Search results for "glial fibrillary acidic protein"

Preservation of glial cytoarchitecture from ex vivo human tumor and non-tumor cerebral cortical explants: A human model to study neurological diseases

2007

For the human brain, in vitro models that accurately represent what occurs in vivo are lacking. Organotypic models may be the closest parallel to human brain tissue outside of a live patient. However, this model has been limited primarily to rodent-derived tissue. We present an organotypic model to maintain intraoperatively collected human tumor and non-tumor explants ex vivo for a prolonged period of time (similar to 11 days) without any significant changes to the tissue cytoarchitecture as evidenced through immunohistochemistry and electron microscopy analyses. The ability to establish and reliably predict the cytoarchitectural changes that occur with time in an organotypic model of tumor…

2015

The pathogenesis of glaucoma, a common neurodegenerative disease, involves an immunologic component. Changes in the natural autoantibody profile of glaucoma patients were detected, showing not only up-regulated but also down-regulated immunoreactivities. In recent studies we were able to demonstrate that the antibody changes have a large influence on protein profiles of neuroretinal cells. Furthermore we could demonstrate neuroprotective potential of one of the down-regulated antibodies (γ-synuclein antibody). Anti-GFAP antibody is another antibody found down-regulated in glaucoma patients. Since GFAP expression is intensified in glaucomatous retina, the aim of this study was to detect the …

Oligodendrocytes in mouse corpus callosum are coupled via gap junction channels formed by connexin47 and connexin32.

2010

According to previously published ultrastructural studies, oligodendrocytes in white matter exhibit gap junctions with astrocytes, but not among each other, while in vitro oligodendrocytes form functional gap junctions. We have studied functional coupling among oligodendrocytes in acute slices of postnatal mouse corpus callosum. By whole-cell patch clamp we dialyzed oligodendrocytes with biocytin, a gap junction-permeable tracer. On average 61 cells were positive for biocytin detected by labeling with streptavidin-Cy3. About 77% of the coupled cells stained positively for the oligodendrocyte marker protein CNPase, 9% for the astrocyte marker GFAP and 14% were negative for both CNPase and GF…

Amyloid-Beta Induces Different Expression Pattern of Tissue Transglutaminase and Its Isoforms on Olfactory Ensheathing Cells: Modulatory Effect of In…

2021

Abstract Alzhèimer Disease (AD) is characterized by protein aggregates in the brain, including amyloid-beta (Aβ), a substrate for tissue transglutaminase (TG2). We assessed the effect of full native peptide of Aβ (1–42), the fragments (25–35 and 35–25) on TG2 expression and its isoforms (Long and Short) on mouse Olfactory Ensheathing Cells (OECs). The levels of cytoskeletal proteins, Vimentin and Glial Fibrillary Acid Protein, were also studied. The effect of the pre-treatment with Indicaxanthin on cell viability, total Reactive Oxygen Species, superoxide anion and apoptotic pathway activation was assessed. Since Nestin is co-expressed in pluripotent stem cells with cyclin D1, their levels …

Nitric oxide synthesis is related to astroglial cell cycle in the mouse retina via p53 gene regulation

2009

Purpose To analyze the influence of p53 gene in retinal astrocytes morphology and function. Methods Adult mice of the strain C57BL/6 were distributed into two groups: 1) wild type TP53, as the controls (cp53; n=20) and 2) mice with an extra copy of p53 (sp53; n=22). Both eyeballs were enucleated, after death by ether narcosis, to obtain the retinas. Right retinas were frozen (-85oC) until processing to assess nitric oxide (NO) synthesis. Left retinas were obtained and proccesed to perform immunohistochemical localization of the glial fibrillary acidic protein (GFAP). Data are expressed as the mean ± SD. Statistical analysis was carried out using Student’s t-test. Confidence interval was tak…

Preclinical Retinal Neurodegeneration in a Model of Multiple Sclerosis

2012

Neurodegeneration plays a major role in multiple sclerosis (MS), in which it is thought to be the main determinant of permanent disability. However, the relationship between the immune response and the onset of neurodegeneration is still a matter of debate. Moreover, recent findings in MS patients raised the question of whether primary neurodegenerative changes can occur in the retina independent of optic nerve inflammation. Using a rat model of MS that frequently leads to optic neuritis, we have investigated the interconnection between neurodegenerative and inflammatory changes in the retina and the optic nerves with special focus on preclinical disease stages. We report that, before manif…

Capture of extracellular zinc ions by astrocytes.

2006

Synaptic zinc ions released during synaptic transmission interact with pre- and postsynaptic neuroreceptors, thus modulating neurotransmission. It is likely that they have to be efficiently cleared from the extracellular milieu to assure subsequent synaptic events. Both neurons and glia are assumed to participate in this clearance by mechanisms that are not fully understood. In this study, electron microscopic zinc cytochemistry has shown zinc-electrondense particles associated with hippocampal astrocytic membranes frequently found accumulated in stacked lamellae. In cultured astrocytes, the use of zinc fluorochromes and endocytic markers allowed the simultaneous imaging of the capture of e…

Neurons and ECM regulate occludin localization in brain endothelial cells

2000

We report that extracellular matrix and neurons modulate the expression of occludin, one of the main components of tight junctions, by rat brain endothelial cells (RBE4.B). Of the three extracellular matrix proteins which we tested (collagen I, collagen IV, and laminin), collagen IV stimulated at the best the expression of occludin mRNA. The corresponding protein, however, was not synthesized. Significant amounts of occludin accumulated only when RBE4.B cells were cultured on collagen IV-coated inserts, in the presence of cortical neurons, plated on laminin-coated companion wells. Finally, occludin segregated at the cell periphery, only when endothelial cells were co- cultured with neurons …

ASTROCYTES SHED EXTRACELLULAR VESICLES THAT CONTAIN FIBROBLAST GROWTH FACTOR-2 AND VASCULAR ENDOTHELIAL GROWTH FACTOR.

2007

An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the perme…

NEURONS PRODUCE FGF-2 AND VEGF SECRETE THEM AT LEST IN PART BY SHEDDING EXTRACELLULAR VESCICLES

2007

Abstract We previously found that neurons are able to affect the ability of brain capillary endothelial cells to form in vitro a monolayer with properties resembling the blood-brain barrier. We then looked, by immunofluorescence and western analysis, for factors, produced by neurons, with the potential to influence growth and differentiation of endothelial cells. In the present paper, we report that neurons produce both vascular endothelial growth factor and fibroblast growth factor 2, two well-known angiogenic factors. More interestingly, we gained evidence that both factors are released by neurons, at least in part, by shedding of extracellular vesicles, that contain β1 integrin, a membra…