Eigenstrain as a mechanical set-point of cells

Area of Science:

• Cellular mechanics
• Biophysics
• Biomaterials

Background:

• Cell contraction is crucial for cells to sense their mechanical surroundings.
• Understanding tensional homeostasis is key to comprehending cell mechanosensing.

Purpose of the Study:

• To identify the set-point of cell contraction, or tensional homeostasis.
• To investigate the relationship between substrate stiffness and cell mechanical properties.

Main Methods:

• Characterization of bovine aortic endothelial cells (BAECs) using traction force microscopy (TFM).
• Development of numerical models to simulate cell-substrate interactions and cell contraction as eigenstrain.
• Comparison of model predictions with experimental TFM measurements.

Main Results:

• Increased substrate stiffness led to larger cell spread area, higher traction force, and increased average cell stress.
• Cell average strain remained constant across different substrate stiffnesses, indicating it as the tensional homeostasis.
• Cell contraction (eigenstrain) was consistent across different cell types (BAECs and fibroblasts) and mechanical environments.

Conclusions:

• Cell average strain serves as a cell type-specific tensional homeostasis.
• A potential mechanical set-point for cell contraction may exist across different cell types.
• Measuring cell contractility can aid in monitoring cell mechanosensing and extracellular matrix remodeling.