Platelet-Endothelial Cell Interactions During Ischemia/Reperfusion: The Role of P-Selectin

• Published in: Blood 1998-07, Vol.92 (2), p.507-515
• Main Authors: Massberg, Steffen, Enders, Georg, Leiderer, Rosmarie, Eisenmenger, Simone, Vestweber, Dietmar, Krombach, Fritz, Messmer, Konrad
• Format: Article
• Language: English
• Subjects: Animals; Arteries - pathology; Biological and medical sciences; Blood and lymphatic vessels; Blood Platelets - pathology; Cardiology. Vascular system; Cell Adhesion - physiology; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Endothelium, Vascular - pathology; Endothelium, Vascular - physiopathology; Female; Intestine, Small - blood supply; Medical sciences; Mice; Mice, Inbred BALB C; P-Selectin - physiology; Platelet Adhesiveness; Reperfusion Injury - pathology; Reperfusion Injury - physiopathology
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V92.2.507

Growing evidence supports a pathophysiological role for platelets during the manifestation of postischemic reperfusion injury; in the current study, we investigated the nature and the molecular determinants of platelet-endothelial cell interactions induced by ischemia/reperfusion (I/R). Platelet-endothelium and leukocyte-endothelium interactions after 1 hour of ischemia were monitored in vivo within mouse small intestine. By intravital fluorescence microscopy, we observed that platelets, like leukocytes, roll along or firmly adhere to postischemic microvascular endothelial cells. In contrast, few leukocyte-endothelial cell interactions were detected in sham-operated controls. Monoclonal antibodies against P-selectin significantly attenuated platelet rolling and adherence in response to I/R. To identify whether platelet or endothelial P-selectin plays the major role in mediating postischemic platelet-endothelial cell interactions, P-selectin-deficient or wild-type platelets were transfused into wild-type or P-selectin-deficient mice, respectively. Whereas platelets lacking P-selectin rolled along or adhered to postischemic wild-type endothelium, interactions between wild-type platelets with mutant endothelium were nearly absent, indicating that I/R-induced platelet-endothelium interactions are dependent on the expression of P-selectin by endothelial cells. Concomitantly, P-selectin expression in the intestinal microvasculature was enhanced in response to I/R, whereas no upregulation of P-selectin was observed on circulating platelets. In summary, we provide first in vivo evidence that platelets accumulate in the postischemic microvasculature early after reperfusion via P-selectin-ligand interactions. Platelet recruitment and subsequent activation might play an important role in the pathogenesis of I/R injury.