scholarly journals A model of cytoskeletal reorientation in response to substrate stretching

2008 ◽  
Vol 35 (1-3) ◽  
pp. 171-190
Author(s):  
K.A. Lazopoulos ◽  
A.K. Lazopoulos ◽  
D. Stamenovic
Keyword(s):  
Flexible Substrate ◽  
Adherent Cells ◽  
Global Minima ◽  
Planar System ◽  
Cyclic Stretching ◽  
Total Potential ◽  
Acting Stress ◽  
Substrate Stretching ◽  
Elastic Cables ◽  
Static Extension

Living adherent cells change their orientation in response to substrate stretching such that their cytoskeletal components reorganize in a new direction. To study this phenomenon, we model the cytoskeleton as a planar system of elastic cables and struts both pinned at their endpoints to a flat flexible substrate. Tensed (pre-strained) cables represent acting stress fibers, whereas compression-bearing struts represent microtubules. We assume that in response to uniaxial substrate stretching the model reorients and deforms into a new configuration that minimizes its total potential energy. Using the Maxwell's global stability criterion, we find global minima configurations during static extension and compression of the substrate. Based on these results, we predict reorientation during cyclic stretching of the substrate. We find that in response to cyclic stretching cells either reorient transversely to the direction of stretching, or exhibit multiple configurations symmetrically distributed relative to the direction of stretching. These predictions are consistent with experimental data on living cells from the literature.

scholarly journals How Epithelial Cells Reorient in Response to Cyclic Stretching

2021 ◽  
Author(s):  
Jui-Chien Lien ◽  
Yu-Li Wang
Keyword(s):  
Epithelial Cells ◽  
Myosin Ii ◽  
Underlying Mechanism ◽  
Adherent Cells ◽  
Static Stretching ◽  
Relaxation Phase ◽  
Cyclic Stretching ◽  
The Difference ◽  
Cell Reorientation

Abstract Many types of adherent cells are known to reorient upon uniaxial cyclic stretching perpendicularly to the direction of stretching to facilitate such important events as wound healing, angiogenesis, and morphogenesis. While this phenomenon has been documented for decades, the underlying mechanism remains poorly understood. Using an on-stage stretching device that allowed programmable stretching with synchronized imaging, we found that the reorientation of NRK epithelial cells took place primarily during the relaxation phase when cells underwent rapid global retraction followed by extension transverse to the direction of stretching. Inhibition of myosin II caused cells to orient along the direction of stretching, whereas disassembly of microtubules enhanced transverse reorientation. Our results indicate distinct roles of stretching and relaxation in cell reorientation and implicate a role of myosin II-dependent contraction via a microtubule-modulated mechanism. The importance of relaxation phase also explains the difference between the responses to cyclic and static stretching.

scholarly journals Cyclic stretching-induced epithelial cell reorientation is driven by microtubule-modulated transverse extension during the relaxation phase

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jui-Chien Lien ◽  
Yu-li Wang
Keyword(s):  
Wound Healing ◽  
Myosin Ii ◽  
Underlying Mechanism ◽  
Adherent Cells ◽  
Static Stretching ◽  
Relaxation Phase ◽  
Cyclic Stretching ◽  
The Difference ◽  
Cell Reorientation

AbstractMany types of adherent cells are known to reorient upon uniaxial cyclic stretching perpendicularly to the direction of stretching to facilitate such important events as wound healing, angiogenesis, and morphogenesis. While this phenomenon has been documented for decades, the underlying mechanism remains poorly understood. Using an on-stage stretching device that allowed programmable stretching with synchronized imaging, we found that the reorientation of NRK epithelial cells took place primarily during the relaxation phase when cells underwent rapid global retraction followed by extension transverse to the direction of stretching. Inhibition of myosin II caused cells to orient along the direction of stretching, whereas disassembly of microtubules enhanced transverse reorientation. Our results indicate distinct roles of stretching and relaxation in cell reorientation and implicate a role of myosin II-dependent contraction via a microtubule-modulated mechanism. The importance of relaxation phase also explains the difference between the responses to cyclic and static stretching.

3-D organization of fibrinogen receptors using computer reconstruction and whole-mount microscopy

1988 ◽  
Vol 46 ◽  
pp. 30-31
Author(s):  
E. T. O'Toole ◽  
R. R. Hantgan ◽  
J. C. Lewis
Keyword(s):  
Whole Blood ◽  
Colloidal Gold ◽  
Blood Platelets ◽  
Cell Contact ◽  
Computer Assisted ◽  
Adherent Cells ◽  
Differential Centrifugation ◽  
Computer Reconstruction ◽  
Sds Page ◽  
Whole Mount

Thrombocytes (TC), the avian equivalent of blood platelets, support hemostasis by aggregating at sites of injury. Studies in our lab suggested that fibrinogen (fib) is a requisite cofactor for TC aggregation but operates by an undefined mechanism. To study the interaction of fib with TC and to identify fib receptors on cells, fib was purified from pigeon plasma, conjugated to colloidal gold and used both to facilitate aggregation and as a receptor probe. Described is the application of computer assisted reconstruction and stereo whole mount microscopy to visualize the 3-D organization of fib receptors at sites of cell contact in TC aggregates and on adherent cells.Pigeon TC were obtained from citrated whole blood by differential centrifugation, washed with Ca++ free Hank's balanced salts containing 0.3% EDTA (pH 6.5) and resuspended in Ca++ free Hank's. Pigeon fib was isolated by precipitation with PEG-1000 and the purity assessed by SDS-PAGE. Fib was conjugated to 25nm colloidal gold by vortexing and the conjugates used as the ligand to identify fib receptors.

Effect of 4-week cyclic stretching program on muscle properties and physical performance in healthy adult men

2020 ◽  
Vol 60 (1) ◽  
Author(s):  
Shogo Sakai ◽  
Noriaki Maeda ◽  
Junpei Sasadai ◽  
Somu Kotoshiba ◽  
Keitaro Anami ◽  
...  
Keyword(s):  
Physical Performance ◽  
Healthy Adult ◽  
Muscle Properties ◽  
Adult Men ◽  
Cyclic Stretching

Thickness Effects on Microwave Magnetic Properties of FeCoBSi Films Deposited on Flexible Substrate

PIERS Online ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 105-108 ◽  
Author(s):  
Haipeng Lu ◽  
Jing Yang ◽  
Longjiang Deng
Keyword(s):  
Magnetic Properties ◽  
Flexible Substrate

Theoretical investigation of Ramachandran plot of N-formyl-L-alanine-amide

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Genetic Algorithm ◽  
Theoretical Investigation ◽  
Energy Analysis ◽  
Empirical Method ◽  
Conformational Space ◽  
Ramachandran Plot ◽  
Global Minima ◽  
Reasonable Time ◽  
Semi Empirical

The full conformational space of N-formyl-L-alanine-amide was explored by the semi-empirical method AM1 coupled to the Multi Niche Crowding (MNC) genetic algorithm implemented in a package of programs developed in our laboratory. The structural and energy analysis of the resulting conformational space E(,ψ) exhibits 5 regions or minima ɣL, ɣD, ɛL, D and αD. The technique provides better detection of local and global minima within a reasonable time.

Electrical Failure and Damage Analysis of Multi-Layer Metal Films on Flexible Substrate during Cyclic Bending Deformation

2011 ◽  
Author(s):  
Byoung-Joon Kim ◽  
Hae-A-Seul Shin ◽  
In-Suk Choi ◽  
Young-Chang Joo
Keyword(s):  
Fatigue Resistance ◽  
Electrical Resistance ◽  
Metal Film ◽  
Flexible Substrate ◽  
Resistance Change ◽  
Cyclic Bending ◽  
Capping Layer ◽  
Bending Strain ◽  
Cu Film ◽  
Electrical Resistance Change

Abstract The electrical resistance Cu film on flexible substrate was investigated in cyclic bending deformation. The electrical resistance of 1 µm thick Cu film on flexible substrate increased up to 120 % after 500,000 cycles in 1.1 % tensile bending strain. Crack and extrusion were observed due to the fatigue damage of metal film. Low bending strain did not cause any damage on metal film but higher bending strain resulted in severe electrical and mechanical damage. Thinner film showed higher fatigue resistance because of the better mechanical property of thin film. Cu film with NiCr under-layer showed poorer fatigue resistance in tensile bending mode. Ni capping layer did not improve the fatigue resistance of Cu film, but Al capping layer suppressed crack formation and lowered electrical resistance change. The NiCr under layer, Ni capping layer, and Al capping layer effect on electrical resistance change of Cu film was compared with Cu only sample.

Structure and Optical Properties CdS and CdTe Films on Flexible Substrate Obtained by DC Magnetron Sputtering for Solar Cells

2017 ◽  
Vol 9 (5) ◽  
pp. 05035-1-05035-6 ◽  
Author(s):  
G. I. Kopach ◽  
◽  
R. P. Mygushchenko ◽  
G. S. Khrypunov ◽  
A. I. Dobrozhan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Magnetron Sputtering ◽  
Flexible Substrate ◽  
Dc Magnetron Sputtering ◽  
Cdte Films

A temperature sensor based on flexible substrate with ultra-high sensitivity for low temperature measurement

2020 ◽  
Vol 315 ◽  
pp. 112341
Author(s):  
Zhaojun Liu ◽  
Bian Tian ◽  
Xu Fan ◽  
Jiangjiang Liu ◽  
Zhongkai Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Measurement ◽  
Temperature Sensor ◽  
Flexible Substrate ◽  
High Sensitivity
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