Human epithelial cells increase their rigidity with ageingin vitro: direct measurements

Abstract

The decrease in elasticity of epithelial tissues with ageing contributes to many human diseases. This change was previously attributed to increased crosslinking of extracellular matrix proteins. Here we show that individual human epithelial cells also become significantly more rigid during ageing in vitro. Using atomic force microscopy (AFM), we found that the Young's modulus of viable cells was consistently increased two-to four-fold in older versus younger cells. Direct visualization of the cytoskeleton using a novel method involving the AFM suggested that increased rigidity of ageing cells was due to a higher density of cytoskeletal fibres. Our results identify a unique mechanism that might contribute to the age-related loss of elasticity in epithelial tissues.

Correlating the viscoelasticity of breast cancer cells with their malignancy

“…Silicon nitride AFM cantilever (Novascan, USA) with an attached 4.5 µm diameter polystyrene spherical bead was used to indent the cells. A spherical-shaped probe was used to prevent large localized strain and to achieve a lower variation of the Young's modulus values by averaging the force over a larger cell surface area during indentation [2]. The photodiode sensitivity (m V ).…”

Stiffening of Human Skin Fibroblasts with Age

“…In this context, age-related changes have been observed for protein synthesis and production of ECM components (1,16,17). Further, atomic force microscopy studies indicate that individual epithelial cells show a considerable increase in stiffness in vitro at higher passage numbers (18,19). Even though comparisons of cells of early and late passage have yielded important insights into the aging process in vitro, such models cannot substitute for studies of cells isolated from aged human donors (aged in vivo).…”

Research progress in quantifying the mechanical properties of single living cells using atomic force microscopy

“…[38] measured the elastic modulus of 3T3 fibroblasts (1-3 kPa) by gluing a polystyrene bead to the cantilever. Berdyyeva et al [58] measured the mechanical properties of old and young human epithelial cells using sphere tip (silica bead with 5 lm diameter), showing that the Young's modulus of older cells was 2-4 times larger than younger cells. Leporatti et al [59] measured the mechanics of resting and activated macrophages (lipopolysaccharide-stimulated), indicating that the Young's modulus of macrophages decreased from (1.5 ± 1.1) kPa to (0.51 ± 0.31) kPa after the stimulation.…”