In Vivo Models To Study Angiogenesis

In Vivo Models to Study Angiogenesis provides the latest information and an overview of the most common assays for studying angiogenesis in vivo. Under physiological conditions, angiogenesis is tightly controlled, whereas increased production of angiogenic stimuli and/or reduced production of angiogenic inhibitors leads to abnormal neovascularization, such as occurs in cancer, chronic inflammatory disease, diabetic retinopathy, macular degeneration and cardiovascular disorders. Several genetic and epigenetic mechanisms are involved in the early development of the vascular system. This book presents the latest information from the extensive literature and research available. Evidence is now emerging that blood vessels themselves have the ability to provide instructive regulatory signals to surrounding non-vascular target cells during organ development. Thus, endothelial cell signaling is currently believed to promote fundamental cues for cell fate specification, embryo patterning, organ differentiation and postnatal tissue remodeling. Provides information on the most common assays to study angiogenesis in vivo Presents an ideal reference for those interested in angiogenesis as a normal and vital process in growth and development Covers wound healing, the formation of granulation tissue, and the transition of tumors from benign to malignant

Angiogenesis, the development of new blood vessels from the existing vasculature, is essential for physiological growth and over 18,000 research articles have been published describing the role of angiogenesis in over 70 different diseases, including cancer, diabetic retinopathy, rheumatoid arthritis and psoriasis. One of the most important technical challenges in such studies has been finding suitable methods for assessing the effects of regulators of eh angiogenic response. While increasing numbers of angiogenesis assays are being described both in vitro and in vivo, it is often still necessary to use a combination of assays to identify the cellular and molecular events in angiogenesis and the full range of effects of a given test protein. Although the endothelial cell - its migration, proliferation, differentiation and structural rearrangement - is central to the angiogenic process, it is not the only cell type involved. the supporting cells, the extracellular matrix and the circulating blood with its cellular and humoral components also contribute. In this book, experts in the use of a diverse range of assays outline key components of these and give a critical appraisal of their strengths and weaknesses. Examples include assays for the proliferation, migration and differentiation of endothelial cells in vitro, vessel outgrowth from organ cultures, assessment of endothelial and mural cell interactions, and such in vivo assays as the chick chorioallantoic membrane, zebrafish, corneal, chamber and tumour angiogenesis models. These are followed by a critical analysis of the biological end-points currently being used in clinical trials to assess the clinical efficacy of anti-angiogenic drugs, which leads into a discussion of the direction future studies should take. This valuable book is of interest to research scientists currently working on angiogenesis in both the academic community and in the biotechnology and pharmaceutical industries. Relevant disciplines include cell and molecular biology, oncology, cardiovascular research, biotechnology, pharmacology, pathology and physiology.

Tumor Vascularization discusses the different types of growth of tumor blood vessels and their implications on research and healthcare. The book is divided into three parts: the first one, General Mechanisms, discusses different vessel growth mechanisms, such as sprouting angiogenesis, non-angiogenesis dependent growth, intussusceptive microvascular growth, vascular co-option and vasculogenic mimicry. The second and third parts, entitled Clinical Implications and Therapeutic Implications are dedicated to translating recent findings in this field to patient treatment and healthcare. This book is a valuable source for cancer researchers, oncologists, graduate students and members of the biomedical field who are interested in tumor progression and blood vessels. Explains new, non-orthodox concepts recently developed and related to the modality of growth of tumor blood vessels Provides information on the types of angiogenesis, non-angiogenesis dependent growth and vascular co-option, discussing both their similarities and differences Encompasses a discussion on clinical implications of tumor vascularization to translate research findings into treatment

Understanding how angiogenesis "works" and how to control it will have massive implications on the management, treatments, and ultimately the prevention of many common (and not so common) diseases. Angiogenesis is the growth of new blood vessels and is an important natural process in the body. A healthy body maintains a perfect balance of angiogenesis modulators. In many serious disease states, however, the body loses control over angiogenesis. Diseases that are angiogenesis-dependent result when blood vessels either grow excessively or insufficiently. Tried-and-tested techniques written by researchers that developed them, used them, and brought them to fruition Provides the "builder's manual" for essential techniques--a one-stop shop that eliminates needless searching among untested techniques Includes step-by-step methods for understanding the cell and molecular basis of wound healing, vascular integrin signaling, mechanical signaling in blood vessels, and vascular proteomics

This volume aims to provide a range of methods and protocols for studying tumor angiogenesis in vitro and in vivo to reflect advances in the field. The chapters in this book cover topics such as: morphological aspects of tumor angiogenesis, aortic ring assay and its use for the study of tumor angiogenesis, ex vivo tissue culture model for anti-angiogenic drug testing, transgenic zebrafish, orthotopic models of ovarian cancer, and uncovering metabolic effects of anti-angiogenic therapy in tumors by induced metabolic bioluminescence imaging. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Cutting edge and thorough, Tumor Angiogenesis Assays: Methods and Protocols is a valuable resource for anyone interested in tumor angiogenesis assay research.

Angiogenesis, the growth of blood vessels from an existing vasculature, can occur by sprouting from preexisting vessels or by vessel splitting (intussusception). Pathological angiogenesis drives choroidal neovascularization (CNV) in age related macular degeneration (AMD) which is commonly restricted under the retinal pigment epithelium (RPE), called occult CNV, but may also involve vessels penetrating through the RPE into the sub-retinal space. Pathological vessels are poorly developed, insufficiently perfused and highly leaky, phenotypes that are considered to drive disease progression and lead to poor prognosis. Currently, a number of anti-angiogenic drugs exists, the majority of which target vascular endothelial factor (VEGF), but although they often are highly beneficial for treating eye diseases in the short-term, they are generally of limited efficacy in other diseases such as cancer, and also have poorer efficacy when used for treatment of eye diseases in the long-term. A better understanding of the mechanisms underlying pathological angiogenesis can generate new targets for treatment leading to development of better drugs for cancer and retinopathies, but perhaps also other angiogenesis-dependent diseases, in the future. In this thesis mechanisms involved in developmental angiogenesis or pathological angiogenesis in the choroid, cornea or melanoma was identified. These findings highlight the need to further elaborate our knowledge related to angiogenesis in different tissues/conditions for a more targeted, and potentially effective treatment of diseases in the future. In paper I, we for the first time identified the choriocapillaries (CCs) in adult zebrafish and found that occult CNV could be induced by exposing the fish to severe hypoxia. Interestingly, we found that occult CNV relied on intussusception, involving not only de novo generation of intussusceptive pillars but also a previously poorly understood mechanism called pillar splitting. This involved HIF-VEGF-VEGFR2 signaling and evidence that this also occurred in both rats and humans suffering from AMD suggested that the mechanism was conserved and clinically relevant. In contrast, we found in paper II that the development of CCs in the zebrafish relies on sprouting angiogenesis, involve continuous remodeling, and delayed maturation of the vasculature in 2D. The initial development was found to occur by a unique process of tissuewide synchronized vasculogenesis. As expected, VEGFA via VEGFR2 was also critical for the development of these vessels in the zebrafish embryo, but surprisingly this was independent on hypoxia-inducible factor (HIF)-1. Inflammatory nuclear factor-kB (NF-kB) signaling is involved in the progression of angiogenesis, but this signaling pathway has mainly been studied in the inflammatory cells and the role of NF-kB in the endothelial cells during angiogenesis is poorly understood. In paper III, we found that blocking NF-kB signaling using a specific IKK2 blocker IMD0354, specifically blocks pathological as well as developmental angiogenesis by targeting endothelial cell NF-kB signaling in the endothelial cells. Using a rat model for suture-induced corneal neovascularization, IMD0354 treatment lead to reduced production of inflammatory C-C motif chemokine ligand 2 (CCL2), C-X-C motif chemokine ligand 5 (CXCL5) and VEGF, and thereby reduced pathological corneal angiogenesis in this model. Using the zebrafish tumor xenograft model in paper IV, we found an association between Microphthalmia associated transcription factor (MITF) and pigment epithelium derived factor (PEDF), which was involved in pathological tumor angiogenesis and metastasis. Similarly, in paper V we used zebrafish transplantation models to study and investigate the use of biocompatible polymers for the delivery of pro-angiogenic FGF-2 as a potential treatment strategy for ischemic diseases such as myocardial infarction (MI). Conclusively, this thesis provides new insights into diverse fields of angiogenic assays using zebrafish, and reveals new mechanisms of angiogenesis in health and disease. This work will hopefully provide a foundation for further studies into occult CNV related to AMD, a process that has not been possible to study previously in pre-clinical models. In addition, zebrafish xenograft or other transplantation models used in this work will likely be important to study cancer biology and to develop more attractive pharmaceutical preparations based on biocompatible hydrogels formulated as microspheres in the future.

This reference work presents the basic principles of angiogenesis induction, including the roles of signaling factors such as hypoxia-inducible factors, biophysical stimulation and angiogenic cells. The book also covers lymphogenesis induction. Both the established fundamentals in the field as well as new trends in the vascularization of engineered tissues are discussed. These include pre-vascularization strategies using preparation of channeled scaffolds and preparation of decellularized blood vessel trees, approaches to inducing formation of microvasculature and approaches to inducing the growth of vascular networks. The authors expand on these concepts with current studies of dual-level approaches to engineer vascularized tissue composites. The book concludes with a discussion of current clinical approaches and the use of vascular grafts in the context of providing clinical practice with new tissue engineering strategies.

A wide range of research methods for the study of vascular development, from basic laboratory protocols to advanced technologies used in clinical practice, are covered in this work. A range of methodologies such as molecular imaging platforms and signalling analysis, along with tumour models are collated here. Four sections explore in vitro techniques, in vivo and ex vivo manipulations, imaging and histological analysis and other novel techniques in vascular biology. Readers will discover basic methodologies used for analysis of endothelial cell growth in vitro, including co-culture models of vessel formation. Authors also explore isolation and purification of cells and methods for analysis of data and visualization of localized vasculature with modern imaging platforms. Both animal models and human disease are covered in this work. Each chapter contains helpful sections on trouble shooting, additional notes and links, supporting the reader to carry out protocols. This book will appeal to students, researchers and medical professionals working in all vascular-linked fields such as cardio- and cerebrovascular, cancer and dementia.