BACKGROUND Hypercholesterolemia is considered a major risk factor for the development of atherosclerosis. Enhanced lipid peroxidation and persistent platelet activation can be observed in vivo in hypercholesterolemic patients and may have pathophysiological implications in the occurrence of cardiovascular events. P-selectin may play an important role in the pathogenesis of multicellular events,...

Although platelets have been implicated in the pathogenesis of human inflammatory bowel diseases, little is known about the magnitude of platelet accumulation in the inflamed bowel, what regulates this process, and its relevance to the overall inflammatory response. In this study, intravital video microscopy was used to monitor the trafficking of platelets and leukocytes and vascular permeabili...

The transient appearance of P-selectin on the surface of endothelial cells helps recruit leukocytes into sites of inflammation. The tight control of cell surface P-selectin on these cells depends on regulated exocytosis of Weibel-Palade bodies where the protein is stored and on its rapid endocytosis. After endocytosis, P-selectin is either sorted via endosomes and the Golgi apparatus for storag...

Interactions of selectins with cell surface glycoconjugates mediate the first step of the adhesion and signaling cascade that recruits circulating leukocytes to sites of infection or injury. P-selectin dimerizes on the surface of endothelial cells and forms dimeric bonds with P-selectin glycoprotein ligand-1 (PSGL-1), a homodimeric sialomucin on leukocytes. It is not known whether leukocyte L-s...

P-selectin is an integral membrane glycoprotein on stimulated platelets and endothelial cells that serves as a receptor for leukocytes. To estimate the density of P-selectin in membranes necessary to support adhesion, we incorporated purified P-selectin at varying concentrations into phospholipid bilayers that encapsulated glass microspheres. Maximal binding of these lipospheres to HLW cells,...

L eukocytes are more likely to grab onto a vascular surface when under fl ow than in the absence of fl ow. This counterintuitive behavior relies on bonds between transmembrane selectins on the blood cell and their vascular ligands. These so-called " catch bonds " get stronger because fl ow fl ips open selectin into a binding-ready conformation, Lou et al. show on page 1107. The authors have sol...

STUDY OBJECTIVES To determine if soluble leukocyte selectin (sL-selectin) levels in serum and pleural fluid (PF) are an inflammatory marker that differentiates pleural effusion transudates from exudates. DESIGN sL-selectin PF and serum levels were measured in consecutive patients and compared to established criteria. SETTING A tertiary-care military medical center. PATIENTS One hundred tw...

Selectins and their ligands have been implicated in tumor growth and progression in carcinomas, but their role in neuroblastoma has not been systematically examined. In the current study we evaluated L-, P- and E-selectin binding to neuroblastoma cells and the expression of some of their known ligands, namely CD44, CD24 and P-selectin glycoprotein ligand-1 (PSGL-1). Genetic loss of PSGL-1 or CD...

L-selectin mediates leukocyte tethering and rolling, the first step in a sequential process of leukocyte adhesion and migration. Additionally, L-selectin has important signaling roles perhaps contributing to leukocyte activation and integrin-mediated adhesion. Because chemokines are critically involved in leukocyte activation, we questioned whether L-selectin signaling affects chemokine recepto...

BACKGROUND Primary Sjögren's syndrome (pSS) is one of the most common chronic systemic autoimmune diseases, and thrombocytopenia is one of the hematological manifestations of pSS. When platelet and endothelial cells are activated, P-selectin is expressed on the cell surface. This study aimed to investigate the role of P-selectin autoantibodies in the pathogenesis of thrombocytopenia in pSS. MAT...