scholarly journals Mechanically induced deformation and strain dynamics in actin stress fibers

2012 ◽  
Vol 5 (6) ◽  
pp. 627-630 ◽  
Author(s):  
Sebastian Hadjiantoniou ◽  
Louise Guolla ◽  
Andrew E. Pelling
Keyword(s):  
Stress Fibers ◽  
Actin Stress Fibers

scholarly journals Delayed stress fiber formation mediates pulmonary myofibroblast differentiation in response to TGF-β

2011 ◽  
Vol 301 (5) ◽  
pp. L656-L666 ◽  
Author(s):  
Nathan Sandbo ◽  
Andrew Lau ◽  
Jacob Kach ◽  
Caitlyn Ngam ◽  
Douglas Yau ◽  
...  
Keyword(s):  
Rho Kinase ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Stress Fibers ◽  
Nuclear Accumulation ◽  
Myofibroblast Differentiation ◽  
Latrunculin B ◽  
Stress Fiber Formation ◽  
Actin Expression ◽  
Actin Stress Fibers

Myofibroblast differentiation induced by transforming growth factor-β (TGF-β) and characterized by de novo expression of smooth muscle (SM)-specific proteins is a key process in wound healing and in the pathogenesis of fibrosis. We have previously shown that TGF-β-induced expression and activation of serum response factor (SRF) is required for this process. In this study, we examined the signaling mechanism for SRF activation by TGF-β as it relates to pulmonary myofibroblast differentiation. TGF-β stimulated a profound, but delayed (18–24 h), activation of Rho kinase and formation of actin stress fibers, which paralleled SM α-actin expression. The translational inhibitor cycloheximide blocked these processes without affecting Smad-dependent gene transcription. Inhibition of Rho kinase by Y-27632 or depolymerization of actin by latrunculin B resulted in inhibition TGF-β-induced SRF activation and SM α-actin expression, having no effect on Smad signaling. Conversely, stabilization of actin stress fibers by jasplakinolide was sufficient to drive these processes in the absence of TGF-β. TGF-β promoted a delayed nuclear accumulation of the SRF coactivator megakaryoblastic leukemia-1 (MKL1)/myocardin-related transcription factor-A, which was inhibited by latrunculin B. Furthermore, TGF-β also induced MKL1 expression, which was inhibited by latrunculin B, by SRF inhibitor CCG-1423, or by SRF knockdown. Together, these data suggest a triphasic model for myofibroblast differentiation in response to TGF-β that involves 1) initial Smad-dependent expression of intermediate signaling molecules driving Rho activation and stress fiber formation, 2) nuclear accumulation of MKL1 and activation of SRF as a result of actin polymerization, and 3) SRF-dependent expression of MKL1, driving further myofibroblast differentiation.

Gliotoxin destructs the pulmonary epithelium barrier function by reducing cofilin oligomer formation to promote the dissolution of actin stress fibers

2018 ◽  
Vol 123 ◽  
pp. 169-176 ◽  
Author(s):  
Changjian Zhang ◽  
Xiaoyu Liu ◽  
Fangyan Chen ◽  
Yingsong Hu ◽  
Zhiqian Li ◽  
...  
Keyword(s):  
Barrier Function ◽  
Stress Fibers ◽  
Pulmonary Epithelium ◽  
Oligomer Formation ◽  
Actin Stress Fibers

Vascular-endothelial-cadherin modulates endothelial monolayer permeability

1999 ◽  
Vol 112 (12) ◽  
pp. 1915-1923 ◽  
Author(s):  
P.L. Hordijk ◽  
E. Anthony ◽  
F.P. Mul ◽  
R. Rientsma ◽  
L.C. Oomen ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Transendothelial Migration ◽  
Stress Fibers ◽  
Vascular Endothelial ◽  
Monolayer Permeability ◽  
Actin Stress Fibers ◽  
Cell Cell

Vascular endothelial (VE)-cadherin is the endothelium-specific member of the cadherin family of homotypic cell adhesion molecules. VE-cadherin, but not the cell adhesion molecule platelet/endothelial cell adhesion molecule (PECAM-1), markedly colocalizes with actin stress fibers at cell-cell junctions between human umbilical vein endothelial cells. Inhibition of VE-cadherin-mediated, but not PECAM-1-mediated, adhesion induced reorganization of the actin cytoskeleton, loss of junctional VE-cadherin staining and loss of cell-cell adhesion. In functional assays, inhibition of VE-cadherin caused increased monolayer permeability and enhanced neutrophil transendothelial migration. In a complementary set of experiments, modulation of the actin cytoskeleton was found to strongly affect VE-cadherin distribution. Brief stimulation of the beta2-adrenergic receptor with isoproterenol induced a loss of actin stress fibers resulting in a linear, rather than ‘jagged’, VE-cadherin distribution. The concomitant, isoproterenol-induced, reduction in monolayer permeability was alleviated by a VE-cadherin-blocking antibody. Finally, cytoskeletal reorganization resulting from the inactivation of p21Rho caused a diffuse localization of VE-cadherin, which was accompanied by reduced cell-cell adhesion. Together, these data show that monolayer permeability and neutrophil transendothelial migration are modulated by VE-cadherin-mediated cell-cell adhesion, which is in turn controlled by the dynamics of the actin cytoskeleton.

Actin stress fibers are at a tipping point between conventional shortening and rapid disassembly at physiological levels of MgATP

2010 ◽  
Vol 395 (3) ◽  
pp. 301-306 ◽  
Author(s):  
Tsubasa S. Matsui ◽  
Kazushi Ito ◽  
Roland Kaunas ◽  
Masaaki Sato ◽  
Shinji Deguchi
Keyword(s):  
Tipping Point ◽  
Stress Fibers ◽  
Actin Stress Fibers

scholarly journals The small GTPase Rif is an alternative trigger for the formation of actin stress fibers in epithelial cells

2010 ◽  
Vol 123 (8) ◽  
pp. 1247-1252 ◽  
Author(s):  
L. Fan ◽  
S. Pellegrin ◽  
A. Scott ◽  
H. Mellor
Keyword(s):  
Epithelial Cells ◽  
Small Gtpase ◽  
Stress Fibers ◽  
Actin Stress Fibers

Mechanosensitive myosin II but not cofilin primarily contributes to cyclic cell stretch-induced selective disassembly of actin stress fibers

2021 ◽  
Author(s):  
Wenjing Huang ◽  
Tsubasa S. Matsui ◽  
Takumi Saito ◽  
Masahiro Kuragano ◽  
Masayuki Takahashi ◽  
...  
Keyword(s):  
Cellular Response ◽  
Early Stage ◽  
Myosin Ii ◽  
Cyclic Stretch ◽  
Stress Fibers ◽  
Lim Kinase ◽  
Lim Kinase 1 ◽  
Chronic Activation ◽  
Selective Disassembly ◽  
Actin Stress Fibers

Cells adapt to applied cyclic stretch (CS) to circumvent chronic activation of proinflammatory signaling. Currently, the molecular mechanism of the selective disassembly of actin stress fibers (SFs) in the stretch direction, which occurs at the early stage of the cellular response to CS, remains controversial. Here we suggest that the mechanosensitive behavior of myosin II, a major cross-linker of SFs, primarily contributes to the directional disassembly of the actomyosin complex SFs in bovine vascular smooth muscle cells and human U2OS osteosarcoma cells. First, we identified that CS with a shortening phase that exceeds in speed the inherent contractile rate of individual SFs leads to the disassembly. To understand the biological basis, we investigated the effect of expressing myosin regulatory light chain mutants and found that SFs with less actomyosin activities disassemble more promptly upon CS. We consequently created a minimal mathematical model that recapitulates the salient features of the direction-selective and threshold-triggered disassembly of SFs to show that disassembly or, more specifically, unbundling of the actomyosin bundle SFs is enhanced with sufficiently fast cell shortening. We further demonstrated that similar disassembly of SFs is inducible in the presence of an active LIM-kinase-1 mutant that deactivates cofilin, suggesting that cofilin is dispensable as opposed to a previously proposed mechanism.

Discovery of a novel ROCK2 inhibitor with anti-migration effects via docking and high-content drug screening

2016 ◽  
Vol 12 (9) ◽  
pp. 2713-2721 ◽  
Author(s):  
Cheong-Meng Chong ◽  
Man-Teng Kou ◽  
Peichen Pan ◽  
Hefeng Zhou ◽  
Nana Ai ◽  
...  
Keyword(s):  
Cell Migration ◽  
Drug Screening ◽  
Stress Fibers ◽  
Neurite Length ◽  
Actin Stress Fibers

Through the combined virtual and high content drug screening, BIPM was identified as a novel and potent ROCK2 inhibitor. Exposure of SH-SY5Y cells to BIPM led to significant changes in neurite length, cell migration and actin stress fibers via mediating ROCK2 downstream proteins.

A Theoretical Model of Stretch-Induced Stress Fiber Remodeling

2008 ◽  
Author(s):  
Roland Kaunas
Keyword(s):  
Focal Adhesion ◽  
Focal Adhesions ◽  
Dynamic Structure ◽  
Cytoskeletal Proteins ◽  
Stress Fibers ◽  
Cell Contractility ◽  
Maximum Stretch ◽  
Tensional Homeostasis ◽  
Tractional Forces ◽  
Actin Stress Fibers

Cyclic stretching of endothelial cells (ECs), such as occurs in arteries during the cardiac cycle, induces ECs and their actin stress fibers to orient perpendicular to the direction of maximum stretch. This perpendicular alignment response is strengthened by increasing the magnitudes of stretch and cell contractility (1). The actin cytoskeleton is a dynamic structure that regulates cell shape changes and mechanical properties. It has been shown that actin stress fibers are ‘prestretched’ under normal, non-perturbed, conditions (2), consistent with the ideas of ‘prestress’ that have motivated tensegrity cell models (3). It has also been shown that ‘tractional forces’ generated by cells at focal adhesions tend to increase proportionately with increasing focal adhesion area, thus suggesting that cells tend to maintain constant the stress borne by a focal adhesion (4). By implication, this suggests that cells try to maintain constant the stress in actin stress fibers. Thus, it seems that cells reorganize or turnover cytoskeletal proteins and adhesion complexes so as to maintain constant a preferred mechanical state. Mizutani et al. (5) referred to this as cellular tensional homeostasis, although they did not suggest a model or theory to account for this dynamic process.

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