Actin-binding proteins differentially regulate endothelial cell stiffness, ICAM-1 function and neutrophil...

Area of Science:

• Immunology
• Cell Biology
• Vascular Biology

Background:

• Chronic vascular inflammation involves leukocyte interactions with the endothelium.
• Leukocyte β2-integrins bind to endothelial intercellular adhesion molecule 1 (ICAM-1), facilitating leukocyte migration.
• Endothelial heterogeneity suggests specific sites for leukocyte transmigration, but the molecular basis is unclear.

Purpose of the Study:

• To investigate the molecular mechanisms underlying endothelial heterogeneity.
• To determine the role of endothelial actin-binding proteins in regulating leukocyte transmigration.
• To explore the relationship between endothelial cell stiffness and ICAM-1 function.

Main Methods:

• Investigated the function of endothelial filamin B, α-actinin-4, and cortactin in neutrophil adhesion, spreading, and transmigration.
• Assessed the impact of these proteins on endothelial cell stiffness gradients.
• Examined α-actinin-4 levels in human and murine atherosclerotic plaques.

Main Results:

• Endothelial filamin B, α-actinin-4, and cortactin differentially regulate neutrophil adhesion, spreading, and transmigration.
• Endothelial cell stiffness, modulated by these proteins, influences ICAM-1 function.
• Endothelial α-actinin-4 is identified as a key regulator of endothelial cell stiffness and ICAM-1-mediated neutrophil transmigration.
• Elevated α-actinin-4 levels are observed in atherosclerotic plaques.

Conclusions:

• Endothelial cell stiffness is a critical regulator of endothelial surface heterogeneity.
• ICAM-1 function and subsequent neutrophil transmigration are controlled by endothelial cell stiffness.
• α-actinin-4 plays a significant role in leukocyte recruitment in vascular inflammation and atherosclerosis.