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Differences in cortical contractile properties between healthy epithelial and cancerous mesenchymal breast cellsWarmt, Enrico, Grosser, Steffen, Blauth, Eliane, Xie, Xiaofan, Kubitschke, Hans, Stange, Roland, Sauer, Frank, Schnauß, Jörg, Tomm, Janina M., von Bergen, Martin, Käs, Josef A. 02 May 2023 (has links)
Cell contractility is mainly imagined as a force dipole-like interaction based on actin stress fibers
that pull on cellular adhesion sites. Here, we present a different type of contractility based on
isotropic contractions within the actomyosin cortex. Measuring mechanosensitive cortical
contractility of suspended cells among various cell lines allowed us to exclude effects caused by
stress fibers. We found that epithelial cells display a higher cortical tension than mesenchymal cells,
directly contrasting to stress fiber-mediated contractility. These two types of contractility can even
be used to distinguish epithelial from mesenchymal cells. These findings from a single cell level
correlate to the rearrangement effects of actomyosin cortices within cells assembled in
multicellular aggregates. Epithelial cells form a collective contractile actin cortex surrounding
multicellular aggregates and further generate a high surface tension reminiscent of tissue
boundaries. Hence, we suggest this intercellular structure as to be crucial for epithelial tissue
integrity. In contrast, mesenchymal cells do not form collective actomyosin cortices reducing
multicellular cohesion and enabling cell escape from the aggregates.
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The Role of Mechanical Loading in Bone Remodeling: A Literature ReviewSlonecker, Holly Nicole 07 May 2010 (has links)
No description available.
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A Comparative Analysis of the Biomechanics and Biochemistry of Cell-Derived and Cell-Remodeled Matrices: Implications for Wound Healing and Regenerative MedicineAhlfors, Jan-Eric Wilhelm 03 May 2004 (has links)
The purpose of this research was to study the synthesis and remodeling of extracellular matrix (ECM) by fibroblasts with special emphasis on the culture environment (media composition and initial ECM composition) and the resulting mechanical integrity of the ECM. This was investigated by culturing fibroblasts for 3 weeks in a variety of culture conditions consisting of collagen gels, fibrin gels, or media permissive to the self-production of ECM (Cell-Derived Matrix), and quantifying the mechanics of the resulting ECM. The mechanical characteristics were related to the biochemistry of the resulting ECM, notably in terms of collagen accumulation and collagen fibril diameters. The ultimate tensile strength (UTS) of the collagen gels and fibrin gels at the end of the 3-week period was 168.5 ± 43.1 kPa and 133.2 ± 10.6 kPa, respectively. The ultimate tensile strength of the cell-derived matrices was 223.2 ± 9 kPa, and up to 697.1 ± 36.1 kPa when cultured in a chemically-defined medium that was developed for the rapid growth of matrix in a more defined environment. Normalizing the strength to collagen density resulted in a UTS / Collagen Density in these groups of 6.4 ± 1.9 kPa/mg/cm3, 25.9 ± 2.4 kPa/mg/cm3, 14.5 ± 1.1 kPa/mg/cm3, and 40.0 ± 1.9 kPa/mg/cm3, respectively. Cells were synthetically more active when they produced their own matrix than when they were placed within gels. The resulting matrix was also significantly stronger when it was self-produced than when the cells rearranged the matrix within gels that corresponded to a significantly larger fraction of non-acid and pepsin extractable collagen. These studies indicate that cell-derived matrices have potential both as in vitro wound healing models and as soft connective tissue substitutes.
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