A prestressed cable network model of the adherent cell cytoskeleton

Area of Science:

• Cellular mechanics and biophysics
• Cytoskeletal dynamics and modeling
• Biomaterials and bioengineering

Background:

• The actin cytoskeleton provides mechanical integrity to cells.
• Understanding cell deformability is crucial for cell biology and disease research.
• Existing models struggle to capture the complex mechanical behavior of the actin network.

Purpose of the Study:

• To develop and validate a computational model of the adherent cell actin cytoskeleton.
• To investigate the mechanical response of the cytoskeleton to external forces.
• To determine the contribution of actin filaments to cell stiffness and deformation.

Main Methods:

• A prestressed cable network model was developed.
• Model parameters were based on experimental data from living cells and actin filaments.
• Simulations mimicked cell poking, magnetic twisting cytometry, and magnetic bead microrheometry.

Main Results:

• The model accurately predicted cell response to cell poking, identifying peripheral actin filaments as key to indentation resistance.
• Estimated actin filament tension was approximately 158 pN, crucial for network integrity.
• Nonlinear mechanical response during cell poking originated from filament kinematics; model limitations noted for MTC/MBM.

Conclusions:

• A prestressed cable network model effectively captures fibroblast cell mechanical responses, particularly indentation resistance.
• Actin filament tension is a critical factor in cytoskeletal mechanical integrity and cellular response.
• The model provides insights into the relationship between cytoskeletal structure and cell mechanical properties.