Although all endothelial cells form a metabolically active, semipermeable interface between blood (or lymphatics) and tissue, considerable heterogeneity in endothelial structure and function exists even within a single vascular segment. Part of this heterogeneity is due to the environment in which a cell resides. However, endothelial cells are also imprinted during their development to impart a stable differentiated phenotype. Accordingly, endothelial cells from different sites within a blood vessel can be discriminated based upon their active gene expression profiles, even when their environments are the same. Interaction between environmental stimuli (as in blood flow patterns or transmural pressure) and the cell's origin (precapillary, capillary, postcapillary) therefore coordinately regulate site-specific endothelial cell behavior.


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Capsule Bibliography

Dr. Al-Mehdi has held academic appointments at the University of Pennsylvania (Institute for Environmental Medicine) and, more recently, at the University of South Alabama (Assistant Professor of Pharmacology, Center for Lung Biology). His work focuses on lung vascular biology, with specific attention given to endothelial cell responses to oxygen transitions, and the role of oxygen in lung metastasis. Work in the Al-Mehdi lab is supported by the NIH.

Dr. Schaphorst has held academic appointments at Johns Hopkins University (Pulmonary and Critical Care Medicine) and, more recently, at the University of South Alabama (Associate Professor of Medicine, Center for Lung Biology). His work has addressed signal transduction networks that interplay to control endothelial cell barrier function, with emphasis on hepatocyte growth factor activation of c-Met signaling.

Dr. Stevens has held academic appointments at the University of Colorado Health Sciences Center (CVP Research Laboratory) and, more recently, at the University of South Alabama, where he is the Director of the Center for Lung Biology. His work seeks to understand the interplay between genetic and environmental factors that control endothelial cell phenotype. A major emphasis in his laboratory is to reveal the unique signal transduction pathways that control macro- and microvascular endothe-lial cell function. Work in the Stevens laboratory is supported by the NIH.

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