Correlating cell shape and cellular stress in motile confluent tissues.

Area of Science:

• Biophysics
• Cell Biology
• Rheology

Background:

• Collective cell migration is crucial for tissue development, repair, and disease.
• Mechanical forces between cells regulate coordinated cell movement.

Purpose of the Study:

• To develop a method for inferring cellular stresses from traction forces in migrating tissues.
• To characterize tissue rheological properties using mechanical stress data.

Main Methods:

• Utilized a self-propelled Voronoi (SPV) model linking cell mechanics, shape, and motility.
• Formulated a generalized mechanical inference method to derive spatiotemporal stress distributions from traction forces.
• Correlated temporal shear stress with tissue viscosity.

Main Results:

• Traction-based stress measurements accurately reflect stresses calculated from cell shapes.
• Identified a 'motility-induced swim stress' contributing to tissue contractility/extensibility.
• Demonstrated that temporal stress correlations predict effective tissue viscosity and liquid-solid transitions.

Conclusions:

• Traction force microscopy provides a powerful tool for quantifying cellular stresses and tissue rheology.
• This approach offers insights into the mechanics of collective cell migration and tissue dynamics.
• Rheological properties of tissues can be extracted directly from traction data.