scholarly journals Active cell mechanics: Measurement and theory

2015 ◽  
Vol 1853 (11) ◽  
pp. 3083-3094 ◽  
Author(s):  
Wylie W. Ahmed ◽  
Étienne Fodor ◽  
Timo Betz
Keyword(s):  
Cell Mechanics ◽  
Active Cell

scholarly journals Large-scale curvature sensing by epithelial monolayers depends on active cell mechanics and nuclear mechanoadaptation

2020 ◽  
Author(s):  
Marine Luciano ◽  
Shi-Lei Xue ◽  
Winnok H. De Vos ◽  
Lorena Redondo Morata ◽  
Mathieu Surin ◽  
...  
Keyword(s):  
Cell Mechanics ◽  
Large Scale ◽  
Chromatin Condensation ◽  
Active Cell ◽  
Epithelial Tissue ◽  
Hippo Signaling ◽  
Curvature Sensing ◽  
Epithelial Monolayers ◽  
Substrate Curvature

AbstractWhile many tissues fold in vivo in a highly reproducible and robust way, epithelial folds remain difficult to reproduce in vitro, so that the effects and underlying mechanisms of local curvature on the epithelial tissue remains unclear. Here, we photoreticulated polyacrylamide hydrogels though an optical photomask to create corrugated hydrogels with isotropic wavy patterns, allowed us to show that concave and convex curvatures affect cellular and nuclear shape. By culturing MDCK epithelial cells at confluency on corrugated hydrogels, we showed that the substrate curvature leads to thicker epithelial zones in the valleys and thinner ones on the crest, as well as corresponding density, which can be generically explained by a simple 2D vertex model, leading us to hypothesize that curvature sensing could arise from resulting density/thickness changes. Additionally, positive and negative local curvatures lead to significant modulations of the nuclear morphology and positioning, which can also be well-explained by an extension of vertex models taking into account membrane-nucleus interactions, where thickness/density modulation generically translate into the corresponding changes in nuclear aspect ratio and position, as seen in the data. Consequently, we find that the spatial distribution of Yes associated proteins (YAP), the main transcriptional effector of the Hippo signaling pathway, is modulated in folded epithelial tissues according to the resulting thickness modulation, an effect that disappears at high cell density. Finally, we showed that these deformations are also associated with changes of A-type and B-type lamin expression, significant chromatin condensation and to lower cell proliferation rate. These findings show that active cell mechanics and nuclear mechanoadaptation are key players of the mechanistic regulation of epithelial monolayers to substrate curvature, with potential application for a number of in vivo situations.

scholarly journals Quantitative Methodologies to Dissect Immune Cell Mechanobiology

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 851
Author(s):  
Veronika Pfannenstill ◽  
Aurélien Barbotin ◽  
Huw Colin-York ◽  
Marco Fritzsche
Keyword(s):  
Mechanical Properties ◽  
Immune Response ◽  
Time Scales ◽  
Immune Cells ◽  
Cell Mechanics ◽  
Immune Cell ◽  
Biological Significance ◽  
Force Generation ◽  
Tissue Microenvironment ◽  
And Behavior

Mechanobiology seeks to understand how cells integrate their biomechanics into their function and behavior. Unravelling the mechanisms underlying these mechanobiological processes is particularly important for immune cells in the context of the dynamic and complex tissue microenvironment. However, it remains largely unknown how cellular mechanical force generation and mechanical properties are regulated and integrated by immune cells, primarily due to a profound lack of technologies with sufficient sensitivity to quantify immune cell mechanics. In this review, we discuss the biological significance of mechanics for immune cells across length and time scales, and highlight several experimental methodologies for quantifying the mechanics of immune cells. Finally, we discuss the importance of quantifying the appropriate mechanical readout to accelerate insights into the mechanobiology of the immune response.

scholarly journals Cell mechanical properties of human breast carcinoma cells depend on temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Aermes ◽  
Alexander Hayn ◽  
Tony Fischer ◽  
Claudia Tanja Mierke
Keyword(s):  
Mechanical Properties ◽  
Power Law ◽  
Cell Mechanics ◽  
Cell Types ◽  
Creep Response ◽  
Temperature Range ◽  
Myosin Filaments ◽  
Cell Mechanical Properties ◽  
Increasing Temperature ◽  
Mcf 7

AbstractThe knowledge of cell mechanics is required to understand cellular processes and functions, such as the movement of cells, and the development of tissue engineering in cancer therapy. Cell mechanical properties depend on a variety of factors, such as cellular environments, and may also rely on external factors, such as the ambient temperature. The impact of temperature on cell mechanics is not clearly understood. To explore the effect of temperature on cell mechanics, we employed magnetic tweezers to apply a force of 1 nN to 4.5 µm superparamagnetic beads. The beads were coated with fibronectin and coupled to human epithelial breast cancer cells, in particular MCF-7 and MDA-MB-231 cells. Cells were measured in a temperature range between 25 and 45 °C. The creep response of both cell types followed a weak power law. At all temperatures, the MDA-MB-231 cells were pronouncedly softer compared to the MCF-7 cells, whereas their fluidity was increased. However, with increasing temperature, the cells became significantly softer and more fluid. Since mechanical properties are manifested in the cell’s cytoskeletal structure and the paramagnetic beads are coupled through cell surface receptors linked to cytoskeletal structures, such as actin and myosin filaments as well as microtubules, the cells were probed with pharmacological drugs impacting the actin filament polymerization, such as Latrunculin A, the myosin filaments, such as Blebbistatin, and the microtubules, such as Demecolcine, during the magnetic tweezer measurements in the specific temperature range. Irrespective of pharmacological interventions, the creep response of cells followed a weak power law at all temperatures. Inhibition of the actin polymerization resulted in increased softness in both cell types and decreased fluidity exclusively in MDA-MB-231 cells. Blebbistatin had an effect on the compliance of MDA-MB-231 cells at lower temperatures, which was minor on the compliance MCF-7 cells. Microtubule inhibition affected the fluidity of MCF-7 cells but did not have a significant effect on the compliance of MCF-7 and MDA-MB-231 cells. In summary, with increasing temperature, the cells became significant softer with specific differences between the investigated drugs and cell lines.

scholarly journals Keratins determine network stress responsiveness in reconstituted actin-keratin filament systems

Soft Matter ◽  
2021 ◽  
Author(s):  
Iman Elbalasy ◽  
Paul Mollenkopf ◽  
Cary Tutmarc ◽  
Harald Herrmann ◽  
Jörg Schnauß
Keyword(s):  
Cell Mechanics ◽  
Major Determinant ◽  
Stress Responsiveness ◽  
Keratin Filament

The cytoskeleton is a major determinant of cell mechanics, and alterations in the central mechanical aspects of cells are observed during many pathological situations. Therefore, it is essential to investigate...

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