Search results for "ASTROCYTES"
showing 10 items of 171 documents
Toxic effects on astrocytes of extracellular vesicles from CSF of multiple sclerosis patients: a pilot in vitro study.
2020
Multiple sclerosis (MS) is an autoimmune and degenerative disorder of the central nervous system (CNS) that causes a progressive loss of motor and cognitive perfor-mances. Moreover, since the earlier phases, axonal loss as well as neuronal degener-ation and a failure of oligodendrocytes to promote myelin repair have been demon-strated. In previous studies, it has been shown that the treatment of rat neuronal primary cultures with serum from MS patients can be toxic for neurons. Here we report a pilot investigation showing that CSF from patients contains extracellular vesicles (EVs) able to induce cell death in rat cultured astrocytes. Although these data are still preliminary, they suggest …
Developing rat brain as well as cultured astrocytes contain H1° mRNA-protein complexes
2015
RNA-binding proteins (RBPs) regulate intracellular transport, pre-localization, stability, and translation of mRNAs [1]. We previously identified a set of proteins which interact with mRNAs encoding H1° and H3.3 histones [2-5]. All these proteins are probably part of a ribonucleoprotein particle [6]. Here we report the results of a more detailed study on the expression and intracellular localization of some of these RBPs, such as hnRNP K and A1, and Hsc70, during rat brain development and in cultured rat astrocytes. We also investigated the presence in the complexes of PIPPin/CSD-C2 protein. Affinity chromatography was performed as already described [6]. Preparation of total lysates and cel…
Role of interleukin-6 and soluble IL-6 receptor in region-specific induction of astrocytic differentiation and neurotrophin expression.
1999
Increasing evidence supports an essential role for interleukin-6 (IL-6) in the development, differentiation, as well as de- and re-generation of neurons in the central nervous system (CNS). Both IL-6 and its specific receptor (IL-6R) are expressed on neurons and glial cells including astrocytes. In this study, we have analyzed the responses of primary rat astrocytes of various brain regions to IL-6 with respect to morphological changes and neurotrophin expression. Since IL-6 alone failed to initiate effects on astrocytes, we have examined whether the soluble IL-6R (sIL-6R) can modulate the responsiveness of to IL-6 in these cells. For this purpose, we used a highly active fusion protein of …
PGC-1α signaling coordinates susceptibility to metabolic and oxidative injury in the inner retina.
2013
Retinal ganglion cells (RGCs), used as a common model of central nervous system injury, are particularly vulnerable to metabolic and oxidative damage. However, molecular mechanisms underlying this sensitivity have not been determined in vivo . PGC-1α (encoded by PPARGC1A ) regulates adaptive metabolism and oxidative stress responses in a tissue- and cell-specific manner. Aberrant PGC-1α signaling is implicated in neurodegeneration, but the mechanism underlying its role in central nervous system injury remains unclear. We provide evidence from a mouse model that PGC-1α expression and activity are induced in adult retina in response to metabolic and oxidative challenge. Deletion of Ppargc1a d…
When the brain goes diving: glial oxidative metabolism may confer hypoxia tolerance to the seal brain.
2009
Deep diving mammals have developed strategies to cope with limited oxygen availability when submerged. These adaptations are associated with an increased neuronal hypoxia tolerance. Brain neurons of the hooded seal Cysto- phora cristata remain much longer active in hypoxic condi- tions than those of mice. To understand the cellular basis of neuronal hypoxia tolerance, we studied neuroglobin and cy- tochrome c in C. cristata brain. Neuroglobin, a respiratory protein typically found in vertebrate neurons, displays three unique amino acid substitutions in hooded seal. However, these substitutions unlikely contribute to a modulation of O2 affinity. Moreover, there is no significant difference i…
Cancer cells can affect behaviour of neighbouring cells by transferring molecules through extracellular vesicles
2017
Most cells release into the extracellular space membrane-bound structures of different sizes, origin and composition, collectively called extracellular vesicles (EVs) [1]. Tumor cells are much more active than normal cells in producing EVs. Because of this property, they are able to transfer both nucleic acids and proteins to the surrounding normal cells, thus inducing in these latter at least some transformed behavior. We previously showed that EVs produced by G26/24 oligodendroglioma cells can horizontally transfer to their neighbours radioactive proteins [2]. In addition, EVs released by these cells contain pro-apoptotic proteins, such as TRAIL and Fas-Ligand, able to induce apoptosis in…
Microscopic evidence of the primary astrocytes' morphological differentiation and migration inside porous Poly-L-lactic acid 3D‑scaffolds
2019
Tissue engineering is an emerging multidisciplinary field that aims at reproducing in vitro and/or in vivo tissues with morphological and functional features similar to the biological tissue of the human body [1]. In the attempt to construct suitable tissue models, a critical step is the setting of 3D scaffolds that mimic the supportive structures of a natural extracellular matrix microenvironment into which cells are normally embedded. In this context, the generation of 3D cultures of brain cells is of particular interest. For instance, the poly L‐lactic acid (PLLA) polymer is wildly used because of its biocompatible and biodegradable potential; the PLLA scaffold topography simulates the n…
CEND1 and NEUROGENIN2 Reprogram Mouse Astrocytes and Embryonic Fibroblasts to Induced Neural Precursors and Differentiated Neurons
2015
Summary Recent studies demonstrate that astroglia from non-neurogenic brain regions can be reprogrammed into functional neurons through forced expression of neurogenic factors. Here we explored the effect of CEND1 and NEUROG2 on reprogramming of mouse cortical astrocytes and embryonic fibroblasts. Forced expression of CEND1, NEUROG2, or both resulted in acquisition of induced neuronal cells expressing subtype-specific markers, while long-term live-cell imaging highlighted the existence of two different modes of neuronal trans-differentiation. Of note, a subpopulation of CEND1 and NEUROG2 double-transduced astrocytes formed spheres exhibiting neural stem cell properties. mRNA and protein exp…
Streptomyces coelicolor secretoma protects astrocytes from oxidative stress
2016
Streptomycetes are gram-positive bacteria that produce about 2/3 of pharmaceutically active secondary metabolites, such as antibiotics, and anti-tumor, immunosuppressive, antifungal and antiparasitic agents. In this study, we investigated the possible effects of Streptomyces coelicolor extracts and putative vesicular fraction on primary cultures of rat astrocytes, in both physiological and stressed conditions, induced by treatment with hydrogen peroxide. Briefly, crude extracts and putative vesicular fractions were prepared from two S.coelicolor strains (M145 wild-type strain and bold F166 strain), and used to treat primary astrocytes, which were then also treated with hydrogen peroxide. Da…
Permeability properties of a three-cell type in vitro model of blood-brain barrier.
2005
We previously found that RBE4.B brain capillary endothelial cells (BCECs) form a layer with blood‐brain barrier (BBB) properties if co‐cultured with neurons for at least one week. As astrocytes are known to modulate BBB functions, we further set a culture system that included RBE4.B BCECs, neurons and astrocytes. In order to test formation of BBB, we measured the amount of (3)H‐sucrose able to cross the BCEC layer in this three‐cell type model of BBB. Herein we report that both neurons and astrocytes induce a decrease in the permeability of the BCEC layer to sucrose. These effects are synergic as if BCECs are cultured with both neurons and astrocytes for 5 days, permeability to sucrose decr…