Single cell morphological metrics and cytoskeletal alignment regulate VCAM-1 protein expression.

Area of Science:

• Biomedical Engineering
• Cell Biology
• Cardiovascular Research

Background:

• Vascular adhesion molecule-1 (VCAM-1) mediates leukocyte adhesion in early atherosclerosis, upregulated by inflammation and modulated by fluid shear stress (FSS).
• High FSS promotes endothelial cell (EC) elongation and VCAM-1 downregulation (athero-protective), while low FSS leads to VCAM-1 upregulation (athero-prone).
• The role of EC morphology and cytoskeletal alignment on VCAM-1 expression independent of FSS remains unclear.

Purpose of the Study:

• To investigate the impact of endothelial cell shape and cytoskeletal alignment on VCAM-1 protein expression.
• To determine if cell elongation and alignment regulate VCAM-1 independently of fluid shear stress.
• To correlate morphological metrics with VCAM-1 expression levels.

Main Methods:

• Utilized topographical micropatterning to control endothelial cell (EC) morphology and alignment.
• Employed single-cell image analysis to quantify cell elongation, cytoskeletal alignment, and VCAM-1 protein expression.
• Assessed monocytic cell adhesion to micropatterned ECs in a VCAM-1 dependent manner.

Main Results:

• Elongated ECs with aligned cytoskeletons showed significantly reduced VCAM-1 protein expression compared to controls, even without FSS.
• Actin alignment demonstrated a stronger negative correlation with VCAM-1 expression than cell elongation.
• Reduced static adhesion of monocytic cells was observed on micropatterned substrates, dependent on VCAM-1 levels.

Conclusions:

• Endothelial cell elongation and cytoskeletal alignment regulate VCAM-1 expression and associated immunogenic functions.
• These morphological factors promote a less inflammatory EC phenotype independent of hemodynamic forces.
• Findings reveal a novel mechanism for controlling VCAM-1-mediated inflammation in atherosclerosis through cell architecture.