scholarly journals Cytoskeletal Mechanics Regulating Amoeboid Cell Locomotion

2014 ◽  
Vol 66 (5) ◽  
Author(s):  
Begoña Álvarez-González ◽  
Effie Bastounis ◽  
Ruedi Meili ◽  
Juan C. del Álamo ◽  
Richard Firtel ◽  
...  

Migrating cells exert traction forces when moving. Amoeboid cell migration is a common type of cell migration that appears in many physiological and pathological processes and is performed by a wide variety of cell types. Understanding the coupling of the biochemistry and mechanics underlying the process of migration has the potential to guide the development of pharmacological treatment or genetic manipulations to treat a wide range of diseases. The measurement of the spatiotemporal evolution of the traction forces that produce the movement is an important aspect for the characterization of the locomotion mechanics. There are several methods to calculate the traction forces exerted by the cells. Currently the most commonly used ones are traction force microscopy methods based on the measurement of the deformation induced by the cells on elastic substrate on which they are moving. Amoeboid cells migrate by implementing a motility cycle based on the sequential repetition of four phases. In this paper, we review the role that specific cytoskeletal components play in the regulation of the cell migration mechanics. We investigate the role of specific cytoskeletal components regarding the ability of the cells to perform the motility cycle effectively and the generation of traction forces. The actin nucleation in the leading edge of the cell, carried by the ARP2/3 complex activated through the SCAR/WAVE complex, has shown to be fundamental to the execution of the cyclic movement and to the generation of the traction forces. The protein PIR121, a member of the SCAR/WAVE complex, is essential to the proper regulation of the periodic movement and the protein SCAR, also included in the SCAR/WAVE complex, is necessary for the generation of the traction forces during migration. The protein Myosin II, an important F-actin cross-linker and motor protein, is essential to cytoskeletal contractility and to the generation and proper organization of the traction forces during migration.

2011 ◽  
Vol 22 (21) ◽  
pp. 3995-4003 ◽  
Author(s):  
Effie Bastounis ◽  
Ruedi Meili ◽  
Baldomero Alonso-Latorre ◽  
Juan C. del Álamo ◽  
Juan C. Lasheras ◽  
...  

Cell migration requires a tightly regulated, spatiotemporal coordination of underlying biochemical pathways. Crucial to cell migration is SCAR/WAVE–mediated dendritic F-actin polymerization at the cell's leading edge. Our goal is to understand the role the SCAR/WAVE complex plays in the mechanics of amoeboid migration. To this aim, we measured and compared the traction stresses exerted by Dictyostelium cells lacking the SCAR/WAVE complex proteins PIR121 (pirA−) and SCAR (scrA−) with those of wild-type cells while they were migrating on flat, elastic substrates. We found that, compared to wild type, both mutant strains exert traction stresses of different strengths that correlate with their F-actin levels. In agreement with previous studies, we found that wild-type cells migrate by repeating a motility cycle in which the cell length and strain energy exerted by the cells on their substrate vary periodically. Our analysis also revealed that scrA− cells display an altered motility cycle with a longer period and a lower migration velocity, whereas pirA− cells migrate in a random manner without implementing a periodic cycle. We present detailed characterization of the traction-stress phenotypes of the various cell lines, providing new insights into the role of F-actin polymerization in regulating cell–substratum interactions and stresses required for motility.


2001 ◽  
Vol 12 (12) ◽  
pp. 3947-3954 ◽  
Author(s):  
Steven Munevar ◽  
Yu-li Wang ◽  
Micah Dembo

Cell migration involves complex physical and chemical interactions with the substrate. To probe the mechanical interactions under different regions of migrating 3T3 fibroblasts, we have disrupted cell-substrate adhesions by local application of the GRGDTP peptide, while imaging stress distribution on the substrate with traction force microscopy. Both spontaneous and GRGDTP-induced detachment of the trailing edge caused extensive cell shortening, without changing the overall level of traction forces or the direction of migration. In contrast, disruption of frontal adhesions caused dramatic, global loss of traction forces before any significant shortening of the cell. Although traction forces and cell migration recovered within 10–20 min of transient frontal treatment, persistent treatment with GRGDTP caused the cell to develop traction forces elsewhere and reorient toward a new direction. We conclude that contractile forces of a fibroblast are transmitted to the substrate through two distinct types of adhesions. Leading edge adhesions are unique in their ability to transmit active propulsive forces. Their functions cannot be transferred directly to existing adhesions upon detachment. Trailing end adhesions create passive resistance during cell migration and readily redistribute their loads upon detachment. Our results indicate the distinct nature of mechanical interactions at the leading versus trailing edges, which together generate the mechanical interactions for fibroblast migration.


2021 ◽  
Vol 17 (6) ◽  
pp. 1079-1087
Author(s):  
Zaozao Chen ◽  
Qiwei Li ◽  
Shihui Xu ◽  
Jun Ouyang ◽  
Hongmei Wei

Matrix nanotopography plays an essential role in regulating cell behaviors including cell proliferation, differentiation, and migration. While studies on isolated single cell migration along the nanostructural orientation have been reported for various cell types, there remains a lack of understanding of how nanotopography regulates the behavior of collectively migrating cells during processes such as epithelial wound healing. We demonstrated that collective migration of epithelial cells was promoted on nanogratings perpendicular to, but not on those parallel to, the wound-healing axis. We further discovered that nanograting-modulated epithelial migration was dominated by the adhesion turnover process, which was Rho-associated protein kinase activity-dependent, and the lamellipodia protrusion at the cell leading edge, which was Rac1-GTPase activity-dependent. This work provides explanations to the distinct migration behavior of epithelial cells on nanogratings, and indicates that the effect of nanotopographic modulations on cell migration is cell-type dependent and involves complex mechanisms


2015 ◽  
Vol 465 (3) ◽  
pp. 383-393 ◽  
Author(s):  
Karry M. Jannie ◽  
Shawn M. Ellerbroek ◽  
Dennis W. Zhou ◽  
Sophia Chen ◽  
David J. Crompton ◽  
...  

Vinculin transduces force and orchestrates mechanical signalling at cell–cell and cell–matrix adhesions. Cells expressing a mutant vinculin deficient in actin binding and bundling display migration and traction force defects. Vinculin binding to actin is critical for cell migration and force generation.


2020 ◽  
Author(s):  
Ah-Lai Law ◽  
Shamsinar Jalal ◽  
Fuad Mosis ◽  
Tommy Pallett ◽  
Ahmad Guni ◽  
...  

AbstractCell migration is important for development and its aberrant regulation contributes to many diseases. The Scar/WAVE complex is essential for Arp2/3 mediated lamellipodia formation during mesenchymal cell migration and several coinciding signals activate it. However, so far, no direct negative regulators are known. We have identified Nance-Horan Syndrome-like 1 protein (NHSL1) as a novel, direct binding partner of the Scar/WAVE complex, which co-localise at protruding lamellipodia. This interaction is mediated by the Abi SH3 domain and two binding sites in NHSL1. Furthermore, active Rac binds to NHSL1 at two regions that mediate leading edge targeting of NHSL1 suggesting that Rac recruits NHSL1. Surprisingly, NHSL1 inhibits cell migration through its interaction with the Scar/WAVE complex. Mechanistically, NHSL1 may reduce cell migration efficiency by impeding Arp2/3 activity, as measured in cells using a novel Arp2/3 FRET-FLIM biosensor, resulting in reduced F-actin content of lamellipodia, and consequently impairing the stability of lamellipodia protrusions.


Author(s):  
Sangyoon J. Han ◽  
Nathan J. Sniadecki

Cells rely on traction forces in order to crawl across a substrate. These traction forces come from dynamic changes in focal adhesions, cytoskeletal structures, and chemical and mechanical signals from the extracellular matrix. Several computational models have been developed that help explain the trajectory or accumulation of cells during migration, but little attention has been placed on traction forces during this process. Here, we investigated the spatial and temporal dynamics of traction forces by using a multiphysics model that describes the cycle of steps for a migrating cell on an array of posts. The migration cycle includes extension of the leading edge, formation of new adhesions at the front, contraction of the cytoskeleton, and the release of adhesions at the rear. In the model, an activation signal triggers the assembly of actin and myosin into a stress fiber, which generates a cytoskeletal tension in a manner similar to Hill’s muscle model. In addition, the role that adhesion dynamics has in regulating cytoskeletal tension has been added to the model. The multiphysics model was simulated in Matlab for 1-D simulations, and in Comsol for 2-D simulations. The model was able to predict the spatial distribution of traction forces observed with previous experiments in which large forces were seen at the leading and trailing edges. The large traction force at the trailing edge during the extension phase likely contributes to detachment of the focal adhesion by overcoming its adhesion strength with the post. Moreover, the model found that the mechanical work of a migrating cell underwent a cyclic relationship that rose with the formation of a new adhesion and fell with the release of an adhesion at its rear. We applied a third activation signal at the time of release and found it helped to maintain a more consistent level of work during migration. Therefore, the results from both our 1-D and 2-D migration simulations strongly suggest that cells use biochemical activation to supplement the loss in cytoskeletal tension upon adhesion release.


2015 ◽  
Vol 211 (3) ◽  
pp. 683-701 ◽  
Author(s):  
Charlotte Guetta-Terrier ◽  
Pascale Monzo ◽  
Jie Zhu ◽  
Hongyan Long ◽  
Lakshmi Venkatraman ◽  
...  

In vivo, cells migrate on complex three-dimensional (3D) fibrous matrices, which has made investigation of the key molecular and physical mechanisms that drive cell migration difficult. Using reductionist approaches based on 3D electrospun fibers, we report for various cell types that single-cell migration along fibronectin-coated nanofibers is associated with lateral actin-based waves. These cyclical waves have a fin-like shape and propagate up to several hundred micrometers from the cell body, extending the leading edge and promoting highly persistent directional movement. Cells generate these waves through balanced activation of the Rac1/N-WASP/Arp2/3 and Rho/formins pathways. The waves originate from one major adhesion site at leading end of the cell body, which is linked through actomyosin contractility to another site at the back of the cell, allowing force generation, matrix deformation and cell translocation. By combining experimental and modeling data, we demonstrate that cell migration in a fibrous environment requires the formation and propagation of dynamic, actin based fin-like protrusions.


2020 ◽  
Author(s):  
Anna Polesskaya ◽  
Arthur Boutillon ◽  
Yanan Wang ◽  
Marc Lavielle ◽  
Sophie Vacher ◽  
...  

ABSTRACTBranched actin networks polymerized by the Arp2/3 complex are critical for cell migration. The WAVE complex is the major Arp2/3 activator at the leading edge of migrating cells. However, multiple distinct WAVE complexes can be assembled in a cell, due to the combinatorial complexity of paralogous subunits. When systematically analyzing the contribution of each WAVE complex subunit to the metastasis-free survival of breast cancer patients, we found that overexpression of the CYFIP2 subunit was surprisingly associated with good prognosis. Gain and loss of function experiments in transformed and untransformed mammary epithelial cells revealed that cell migration was always inversely related to CYFIP2 levels. The role of CYFIP2 was systematically opposite to the role of the paralogous subunit CYFIP1 or of the NCKAP1 subunit. The specific CYFIP2 function in inhibiting cell migration was related to its unique ability to down-regulate classical pro-migratory WAVE complexes. The anti-migratory function of CYFIP2 was also revealed in migration of prechordal plate cells during gastrulation of the zebrafish embryo, indicating that the unique function of CYFIP2 is critically important in both physiological and pathophysiological migrations.


2014 ◽  
Vol 66 (5) ◽  
Author(s):  
Xavier Trepat

A virtually universal feature of adherent cells is their ability to exert traction forces. To measure these forces, several methods have been developed over the past 15 years. In this issue of Applied Mechanics Reviews, Álvarez-González and co-workers review their own traction force microscopy approach and its application to the study of amoeboid cell locomotion. They show that the cycle of cell motility is exquisitely synchronized by a cycle of traction forces. In addition, they show how traction forces and cell cycle synchronization are affected by myosin and SCAR/WAVE mutants. Here, I discuss some open questions that derive from the work of the authors and other laboratories as regards the relationship between cell motility and traction forces.


2021 ◽  
Vol 220 (7) ◽  
Author(s):  
Yihong Yang ◽  
Dong Li ◽  
Xiaoting Chao ◽  
Shashi P. Singh ◽  
Peter Thomason ◽  
...  

Polarity is essential for diverse functions in many cell types. Establishing polarity requires targeting a network of specific signaling and cytoskeleton molecules to different subregions of the cell, yet the full complement of polarity regulators and how their activities are integrated over space and time to form morphologically and functionally distinct domains remain to be uncovered. Here, by using the model system Dictyostelium and exploiting the characteristic chemoattractant-stimulated translocation of polarly distributed molecules, we developed a proteomic screening approach, through which we identified a leucine-rich repeat domain–containing protein we named Leep1 as a novel polarity regulator. We combined imaging, biochemical, and phenotypic analyses to demonstrate that Leep1 localizes selectively at the leading edge of cells by binding to PIP3, where it modulates pseudopod and macropinocytic cup dynamics by negatively regulating the Scar/WAVE complex. The spatiotemporal coordination of PIP3 signaling, Leep1, and the Scar/WAVE complex provides a cellular mechanism for organizing protrusive structures at the leading edge.


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