1,721,021 research outputs found
Chorioallantoic membrane vascularization. A meta-analysis
The CAM is a widely used experimental assay to study angiogenesis, wound healing, tumor growth and metastatic process. In this study, we have analyzed and compared the existent literature data concerning the growth of the CAM. Moreover, we have analyzed the data concerning the development of the vascular system and the expression of the most important pro-angiogenic and anti-angiogenic factors. The availability of these data and their comparative evaluation allow to better analyze the experimental data concerning the testing of different pro-angiogenic and anti-angiogenic molecules, as well as biomaterials in the CAM assay. Moreover, the dynamic of the angiogenic response to different tumor cell lines and or tumor bioptic specimens, may be also better evaluated and estimated
Mast cells and angiogenesis in multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease, characterized by multiple demyelination of axons in both white and gray matter in the Central Nervous System (CNS). There is increasing evidence to support the notion that angiogenesis and chronic inflammation are mutually related. Different immune cells, including monocytes–macrophages, lymphocytes, neutrophils, mast cells (MCs) and dendritic cells are able to secrete an array of angiogenic cytokines, which promote growth, migration, and activation of endothelial cells. MCs play various roles in MS pathogenesis, influencing the innate immune response in peripheral tissues and in CNS. The aim of this review article is to discuss the role of MCs in MS pathogenesis with particular reference to the involvement of these inflammatory cells in the angiogenic processes occurring during MS
Adipocytes, mast cells and angiogenesis
Healthy adipose tissue contains a wide variety of innate and adaptive immune cells, including macrophages, dendritic cells, mast cells, eosinophils, neutrophils, and lymphocytes. Numerous signaling molecules in the adipose microenvironment can positively or negatively modulate angiogenic processes, regulate the interaction between the vascular system and adipocytes, and participate in tumor progression. Mast cells are involved in the new formation or metabolism of fat, are present in abundant quantities in fatty tissue, among fat cells, and a number of mediators released from mast cells play a role in adipogenesis. Moreover, mast cells produce several pro-angiogenic factors and are involved in tumor angiogenesis. In this context, the angiogenic effect might be amplified when the adipocytes and mast cells act in concert, and treatment of adipose tissue-and mast cell-associated cancers with anti-angiogenic drugs may represent an alternative or adjuvant strategy for the treatment of these tumors
The role of vascular niche and endothelial cells in organogenesis and regeneration
The term vascular niche indicate the physical and biochemical microenvironment around blood vessel where endothelial cells, pericytes, and smooth muscle cells organize themselves to form blood vessels and release molecules involved in the recruitment of hematopoietic stem cells, endothelial progenitor cells and mesenchymal stem cells. The vascular niche creates a permissive environment that enables different cell types to realize their developmental or regenerative programs. In this context, the proximity between the endothelium and the new-forming cellular components of organs suggests an essential role of endothelial cells in the organs maturation. Dynamic interactions between specific organ endothelial cells and different cellular conponents are crucial for different organ morphogenesis and function. Conversely, organs provide cues shaping vascular network structure
The use of the chick embryo CAM assay in the study of angiogenic activiy of biomaterials
The chick embryo chorioallantoic membrane (CAM) is a highly vascularized extraembryonic membrane, which carries out several functions during embryonic development, including exchange of respiratory gases, calcium transport from the eggshell, acid-base homeostasis in the embryo, and ion and water reabsorption from the allantoic fluid. Due to its easy accessibility, affordability and given that it constitutes an immunodeficient environment, CAM has been used as an experimental model for >50 years and in particular it has been broadly used to study angiogenesis and anti-angiogenesis. This review article describes the use of the CAM assay as a valuable assay to test angiogenic activity of biomaterials in vivo before they are further investigated in animal models. In this context, the use of CAM has become an integral part of the biocompatibility testing process for developing potential biomaterials
Controversial role of mast cells in breast cancer tumor progression and angiogenesis
Breast cancer is a neoplastic disease and is a cause of cancer-related mortality for women. Among cellular and molecular regulators of the microenvironment, mast cells and vascular endothelial growth factor (VEGF), are correlated with tumor progression and prognosis in breast cancer. Clinical and experimental studies on breast cancer have revealed a marked correlation between increased angiogenesis, metastasization, and poorer prognosis. After a brief introduction on angiogenesis evidence and angiogenic factors role in different breast cancer subtypes, in this article, we have discerned the relationship between mast cell infiltration, angiogenesis, and tumor progression in human breast cancer with particular reference to the dual role of mast cells, in terms of both pro- or anti-tumoral activity and poor or good biomarker
RNAscope for VEGF-A Detection in Human Tumor Bioptic Specimens
Different pro-angiogenic factors, such as vascular endothelial growth factor-A (VEGF-A), have been related to microvascular density, clinicopathologic factors, and poor prognosis in many tumors. VEGF-A binds its receptor 2 (VEGFR2) to induce neo-angiogenesis, a constant hallmark of tumor initiation and progression. Based on VEGF-A/VEGFR2 relevance in tumor angiogenesis, several inhibitors were developed. However, the clinical benefits of anti-angiogenic therapies are limited because tumors activate different mechanisms of drug resistance.The need for understanding tumor biology, limitation or failure of anti-angiogenic therapies, and the demand for a personalized therapeutic approach has boosted the search for robust biomarkers for patient stratification as responder or non-responder to anti-VEGF therapies.This chapter presents a detailed protocol to perform chromogenic VEGF-A mRNA detection and quantification in human tumor bioptic specimens using RNAscope technology and RNA-in situ hybridization (ISH) algorithm. RNAscope for VEGF-A detection, even for small amounts, is compatible with precious clinical samples and diagnostic laboratory workflows
microRNAs Biogenesis, Functions and Role in Tumor Angiogenesis
microRNAs (miRNAs) are small non-coding RNA molecules, evolutionary conserved. They target more than one mRNAs, thus influencing multiple molecular pathways, but also mRNAs may bind to a variety of miRNAs, either simultaneously or in a context-dependent manner. miRNAs biogenesis, including miRNA transcription, processing by Drosha and Dicer, transportation, RISC biding, and miRNA decay, are finely controlled in space and time. miRNAs are critical regulators in various biological processes, such as differentiation, proliferation, apoptosis, and development in both health and disease. Their dysregulation is involved in tumor initiation and progression. In tumors, they can act as onco-miRNAs or oncosuppressor-miRNA participating in distinct cellular pathways, and the same miRNA can perform both activities depending on the context. In tumor progression, the angiogenic switch is fundamental. miRNAs derived from tumor cells, endothelial cells, and cells of the surrounding microenvironment regulate tumor angiogenesis, acting as pro-angiomiR or anti-angiomiR. In this review, we described miRNA biogenesis and function, and we update the non-classical aspects of them. The most recent role in the nucleus, as transcriptional gene regulators and the different mechanisms by which they could be dysregulated, in tumor initiation and progression, are treated. In particular, we describe the role of miRNAs in sprouting angiogenesis, vessel co-option, and vasculogenic mimicry. The role of miRNAs in lymphoma angiogenesis is also discussed despite the scarcity of data. The information presented in this review reveals the need to do much more to discover the complete miRNA network regulating angiogenesis, not only using high-throughput computational analysis approaches but also morphological ones
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