Salivary Glands: Development, Adaptation and Disease

Salivary Glands: Development, Adaptation and Disease Edited by A. S. Tucker, I. Miletich . [ ISBN 978–3–8055–9406–6; e-ISBN 978–3–8055–9407–3; Vol 14 Frontier of Oral Biology (P. Sharpe, series Editor); hard cover; 2010CHF 159.–/EUR 113.50/USD 159.00; VIII + 150 p., 34 fig., 12 tab . ] Basel : Karger . 2010 . This book consists of eight chapters written by well-known specialists: five from London and three from the USA. It succeeds in bringing together basic scientists and clinicians to produce an up to date and interesting review of some of the latest advances in basic and applied research on salivary glands. As indicated in the first of the three subtitles, particular emphasis is focused on developmental biology and, particularly, on the interaction between epithelium and mesenchyme in branching morphogenesis. In this context it may be worth recalling that this process was first highlighted in the two seminal papers on mouse submandibular and sublingual glands published, just 60 years ago, in the Journal of Anatomy, by Elio Borghese (1909–1993), then working, as visiting scientist at Strangeways Research Laboratories, Cambridge, under the direction of Honor Fell (1900–1986). The first chapter, by Isabelle Miletich, provides a concise but comprehensive and well balanced panoramic view of the structure–function relationship in salivary glands and on the role of salivary secretions in health and disease. It gives a clear description of salivary gland development that constitutes an excellent introduction to most of the following chapters; furthermore, it demonstrates that the interactive processes underlying salivary gland development and differentiation, particularly those concerning the mouse submandibular gland, represent the key to understanding the processes that occur in the organogenesis of many other important organs. The second chapter, by the senior editor Abigail Tucker, belies the statement made at very end of the preface (written by the same author), that this book will be of interest ‘to developmental biologists, anatomists and clinicians’. It is, in fact a well-written and intriguing review on the structural and functional adaptive variations exhibited by salivary glands across the animal kingdom. This broad survey makes a fascinating read for a broad range of biologists, even non-professionals. From it we learn, inter alia, that the salivary glands of certain animals differentiate to produce not only silk and a wide variety of venoms, but also one of the most expensive and sought-after foods: the edible nests of cave swifts. Very attractive also is the section describing the interaction of glands and teeth in the venom system of certain reptiles during development, ending, in a sort of crescendo, with this intriguing question: what molecular signals lead an oral lamina to form teeth, while an adjacent lamina branches and gives origin to glands? The next three chapters by Pirraglia and Myat, Sequeira et al., and Wells and Patel, develop in more depth some of the topics highlighted in the introductory chapter on the study of the basic mechanisms of gland development. The first of the three, using Drosophila as a model, describes in detail current knowledge of the genes and genetic networks that regulate salivary gland invagination, lumen elongation, and migration. Many of the features of Drosophila salivary gland morphogenesis are conserved during the development of other tubular organs such as mammalian salivary glands, kidney, lungs, and vessels. The article by Sequeira et al. describes the role of interstitial extracellular matrix and of the epithelial cell basement membrane and their associated proteins in salivary gland development. Molecular characterization of these structures is critical also for understanding some pathologies and for the future development of therapeutic approaches. The chapter by Wells and Patel deals with lumen formation: this is a crucial and not fully understood event that takes place during branching morphogenesis, coinciding with cell polarization and junction formation. As in the other chapters, alterations of the underlying mechanism are placed in the context of pathological states of branched organs. Topics dealt with in the following chapters provide state-of-the-art data on one the hottest topics of biomedicine: embryonic and adult stem cells, with highlights on their possible role in tissue regeneration. Lombaert and Hoffman demonstrate that at embryonic stage 13, salivary epithelial cells contain different cell types based on their transcriptional profiles. They also show that several growth factors of mesenchymal origin directly influence the fate of these cells by regulating the level of both transcriptional factors and cytokeratins. The article by Carpenter and Cotroneo, utilizing a rat model of gland regeneration, investigates the role of stem cells in adult glands and the signals that, following a mechanical injury, trigger their further development into novel salivary tissue. The last chapter, written by Thomas, Brown and McGurk, two radiologists and a surgeon, provides a punctual and updated review on the diagnosis and treatment of diseases affecting salivary glands, reporting the significant improvements occurred in the last two decades. It also discusses age-related degenerative changes and sialosis, a poorly understood, non pathological, enlargement of salivary glands whose study, together with information obtained by investigating stem cells, may help in developing new strategies for regenerating salivary gland tissue. In conclusion, I strongly recommend this well-organized and excellent book, which represents a very valuable addition to current literature on salivary glands. From the preface onwards, I felt, in every chapter, a vein of contagious enthusiasm for salivary glands and their secretions, not so long ago regarded with a faint aura of opprobrium.