Platelet-endothelial interactions in inflamed mesenteric venules

Blood. 1998 Feb 15;91(4):1318-24.

Abstract

The selectins are membrane glycoproteins promoting adhesive events between leukocytes, platelets, and endothelial cells. We have previously demonstrated that platelets roll on P-selectin expressed on stimulated endothelium. In this study, we wished to examine the function of both the platelet and endothelial selectins, P- and E-selectins, in mediating platelet-endothelial interactions during inflammation. We demonstrate, using intravital microscopic examination of venules inflamed with tumor necrosis factor-alpha (TNF-alpha), that resting platelets interact with both P- and E-selectins and that the leukocyte alpha(1,3)fucosyltransferases FucT IV and FucT VII do not provide platelets with selectin ligand activity. We also show that after thrombin activation of wild-type (+/+) platelets, platelet P-selectin can mediate interactions on a TNF-alpha-inducible endothelial ligand. To evaluate the potential role of platelet P-selectin in the recruitment of leukocytes to inflammatory sites, we reconstituted the bone marrow of mice deficient in both P- and E-selectins (P/E-/-) with wild-type (+/+) or P-selectin-deficient (P-/-) bone marrow containing megakaryocytic precursors. Providing +/+ platelets to P/E-/- mice by bone marrow transplantation did not rescue the immunodeficient phenotype, suggesting that platelet P-selectin does not have an active function in the recruitment of leukocytes into inflammatory sites. To participate in inflammatory or hemostatic responses, platelets may use the endothelial selectins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blood Platelets / metabolism
  • Blood Platelets / pathology*
  • Cell Adhesion
  • Cell Movement*
  • E-Selectin / physiology
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology*
  • Inflammation / pathology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • P-Selectin / physiology
  • Splanchnic Circulation*
  • Venules / pathology*

Substances

  • E-Selectin
  • P-Selectin