A model for cell density effect on stress fiber alignment and collective directional migration

Area of Science:

• Biophysics
• Cell Biology
• Computational Biology

Background:

• Collective cell migration is crucial for tissue development and repair.
• Endothelial cells migrate in response to biochemical gradients (chemotaxis).
• Understanding the biophysical mechanisms governing this process is essential.

Purpose of the Study:

• To develop and validate a 2D numerical model of collective endothelial cell migration.
• To investigate the influence of cell density, cytoskeleton organization, and intracellular forces on chemotaxis.
• To analyze how cellular rearrangements contribute to group migration dynamics.

Main Methods:

• Developed a 2D viscoelastic cell mechanics model incorporating cell membrane and cytoskeleton.
• Simulated cell random walk, cell-cell interactions, chemotaxis, and cytoskeleton rearrangements.
• Validated the model against experimental data for collective endothelial cell migration.

Main Results:

• Increased cell density promotes alignment of cytoskeletal stress fibers along the concentration gradient.
• Enhanced stress fiber alignment correlates with intensified intracellular forces in the gradient direction.
• The model accurately reproduces experimental observations of collective endothelial cell chemotaxis.

Conclusions:

• Cell density is a key factor regulating collective cell migration through cytoskeletal organization.
• Intracellular force transmission, modulated by stress fiber alignment, drives directed group movement.
• The validated model provides a valuable tool for studying collective cell migration in various biological contexts.