Dynamic rigidity changes enable rapid cell migration on soft substrates

Area of Science:

• Cell Biology
• Biophysics
• Mechanobiology

Background:

• Cell migration is vital for biological processes and typically requires rigid substrates for adequate cell traction forces.
• Softer substrates (<4 kPa) are generally considered insufficient for efficient cell migration under static conditions.

Purpose of the Study:

• To investigate if mesenchymal stem cells (MSCs) can migrate on soft substrates under dynamic rigidity conditions.
• To understand the cellular mechanisms and theoretical basis for cell migration on cyclically changing substrates.

Main Methods:

• Utilized dynamic substrate rigidity changes to study mesenchymal stem cell (MSC) migration.
• Measured cell traction forces and focal adhesion turnover under dynamic conditions.
• Developed a theoretical model incorporating force balance under dynamic substrate rigidity.

Main Results:

• MSCs demonstrated rapid migration on soft substrates when exposed to rapid cyclic rigidity changes.
• Dynamic conditions led to increased cell traction forces and accelerated focal adhesion turnover.
• The study's theoretical model accurately predicted migration speed and cell shape evolution.

Conclusions:

• Cells possess an innate ability to navigate fluctuating mechanical cues, overcoming limitations of static soft substrates.
• Dynamic substrate rigidity offers a novel mechanism for cell migration, independent of traditional cell polarity and focal adhesion turnover.
• Findings provide insights into cellular behavior in dynamic physiological and pathological environments.