2020 ◽  
Vol 295 (19) ◽  
pp. 6700-6709 ◽  
Author(s):  
Sandrine B. Lavenus ◽  
Sara M. Tudor ◽  
Maria F. Ullo ◽  
Karl W. Vosatka ◽  
Jeremy S. Logue
Keyword(s):  
Mechanical Properties ◽  
Cancer Cells ◽  
Intermediate Filament ◽  
Epithelial To Mesenchymal Transition ◽  
Human Cancer ◽  
Cell Stiffness ◽  
Mesenchymal Transition ◽  
Cell Mechanical Properties ◽  
Vimentin Intermediate Filament

Tumor cells can spread to distant sites through their ability to switch between mesenchymal and amoeboid (bleb-based) migration. Because of this difference, inhibitors of metastasis must account for each migration mode. However, the role of vimentin in amoeboid migration has not been determined. Because amoeboid leader bleb–based migration (LBBM) occurs in confined spaces and vimentin is known to strongly influence cell-mechanical properties, we hypothesized that a flexible vimentin network is required for fast amoeboid migration. To this end, here we determined the precise role of the vimentin intermediate filament system in regulating the migration of amoeboid human cancer cells. Vimentin is a classic marker of epithelial-to-mesenchymal transition and is therefore an ideal target for a metastasis inhibitor. Using a previously developed polydimethylsiloxane slab–based approach to confine cells, RNAi-based vimentin silencing, vimentin overexpression, pharmacological treatments, and measurements of cell stiffness, we found that RNAi-mediated depletion of vimentin increases LBBM by ∼50% compared with control cells and that vimentin overexpression and simvastatin-induced vimentin bundling inhibit fast amoeboid migration and proliferation. Importantly, these effects were independent of changes in actomyosin contractility. Our results indicate that a flexible vimentin intermediate filament network promotes LBBM of amoeboid cancer cells in confined environments and that vimentin bundling perturbs cell-mechanical properties and inhibits the invasive properties of cancer cells.

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