The Role Of Caveolae In The Regulation Of Endothelial Cells Barrier Function

The vascular endothelium lining the inner surface of blood vessels serves as the first interface for circulating blood components to interact with cells of the vascular wall and surrounding extravascular tissues. In addition to regulating blood delivery and perfusion, a major function of vascular endothelia, especially those in exchange microvessels (capillaries and postcapillary venules), is to provide a semipermeable barrier that controls blood–tissue exchange of fluids, nutrients, and metabolic wastes while preventing pathogens or harmful materials in the circulation from entering into tissues. During host defense against infection or tissue injury, endothelial barrier dysfunction occurs as a consequence as well as cause of inflammatory responses. Plasma leakage disturbs fluid homeostasis and impairs tissue oxygenation, a pathophysiological process contributing to multiple organ dysfunction associated with trauma, infection, metabolic disorder, and other forms of disease. In this book, we provide an updated overview of microvascular endothelial barrier structure and function in health and disease. The discussion is initiated with the basic physiological principles of fluid and solute transport across microvascular endothelium, followed by detailed information on endothelial cell–cell and cell–matrix interactions and the experimental techniques that are employed to measure endothelial permeability. Further discussion focuses on the signaling and molecular mechanisms of endothelial barrier responses to various stimulations or drugs, as well as their relevance to several common clinical conditions. Taken together, this book provides a comprehensive analysis of microvascular endothelial cell and molecular pathophysiology. Such information will assist scientists and clinicians in advanced basic and clinical research for improved health care.

The endothelium, a monolayer of endothelial cells, constitutes the inner cellular lining of the blood vessels (arteries, veins and capillaries) and the lymphatic system, and therefore is in direct contact with the blood/lymph and the circulating cells. The endothelium is a major player in the control of blood fluidity, platelet aggregation and vascular tone, a major actor in the regulation of immunology, inflammation and angiogenesis, and an important metabolizing and an endocrine organ. Endothelial cells controls vascular tone, and thereby blood flow, by synthesizing and releasing relaxing and contracting factors such as nitric oxide, metabolites of arachidonic acid via the cyclooxygenases, lipoxygenases and cytochrome P450 pathways, various peptides (endothelin, urotensin, CNP, adrenomedullin, etc.), adenosine, purines, reactive oxygen species and so on. Additionally, endothelial ectoenzymes are required steps in the generation of vasoactive hormones such as angiotensin II. An endothelial dysfunction linked to an imbalance in the synthesis and/or the release of these various endothelial factors may explain the initiation of cardiovascular pathologies (from hypertension to atherosclerosis) or their development and perpetuation. Table of Contents: Introduction / Multiple Functions of the Endothelial Cells / Calcium Signaling in Vascular Cells and Cell-to-Cell Communications / Endothelium-Dependent Regulation of Vascular Tone / Conclusion / References

The focus of this collection of illustrated reviews is to discuss the systems biology of free radicals and anti-oxidants. Free radical induced cellular damage in a variety of tissues and organs is reviewed, with detailed discussion of molecular and cellular mechanisms. The collection is aimed at those new to the field, as well as clinicians and scientists with long standing interests in free radical biology. A feature of this collection is that the material also brings insights into various diseases where free radicals are thought to play a role. There is extensive discussion of the success and limitations of the use of antioxidants in several clinical settings.

Caveolae (latin for little caves) are small structures found at the surface of cells. They are responsible for the regulation of important metabolic pathway. As a consequence, they may play a critical role in several human diseases such as atherosclerosis, cancer, diabetes, and muscular dystrophies. This book analyzes the role and function of caveolae in these aspects and serves as the first textbook currently available on caveolae/caveolin.

This book presents a concise synthesis of the current knowledge and recent advances in the structure, organization and functional role of the cytoskeleton in endothelial cells. Particular attention has been given to the different features of the regulation of vascular function mediated by the endothelium. Since cytoskeleton is a scaffolding element that regulates the architecture of the cell and additionally controls several fundamental aspects of intracellular signaling, this book will serve as a comprehensive resource for those interested in these fascinating biological processes associated with vascular biology. The book has been divided into two major sections: general aspects of the endothelial cytoskeleton and the role of the role of the endothelial cytoskeleton in different functions of the vascular wall.

Caveolae are 50-100 nm flask-shaped invaginations of the plasma membrane that are primarily composed of cholesterol and sphingolipids. Using modern electron microscopy techniques, caveolae can be observed as omega-shaped invaginations of the plasma membrane, fully-invaginated caveolae, grape-like clusters of interconnected caveolae (caveosome), or as transcellular channels as a consequence of the fusion of individual caveolae. The caveolin gene family consists of three distinct members, namely Cav-1, Cav-2 and Cav-3. Cav-1 and Cav-2 proteins are usually co-expressed and particularly abundant in epithelial, endothelial, and smooth muscle cells as well as adipocytes and fibroblasts. On the other hand, the Cav-3 protein appears to be muscle-specific and is therefore only expressed in smooth, skeletal and cardiac muscles. Caveolin proteins form high molecular weight homo- and/or hetero-oligomers and assume an unusual topology with both their N- and C-terminal domains facing the cytoplasm.

Caveolae are 50-100 nm flask-shaped invaginations of the plasma membrane that are primarily composed of cholesterol and sphingolipids. Using modern electron microscopy techniques, caveolae can be observed as omega-shaped invaginations of the plasma membrane, fully-invaginated caveolae, grape-like clusters of interconnected caveolae (caveosome), or as transcellular channels as a consequence of the fusion of individual caveolae. The caveolin gene family consists of three distinct members, namely Cav-1, Cav-2 and Cav-3. Cav-1 and Cav-2 proteins are usually co-expressed and particularly abundant in epithelial, endothelial, and smooth muscle cells as well as adipocytes and fibroblasts. On the other hand, the Cav-3 protein appears to be muscle-specific and is therefore only expressed in smooth, skeletal and cardiac muscles. Caveolin proteins form high molecular weight homo- and/or hetero-oligomers and assume an unusual topology with both their N- and C-terminal domains facing the cytoplasm.

This wide ranging work provides a complete representation of the present state of knowledge of the vascular endothelium. The volume comprises 20 chapters by experts who have made significant contributions to research in the vascular endothelium. The text discusses the structure, development and function of the normal vascular endothelium, considers conditions that lead to the disruption of vascular physiology and provides a comprehensive description of pathologies and their treatment.