scholarly journals Chemotaxis and topotaxis add vectorially for amoeboid cell migration

2019 ◽  
Author(s):  
Joeri A. J. Wondergem ◽  
Maria Mytiliniou ◽  
Falko C. H. de Wit ◽  
Thom G. A. Reuvers ◽  
David Holcman ◽  
...  
Keyword(s):  
Cell Migration ◽  
Chemical Cues ◽  
Effective Diffusion ◽  
Diffusion Constant ◽  
Emergent Property ◽  
Coarse Grained ◽  
Chemical Gradients ◽  
Amoeboid Cell ◽  
Physical And Chemical ◽  
Chemotactic Gradient

AbstractCells encounter a wide variety of physical and chemical cues when navigating their native environments. However, their response to multiple simultaneous cues is not yet clear. In particular, the influence of topography, in the presence of a chemotactic gradient, on their migratory behavior is understudied. Here, we investigate the effects of topographical guidance on highly motile amoeboid cell migration (topotaxis) generated by asymmetrically placed micropillars. The micropillar field allows for an additional, natural chemotactic gradient in two different directions, thereby revealing the relevance of topotaxis in the presence of cell migration directed by chemical gradients (chemotaxis). Interestingly, we found that the topotactic drift generated by the pillar field is conserved during chemotaxis. We show that the drifts generated by both these cues add up linearly. A coarse-grained analysis as a function of pillar spacing subsequently revealed that the strength and direction of the topotactic drift is determined by (i) the pore size, (ii) space between pores, and (iii) the effective diffusion constant of the cells. Finally, we argue that topotaxis must be conserved during chemotaxis, as it is an emergent property of both the asymmetric properties of the pillar field and the inherent stochasticity of (biased) amoeboid migration.

scholarly journals Excitable actin dynamics and amoeboid cell migration

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246311
Author(s):  
Nicolas Ecker ◽  
Karsten Kruse
Keyword(s):  
Cell Migration ◽  
Random Walk ◽  
Random Walks ◽  
Effective Diffusion ◽  
Diffusion Constant ◽  
Actin Dynamics ◽  
Actin Assembly ◽  
Amoeboid Cell ◽  
Long Time ◽  
Actin Nucleator

Amoeboid cell migration is characterized by frequent changes of the direction of motion and resembles a persistent random walk on long time scales. Although it is well known that cell migration is typically driven by the actin cytoskeleton, the cause of this migratory behavior remains poorly understood. We analyze the spontaneous dynamics of actin assembly due to nucleation promoting factors, where actin filaments lead to an inactivation of these factors. We show that this system exhibits excitable dynamics and can spontaneously generate waves, which we analyze in detail. By using a phase-field approach, we show that these waves can generate cellular random walks. We explore how the characteristics of these persistent random walks depend on the parameters governing the actin-nucleator dynamics. In particular, we find that the effective diffusion constant and the persistence time depend strongly on the speed of filament assembly and the rate of nucleator inactivation. Our findings point to a deterministic origin of the random walk behavior and suggest that cells could adapt their migration pattern by modifying the pool of available actin.

scholarly journals Airborne infection in a fully air-conditioned hospital: III. Transport of gaseous and airborne particulate material along ventilated passageways

1975 ◽  
Vol 75 (1) ◽  
pp. 45-56 ◽  
Author(s):  
O. M. Lidwell
Keyword(s):  
Mathematical Model ◽  
Flow Velocity ◽  
Effective Diffusion ◽  
Diffusion Constant ◽  
Particulate Material ◽  
Airborne Particulate ◽  
Airborne Infection ◽  
Directional Flow ◽  
A Value

SUMMARYA mathematical model is described for the transport of gaseous or airborne particulate material between rooms along ventilated passageways.Experimental observations in three hospitals lead to a value of about 0.06m.2/sec. for the effective diffusion constant in air without any systematic directional flow. The ‘constant’ appears to increase if there is any directional flow along the passage, reaching about 0.12 m.2/sec. at a flow velocity of 0.04 m./sec.Together with previously published methods the present formulae make it possible to calculate the expected average amounts of gaseous or particulate material that will be transported from room to room in ventilated buildings in which the ventilation and exchange airflows can be calculated.The actual amounts transported in occupied buildings, however, vary greatly from time to time.

Physical and chemical cues influencing the oviposition behaviour of Aphidius ervi

2000 ◽  
Vol 94 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Donatella Battaglia ◽  
Guy Poppy ◽  
Wilf Powell ◽  
Antonio Romano ◽  
Antonio Tranfaglia ◽  
...  
Keyword(s):  
Chemical Cues ◽  
Oviposition Behaviour ◽  
Aphidius Ervi ◽  
Physical And Chemical

scholarly journals Grip and slip of L1-CAM on adhesive substrates direct growth cone haptotaxis

2018 ◽  
Vol 115 (11) ◽  
pp. 2764-2769 ◽  
Author(s):  
Kouki Abe ◽  
Hiroko Katsuno ◽  
Michinori Toriyama ◽  
Kentarou Baba ◽  
Tomoyuki Mori ◽  
...  
Keyword(s):  
Cell Migration ◽  
Growth Cone ◽  
Cell Adhesion Molecule ◽  
Chemical Cues ◽  
Traction Force ◽  
Human Patient ◽  
Direct Growth ◽  
Direct Cell ◽  
Conventional Cell ◽  
Directional Cell Migration

Chemical cues presented on the adhesive substrate direct cell migration, a process termed haptotaxis. To migrate, cells must generate traction forces upon the substrate. However, how cells probe substrate-bound cues and generate directional forces for migration remains unclear. Here, we show that the cell adhesion molecule (CAM) L1-CAM is involved in laminin-induced haptotaxis of axonal growth cones. L1-CAM underwent grip and slip on the substrate. The ratio of the grip state was higher on laminin than on the control substrate polylysine; this was accompanied by an increase in the traction force upon laminin. Our data suggest that the directional force for laminin-induced growth cone haptotaxis is generated by the grip and slip of L1-CAM on the substrates, which occur asymmetrically under the growth cone. This mechanism is distinct from the conventional cell signaling models for directional cell migration. We further show that this mechanism is disrupted in a human patient with L1-CAM syndrome, suffering corpus callosum agenesis and corticospinal tract hypoplasia.

scholarly journals Regulation and Directing Stem Cell Fate by Tissue Engineering Functional Microenvironments: Scaffold Physical and Chemical Cues

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Fei Xing ◽  
Lang Li ◽  
Changchun Zhou ◽  
Cheng Long ◽  
Lina Wu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Stem Cell ◽  
Growth Factors ◽  
Cell Fate ◽  
Chemical Cues ◽  
Physical Factors ◽  
Stem Cell Fate ◽  
Physical And Chemical

It is well known that stem cells reside within tissue engineering functional microenvironments that physically localize them and direct their stem cell fate. Recent efforts in the development of more complex and engineered scaffold technologies, together with new understanding of stem cell behavior in vitro, have provided a new impetus to study regulation and directing stem cell fate. A variety of tissue engineering technologies have been developed to regulate the fate of stem cells. Traditional methods to change the fate of stem cells are adding growth factors or some signaling pathways. In recent years, many studies have revealed that the geometrical microenvironment played an essential role in regulating the fate of stem cells, and the physical factors of scaffolds including mechanical properties, pore sizes, porosity, surface stiffness, three-dimensional structures, and mechanical stimulation may affect the fate of stem cells. Chemical factors such as cell-adhesive ligands and exogenous growth factors would also regulate the fate of stem cells. Understanding how these physical and chemical cues affect the fate of stem cells is essential for building more complex and controlled scaffolds for directing stem cell fate.

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