Search results for "astrocytes"
showing 10 items of 171 documents
Astrocytes and hypothalamic glucose sensing: metabolic role and involvement of astroglial connexins
2012
The hypothalamus plays a pivotal role in the nervous control of glucose homeostasis. This area contains gluco-sensitive neurons. Some of them detect increases in glucose levels and regulate glucose homeostasis by stimulating insulin secretion or inhibiting food intake. It is widely accepted that astrocytes are metabolically coupled to neurons. Lactate, resulting from the metabolism of glucose by astrocytes, is transported via the monocarboxylate transporters (MCTs). In addition, gap junctions (GJ), that form networks within astrocytes, are essential to transfer glucose from the bloodstream to the active neurons. These astroglial GJ mainly consist of connexins 43 and 30 (Cxs).The aims of my …
An Intercellular Flow of Glutathione Regulated by Interleukin 6 Links Astrocytes and the Liver in the Pathophysiology of Amyotrophic Lateral Sclerosis
2021
Oxidative stress has been proposed as a major mechanism of damage to motor neurons associated with the progression of amyotrophic lateral sclerosis (ALS). Astrocytes are the most numerous glial cells in the central nervous system and, under physiological conditions, protect neurons from oxidative damage. However, it is uncertain how their reactive phenotype may affect motor neurons during ALS progression. In two different ALS mouse models (SOD1G93A and FUS-R521C), we found that increased levels of proinflammatory interleukin 6 facilitate glutathione (GSH) release from the liver to blood circulation, which can reach the astrocytes and be channeled towards motor neurons as a mechanism of anti…
Synergistic effects of neurons and astrocytes on the differentiation of brain capillary endothelial cells in culture
2003
Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary …
Fabry Disease With Concomitant Lewy Body Disease
2019
AbstractAlthough Gaucher disease can be accompanied by Lewy pathology (LP) and extrapyramidal symptoms, it is unknown if LP exists in Fabry disease (FD), another progressive multisystem lysosomal storage disorder. We aimed to elucidate the distribution patterns of FD-related inclusions and LP in the brain of a 58-year-old cognitively unimpaired male FD patient suffering from predominant hypokinesia. Immunohistochemistry (CD77, α-synuclein, collagen IV) and neuropathological staging were performed on 100-µm sections. Tissue from the enteric or peripheral nervous system was unavailable. As controls, a second cognitively unimpaired 50-year-old male FD patient without LP or motor symptoms and 3…
Ethanol impairs extracellular zinc intake in cultured astrocytes
2009
Zinc (Zn) deficiency is present in many physiological and health problems. Among circumstances involved in Zn deficiency, ethanol consumption appears as a prominent cause. In the CNS substantial amounts of Zn appear accumulated in synaptic vesicles of a particular class of neurons: the Zn enriched neurons very abundant in the telencephalon and cerebral cortex. This is the so called synaptic Zn which is simultaneously released with the neurotransmitter thus exerting a neuromodulator role during synaptic transmission. Neighbour astrocytic processes have to capture the excess of both extracellular Zn and neurotransmitter in order to maintain efficient synaptic transmission between neurons. In …
Downregulation of the Astroglial Connexin Expression and Neurodegeneration after Pilocarpine-Induced Status Epilepticus
2022
Astrocytic networks and gap junctional communication mediated by connexins (Cxs) have been repeatedly implicated in seizures, epileptogenesis, and epilepsy. However, the effect of seizures on Cx expression is controversial. The present study focused on the response of Cxs to status epilepticus (SE), which is in turn an epileptogenic insult. The expression of neuronal Cx36 and astrocytic Cx30 and Cx43 mRNAs was investigated in the brain of rats in the first day after pilocarpine-induced SE. In situ hybridization revealed a progressive decrease in Cx43 and Cx30 mRNA levels, significantly marked 24 h after SE onset in neocortical areas and the hippocampus, and in most thalamic domains, whereas…
Effect of extracellular vesicles from CSF of multiple sclerosis patients and healthy controls on astrocytes in culture
2017
INTRODUCTION Secretion of extracellular vesicles (EVs) and EV-mediated exchange of molecules among brain cells, under physiological conditions, has been described years ago. At the same time, ability of EVs to transfer proteins and nucleic acids to the surrounding cells, thus modifying their phenotypes, has been clearly demonstrated for tumor cells of different origins, including brain cancers. More recently, involvement of EVs in pathological processes affecting the Central Nervous System (CNS), and their capacity of transferring damaging cargoes have been also suggested. To explore these functions, we exposed primary cultures of astrocytes to EVs isolated from cerebral spinal fluid (CSF) …
Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology
2020
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysi…
Healthy mitochondria for stroke cells.
2018
Stroke is a debilitating disease that remains as a significant unmet need. Although our understanding of the disease pathology has advanced over the years, treatment options for stroke are limited. Recent studies have implicated the important role of healthy mitochondria in neuroprotection against stroke. Under the stroke pathological condition, transfer of healthy mitochondria is observed from astrocytes to ischemic neurons. However, without additional therapeutic intervention, such astrocyte-to-neuron transfer of mitochondria may not sufficiently afford a robust and stable therapeutic effect against the devastating primary insult and progressive neurodegeneration associated with stroke. W…
Clearance and metabolism of arachidonic acid by C6 glioma cells and astrocytes.
1995
Effects of increased levels of arachidonic acid (AA) were analyzed in vitro by employment of C6 glioma cells and astrocytes from primary culture. The cells were suspended in a physiological medium added with arachidonic acid (AA) in a concentration range from 0.01 to 0.5 mM. The concentration profiles of the fatty acid and AA-metabolites were subsequently followed for 90 min. AA was measured by gas chromatography, whereas the AA-metabolites PGF2 alpha and LTB4 by radioimmunoassay (RIA). Following administration of AA at 0.05 or 0.1 mM the medium was completely cleared from the fatty acid within 10 to 15 min. However, when 0.5 mM were added, AA concentrations of 0.36 +/- 0.055 mM were found …