Search results for "XOS"

Microparticles: Modulators and biomarkers of liver disease

2012

Division of Molecular and Translational Medicine,Dept. of Medicine I, Johannes Gutenberg University, Mainz, GermanyEmerging role of microparticlesMicroparticles (MP) have gained increasing attention as biomark-ers for various diseases. First described as platelet dust, MP wereregarded as unspecific debris [1]. However, it has become appar-ent that cell derived MP or ectosomes represent a novel route ofhorizontal communication between cells. MP are between 100–1000 nm in size and generated through cell membrane shedding(ectocytosis), a process that can be triggered by the activation ofthe complement C5b-9 complex, as shown for platelet derivedMP, or by inhibition of flippase activitythroughCa

Multifaceted effects of oligodendroglial exosomes on neurons: impact on neuronal firing rate, signal transduction and gene regulation.

2014

Exosomes are small membranous vesicles of endocytic origin that are released by almost every cell type. They exert versatile functions in intercellular communication important for many physiological and pathological processes. Recently, exosomes attracted interest with regard to their role in cell–cell communication in the nervous system. We have shown that exosomes released from oligodendrocytes upon stimulation with the neurotransmitter glutamate are internalized by neurons and enhance the neuronal stress tolerance. Here, we demonstrate that oligodendroglial exosomes also promote neuronal survival during oxygen–glucose deprivation, a model of cerebral ischaemia. We show the transfer from…

Exosomes as Intercellular Signaling Organelles Involved in Health and Disease: Basic Science and Clinical Applications

2013

Cell to cell communication is essential for the coordination and proper organization of different cell types in multicellular systems. Cells exchange information through a multitude of mechanisms such as secreted growth factors and chemokines, small molecules (peptides, ions, bioactive lipids and nucleotides), cell-cell contact and the secretion of extracellular matrix components. Over the last few years, however, a considerable amount of experimental evidence has demonstrated the occurrence of a sophisticated method of cell communication based on the release of specialized membranous nano-sized vesicles termed exosomes. Exosome biogenesis involves the endosomal compartment, the multivesicu…

Identification and characterization of the nano-sized vesicles released by muscle cells

2013

AbstractSeveral cell types secrete small membranous vesicles that contain cell-specific collections of proteins, lipids, and genetic material. The function of these vesicles is to allow cell-to-cell signaling and the horizontal transfer of their cargo molecules. Here, we demonstrate that muscle cells secrete nano-sized vesicles and that their release increases during muscle differentiation. Analysis of these nanovesicles allowed us to characterize them as exosome-like particles and to define the potential role of the multifunctional protein Alix in their biogenesis.

Mast cells control the expansion and differentiation of IL-10-competent B cells

2014

Abstract The discovery of B cell subsets with regulatory properties, dependent on IL-10 production, has expanded our view on the mechanisms that control inflammation. Regulatory B cells acquire the ability to produce IL-10 in a stepwise process: first, they become IL-10 competent, a poised state in which B cells are sensitive to trigger signals but do not actually express the Il-10 gene; then, when exposed to appropriate stimuli, they start producing IL-10. Even if the existence of IL-10–competent B cells is now well established, it is not yet known how different immune cell types cross talk with B cells and affect IL-10–competent B cell differentiation and expansion. Mast cells (MCs) contr…

Novel Lipid and Polymeric Materials as Delivery Systems for Nucleic Acid Based Drugs

2015

Nucleic acid based drugs (NADBs) are short DNA/RNA molecules that include among others, antisense oligonucleotides, aptamers, small interfering RNAs and micro-interfering RNAs. Despite the different mechanisms of actions, NABDs have the ability to combat the effects of pathological gene expression in many experimental systems. Thus, nowadays, NABDs are considered to have a great therapeutic potential, possibly superior to that of available drugs. Unfortunately, however, the lack of effective delivery systems limits the practical use of NABDs. Due to their hydrophilic nature, NABDs cannot efficiently cross cellular membrane; in addition, they are subjected to fast degradation by cellular and…

Mechanisms of RNA loading into exosomes

2015

AbstractUpon fusion of multivesicular bodies (MVBs) with the plasma membrane, intraluminal vesicles (ILVs) are released into the extracellular space as exosomes. Since the lipid composition of the exosomal membrane resembles that of raft microdomains, the inward budding process involves the raft-like region of the MVB limiting membrane. Although published research suggests that cellular RNAs may be selectively sorted into exosomes, the molecular mechanisms remain elusive. In this review, we suggest that there is a continuous interaction of cellular RNAs with the outer (cytoplasmic) surface of MVBs and that the selection for incorporation of these RNAs into ILVs is based on their affinity to…

ROLE OF EXOSOMES RELEASED BY CHRONIC MYELOGENOUS LEUKEMIA CELLS IN THE CROSS-TALK WITH ENDOTHELIAL CELLS

2016

Le Cycle des Myxozoa et les Cnidaires: comparaison des formes planctoniques

2007

Les études moléculaires rapprochent désormais les Myxozoaires des Cnidaires. Les deux groupes sont présents exclusivement en milieu aquatique et utilisent l’eau comme vecteur de prolifération et de dissémination Au cours de leur cycle de vie, les Cnidaires passent d’une phase sessile fixée sur des substrats, la forme Polype, à une phase libre autonome ou planctonique, la forme méduse et planula. Chez les Myxozoa on observe aussi une phase planctonique à morphologie actinomyxidie issue de la reproduction sexuée chez un annélide et une phase non planctonique à morphologie myxosporidie produite par reproduction sexuée chez le poisson. Toutefois, les connaissances sur la sexualité des Cnidaires…

Proteomic profiling and functional characterization of metastatic colon cancer exosomes spreading malignant properties in tumor microenvironment

2016

Human tumors display a remarkable intratumor heterogeneity affecting clinically relevant phenotypes such as ability to metastasize or to tolerate cytotoxic drugs. Recent published data indicate that tumor derived exosomes (TDEs) can have a pivotal role in regulating tumor heterogeneity by transferring functional biomolecules between various populations of tumor cells and between tumor cells and nontumor cells with consequences for whole tumor microenvironment. In this context, our goal was to understand if exosomes derived from highly metastatic cell line may influence the behaviour of less aggressive tumor cells and the properties of endhothelium.