Capped high-force integrin bond lifetimes and spacing-tuned binding frequency drive rapid fibroblast migration

Area of Science:

• Cell Biology
• Biophysics
• Materials Science

Background:

• Cell migration requires balancing focal adhesion (FA) stability for traction and turnover for translocation.
• Integrin binding frequency and force-dependent duration are critical but poorly understood regulators of this balance.

Purpose of the Study:

• To investigate how integrin binding frequency and force-dependent bond duration jointly regulate focal adhesion dynamics and fibroblast migration speed.
• To challenge the established view of fibroblasts as slow-moving cells.

Main Methods:

• Utilized block copolymer micelle nanolithography to create gold nanoparticle arrays with controlled spacings, modulating integrin-ligand binding frequency.
• Employed tension gauge tethers (TGTs) to control the force threshold and thus the lifetime of high-force integrin bonds.
• Performed knockout and blocking experiments to identify key integrin subtypes involved.

Main Results:

• Intermediate ligand spacing and moderate TGT force thresholds accelerated fibroblast migration up to twelvefold.
• Achieved rapid FA turnover and a dendritic actin architecture driven by lamellipodia.
• Identified α5β1 integrin as the mechanically dominant subtype crucial for rapid migration.

Conclusions:

• Optimized adhesion mechanics, considering both binding frequency and duration, significantly enhance cell migration speed.
• Refined the classic biphasic cell migration model into a two-dimensional framework.
• Findings provide avenues for tissue engineering and therapeutics by modulating cell speed and phenotype through adhesion control.