Search results: Found 9

Listing 1 - 9 of 9
Sort by
Dual role of microglia in health and disease: pushing the balance towards repair

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194926 Year: Pages: 101 DOI: 10.3389/978-2-88919-492-6 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2015-11-16 15:44:59
License:

Loading...
Export citation

Choose an application

Abstract

Microglial cells play a vital role in the innate immune response occurring in the Central Nervous System (CNS). Under physiologic conditions, microglia dynamically patrol the brain parenchyma and participate in the remodeling of active neuronal circuits. Accordingly, microglia can boost synaptic plasticity by removing apoptotic cells and by phagocytizing axon terminals and dendritic spines that form inappropriate neural connections. Upon brain and spinal cord injury or infection, microglia act as the first line of immune defense by promoting the clearance of damaged cells or infectious agents and by releasing neurotrophins and/ or proneurogenic factors that support neuronal survival and regeneration.Recently, two main pathways were suggested for microglia activation upon stimuli. Classical activation is induced by Toll-like receptor agonists and Th1 cytokines and polarizes cells to an M1 state, mainly leading to the release of TNF-alpha, IL-6 and nitric oxide and to grave neural damage. Alternative activation is mediated by Th2 cytokines and polarizes cells to an M2a state inducing the release of antiinflammatory factors. These findings have further fueled the discussion on whether microglia has a detrimental or beneficial action (M1 or M2-associated phenotypes, respectively) in the diseased or injured CNS and, more importantly, on whether we can shift the balance to a positive outcome.Although microglia and macrophages share several common features, upon M1 and M2 polarizing conditions, they are believed to develop distinct phenotypic and functional properties which translate into different patterns of activity. Moreover, microglia/macrophages seem to have developed a tightly organized system of maintenance of CNS homeostasis, since cells found in different structures have different morphology and specific function (e.g. meningeal macrophages, perivascular macrophages, choroid plexus macrophages). Nevertheless, though substantial work has been devoted to microglia function, consensus around their exact origin, their role during development, as well as the exact nature of their interaction with other cells of the CNS has not been met.This issue discusses how microglial cells sustain neuronal activity and plasticity in the healthy CNS as well as the cellular and molecular mechanisms developed by microglia in response to injury and disease. Understanding the mechanisms involved in microglia actions will enforce the development of new strategies to promote an efficient CNS repair by committing microglia towards neuronal survival and regeneration.

Epigenetics as a Deep Intimate Dialogue between Host and Symbionts

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198757 Year: Pages: 98 DOI: 10.3389/978-2-88919-875-7 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Genetics
Added to DOAB on : 2016-01-19 14:05:46
License:

Loading...
Export citation

Choose an application

Abstract

Symbiosis is an intimate relationship between different living entities and is widespread in virtually all organisms. It was critical for the origin and diversification of Eukaryotes and represents a major driving force in evolution. Indeed, symbiosis may support a wide range of biological processes, including those underlying the physiology, development, reproduction, health, behavior, ecology and evolution of the organisms involved in the relationship. Although often confused with mutualism, when both organisms benefit from the association, symbiosis actually encompasses several and variable relationships. Among them is parasitism, when one organism benefits but the other is harmed, and commensalism, when one organism benefits and the other remains unaffected. Even if many symbiotic lifestyles do exist in nature, in many cases the intimacy between the partners is so deep that the “symbiont” (sensu strictu) resides into the tissues and/or cells of the other partner. Since the partners frequently belong to different kingdoms, e.g. bacteria, fungi, protists and viruses living in association with animal and plant hosts, their shared “language” should be a basic and ancient form of communication able to effectively blur the boundaries between extremely different living entities. In recent years studies on the role of epigenetics in shaping host-symbiont interactions have been flourishing. Epigenetic changes include, but are not limited to, DNA methylation, remodelling of chromatin structure through histone chemical modifications and RNA interference. In this E-book we present a series of papers exploring the fascinating developmental and evolutionary relationship between symbionts and hosts, by focusing on the mediating epigenetic processes that enable the communication to be effective and robust at both the individual, the ecological and the evolutionary time scales. In particular, the papers consider the role of epigenetic factors and mechanisms in the interactions among different species, comprising the holobiont and host-parasite relationships. On the whole, since epigenetics is fast-acting and reversible, enabling dynamic developmental communication between hosts and symbionts at several different time scale, we argue that it could account for the enormous plasticity that characterizes the interactions between all the organisms living symbiotically on our planet.

Cellular and Phenotypic Plasticity in Cancer

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196623 Year: Pages: 77 DOI: 10.3389/978-2-88919-662-3 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Oncology
Added to DOAB on : 2016-08-16 10:34:25
License:

Loading...
Export citation

Choose an application

Abstract

The process of Epithelial-Mesenchymal-Transition (EMT) is known to result in a phenotype change in cells from a proliferative state to a more invasive state. EMT has been reported to drive the metastatic spread of various cancers and has also been associated with drug resistance to cytotoxics and targeted therapeutics. Recently phenotype switching akin to EMT has been reported in non-epithelial cancers such as metastatic melanoma. This process involves changes in EMT-Transcription Factors (EMT-TFs), suggesting that phenotype-switching may be common to several tumour types. It remains unclear as to whether the presence of both Epilthelial-like and Mesenchymal-like cells are a pre-requisite for phenotype switching within a tumour, how this heterogeneity is regulated, and if alteration of cell phenotype is sufficient to mediate migratory changes, or whether drivers of cell migration result in an associated phenotype switch in cancer cells. Similarly it has yet to be clarified if cells in an altered phenotype can be refractory to drug therapy or whether mediators of drug resistance induce a concurrent phenotypic change. Little is known today about the underlying genetic, epigenetic and transient changes that accompany this phenotypic switch and about the role for the tumor micro-environment in influencing it. Hence this is currently an area of speculation and keen interest in the Oncology field with wide-ranging translational implications. In this Frontiers Research Topic, we discuss our current understanding of these concepts in various cancer types including breast cancer, colorectal cancer and metastatic melanoma. This topic covers how these processes of cellular and phenotypic plasticity are regulated and how they relate to cancer initiation, progression, dormancy, metastases and response to cytotoxics or targeted therapies.

Salicylic Acid Signaling Networks

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198276 Year: Pages: 188 DOI: 10.3389/978-2-88919-827-6 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
License:

Loading...
Export citation

Choose an application

Abstract

The small phenolic compound salicylic acid (SA) is critical for plant defense against a broad spectrum of pathogens. SA is also involved in multi-layered defense responses, from pathogen-associated molecular pattern triggered basal defense, resistance gene-mediated defense, to systemic acquired resistance. Recent decades have witnessed tremendous progress towards our understanding of SA-mediated signaling networks. Many genes have been identified to have direct or indirect effect on SA biosynthesis or to regulate SA accumulation. Several SA receptors have been identified and characterization of these receptors has shed light on the mechanisms of SA-mediated defense signaling, which encompass chromosomal remodeling, DNA repair, epigenetics, to transcriptional reprogramming. Molecules from plant-associated microbes have been identified, which manipulate SA levels and/or SA signaling. SA does not act alone. It engages in crosstalk with other signaling pathways, such as those mediated by other phytohormones, in an agonistic or antagonistic manner, depending on hormones and pathosystems. Besides affecting plant innate immunity, SA has also been implicated in other cellular processes, such as flowering time determination, lipid metabolism, circadian clock control, and abiotic stress responses, possibly contributing to the regulation of plant development. The multifaceted function of SA makes it critically important to further identify genes involved in SA signaling networks, understand their modes of action, and delineate interactions among the components of SA signaling networks. In addition, genetic manipulation of genes involved in SA signaling networks has also provided a promising approach to enhance disease resistance in economically important plants. This ebook collects articles in the Research Topic "Salicylic Acid Signaling Networks". For this collection we solicited reviews, perspectives, and original research articles that highlight recent exciting progress on the understanding of molecular mechanisms underlying SA-mediated defense, SA-crosstalk with other pathways and how microbes impact these events.

The Role of Aire, microRNAs and Cell-Cell Interactions on Thymic Architecture and Induction of Tolerance

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197705 Year: Pages: 107 DOI: 10.3389/978-2-88919-770-5 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2016-04-07 11:22:02
License:

Loading...
Export citation

Choose an application

Abstract

The focus of this eBook is to bring new insights into central immune tolerance. To fulfill that, much has been discussed about the master in the regulation of tolerance, the autoimmune regulator (Aire) gene the main thymus cell type that expresses this gene, the medullary thymic epithelial cells (mTECs). It includes one Editorial and 12 other excellent contributions in the format of mini reviews or original research papers covering one or more of these aspects: promiscuous gene expression (PGE), epigenetics, miRNAs, association of the Aire gene and miRNAs, thymocyte–TEC interaction, coxsackievirus and type 1 diabetes, exosomes in the thymus, thymic crosstalk, thymic B cells, T cell development, chemokines and migration of T cells, miRNAs and the thymic atrophy, cell–cell interactions, and thymus ontogeny. Authors raised hypothesis, discuss concepts, and show open questions. The remaining important issues to resolve questions within the central tolerance research are briefly discussed below.

Biological Networks

Authors: ---
ISBN: 9783038974338 9783038974345 Year: Pages: 174 DOI: 10.3390/books978-3-03897-434-5 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Internal medicine --- Biology
Added to DOAB on : 2019-01-10 11:14:23
License:

Loading...
Export citation

Choose an application

Abstract

Networks of coordinated interactions among biological entities govern a myriad of biological functions that span a wide range of both length and time scales—from ecosystems to individual cells and from years to milliseconds. For these networks, the concept “the whole is greater than the sum of its parts” applies as a norm rather than an exception. Meanwhile, continued advances in molecular biology and high-throughput technology have enabled a broad and systematic interrogation of whole-cell networks, allowing the investigation of biological processes and functions at unprecedented breadth and resolution—even down to the single-cell level. The explosion of biological data, especially molecular-level intracellular data, necessitates new paradigms for unraveling the complexity of biological networks and for understanding how biological functions emerge from such networks. These paradigms introduce new challenges related to the analysis of networks in which quantitative approaches such as machine learning and mathematical modeling play an indispensable role. The Special Issue on “Biological Networks” showcases advances in the development and application of in silico network modeling and analysis of biological systems.

Jasmonic Acid Pathway in Plants

Author:
ISBN: 9783039284887 / 9783039284894 Year: Pages: 346 DOI: 10.3390/books978-3-03928-489-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Plant Sciences
Added to DOAB on : 2020-06-09 16:38:57
License:

Loading...
Export citation

Choose an application

Abstract

The plant hormone jasmonic acid (JA) and its derivative, an amino acid conjugate of JA (jasmonoyl isoleucine, JA-Ile), are signaling compounds involved in the regulation of defense and development in plants. The number of articles studying on JA has dramatically increased since the 1990s. JA is recognized as a stress hormone that regulates the plant response to biotic stresses such as herbivore and pathogen attacks, as well as abiotic stresses such as wounding and ultraviolet radiation. Recent studies have remarkably progressed the understanding of the importance of JA in the life cycle of plants. JA is directly involved in many physiological processes, including stamen growth, senescence, and root growth. JA regulates production of various metabolites such as phytoalexins and terpenoids. Many regulatory proteins involved in JA signaling have been identified by screening for Arabidopsis mutants. However, much more remains to be learned about JA signaling in other plant species. This Special Issue, “Jasmonic Acid Pathway in Plants”, contains 5 review and 15 research articles published by field experts. These articles will help with understanding the crucial roles of JA in its response to the several environmental stresses and development in plants.

Keywords

albino --- aroma --- Camellia sinensis --- chloroplast --- jasmonic acid --- light-sensitive --- stress --- tea --- volatile --- Panax ginseng --- gene expression --- ginsenoside --- methyl jasmonate --- MYB transcription factor --- dammarenediol synthase --- jasmonic acid --- signaling pathway --- environmental response --- biological function --- MeJA --- priming --- rice --- proteomics --- ROS --- chlorophyll fluorescence imaging --- MAP kinase --- jasmonate --- rice bacterial blight --- salicylic acid --- grain development --- Prunus avium --- Tuscan varieties --- jasmonic acid --- lipoxygenase --- bioinformatics --- gene expression --- heterotrimeric G proteins --- AtRGS1 --- jasmonates --- endocytosis --- diffusion dynamics --- Chinese flowering cabbage --- leaf senescence --- JA --- transcriptional activation --- adventitious rooting --- auxin --- ectopic metaxylem --- ectopic protoxylem --- ethylene --- hypocotyl --- jasmonates --- nitric oxide --- xylogenesis --- transcriptional regulators --- plant development --- jasmonic acid signaling --- gene expression --- Jasmonate-ZIM domain --- JAZ repressors --- Jas domain --- TIFY --- degron --- phylogenetic analysis --- ancestral sequences --- circadian clock --- jasmonic acid --- crosstalk --- jasmonic acid --- fatty acid desaturase --- multiseeded --- msd --- grain number --- MutMap --- sorghum --- Ralstonia solanacearum --- type III effector --- jasmonic acid --- salicylic acid --- Nicotiana plants --- PatJAZ6 --- jasmonic acid (JA) signaling pathway --- Pogostemon cablin --- patchouli alcohol --- biosynthesis --- jasmonate --- salt response --- Zea mays --- ROS --- proline --- ABA biosynthesis --- jasmonic acid --- crosstalk --- gibberellic acid --- cytokinin --- auxin --- jasmonic acid --- opr3 --- stress defense --- quantitative proteomics --- abiotic stresses --- jasmonates --- JA-Ile --- JAZ repressors --- transcription factor --- signaling --- antioxidant enzyme activity --- elicitor --- methyl jasmonate --- secondary metabolite --- signal molecules --- n/a

Ultrasound B-mode Imaging: Beamforming and Image Formation Techniques

Authors: --- ---
ISBN: 9783039211999 9783039212002 Year: Pages: 146 DOI: 10.3390/books978-3-03921-200-2 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-12-09 11:49:15
License:

Loading...
Export citation

Choose an application

Abstract

Ultrasound medical imaging stands out among the other diagnostic imaging modalities for its patient-friendliness, high temporal resolution, low cost, and absence of ionizing radiation. On the other hand, it may still suffer from limited detail level, low signal-to-noise ratio, and narrow field-of-view. In the last decade, new beamforming and image reconstruction techniques have emerged which aim at improving resolution, contrast, and clutter suppression, especially in difficult-to-image patients. Nevertheless, achieving a higher image quality is of the utmost importance in diagnostic ultrasound medical imaging, and further developments are still indispensable. From this point of view, a crucial role can be played by novel beamforming techniques as well as by non-conventional image formation techniques (e.g., advanced transmission strategies, and compounding, coded, and harmonic imaging). This Special Issue includes novel contributions on both ultrasound beamforming and image formation techniques, particularly addressed at improving B-mode image quality and related diagnostic content. This indeed represents a hot topic in the ultrasound imaging community, and further active research in this field is expected, where many challenges still persist.

Optical Communications and Networking: Prospects in Industrial Applications

Authors: --- --- --- --- et al.
ISBN: 9783039282586 9783039282593 Year: Pages: 132 DOI: 10.3390/books978-3-03928-259-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2020-04-07 23:07:09
License:

Loading...
Export citation

Choose an application

Abstract

In the past few decades, the optical communication industry has explored multiple degrees of freedom of the photon, such as time, wavelength, amplitude, phase, polarization, and space, to significantly reduce the cost/bit of data transmission by increasing the capacity per fiber through multiplexing technology and by reducing the size and power through electronic and photonic integration. This book aims to explore the latest advancements in this industry, including the technologies in devices, systems, and network levels with applications from short-reach chip-to-chip interconnections to long-haul backbone communications at the trans-oceanic distance.

Listing 1 - 9 of 9
Sort by
Narrow your search