Tumor necrosis factor alpha-induced vascular leakage involves PECAM1 phosphorylation

Area of Science:

• Endothelial cell biology
• Molecular mechanisms of vascular permeability
• Inflammatory signaling pathways

Background:

• Vascular permeability is crucial for nutrient exchange but its dysregulation contributes to diseases.
• Endothelial cell junctions and adhesion molecules play a key role in controlling vascular permeability.
• Tumor necrosis factor alpha (TNFalpha) is a pro-inflammatory cytokine known to increase vascular permeability.

Purpose of the Study:

• To investigate the role of platelet endothelial cell adhesion molecule-1 (PECAM1) in TNFalpha-induced vascular permeability.
• To identify the molecular mechanisms underlying PECAM1 involvement in endothelial cell responses to TNFalpha.
• To evaluate the potential of kinase inhibitors in preventing TNFalpha-mediated vascular leakage.

Main Methods:

• Exposure of human umbilical vein endothelial cells (HUVECs) to TNFalpha.
• Analysis of PECAM1 surface redistribution, cytoskeletal changes, and phosphorylation.
• In vitro treatment with tyrosine and serine-threonine kinase inhibitors.
• In vivo administration of lavendustin A in a mouse model of vascular leakage.

Main Results:

• TNFalpha induced PECAM1 redistribution, cytoskeletal disruption, and increased PECAM1 phosphorylation in HUVECs.
• Kinase inhibitors prevented PECAM1 redistribution and the associated increase in endothelial permeability.
• In vivo, lavendustin A protected against TNFalpha-induced vascular leakage in mouse liver.

Conclusions:

• PECAM1 phosphorylation and dynamic cytoskeletal association are critical for TNFalpha-mediated vascular permeability.
• Targeting tyrosine and serine-threonine kinases may offer a therapeutic strategy to control vascular leakage.
• PECAM1's role in vascular permeability is modulated by its phosphorylation status and cytoskeletal interactions.