Sphingolipids

Sphingolipids are lipid components of the plasma membrane in eukaryotic cells. They have an important function in signaling mechanisms in the cell. This book on sphingolipids provides insights into the basics of sphingolipid biology and drug development, with a particular emphasis on the sphingolipid derivative ceramide. In the first part basic functions of sphingolipids are described, as well as the genetics of important enzymes, sphingolipid metabolism and synthesis. The second part of this first volume focuses on drug development and pharmacology. The book is intended for scientists in pharmacology, biochemistry and cell biology with a focus on biomedical research as well as for clinicians working in pharmacology, oncology, cardiology, neurology and infectious disease. Together with Volume 216 by the same editors, the collection represents a unique, comprehensive work on sphingolipids, providing information on both sphingolipids’ basic biology (including synthesis, metabolism and cell biology) and their important function in a (patho-)physiological context.

This book presents an overview of sphingolipids: biology, synthesis and functions. The topics analysed in this book cover a broad spectrum of functions played by sphingolipids including: the role of sphingomyelin in the regulation of membrane physical state; tricyclic antidepressants as modulators of sphingolipid turnover and cell sensitivity to insulin action; sphingolipid diversity, biosynthesis and regulation; metabolism of glycolipids at the cell's surface: modulation and functional implications; the specific role of sphingomyelins in cell physiology; the role of sphingosine-based lipids using sphingolipidomics; sphingolipids and ceramides of aqueous humor and trabecular meshwork; the effect of membrane microdomains containing sphingolipids on lipid peroxidation; and roles of sphingolipids in skeletal development and homeostasis.

This book attempts to analyze the latest discoveries in sphingolipid biology and how the alteration of their metabolism leads to altered signaling events and to the development of pathobiological disorders, such as cancer, cardiovascular diseases, asthma, diabetes, inflammation and infectious diseases.

Sphingolipids are fundamental to the structures of cell membranes, lipoproteins, and the stratum cornea of the skin. Many complex sphingolipids, as well as simpler sphingoid bases and derivatives, are highly bioactive as extra- and intracellular regulators of growth, differentiation, migration, survival, senescence, and numerous cellular responses to stress. This book reviews exciting new developments in sphingolipid biology/sphingolipidology that challenge our understanding of how multicellular organisms grow, develop, function, age, and die.

This book is about the various roles of bioactive ceramides and other sphingolipids in cellular biology. The enigmatic biophysical and biochemical properties of ceramides and their propensity to influence membranes whether as rafts or protein-permeable channels are heavily discussed. Metabolism of ceramides and their metabolites is also focused with ceramide synthase family of proteins being a target of extensive review. Ceramide 1-phosphate and other sphingolipids are also presented in cellular physiology and pathophysiology. Prokaryotic origins of mitochondria at the level of membranes and the occurrence of apoptosis in bacteria are presented. Many aspects of ceramide and sphingolipid biology are addressed in this book. Its focus is the metabolism of ceramide in normal and diseased states and the biophysical and biochemical mechanisms governing the bioactivity of these molecules. Sphingolipid research has surged over the past thirty years and this book gathers the recent findings of various aspects of sphingolipid biochemistry. World-renowned scientists from the field of lipid biology, specifically sphingolipid biochemistry, were gathered to write this book. Scholars from most continents of the globe committed to write diligently about their expertise and the newest findings in the relevant fields. This book came to fruition after almost a year and a half of laborious preparation and diligent writings. This book is targeted to the experienced reader who is looking to read about the various aspects of bioactive ceramide signaling, as well as to the newcomer into the field, as the topics are explained in concise yet very informative manner. The authors and editor wish all readers a pleasant time reading this volume, and are adamant that this book will meet all expectations.

This volume presents information on both the basic and clinical aspects of sphingolipid-metabolizing enzymes in various cancers. The volume also includes discussions of the innovative techniques and approaches for quantitative analysis and imaging that could significantly impact the general understanding of this topic, and the potential benefit of targeting sphingolipid enzymes to develop novel cancer therapeutics. As well, the volume includes a critical examination of the specific pathways and pathobiologies associated with the altered regulation of sphingolipid metabolism as a contributor to the development and/or maintenance of pathological conditions such as cancer.

Although sphingolipids are ubiquitous components of cellular membranes, their abundance in cells is generally lower than glycerolipids or cholesterol, representing less than 20% of total lipid mass. Following their discovery in the brain—which contains the largest amounts of sphingolipids in the body—and first description in 1884 by J.L.W. Thudichum, sphingolipids have been overlooked for almost a century, perhaps due to their complexity and enigmatic nature. When sphingolipidoses were discovered, a series of inherited diseases caused by enzyme mutations involved in sphingolipid degradation returned to the limelight. The essential breakthrough came decades later, in the 1990s, with the discovery that sphingolipids were not just structural elements of cellular membranes but intra- and extracellular signaling molecules. It turned out that their lipid backbones, including ceramide and sphingosine-1-phosphate, had selective physiological functions. Thus, sphingolipids emerged as essential players in several pathologies including cancer, diabetes, neurodegenerative disorders, and autoimmune diseases. The present volume reflects upon the unexpectedly eclectic functions of sphingolipids in health, disease, and therapy. This fascinating lipid class will continue to be the subject of up-and-coming future discoveries, especially with regard to new therapeutic strategies.