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Acta Physiologica 2012; Volume 204, Supplement 689
91st Annual Meeting of The German Physiological Society
3/22/2012-3/25/2012
Dresden, Germany
DYNAMIC ADHESION OF ERYPTOTIC ERYTHROCYTES TO ENDOTHELIAL CELLS VIA CXCL16/SR-PSOX
Abstract number: P221
Abed1 *M., Borst1 O., Alesutan1 I., Towhid1 S., Qadri1 S., Foller1 M., Gawaz2 M., Lang1 F.
1University of Tbingen, Department of Physiology, Tbingen, Germany
2University of Tbingen, Department of Cardiology, Tbingen, Germany
Suicidal death of erythrocytes or eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine exposure at the cell surface. Eryptosis is triggered by increase of cytosolic Ca2+ activity, which may result from treatment with the Ca2+ ionophore ionomycin or from energy depletion by removal of glucose. The present study tested the hypothesis that phosphatidylserine exposure at the erythrocyte surface fosters adherence to endothelial cells of the vascular wall under flow conditions at arterial shear rates and that binding of eryptotic cells to endothelial cells is mediated by the transmembrane CXC chemokine ligand 16 (CXCL16). To this end, human erythrocytes were exposed to energy depletion (for 48 h) or treated with the Ca2+ ionophore ionomycin (1 mM for 30 min). Phosphatidylserine exposure was quantified utilizing annexin-V binding, cell volume estimated from forward scatter in FACS analysis and erythrocyte adhesion to human vascular endothelial cells (HUVEC) determined in a flow chamber model. As a result, both, ionomycin and glucose depletion, triggered eryptosis and enhanced the percentage of erythrocytes adhering to HUVEC under flow conditions at arterial shear rates. The adhesion was significantly blunted in the presence of erythrocyte phosphatidylserine-coating annexin-V (5 ml/ml), of a neutralizing antibody against endothelial CXCL16 (4 mg/ml) and following silencing of endothelial CXCL16 with siRNA. The present observations demonstrate that eryptotic erythrocytes adhere to endothelial cells of the vascular wall in part by interaction of phosphatidylserine exposed at the erythrocyte surface with endothelial CXCL16.
To cite this abstract, please use the following information:
Acta Physiologica 2012; Volume 204, Supplement 689 :P221