The force loading rate drives cell mechanosensing through both reinforcement and fluidization

2021 ◽  
Author(s):  
Jessica L. Teo
Keyword(s):  
Loading Rate ◽  
Force Loading ◽  
Cell Mechanosensing

scholarly journals Association between increase in vertical ground reaction force loading rate and pain level in women with patellofemoral pain after a patellofemoral joint loading protocol

The Knee ◽  
2018 ◽  
Vol 25 (3) ◽  
pp. 398-405 ◽  
Author(s):  
Ronaldo Valdir Briani ◽  
Marcella Ferraz Pazzinatto ◽  
Marina Cabral Waiteman ◽  
Danilo de Oliveira Silva ◽  
Fábio Mícolis de Azevedo
Keyword(s):  
Ground Reaction Force ◽  
Patellofemoral Joint ◽  
Loading Rate ◽  
Reaction Force ◽  
Patellofemoral Pain ◽  
Pain Level ◽  
Joint Loading ◽  
Vertical Ground Reaction Force ◽  
Force Loading ◽  
Vertical Ground

scholarly journals Does cellular adaptation to force loading rate determine the biphasic vs monotonic response of actin retrograde flow with substrate rigidity?

2021 ◽  
Author(s):  
Partho Sakha De ◽  
Rumi De
Keyword(s):  
Cancer Progression ◽  
Loading Rate ◽  
Focal Adhesions ◽  
Traction Force ◽  
Leading Edge ◽  
Substrate Stiffness ◽  
Retrograde Flow ◽  
Force Loading ◽  
Substrate Rigidity ◽  
Cell Traction

AbstractThe transmission of cytoskeletal forces to the extracellular matrix through focal adhesion complexes is essential for a multitude of biological processes such as cell migration, differentiation, tissue development, cancer progression, among others. During migration, focal adhesions arrest the actin retrograde flow towards the cell interior, allowing the cell front to move forward. Here, we address a puzzling observation of the existence of two distinct phenomena: a biphasic relationship of the retrograde flow and cell traction force with increasing substrate rigidity, with maximum traction force and minimum retrograde flow velocity being present at an optimal substrate stiffness; in contrast, a monotonic relationship between them where the retrograde flow decreases and traction force increases with substrate stiffness. We propose a theoretical model for cell-matrix adhesions at the leading edge of a migrating cell, incorporating a novel approach in force loading rate sensitive binding and reinforcement of focal adhesions assembly and the subsequent force-induced slowing down of actin flow. Our model unravels both biphasic and monotonic responses of the retrograde flow and cell traction force with increasing substrate rigidity, owing to the cell’s ability to sense and adapt to the fast-growing forces. Moreover, we also elucidate how the viscoelastic properties of the substrate regulate these nonlinear responses and alter cellular behaviours.

scholarly journals Molecular clutch drives cell response to surface viscosity

2018 ◽  
Vol 115 (6) ◽  
pp. 1192-1197 ◽  
Author(s):  
Mark Bennett ◽  
Marco Cantini ◽  
Julien Reboud ◽  
Jonathan M. Cooper ◽  
Pere Roca-Cusachs ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Cell Response ◽  
Loading Rate ◽  
Control Cell ◽  
Focal Adhesions ◽  
Surface Viscosity ◽  
Force Loading ◽  
Lower Viscosity ◽  
Order Of Magnitude ◽  
Myoblast Cells

Cell response to matrix rigidity has been explained by the mechanical properties of the actin-talin-integrin-fibronectin clutch. Here the molecular clutch model is extended to account for cell interactions with purely viscous surfaces (i.e., without an elastic component). Supported lipid bilayers present an idealized and controllable system through which to study this concept. Using lipids of different diffusion coefficients, the mobility (i.e., surface viscosity) of the presented ligands (in this case RGD) was altered by an order of magnitude. Cell size and cytoskeletal organization were proportional to viscosity. Furthermore, there was a higher number of focal adhesions and a higher phosphorylation of FAK on less-mobile (more-viscous) surfaces. Actin retrograde flow, an indicator of the force exerted on surfaces, was also seen to be faster on more mobile surfaces. This has consequential effects on downstream molecules; the mechanosensitive YAP protein localized to the nucleus more on less-mobile (more-viscous) surfaces and differentiation of myoblast cells was enhanced on higher viscosity. This behavior was explained within the framework of the molecular clutch model, with lower viscosity leading to a low force loading rate, preventing the exposure of mechanosensitive proteins, and with a higher viscosity causing a higher force loading rate exposing these sites, activating downstream pathways. Consequently, the understanding of how viscosity (regardless of matrix stiffness) influences cell response adds a further tool to engineer materials that control cell behavior.

scholarly journals Human neutrophil surface protrusion under a point load: location independence and viscoelasticity

2008 ◽  
Vol 295 (5) ◽  
pp. C1434-C1444 ◽  
Author(s):  
Gang Xu ◽  
Jin-Yu Shao
Keyword(s):  
Loading Rate ◽  
Optical Trap ◽  
Point Load ◽  
Force Loading ◽  
Tether Extraction ◽  
Actin Cortex ◽  
Force Relaxation ◽  
Pulling Forces ◽  
Surface Protrusion ◽  
Neutrophil Surface

Mechanical properties of neutrophils have been recognized as key contributors to stabilizing neutrophil rolling on the endothelium during the inflammatory response. In particular, accumulating evidence suggests that surface protrusion and tether extraction from neutrophils facilitate stable rolling by relieving the disruptive forces on adhesive bonds. Using a customized optical trap setup, we applied piconewton-level pulling forces on targeted receptors that were located either on the microvillus tip (CD162) or intermicrovillus surface of neutrophils (CD18 and CD44). Under a constant force-loading rate, there always occurred an initial tent-like surface protrusion that was terminated either by rupture of the adhesion or by a “yield” or “crossover” to tether extraction. The corresponding protrusional stiffness of neutrophils was found to be between 0.06 and 0.11 pN/nm, depending on the force-loading rate and the cytoskeletal integrity, but not on the force location, the medium osmolality, nor the temperature increase from 22°C to 37°C. More importantly, we found that neutrophil surface protrusion was accompanied by force relaxation and hysteresis. In addition, the crossover force did not change much in the range of force-loading rates studied, and the protrusional stiffness of lymphocytes was similar to that of neutrophils. These results show that neutrophil surface protrusion is essentially viscoelastic, with a protrusional stiffness that stems primarily from the actin cortex, and the crossover force is independent of the receptor-cytoskeleton interaction.

Effect of loading rate on cohesive parameters of the adhesive Araldite 2015

2020 ◽  
Vol 62 (9) ◽  
pp. 943-949
Author(s):  
Engin Erbayrak ◽  
Halil Ozer
Keyword(s):  
Loading Rate
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