AFM functional imaging on vascular endothelial cells

Area of Science:

• Cell Biology
• Biophysics
• Nanotechnology

Background:

• Vascular endothelial (VE)-cadherin mediates mechanical linkage between endothelial cells.
• VE-cadherin forms clusters linked to the actin cytoskeleton, a dynamic process influenced by cell function.

Purpose of the Study:

• To nano-map VE-cadherin distribution and clustering in mouse myocardial microvascular endothelial cells (MyEnd).
• To investigate the relationship between VE-cadherin clusters and the actin cytoskeleton.

Main Methods:

• Simultaneous topography and recognition imaging (TREC) technique was employed.
• TREC provided high lateral resolution (nanometer scale) mapping of VE-cadherin on cell surfaces.
• Microtubule depolymerization using nocodazole was performed to assess cytoskeletal interactions.

Main Results:

• TREC revealed prominent VE-cadherin 'dark' spots (10-250 nm domains/clusters) arising from cis-dimer binding.
• These domains collocalized with cytoskeletal filaments, even after microtubule depolymerization.
• VE-cadherin clusters were confirmed to be linked to actin filaments.

Conclusions:

• TREC is an effective method for high-resolution mapping of cell surface receptors.
• VE-cadherin is dynamically linked to the actin cytoskeleton in endothelial cells.
• The findings support the hypothesis of VE-cadherin's direct association with actin filaments.