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P-Selectin Glycoprotein Ligand-1 Is Expressed on Endothelial Cells and Mediates Monocyte Adhesion to Activated Endothelium

2007; Lippincott Williams & Wilkins; Volume: 27; Issue: 5 Linguagem: Inglês

10.1161/atvbaha.107.140442

1524-4636

Paula A. da Costa Martins, Juan J. García‐Vallejo, Johannes V. van Thienen, Mar Fernandez‐Borja, Janine M. van Gils, Cora Beckers, Anton J.G. Horrevoets, Peter L. Hordijk, Jaap Jan Zwaginga,

Immune Response and Inflammation

Objective— The purpose of this study was to investigate the presence and functionality of P-selectin glycoprotein ligand-1 (PSGL-1) on activated endothelial cells (ECs). Methods and Results— We show here that PSGL-1 is expressed at the mRNA and protein levels in umbilical vein and microvascular ECs. Furthermore, this endothelial PSGL-1 (ePSGL-1) is functional and mediates adhesion of monocytes or platelet-monocyte complexes (PMCs) to the activated endothelium in a flow model. ePSGL-1 expression was not affected by treating ECs with inflammatory stimuli (tumor necrosis factor α, interleukin-1β, thrombin, or histamine). However, the functional binding capacity of ePSGL-1 to monocytes or P-selectin/Fc chimera significantly increased by stimulation of the ECs with TNFα. By means of a siRNA approach to specifically knock-down the genes involved in the glycosylation of PSGL-1 we could show that tumor necrosis factor α–induced glycosylation of ePSGL-1 is critical for its binding capacity. Conclusion— Our results show that ECs express functional PSGL-1 which mediates tethering and firm adhesion of monocytes and platelets to inflamed endothelium.