CD109-regulated mechanical properties of endothelial cells

Area of Science:

• Biophysics
• Cell Biology
• Vascular Biology

Background:

• CD109 antigen is present on endothelial cell surfaces and implicated in vascular pathology.
• Understanding CD109's role in endothelial cell mechanics is crucial for vascular health.

Purpose of the Study:

• To investigate the impact of CD109 antigen immobilization via specific antibodies on the nanomechanical properties of human umbilical endothelial cells (HUVECs).
• To explore the relationship between CD109 binding and cellular mechanical changes, including cytoskeletal reorganization and signaling pathways.

Main Methods:

• Utilized atomic force microscopy (AFM) in quantitative nanomechanical property mapping (PeakForce QNM) mode.
• Applied anti-CD109 antibodies to both fixed and living HUVECs to assess nanomechanical property changes.
• Analyzed the activation of the TGF-β/Smad2/3 signaling pathway and cytoskeletal elements (vimentin, actin).

Main Results:

• Immobilization of CD109 antigen with anti-CD109 antibodies significantly increased HUVEC surface stiffness.
• Living cells showed a 4.9-fold increase in stiffness, while fixed cells showed a 1.45-fold increase compared to controls.
• Observed changes in the spatial distribution of mechanical properties, TGF-β/Smad2/3 pathway activation, and reorganization of vimentin and actin cytoskeletons.

Conclusions:

• Blocking CD109 antigen on HUVECs induces mechanical property changes and cytoskeletal remodeling similar to TGF-β signaling activation.
• Suggests a potential role for CD109 antigen in regulating the mechanical behavior of endothelial cells.
• Highlights the utility of AFM for probing cell surface mechanics and molecular interactions.