Talin-Dependent Integrin Activation Regulates VE-Cadherin Localization and Endothelial Cell Barrier Function

Area of Science:

• Cell biology
• Vascular biology
• Integrin signaling

Background:

• Endothelial barrier integrity relies on vascular endothelial (VE)-cadherin.
• The molecular links between integrin adhesion and VE-cadherin are not fully understood.
• Talin binding to beta-integrin regulates integrin affinity but its role in endothelial barrier function is unknown.

Purpose of the Study:

• To investigate the necessity of talin-dependent beta-1 integrin activation for VE-cadherin organization.
• To determine the role of talin-dependent beta-1 integrin activation in endothelial cell barrier function.

Main Methods:

• Generated endothelial cell-specific talin knockout mice.
• Utilized short hairpin RNA (shRNA) to knockdown talin1 in cultured endothelial cells.
• Measured endothelial permeability using electrical cell-substrate impedance sensing (ECIS).
• Employed beta-1 integrin activating antibodies and talin reexpression for rescue experiments.

Main Results:

• EC-specific talin deletion in mice led to microvascular instability, hemorrhage, and mortality.
• Talin deficiency in endothelial cells increased monolayer permeability and altered VE-cadherin localization.
• Restoring beta-1 integrin activation normalized VE-cadherin organization and endothelial barrier function.

Conclusions:

• Talin-dependent beta-1 integrin activation is vital for stabilizing VE-cadherin at endothelial junctions.
• This mechanism is critical for maintaining endothelial barrier function.