Polarization of plasma membrane microviscosity during endothelial cell migration

Area of Science:

• Cell biology
• Biophysics
• Endothelial cell function

Background:

• Cell movement relies on polarized cell structures.
• Endothelial cells (ECs) exhibit anterior-posterior polarization during migration.
• Plasma membrane properties are critical for cell motility.

Purpose of the Study:

• To investigate the role of plasma membrane microviscosity (PMM) in endothelial cell migration.
• To determine the influence of cholesterol on PMM and actin dynamics.
• To elucidate the relationship between PMM, actin polymerization, and cell movement speed.

Main Methods:

• Utilized synthetic lipid vesicles to study membrane microviscosity effects on actin dynamics.
• Employed live-cell imaging to analyze PMM and actin polymerization in migrating ECs.
• Stimulated ECs with angiogenic growth factors to observe migration responses.

Main Results:

• Plasma membrane microviscosity (PMM) is elevated at the leading edge of migrating ECs.
• Cholesterol plays a key role in establishing the PMM gradient.
• Increased PMM showed a biphasic effect on actin dynamics, enhancing vesicle deformation at low concentrations and inhibiting it at high concentrations.
• Migrating ECs with increased PMM exhibited reduced actin polymerization rates but enhanced cell movement.

Conclusions:

• Elevated PMM at the cell front is a feature of migrating ECs.
• Increased PMM, influenced by cholesterol, is crucial for regulating actin dynamics.
• Higher PMM in lamellipodia may facilitate efficient actin network formation, leading to faster endothelial cell migration.