The Cytoskeleton Regulates Cell Attachment Strength

Abstract

Quantitative information about adhesion strength is a fundamental part of our understanding of cell-extracellular matrix (ECM) interactions. Adhesion assays should measure integrin-ECM bond strength, but reports now suggest that cell components remain behind after exposure to acute force for radial shear assays in the presence of divalent cations that increase integrin-ECM affinity. Here, we show that focal adhesion proteins FAK, paxillin, and vinculin but not the cytoskeletal protein actin remain behind after shear-induced detachment of HT1080 fibrosarcoma cells. Cytoskeletal stabilization increased attachment strength by eightfold, whereas cross-linking integrins to the substrate only caused a 1.5-fold increase. Reducing temperature-only during shear application-also increased attachment strength eightfold, with detachment again occurring between focal adhesion proteins and actin. Detachment at the focal adhesion-cytoskeleton interface was also observed in mouse and human fibroblasts and was ligand-independent, highlighting the ubiquity of this mode of detachment in the presence of divalent cations. These data show that the cytoskeleton and its dynamic coupling to focal adhesions are critically important for cell adhesion in niche with divalent cations.

Equilibrium unzipping at finite temperature

“…Our study complements the analysis of a closely related actomyosin system represented by a parallel bundle of bi-stable units loaded in a soft device [47]. In the context of cell adhesion and cell motility, the out-of-equilibrium behavior of similar systems has been studied previously in [48][49][50].…”

Impaired Release of Neutrophil Extracellular Traps and Anemia-Associated T Cell Deficiency in Hereditary Hemorrhagic Telangiectasia

“…This also correlated with increased motility of the cells towards LPS. As cell-matrix adhesions represent the focal sites of convergence between the actin cytoskeleton and extracellular matrix [63], the appearance of focal adhesions may retard cellular movement. In agreement, a reverse correlation between cell spreading on the extracellular matrix or poly-d-lysine and motility was described [64].…”

Matrix stiffness mechanically conditions EMT and migratory behavior of oral squamous cell carcinoma

“…Once immersed in spinning buffer, coverslips were spun for 5 min at defined angular velocities; cells were fixed with 3.7% formaldehyde immediately after spinning. Quantification of adhesion strength was used according to previous publications (Fuhrmann et al, 2017;Fuhrmann and Engler, 2015). Briefly, coverslips were stained with Hoechst 33342 (Invitrogen, H3570) and imaged at 10× magnification on a Nikon (Melville, NY) Ti-S microscope (∼1000 individual images stitched together with Metamorph 7.6 software and custom macros) and analyzed using a custom-written MATLAB (The MathWorks, Natick, MA) program.…”