Search results for "ASTROCYTES"
showing 10 items of 171 documents
Inflammation-Induced Alteration of Astrocyte Mitochondrial Dynamics Requires Autophagy for Mitochondrial Network Maintenance
2013
Accumulating evidence suggests that changes in the metabolic signature of astrocytes underlie their response to neuroinflammation, but how proinflammatory stimuli induce these changes is poorly understood. By monitoring astrocytes following acute cortical injury, we identified a differential and region-specific remodeling of their mitochondrial network: while astrocytes within the penumbra of the lesion undergo mitochondrial elongation, those located in the core-the area invaded by proinflammatory cells-experience transient mitochondrial fragmentation. In brain slices, proinflammatory stimuli reproduced localized changes in mitochondrial dynamics, favoring fission over fusion. This effect w…
ZBTB20 is crucial for the specification of a subset of callosal projection neurons and astrocytes in the mammalian neocortex
2021
ABSTRACT Neocortical progenitor cells generate subtypes of excitatory projection neurons in sequential order followed by the generation of astrocytes. The transcription factor zinc finger and BTB domain-containing protein 20 (ZBTB20) has been implicated in regulation of cell specification during neocortical development. Here, we show that ZBTB20 instructs the generation of a subset of callosal projections neurons in cortical layers II/III in mouse. Conditional deletion of Zbtb20 in cortical progenitors, and to a lesser degree in differentiating neurons, leads to an increase in the number of layer IV neurons at the expense of layer II/III neurons. Astrogliogenesis is also affected in the mut…
BLBP-expression in astrocytes during experimental demyelination and in human multiple sclerosis lesions
2011
Several lines of evidence indicate that remyelination represents one of the most effective mechanisms to achieve axonal protection. For reasons that are not yet understood, this process is often incomplete or fails in multiple sclerosis (MS). Activated astrocytes appear to be able to boost or inhibit endogenous repair processes. A better understanding of remyelination in MS and possible reasons for its failure is needed. Using the well-established toxic demyelination cuprizone model, we created lesions with either robust or impaired endogenous remyelination capacity. Lesions were analyzed for mRNA expression levels by Affymetrix GeneChip® arrays. One finding was the predominance of immune a…
Subventricular Zone Astrocytes Are Neural Stem Cells in the Adult Mammalian Brain
1999
AbstractNeural stem cells reside in the subventricular zone (SVZ) of the adult mammalian brain. This germinal region, which continually generates new neurons destined for the olfactory bulb, is composed of four cell types: migrating neuroblasts, immature precursors, astrocytes, and ependymal cells. Here we show that SVZ astrocytes, and not ependymal cells, remain labeled with proliferation markers after long survivals in adult mice. After elimination of immature precursors and neuroblasts by an antimitotic treatment, SVZ astrocytes divide to generate immature precursors and neuroblasts. Furthermore, in untreated mice, SVZ astrocytes specifically infected with a retrovirus give rise to new n…
Thyroid hormone induction of the adrenoleukodystrophy-related gene (ABCD2).
2003
X-linked adrenoleukodystrophy (X-ALD) is a demyelinating disorder associated with impaired very-long-chain fatty-acid (VLCFA) beta-oxidation caused by mutations in the ABCD1 (ALD) gene that encodes a peroxisomal membrane ABC transporter. ABCD2 (ALDR) displays partial functional redundancy because when overexpressed, it is able to correct the X-ALD biochemical phenotype. The ABCD2 promoter contains a putative thyroid hormone-response element conserved in rodents and humans. In this report, we demonstrate that the element is capable of binding retinoid X receptor and 3,5,3'-tri-iodothyronine (T3) receptor (TRbeta) as a heterodimer and mediating T3 responsiveness of ABCD2 in its promoter conte…
Incidence of Abcd1 level on the induction of cell death and organelle dysfunctions triggered by very long chain fatty acids and TNF-alpha on oligoden…
2012
X-linked adrenoleukodystrophy (X-ALD) is characterized by ABCD1 deficiency. This disease is associated with elevated concentrations of very long chain fatty acids (C24:0 and C26:0) in the plasma and tissues of patients. Under its severe form, brain demyelination and inflammation are observed. Therefore, we determined the effects of C24:0 and C26:0 on glial cells:oligodendrocytes, which synthesize myelin, and astrocytes, which participate in immune response. So, 158N murine oligodendrocytes, rat C6 glioma cells, rat primary cultures of neuronal-glial cells, and of oligodendrocytes were treated for various periods of time in the absence or presence of C24:0 and C26:0 used at plasmatic concent…
Subventricular zone localized irradiation affects the generation of proliferating neural precursor cells and the migration of neuroblasts
2012
Radiation therapy is a part of the standard treatment for brain tumor patients, often resulting in irreversible neuropsychological deficits. These deficits may be due to permanent damage to the neural stem cell (NSC) niche, damage to local neural progenitors, or neurotoxicity. Using a computed tomography-guided localized radiation technique, we studied the effects of radiation on NSC proliferation and neuroblast migration in the mouse brain. Localized irradiation of the subventricular zone (SVZ) eliminated the proliferating neural precursor cells and migrating neuroblasts. After irradiation, type B cells in the SVZ lacked the ability to generate migrating neuroblasts. Neuroblasts from the u…
Characterization of rodent pineal astrocytes by immunofluorescence microscopy using a monoclonal antibody (J1-31).
1987
In previous studies pineal astrocytes have been characterized immunohistochemically mainly by use of antisera to glial fibrillary acidic protein. Because of the recent demonstration of this protein in non-astrocytic cells the question of its specificity as an astrocytic marker has been raised. A possible alternative tool for characterizing pineal astrocytes is the J1-31 monoclonal antibody, which is directed against a 30 000 dalton astrocytic protein clearly distinguishable from glial fibrillary acidic protein. Immunofluorescence microscopy of this antibody in the pineal gland of rat and guinea-pig revealed a staining pattern similar to that obtained by glial acidic fibrillary protein antis…
Acute intermittent nicotine treatment produces a reduction in the total number of FGF-2 immunoreactive astroglial cells in the substantia nigra of th…
2004
To understand the morphological substrate of the nicotine effect on nigral FGF-2 expression, a stereological analysis of FGF-2 immunoreactive neuronal and glial profiles has been performed in the substantia nigra of the rat after acute intermittent nicotine treatment. The major finding of this paper is the demonstration that this type of nicotine treatment produces a significant reduction in the total number of nuclear FGF-2 immunoreactive astroglial profiles in the substantia nigra. A parallel analysis of nigral FGF-1 and FGF-5 immunoreactivities showed no effect of this type of nicotine treatment. The results may be explained by an inhibition of FGF-2 synthesis in a subpopulation of nigra…
Molecular and functional interactions between tumor necrosis factor-alpha receptors and the glutamatergic system in the mouse hippocampus: Implicatio…
2009
Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine acting on two distinct receptor subtypes, namely p55 and p75 receptors. TNF-alpha p55 and p75 receptor knockout mice were previously shown to display a decreased or enhanced susceptibility to seizures, respectively, suggesting intrinsic modifications in neuronal excitability. We investigated whether alterations in glutamate system function occur in these naive knockout mice with perturbed cytokine signaling that could explain their different propensity to develop seizures. Using Western blot analysis of hippocampal homogenates, we found that p55(-/-) mice have decreased levels of membrane GluR3 and NR1 glutamate receptor subuni…