Astrocytes: A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.Glial Fibrillary Acidic Protein: An intermediate filament protein found only in glial cells or cells of glial origin. MW 51,000.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Neuroglia: The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.Gliosis: The production of a dense fibrous network of neuroglia; includes astrocytosis, which is a proliferation of astrocytes in the area of a degenerative lesion.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Oligodendroglia: A class of large neuroglial (macroglial) cells in the central nervous system. Oligodendroglia may be called interfascicular, perivascular, or perineuronal (not the same as SATELLITE CELLS, PERINEURONAL of GANGLIA) according to their location. They form the insulating MYELIN SHEATH of axons in the central nervous system.Animals, Newborn: Refers to animals in the period of time just after birth.Excitatory Amino Acid Transporter 2: A glutamate plasma membrane transporter protein found in ASTROCYTES and in the LIVER.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Microglia: The third type of glial cell, along with astrocytes and oligodendrocytes (which together form the macroglia). Microglia vary in appearance depending on developmental stage, functional state, and anatomical location; subtype terms include ramified, perivascular, ameboid, resting, and activated. Microglia clearly are capable of phagocytosis and play an important role in a wide spectrum of neuropathologies. They have also been suggested to act in several other roles including in secretion (e.g., of cytokines and neural growth factors), in immunological processing (e.g., antigen presentation), and in central nervous system development and remodeling.Aquaporin 4: Aquaporin 4 is the major water-selective channel in the CENTRAL NERVOUS SYSTEM of mammals.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Excitatory Amino Acid Transporter 1: A glial type glutamate plasma membrane transporter protein found predominately in ASTROCYTES. It is also expressed in HEART and SKELETAL MUSCLE and in the PLACENTA.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.S100 Calcium Binding Protein beta Subunit: A calcium-binding protein that is 92 AA long, contains 2 EF-hand domains, and is concentrated mainly in GLIAL CELLS. Elevation of S100B levels in brain tissue correlates with a role in neurological disorders.Coculture Techniques: A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.Cell Communication: Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.Mice, Inbred C57BLSpinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Nerve Tissue ProteinsOptic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.Amino Acid Transport System X-AG: A family of POTASSIUM and SODIUM-dependent acidic amino acid transporters that demonstrate a high affinity for GLUTAMIC ACID and ASPARTIC ACID. Several variants of this system are found in neuronal tissue.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Central Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.Astrocytoma: Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Gap Junctions: Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions.Connexin 43: A 43-kDa peptide which is a member of the connexin family of gap junction proteins. Connexin 43 is a product of a gene in the alpha class of connexin genes (the alpha-1 gene). It was first isolated from mammalian heart, but is widespread in the body including the brain.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.S100 Proteins: A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. They are also found in other organs in the body. They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. The name of this family derives from the property of being soluble in a 100% saturated ammonium sulfate solution.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Culture Media, Conditioned: Culture media containing biologically active components obtained from previously cultured cells or tissues that have released into the media substances affecting certain cell functions (e.g., growth, lysis).Neural Stem Cells: Self-renewing cells that generate the main phenotypes of the nervous system in both the embryo and adult. Neural stem cells are precursors to both NEURONS and NEUROGLIA.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.Blood-Brain Barrier: Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.Glioma: Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)Up-Regulation: A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Cerebellum: The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.Vimentin: An intermediate filament protein found in most differentiating cells, in cells grown in tissue culture, and in certain fully differentiated cells. Its insolubility suggests that it serves a structural function in the cytoplasm. MW 52,000.Primary Cell Culture: The initial culturing of cells derived directly from fresh TISSUES.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.

Astrocyte-specific expression of tyrosine hydroxylase after intracerebral gene transfer induces behavioral recovery in experimental parkinsonism. (1/6371)

Parkinson's disease is a neurodegenerative disorder characterized by the depletion of dopamine in the caudate putamen. Dopamine replacement with levodopa, a precursor of the neurotransmitter, is presently the most common treatment for this disease. However, in an effort to obtain better therapeutic results, tissue or cells that synthesize catecholamines have been grafted into experimental animals and human patients. In this paper, we present a novel technique to express tyrosine hydroxylase (TH) in the host's own astrocytes. This procedure uses a transgene in which the expression of a TH cDNA is under the control of a glial fibrillary acidic protein (GFAP) promoter, which confers astrocyte-specific expression and also increases its activity in response to brain injury. The method was tested in a rat model of Parkinson's disease produced by lesioning the striatum with 6-hydroxydopamine. Following microinjection of the transgene into the denervated striatum as a DNA-liposome complex, expression of the transgene was detected by RT-PCR and TH protein was observed specifically in astrocytes by using double-labeling immunofluorescence for GFAP and TH coupled with laser confocal microscopy. Efficacy was demonstrated by significant behavioral recovery, as assessed by a decrease in the pharmacologically induced turning behavior generated by the unilateral denervation of the rat striatum. These results suggest this is a valuable technique to express molecules of therapeutic interest in the brain.  (+info)

Activated macrophages and microglia induce dopaminergic sprouting in the injured striatum and express brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. (2/6371)

Nigrostriatal dopaminergic neurons undergo sprouting around the margins of a striatal wound. The mechanism of this periwound sprouting has been unclear. In this study, we have examined the role played by the macrophage and microglial response that follows striatal injury. Macrophages and activated microglia quickly accumulate after injury and reach their greatest numbers in the first week. Subsequently, the number of both cell types declines rapidly in the first month and thereafter more slowly. Macrophage numbers eventually cease to decline, and a sizable group of these cells remains at the wound site and forms a long-term, highly activated resident population. This population of macrophages expresses increasing amounts of glial cell line-derived neurotrophic factor mRNA with time. Brain-derived neurotrophic factor mRNA is also expressed in and around the wound site. Production of this factor is by both activated microglia and, to a lesser extent, macrophages. The production of these potent dopaminergic neurotrophic factors occurs in a similar spatial distribution to sprouting dopaminergic fibers. Moreover, dopamine transporter-positive dopaminergic neurites can be seen growing toward and embracing hemosiderin-filled wound macrophages. The dopaminergic sprouting that accompanies striatal injury thus appears to result from neurotrophic factor secretion by activated macrophages and microglia at the wound site.  (+info)

Early induction of angiogenetic signals in gliomas of GFAP-v-src transgenic mice. (3/6371)

Angiogenesis is a prerequisite for solid tumor growth. Glioblastoma multiforme, the most common malignant brain tumor, is characterized by extensive vascular proliferation. We previously showed that transgenic mice expressing a GFAP-v-src fusion gene in astrocytes develop low-grade astrocytomas that progressively evolve into hypervascularized glioblastomas. Here, we examined whether tumor progression triggers angiogenetic signals. We found abundant transcription of vascular endothelial growth factor (VEGF) in neoplastic astrocytes at surprisingly early stages of tumorigenesis. VEGF and v-src expression patterns were not identical, suggesting that VEGF activation was not only dependent on v-src. Late-stage gliomas showed perinecrotic VEGF up-regulation similarly to human glioblastoma. Expression patterns of the endothelial angiogenic receptors flt-1, flk-1, tie-1, and tie-2 were similar to those described in human gliomas, but flt-1 was expressed also in neoplastic astrocytes, suggesting an autocrine role in tumor growth. In crossbreeding experiments, hemizygous ablation of the tumor suppressor genes Rb and p53 had no significant effect on the expression of VEGF, flt-1, flk-1, tie-1, and tie-2. Therefore, expression of angiogenic signals is an early event during progression of GFAP-v-src tumors and precedes hypervascularization. Given the close similarities in the progression pattern between GFAP-v-src and human gliomas, the present results suggest that these mice may provide a useful tool for antiangiogenic therapy research.  (+info)

Expression of neuropeptide Y receptors mRNA and protein in human brain vessels and cerebromicrovascular cells in culture. (4/6371)

Neuropeptide Y (NPY) has been suggested as an important regulator of CBF. However, except for the presence of Y1 receptors in large cerebral arteries, little is known about its possible sites of action on brain vessels. In this study, we sought to identify the NPY receptors present in the human cerebrovascular bed. Specific Y1 receptor binding sites, localized on the smooth muscle of human pial vessels and potently competed by NPY, polypeptide YY (PYY), and the selective Y1 receptor antagonist BIBP 3226, were identified by quantitative radioautography of the Y1 radioligand [125I]-[Leu31, Pro34]-PYY. In contrast, no specific binding of the Y2-([125I]-PYY3-36) and Y4/Y5-(125I-human pancreatic polypeptide [hPP]) radioligands could be detected. By in situ hybridization, expression of Y1 receptor mRNA was restricted to the smooth muscle layer of pial vessels, whereas no specific signals were detected for either Y2, Y4, or Y5 receptors. Similarly, using reverse transcriptase-polymerase chain reaction (RT-PCR), mRNA for Y1 but not Y2, Y4, or Y5 receptors was consistently detected in isolated human pial vessels, intracortical microvessels, and capillaries. In human brain microvascular cells in culture, PCR products for the Y1 receptors were exclusively found in the smooth muscle cells. In cultures of human brain astrocytes, a cell type that associates intimately with brain microvessels, PCR products for Y1, Y2, and Y4 but not Y5 receptors were identified. Finally, NPY significantly inhibited the forskolin-induced cAMP production in smooth muscle but not in endothelial cell cultures. We conclude that smooth muscle Y1 receptors are the primary if not exclusive NPY receptors associated with human brain extraparenchymal and intraparenchymal blood vessels, where they most likely mediate cerebral vasoconstriction.  (+info)

Translation of the alzheimer amyloid precursor protein mRNA is up-regulated by interleukin-1 through 5'-untranslated region sequences. (5/6371)

The amyloid precursor protein (APP) has been associated with Alzheimer's disease (AD) because APP is processed into the beta-peptide that accumulates in amyloid plaques, and APP gene mutations can cause early onset AD. Inflammation is also associated with AD as exemplified by increased expression of interleukin-1 (IL-1) in microglia in affected areas of the AD brain. Here we demonstrate that IL-1alpha and IL-1beta increase APP synthesis by up to 6-fold in primary human astrocytes and by 15-fold in human astrocytoma cells without changing the steady-state levels of APP mRNA. A 90-nucleotide sequence in the APP gene 5'-untranslated region (5'-UTR) conferred translational regulation by IL-1alpha and IL-1beta to a chloramphenicol acetyltransferase (CAT) reporter gene. Steady-state levels of transfected APP(5'-UTR)/CAT mRNAs were unchanged, whereas both base-line and IL-1-dependent CAT protein synthesis were increased. This APP mRNA translational enhancer maps from +55 to +144 nucleotides from the 5'-cap site and is homologous to related translational control elements in the 5'-UTR of the light and and heavy ferritin genes. Enhanced translation of APP mRNA provides a mechanism by which IL-1 influences the pathogenesis of AD.  (+info)

Micronucleus test using cultured new born rat astrocytes. (6/6371)

Micronuclei is induced in cytoplasm as a consequence of the formation of chromosomal fragments or remaining chromosomes during cell division by the cause of clastogens or spindle poisons, and is used as an indicator of genotoxicity screening tests. There are few short-term genotoxicity screening tests using brain cells. We attempted to establish a new in vitro micronucleus test (MN test) system by use of central nervous system cells. Primary cultured astrocytes were prepared from newborn male Sprague-Dawley (SD) rats. In growth curve of astrocytes, doubling time was determined to be 31 h. In time study, the highest frequency of micronuclei was observed at 48 h, 72 h and 6 h-exposure-66 h-recovery by vincristine (VCR), mitomycin C (MMC) without metabolic activation system and cyclophosphamide (CPM) with metabolic activation system, respectively. Dose-response relationships between micronucleus frequency and concentrations of MMC, VCR and CPM were observed, respectively. It is suggested that the in vitro MN test using new born rat-astrocytes could be used as a screening test of environmental and occupational genotoxic chemicals in the central nervous system cells.  (+info)

Glutamate-, kainate- and NMDA-evoked membrane currents in identified glial cells in rat spinal cord slice. (7/6371)

The effect of L-glutamate, kainate and N-methyl-D-aspartate (NMDA) on membrane currents of astrocytes, oligodendrocytes and their respective precursors was studied in acute spinal cord slices of rats between the ages of postnatal days 5 and 13 using the whole-cell patch-clamp technique. L-glutamate (10(-3) M), kainate (10(-3) M), and NMDA (2x10(-3) M) evoked inward currents in all glial cells. Kainate evoked larger currents in precursors than in astrocytes and oligodendrocytes, while NMDA induced larger currents in astrocytes and oligodendrocytes than in precursors. Kainate-evoked currents were blocked by the AMPA/kainate receptor antagonist CNQX (10(-4) M) and were, with the exception of the precursors, larger in dorsal than in ventral horns, as were NMDA-evoked currents. Currents evoked by NMDA were unaffected by CNQX and, in contrast to those seen in neurones, were not sensitive to Mg2+. In addition, they significantly decreased during development and were present when synaptic transmission was blocked in a Ca2+-free solution. NMDA-evoked currents were not abolished during the block of K+ inward currents in glial cells by Ba2+; thus they are unlikely to be mediated by an increase in extracellular K+ during neuronal activity. We provide evidence that spinal cord glial cells are sensitive to the application of L-glutamate, kainate and transiently, during postnatal development, to NMDA.  (+info)

Carbamazepine-induced upregulation of adenosine A1-receptors in astrocyte cultures affects coupling to the phosphoinositol signaling pathway. (8/6371)

The anticonvulsant and antibipolar drug carbamazepine (CBZ) is known to act as a specific antagonist at adenosine A1-receptors. After a 3-week application of CBZ, A1-receptors are upregulated in the rat brain. We have investigated the consequences of this upregulation for the A1-receptor-mediated signal transduction in primary astrocyte cultures from different regions of the rat brain. CBZ treatment for 10 days had no effect on adenosine A1-receptor mRNA expression in cultures with high basal A1-receptor mRNA levels, but increased A1-receptor mRNA in cultures exhibiting low basal A1-receptor mRNA levels. This upregulation of A1-receptor mRNA was accompanied by an upregulation or induction of A1-receptor-mediated potentiation of PLC activity, a property that was not found in these cultures before CBZ treatment. Thus, CBZ treatment for 10 days induces a new quality of adenosine A1-receptor-mediated signal transduction in cells that express low basal A1-receptor numbers.  (+info)

*Astrocyte

After astrocyte specification has occurred in the developing CNS, it is believed that astrocyte precursors migrate to their ... When in proximity to the pia mater, all three forms of astrocytes send out processes to form the pia-glial membrane. Astrocytes ... Gömöri-positive astrocytes. These are a subset of protoplasmic astrocytes that contain numerous cytoplasmic inclusions, or ... Because of this ability of astrocytes to communicate with their neighbors, changes in the activity of one astrocyte can have ...

*Alzheimer type II astrocyte

Although these astrocytes are present in this disease, it has not yet been determined if Alzheimer type II astrocytes are a ... Like other astrocytes, it is a non-neuronal glial cell. They are not associated with Alzheimer's disease. Astrocytes belong to ... Alzheimer type II astrocytes are visually characterized by an enlarged size and lack of cytoplasm. These astrocytes appear to ... For example, astrocytes have many transporters and ion channels that allow for ion balance and static pH levels in order to ...

*Gliosis

... in which demyelinated plaques are surrounded by reactive astrocytes. These astrocytes often exhibit extreme hypertrophy and ... Astrocytes themselves also produce cytokines, which may be used for self-regulation or for the regulation of microglia, which ... Exposure of reactive astrocytes to β-amyloid (Αβ) peptide, the main component of amyloid plaques, may also induce astroglial ... Reactive astrocytes are affected by molecular signals released from a variety of CNS cell types including neurons, microglia, ...

*Glial scar

Astrocytes form a dense network of gap junctions that generates a physical barrier to axonal regrowth. Further, the astrocytes ... Reactive astrocytes are the main cellular component of the glial scar. After injury, astrocytes undergo morphological changes, ... David S, Ness R. (1993). "Heterogeneity of reactive astrocytes." In: Fedoroff S (ed) Biology and pathology of astrocyte-neuron ... thus compounding the response of other astrocytes and contributing to the heterogeneity. Particularly, astrocytes closest to ...

*Nervous tissue

Astrocytes: Star-shaped macroglial cells with many processes found in the CNS. They are the most abundant cell type in the ... NG2 glia: CNS cells that are distinct from astrocytes, oligodendrocytes, and microglia, and serve as the developmental ... In the central nervous system: Grey matter is composed of cell bodies, dendrites, unmyelinated axons, protoplasmic astrocytes ( ... White matter is composed of myelinated axons, fibrous astrocytes, myelinating oligodendrocytes, and microglia. In the ...

*Glomerulus (cerebellum)

The glia that ensheath the glomeruli are called velate astrocytes. Velate astrocytes are protoplasmic astrocytes with extremely ... Chan-Palay, Victoria; Palay, Sanford L. (1972). "The form of velate astrocytes in the cerebellar cortex of monkey and rat: High ... "Velate astrocyte". NeuroLex. The Neuroscience Information Framework. 29 May 2009. Retrieved 24 June 2014. ...

*Haemodynamic response

Astrocytes are unique in that they are intermediaries that lie between blood vessels and neurons. They are able to communicate ... Constriction has been shown in vitro to occur when NE is placed in the synapse and is taken up by astrocyte receptors. NE ... When these calcium ion waves spread down the length of the astrocyte, phospholipase A (PLA2) is activated which in turn ... It has been shown that NO inhibits 20-HETE synthesis, which may interfere with astrocytes' constriction pathways and lead to ...

*Gap junction

It appears that astrocytes are coupled by gap junctions, both to other astrocytes and to oligodendrocytes. Moreover, mutations ... Orthmann-Murphy, Jennifer L.; Abrams, Charles K.; Scherer, Steven S. (May 2008). "Gap Junctions Couple Astrocytes and ... with antibodies against external loop domains in astrocytes". Glia. 24 (1): 141-54. doi:10.1002/(SICI)1098-1136(199809)24:1. ...

*S100B

... is glial-specific and is expressed primarily by astrocytes, but not all astrocytes express S100B. It has been shown that ... S100B is secreted by astrocytes or can spill from injured cells and enter the extracellular space or bloodstream. Serum levels ... "The astrocyte odyssey". Prog. Neurobiol. 86 (4): 342-67. doi:10.1016/j.pneurobio.2008.09.015. PMC 2613184 . PMID 18948166. " ... "beta-Amyloid regulates gene expression of glial trophic substance S100 beta in C6 glioma and primary astrocyte cultures". Brain ...

*Plasma membrane Ca2+ ATPase

Astrocytes help to maintain ionic balance in the extracellular space in the brain. Knock-out of PMCA2 causes inner ear problems ... PMCA types 1, 2, and 4 have been found in glial cells called astrocytes in mammals, though it was previously thought that only ... "Plasma membrane calcium ATPase isoforms in astrocytes". Glia (published 1999-10-22). 28 (2): 150-155. doi:10.1002/(SICI)1098- ...

*Biochemical cascade

Vargas, MR; Johnson, JA (Jun 3, 2009). "The Nrf2-ARE cytoprotective pathway in astrocytes". Expert Reviews in Molecular ... This neuroprotective pathway involves control of neuronal activity by perisynaptic astrocytes and neuronal glutamate release, ...

*Rage (emotion)

... these astrocytes are found in close proximity to the 'end feet' of blood vessels. These astrocytes aid in the tightening and ... Astrocytes play a pivotal role in regulating blood flow to and from neurons by creating the blood-brain barrier (BBB). More ... The crucial role that astrocytes play in the formation of muscle memory may also shed light on the beneficial impact of ... Gold, P. E. Regulation of memory - From the adrenal medulla to liver to astrocytes to neurons. Brain Res. Bull. 2014,doi= ...

*Brain healing

Around the edge of necrosis, astrocytes proliferate. These cells extend processes, and form a delicate rim of gliosis around ...

*Oscar Gonzalez-Perez

"Astrocytes: Structure, Functions and Role in Disease". Novapublishers.com. Retrieved 2016-11-29. "Neuro-Immune Interactions in ... Additionally, Gonzalez has published three books: Astrocytes: Structure, Functions and Role in Disease, Neuro-Immune ...

*Oncolytic adenovirus

Colin, A (2009). "Engineered lentiviral vector targeting astrocytes in vivo". Glia. 57 (6): 667-679. doi:10.1002/glia.20795. ...

*Urotensin-II

It is also found in rat astrocytes. Pre-pro U-II in both humans and rats are primarily expressed in the motorneurons of the ... "Biochemical and functional characterization of high-affinity urotensin II receptors in rat cortical astrocytes". (primary). ...

*Leukoencephalopathy with vanishing white matter

Strangely, astrocytes are affected more than oligodendrocytes; there is even a reduction in the astrocyte progenitors, yet ... Abnormally shaped astrocytes with fibrile infections are very prevalent throughout the capillaries in the brain. ... These areas were surrounded by a dense net of oligodendrocytes in which only mild fibrillary astrocytes and scant sudanophilic ... A unique characteristic of VWM is that only oligodendrocytes and astrocytes are negatively affected while other glial cells and ...

*Neurodegeneration

provide in vitro evidence that the primary cellular sites where SOD1 mutations act are located on astrocytes. Astrocytes then ... May 2007). "Astrocytes expressing ALS-linked mutated SOD1 release factors selectively toxic to motor neurons". Nature ... Julien JP (May 2007). "ALS: astrocytes move in as deadly neighbors". Nature Neuroscience. 10 (5): 535-7. doi:10.1038/nn0507-535 ...

*Fananas cell

Fañanas cells are sometimes defined as "specialised astrocytes". The feathered cells are named after Jorge Ramón y Cajal ... of the study did not point at significant mutations in Fañanas cells but rather described the possible importance of astrocytes ...

*Neuroglia

Astrocytes are crucial in clearance of neurotransmitters from within the synaptic cleft, which provides distinction between ... July 2010). "Astrocytes control breathing through pH-dependent release of ATP". Science. 329 (5991): 571-5. doi:10.1126/science ... Glial cells known as astrocytes enlarge and proliferate to form a scar and produce inhibitory molecules that inhibit regrowth ... Pituicytes from the posterior pituitary are glia cells with characteristics in common to astrocytes. Tanycytes in the median ...

*Neuronal self-avoidance

Protoplasmic astrocytes in CA1 stratum radiatum occupy separate anatomical domains. J Neurosci 22(1):183-92 Ogata K, Kosaka T. ... N-cadherin, NCAM, and integrins promote retinal neurite outgrowth on astrocytes in vitro. J. Cell Biol. 107:1177-87 Tomaselli ... Later, this was also observed in mammalian astrocytes. Wang and Macagno, in 1998, again recurring to Hirudo medicinalis ... N-cadherin and integrins: two receptor systems that mediate neuronal process outgrowth on astrocyte surfaces. Neuron 1:33-43 ...

*Tripartite synapse

Astrocytes are capable of responding selectively to stimuli: Astrocytes of the hippocampal stratum oriens form tripartite ... Astrocytes are excitable cells: In response to stimuli from any of the three components of the tripartite synapse, astrocytes ... "Properties of Synaptically Evoked Astrocyte Calcium Signal Reveal Synaptic Information Processing by Astrocytes". The Journal ... Tripartite synapses occur at a number of locations in the central nervous system with astrocytes and may also exist with Muller ...

*Clonazepam

"Benzodiazepine receptors on primary cultures of mouse astrocytes". J Neurochem. 36 (4): 1587-9. doi:10.1111/j.1471-4159.1981. ...

*Gemistocyte

Such astrocytes are also known as gemistocytic astrocytes. Gemistocytes are also found in some chronic diseases and within ... Astrocytes participating in gliosis are referred to as reactive astrocytes. They have a large cytoplasmic mass, long, branching ... dʒɛˈmɪstəsaɪt/ je-MIS-tə-syt)(from Greek "γέμιζω", to fill up) is a swollen, reactive astrocyte. These cells usually appear ...

*Hepatic encephalopathy

Astrocytes use ammonia when synthesising glutamine from glutamate. The increased levels of glutamine lead to an increase in ... This small molecule crosses the blood-brain barrier and is absorbed and metabolised by the astrocytes, a population of cells in ... osmotic pressure in the astrocytes, which become swollen. There is increased activity of the inhibitory γ-aminobutyric acid ( ... in the body may precipitate encephalopathy through the action of cytokines and bacterial lipopolysaccharide on astrocytes. The ...
TY - JOUR. T1 - Infection of primary human fetal astrocytes by human herpesvirus 6. AU - Jun, H. E.. AU - McCarthy, Micheline. AU - Zhou, Y. I.. AU - Chandran, Bala. AU - Wood, Charles. PY - 1996/1/29. Y1 - 1996/1/29. N2 - Human herpesvirus 6 (HHV-6) is a lymphotropic betaherpesvirus which productively infects human CD4+ T cells and monocytes. HHV-6 is the etiologic agent for exanthem subitum (roseola), and it is well-known that central nervous system complications occur frequently during the course of HHV-6-associated disease. In addition, HHV-6 has been associated with encephalitis or encephalopathy. However, very little is known about its tropism for neural cells. There are reports that HHV-6 may infect some glial cell lines, but whether it can infect any primary neural cells is not known. Our studies show that both HHV-6A (GS) and HHV-6B (Z-29) can infect highly purified primary fetal astrocytes in vitro. Infected cells showed cytopathic effects, forming giant syncytia. In dual ...
We report here a novel live imaging approach to study astrocyte response to ischemic injury in the brains of living mice. Our results revealed marked effects of sex and estrogen on astrocyte response to ischemic injury. We report here that: (1) bioluminescent signal intensities/GFAP induction were significantly higher in female mice (out of estrus) compared with males (confirmed by immunohistochemistry); (2) in female mice, astrocyte response to ischemia/GFAP upregulation was strongly dependent on the estrus cycle and serum estrogen level; and (3) contrary to the findings in male mice, there was no correlation between bioluminescent signal intensity/GFAP upregulation and size of the ischemic lesion in female GFAP-luc mice.. GFAP is a 50-kDa intermediate filament, predominantly expressed by mature astrocytes in the central nervous system.24,25 Reactive astrogliosis is a key component of the inflammatory cellular response to central nervous system injury, including ischemia.2,26 It is ...
article{9714ffdf-1e21-475d-ac0b-daebdc2182ca, abstract = {Clearance of the amyloid-P peptide (A beta) as a remedy for Alzheimers disease (AD) is a major target in on-going clinical trials. In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta clearance is sparse. Therefore, by means of flow cytometry and confocal laser scanning microscopy (CLSM), we evaluated the binding and internalization of A beta 1-42 by primary human fetal astrocytes and adult astrocytes, isolated from nondemented subjects (n = 8) and AD subjects (n = 6). Furthermore, we analyzed whether alpha 1-antichymotrypsin (ACT), which is found in amyloid plaques and can influence A beta fibrillogenesis, affects the A beta uptake by human astrocytes. Upon over night exposure of astrocytes to FAM-labeled A beta 1-42 (10 mu M) preparations, (80.7 +/- 17.7)% fetal and (52.9 +/- 20.9)% adult A beta-positive astrocytes (P = 0.018) were observed. No significant difference ...
Astrocytes are the major glial subtype in the brain and mediate numerous functions ranging from metabolic support to gliotransmitter release through signaling mechanisms controlled by Ca2+. Despite intense interest, the Ca2+ influx pathways in astrocytes remain obscure, hindering mechanistic insights into how Ca2+ signaling is coupled to downstream astrocyte-mediated effector functions. Here, we identified store-operated Ca2+ release-activated Ca2+ (CRAC) channels encoded by Orai1 and STIM1 as a major route of Ca2+ entry for driving sustained and oscillatory Ca2+ signals in astrocytes after stimulation of metabotropic purinergic and protease-activated receptors. Using synaptopHluorin as an optical reporter, we showed that the opening of astrocyte CRAC channels stimulated vesicular exocytosis to mediate the release of gliotransmitters, including ATP. Furthermore, slice electrophysiological recordings showed that activation of astrocytes by protease-activated receptors stimulated interneurons in ...
Astrocytes derived from Y757F mutant mice defective in gp130-SHP2/SOCS3 signaling were investigated into their ability to respond to IL-6. Compared with WT astrocytes, Y757F astrocytes treated with hyper-IL6, had higher and more sustained activation of STAT3, while the levels of pY-SHP2 and pERK remained unchanged. Gene expression was investigated by Affymetrix gene chip analysis. At 2 hr, 306 genes were upregulated in WT astrocytes and of these, 28 did not increase in Y757F astrocytes. Of 238 genes upregulated in Y757F astrocytes, 9 were not upregulated in WT astrocytes. Some 99 genes were downregulated in WT astrocytes and of those 55 were not decreased in Y757F astrocytes. In WT astrocytes after 12 hrs the level of expression of many genes was reduced back to or near levels seen in the untreated cells, however, in Y757F astrocytes 109 genes either maintained their 2hr upregulated levels or were further increased. A number of candidate genes upregulated by hyper-IL6 in WT and Y757F astrocytes ...
Reactive astrocytes are associated with every form of neurological injury. Despite their ubiquity, the molecular mechanisms controlling their production and diverse functions remain poorly defined. Because many features of astrocyte development are recapitulated in reactive astrocytes, we investigated the role of nuclear factor I-A (NFIA), a key transcriptional regulator of astrocyte development whose contributions to reactive astrocytes remain undefined. Here, we show that NFIA is highly expressed in reactive astrocytes in human neurological injury and identify unique roles across distinct injury states and regions of the CNS. In the spinal cord, after white matter injury (WMI), NFIA-deficient astrocytes exhibit defects in blood-brain barrier remodeling, which are correlated with the suppression of timely remyelination. In the cortex, after ischemic stroke, NFIA is required for the production of reactive astrocytes from the subventricular zone (SVZ). Mechanistically, NFIA directly regulates the ...
Astrocyte activation is presumed to depress neuronal regeneration after CNS injury due to the glial scar, a formation of a physical barrier, and overproduction of multiple proinflammatory cytokines, including IL-1β, IL-6, and TNFα, which further aggravate the glial activation and injure the remaining neurons through positive feedback [4, 31, 38, 39]. The recombinant IL-1β used in the present study was shown to be biologically active as previously demonstrated by its ability to induce astrocyte activation in an in vitro astrocyte activation model [4, 40-42]. Therefore, we speculate that our IL-1β stimulation model is suitable and credible for the detection of the astrocyte activation in vitro. Upregulation of GFAP and hypertrophy of astrocyte cellular processes play a major and prominent role in astrocyte activation and the formation of glial scar [6, 12]. In the present study, the IL-1β stimulation triggered an elevated level of GFAP and induced the astrocyte hypertrophy; this phenomenon ...
Introduction Astrocytes are the most abundant glial cell type. in C57BL/6 mice TNFSF11 astroglial cells in response to lipopolysaccharide (LPS) using reverse-transcription polymerase BMS-911543 BMS-911543 chain reaction (RT-PCR) method. Results We provide for the first time evidence that astrocytes can express IL-19 mRNA following LPS stimulation. Furthermore we have found the expression of IL-19 mRNA in the cortex of adult C57BL/6 mice following intraperitoneal (i.p.) administration of LPS. Discussion This finding will contribute to current knowledge on the function and behavior of cells and mediators during inflammatory conditions in BMS-911543 the brain. Keywords: IL-19 Mice Astroglial Cells brain Cortex Lipopolysaccharide 1 Introduction Glial cells play an important role in controlling of CNS inflammation. Astrocytes are the most abundant glial cell type in the brain (Kim Hong & BMS-911543 Ro 2011 BMS-911543 Astrocytes are multifunctional glial cells that regulate extracellular ion and ...
In the present study, we aim to elucidate the role of caveolin-1 in modulating astroglial differentiation of neural progenitor cells (NPCs) and the potential mechanisms involved. We first investigated astroglial differentiation and Notch signaling by detecting the expressions of S100β, GFAP, NICD and hairy enhancer of split 1 (Hes1) in the brains of wild-type and caveolin-1 knockout mice. Caveolin-1 knockout mice revealed remarkably less astroglial differentiation and lower levels of NICD and Hes1 expressions than wild type mice. We then studied the potential roles of caveolin-1 in modulating NICD and Hes1 expressions and astroglial differentiation in isolated cultured NPCs by using caveolin-1 peptide and caveolin-1 RNA silencing. In the differentiating NPCs, caveolin-1 peptide markedly promoted astroglial formation and up-regulated the expressions of NICD and Hes1. In contrast, the knockdown of caveolin-1 inhibited astroglial differentiation of NPCs and the expressions of NICD and Hes1. Taken ...
Antigen presentation reactions are dependent upon the expression of the class II major histocompatibility antigens (MHC), the T-cell receptor, and the presented antigen. Recent studies demonstrate that such processes also require the presence of adhesion molecules such as lymphocyte functional antigen 1 (LFA-1) and its cell surface ligand, intercellular adhesion molecule 1 (ICAM-1). It has been suggested that the brain astrocyte can function as a facultative antigen presenting cell (APC). This hypothesis is based upon the ability to induce the expression of the class II MHC antigens on astrocytes, and on their ability to present myelin basic protein to encephalitogenic T-cells in vitro. The best in vivo data showing that astrocytes serve as intracerebral APCs is the finding that astrocytes in multiple sclerosis plaques are DR+ (class II MHC in human). However, it still remains to be resolved whether the in vivo expression of the MHC antigens in disease states is instrumental to antigen presentation
In this study, we focused on four glial proteins that are abundant in amyloid plaques and/or that are known to interact with Abeta: alpha1-antichymotrypsin (ACT), interleukin-1beta (IL-1beta), S100beta, and butyrylcholinesterase (BChE). We examined the ability of these proteins to activate rat cortical astrocyte cultures and to influence the ability of Abeta to activate astrocytes. Treatment of astrocytes with ACT, IL-1beta, or S100beta resulted in glial activation, as assessed by reactive morphology, upregulation of IL-1beta, and production of inducible nitric oxide synthase and nitric oxide. The ability of Abeta to induce astrocyte activation was also enhanced in the presence of each of these three proteins. In contrast, BChE alone did not activate astrocytes and had no effect on Abeta-induced activation ...
Astrocytes, which constitute 40% to 70% of total cells in the CNS [1], perform key regulatory functions critical to brain function. The different CNS cell types are differentially infected with HIV; microglia being highly susceptible, astrocytes moderately restrictive, and neurons highly restrictive. Despite the lack of CD4 receptors, astrocytes become infected via CD4-independent mechanism [6,44]. In line with the earlier studies [1,2], we also found low level of HIV replication in astrocytes compared to microglia. After the initial productive phase, infection subsides to a persistent stage in astrocytes, which goes in hand with reports from other investigators [1,2,32]. Infected astrocytes produce very low levels of virus even in the acute phase in contrast to infection of T-lymphocytes [45,46]. Our results with pseudotyped virus confirm that regardless of the entry routes, there are post-entry blocks to infection in astrocytes. Though the introduction of potent HAART has significantly ...
When DArcy Wentworth Thompsons On Growth and Form was published 100 years ago, it raised the question of how biological forms arise during development and across evolution. In light of the advances in molecular and cellular biology since then, a succinct modern view of the question states: how do genes encode geometry? Our new special issue is packed with articles that use mathematical and physical approaches to gain insights into cell and tissue patterning, morphogenesis and dynamics, and that provide a physical framework to capture these processes operating across scales.. Read the Editorial by guest editors Thomas Lecuit and L. Mahadevan, as they provide a perspective on the influence of DArcy Thompsons work and an overview of the articles in this issue.. ...
In the astrocyte lineage, Meteorin expression appears to be restricted to relatively immature cell populations. Meteorin expression is gradually lost in GLAST‐expressing astrocytes located in the postnatal cerebral parenchyma (Figure 2K and L), and is not detected in two major types of astrocytes in the adult cerebrum, fibrous astrocytes and protoplasmic astrocytes (Miller and Raff, 1984) (Supplementary Figure 3G). In the developing cerebellum, Meteorin is expressed in the VZ and GLAST‐positive migrating glial precursors. Among three subclasses of astrocytes in the adult cerebellar cortex, bushy protoplasmic astrocytes, smooth protoplasmic astrocytes, and Bergmann glia (Palay and Chan‐Palay, 1974), Meteorin expression is restricted to Bergmann glia (Figure 2M and N) (Supplementary Figure 3H and I). Expression of Meteorin in Bergmann glia may be regulated by neurons that interact with Bergmann glia. For instance, dendritic spines of Purkinje cells were completely enwrapped by Bergmann glial ...
The cells we identify here as primary precursors for new neurons in the adult hippocampus have the characteristics of astrocytes at the light and electron microscope. They contain multiple processes with intermediate filaments rich in GFAP. Results from three independent experiments support this conclusion. First, many proliferating SGL astrocytes rapidly convert to a cell type that is GFAP negative and that possesses characteristics of D cells. Second, anti-mitotic treatment resulted in the elimination of D cells from the SGL, but neurogenesis returned. Because new neurons are born at a time when [3H]thymidine-labeled astrocytes were observed, we infer that astrocytes function as primary precursors. Finally, we show that SGL astrocytes, specifically labeled with an avian retrovirus, give rise to granule neurons. We observed granule neurons at different stages of maturation by killing animals at different survivals after retroviral infection. Some SGL astrocytes remain labeled with thymidine ...
Tenascin-C is an extracellular matrix glycoprotein with trophic and repulsive properties on neuronal cells, involved in migratory processes of immature neurons. Previous reports demonstrated that this molecule is produced and secreted by astrocytes, in vitro after activation by bFGF or in vivo after CNS lesion. In injured brain the expression of tenascin-C has been correlated with the glial reaction since it was observed in regions suffering a dramatic glial proliferation and hypertrophy. In this report we show that the treatment of cultured hippocampal astrocytes with tenascin-C results in an increased fibronectin and NCAM immunoreactivities. In addition, treated astrocytes form longer extensions than control ones. The number of cells as well as the levels of GFAP mRNA and protein immunoreactivity are not modified after tenascin-C treatment. The present changes may, therefore, be related to the modification of the adhesive properties of astrocytes to the substrate. These observations are compatible
Repairing trauma to the central nervous system by replacement of glial support cells is an increasingly attractive therapeutic strategy. We have focused on the less-studied replacement of astrocytes, the major support cell in the central nervous system, by generating astrocytes from embryonic human glial precursor cells using two different astrocyte differentiation inducing factors. The resulting astrocytes differed in expression of multiple proteins thought to either promote or inhibit central nervous system homeostasis and regeneration. When transplanted into acute transection injuries of the adult rat spinal cord, astrocytes generated by exposing human glial precursor cells to bone morphogenetic protein promoted significant recovery of volitional foot placement, axonal growth and notably robust increases in neuronal survival in multiple spinal cord laminae. In marked contrast, human glial precursor cells and astrocytes generated from these cells by exposure to ciliary neurotrophic factor both failed
One barrier to studying astrocytes has been the difficulty of isolating and culturing the mature cell from the brain. Most current protocols isolate precursor cells rather than mature astrocytes. These precursor cells proliferate in culture in the presence of serum, developing a flat, fibroblast-like appearance that bears little resemblance to astrocytes in the brain (see image above). Other isolation methods, such as fluorescence-activated cell sorting, are too harsh to produce viable cells, co-first author Ye Zhang told Alzforum.. To gently isolate mature astrocytes for culturing, Zhang and co-first author Steven Sloan developed an immunopanning protocol. In this procedure, dissociated cells from brain tissue were passed through several culture dishes coated with antibodies to specific cell-surface markers. The first several plates removed unwanted cell types, while the final plate contained anti-HepaCAM to capture astrocytes. After washing off contaminating cells, the authors detached the ...
The 14-3-3 protein family plays critical regulatory roles in signaling pathways in cell division and apoptosis. 14-3-3gamma is mainly expressed in brain. Using primary cultures of cerebral cortical astrocytes, we investigated the relationships between 14-3-3gamma proteins and actin in astrocytes in cell division and under ischemia. Our results showed that endogenous 14-3-3gamma proteins in immature astrocytes appeared filamentous and co-localized with filamentous actin (F-actin). During certain stages of mitosis, 14-3-3gamma proteins first aggregated and then formed a ring-like structure that surrounded the daughter nuclei and enclosed the F-actin. In 4-week-old cultures of astrocytes, 14-3-3gamma proteins appeared as punctate aggregates in the cytoplasm. Under ischemia, 14-3-3gamma proteins formed filamentous structures and were closely associated with F-actin in surviving astrocytes. However, in apoptotic astrocytes, the intensity of immunostaining of 14-3-3gamma proteins in the cytoplasm ...
In cell migration assays, spheroids are seeded on an astrocyte monolayer culture, so the glioma cells do not penetrate the astrocyte culture and the migration is two-dimensional. This is the reason why we considered two layers in the model: one layer is the astrocyte on top of which lies the tumour cell layer. Thus, glioma cells and astrocytes can occupy the same position but on different planes. For all practical purposes, astrocytes in a confluent monolayer culture could be considered as non-motile cells. Time-lapse experiments registered only chaotic non-directional movements of negligible magnitude 1.24±0.36 μm in 5 h.. The rules of motion inside the layer of glioma cells are exactly the same as described before, for migration on a passive substrate: in the control situation we have p+=1, whereas in the treated situation we take p−=0.5. For the sake of coherency, we model the heterotype GJ communication as we did for homotype communication, i.e. with a parameter q which quantifies the ...
We found that cultured mouse cortical astrocytes display circadian rhythms in extracellular ATP, in agreement with recent results from rat astrocyte cultures, SCN and SCN2.2 cells (Womac et al., 2009). We used a stabilized form of luciferase that allowed long-term recordings of extracellular ATP from the same cells without perturbations that can affect circadian clock-gene expression in astrocytes (Prolo et al., 2005). We found that Clock/Clock, Per1m Per2m, Cry1−/−Cry2−/− and Bmal1−/− astrocytes are arrhythmic, similar to the locomotor behavior deficits of these mice (Vitaterna et al., 1994; van der Horst et al., 1999; Bunger et al., 2000; Zheng et al., 2001). We found that Bmal1, Clock−/+ and Cry1−/−Cry2−/+ glia have abnormal periods, much like the heterozygous mouse behavior. The correlations between rhythmicity in clock genes, extracellular ATP in glia and locomotor behavior suggest they may be tightly related.. Most of the astrocyte cultures deficient for functional ...
The central finding of the present study is that Mt3 plays a key role in the clathrin-dependent endocytosis of Aβ in astrocytes. In Mt3 −/− astrocytes, clathrin-mediated endocytosis, the mechanism responsible for Aβ endocytosis, was markedly decreased, whereas caveolin-mediated endocytosis was not altered. Astrocytes are likely key players in the clearance of extracellular Aβ; thus, our results suggest that changes in the Mt3 expression in astrocytes may have clinical relevance in AD. Taken together with our previous findings that Mt3 helps to maintain lysosomal degradation in astrocytes, the reduction in Mt3 in astrocytes may aggravate Aβ accumulation in the extracellular space.. Early studies showed that AD brain extracts induce more neurite outgrowth in cell cultures than do control brain extracts [27], suggesting upregulation of a growth-inducing factor or downregulation of a growth-inhibitory factor (GIF) in AD brains. The latter was shown to be the case, and a subsequent study ...
To better characterize the electrophysiological properties of neonatal astrocytes, we purposely narrowed the animal age to the dormant P1-3 period for examining potential diversity in ion channel expression among neonatal astrocytes. Interestingly, two electrophysiological phenotypes could be readily identified during this early postnatal age. The neonatal astrocytes in P1 homogeneously show a variably rectifying whole cell current profile, whereas electrophysiologically passive astrocytes (PAs) first appear in P2, and the percentage of PAs rapidly increased from 6.67 % in P2 to 20.83 % at P3. Interestingly, the appearance of PA in mice is 2 days earlier than rats [2], which seemingly follows a longer gestation time in rats (22 day) than mice (20 day).. We show that the passive behavior of neonatal astrocytes is solely attributable to gap junction coupling (Fig. 3). This differs fundamentally from the passive behavior of membrane conductance in mature astrocytes that is caused by intrinsic K+ ...
Neurogenesis is restricted in the adult mammalian brain; most neurons are neither exchanged during normal life nor replaced in pathological situations. We report that stroke elicits a latent neurogenic program in striatal astrocytes in mice. Notch1 signaling is reduced in astrocytes after stroke, and attenuated Notch1 signaling is necessary for neurogenesis by striatal astrocytes. Blocking Notch signaling triggers astrocytes in the striatum and the medial cortex to enter a neurogenic program, even in the absence of stroke, resulting in 850 ± 210 (mean ± SEM) new neurons in a mouse striatum. Thus, under Notch signaling regulation, astrocytes in the adult mouse brain parenchyma carry a latent neurogenic program that may potentially be useful for neuronal replacement strategies. ...
Astrocytes are now recognized as dynamic signaling elements in the brain. Bidirectional communication between neurons and astrocytes involves integration of neuronal inputs by astrocytes and release of gliotransmitters that modulate neuronal excitability and synaptic transmission. The ovarian steroid hormone, 17\beta-estradiol, in addition to its rapid actions on neuronal electrical activity can rapidly alter astrocyte intracellular calcium concentration $([Ca^{2+}]_i)$ through a membrane-associated estrogen receptor. Using calcium imaging and electrophysiological techniques, we investigated the functional consequences of acute treatment with estradiol on astrocyte-astrocyte and astrocyte-neuron communication in mixed hippocampal cultures. Mechanical stimulation of an astrocyte evoked a $[Ca^{2+}]_i$ rise in the stimulated astrocyte, which propagated to the surrounding astrocytes as a $[Ca^{2+}]_i$ wave. Following acute treatment with estradiol, the amplitude of the $([Ca^{2+}]_i)$ elevation in ...
Aquaporin-4 (AQP4) is the predominant water channel in brain and is selectively expressed in astrocytes. Astrocytic endfoot membranes exhibit tenfold higher densities of AQP4 than non-endfoot membranes, making AQP4 an excellent marker of astrocyte polarization. Loss of astrocyte polarization is known to compromise astrocytic function and to be associated with impaired water and K+ homeostasis. Here we investigate by a combination of light and electron microscopic immunocytochemistry whether amyloid deposition is associated with a loss of astrocyte polarization, using AQP4 as a marker. We used the tg-ArcSwe mouse model of Alzheimers disease, as this model displays perivascular plaques as well as plaques confined to the neuropil. 3D reconstructions were done to establish the spatial relation between plaques and astrocytic endfeet, the latter known to contain the perivascular pool of AQP4. Changes in AQP4 expression emerge just after the appearance of the first plaques. Typically, there is a loss ...
This cellular imaging study in animal models will explore whether two genetically determined forms of autism spectrum disorder (ASD) have similar deleterious alterations in star-shaped cells, called "astrocytes," that adversely affect brain development. Two genetic forms of ASD are Retts syndrome, which occurs almost exclusively in girls, and Fragile X syndrome, which occurs predominately in boys. Prior research showed that defects occur in neurons. More recent research indicates that defects occur as well in other types of cells in the brain, including astrocytes. While there are billions of nerve cells in the brain, there are even more astrocytes. Research suggests that astrocytes can produce both advantageous and deleterious effects. In the developing brain, astrocytes have a key role in regulating nerve cells functions. If astrocytes are altered, however, they may adversely affect brain development. The investigators hypothesize that both in Retts syndrome and Fragile X syndrome, as well ...
There is now growing evidence that astrocytes, like neurons, can release transmitters. One transmitter that in a vast number of studies has been shown to be released from astrocytes is glutamate. Although asytrocytic glutamate may be released by several mechanisms, the evidence in favor of exocytosis is most compelling. Astrocytes may respond to neuronal activity by such exocytotic release of glutamate. The astrocyte derived glutamate can in turn activate neuronal glutamate receptors, in particular N-methyl-D-aspartate (NMDA) receptors. Here we review the morphological data supporting that astrocytes possess the machinery for exocytosis of glutamate. We describe the presence of small synaptic-like microvesicles, SNARE proteins and vesicular glutamate transporters in astrocytes, as well as NMDA receptors situated in vicinity of the astrocytic vesicles.
The pathophysiology of a traumatic brain injury (TBI) involves the dysfunction of the blood-brain barrier (BBB). The lumen of the BBB is lined with cerebrovascular endothelial cells (CVEC) that are ensheathed with perivascular astrocyte endfeet. We investigated the cellular response of human-astrocytes and human-CVEC following trauma in vitro. Astrocytes and CVEC were subjected to a concussive injury (CI; mechanical stretch), then assessed for markers of injury (monolayer retraction) and activation (mitogen-activated protein kinases (MAPK) phosphorylation). CI induces astrocyte monolayer retraction and activation, with predominant phosphorylation of JNK1/2 MAPK. Interfering with JNK1/2 activation (selective JNK inhibitors) reduces trauma-induced astrocyte retraction. On the contrary, CI does not induce CVEC retraction, however up-regulates CVEC pro-adhesive phenotype resulting in increased polymorphonuclear leukocyte (PMN) adhesion. These findings indicate that CI elicits differential BBB cell responses
We used the pH-sensitive fluorescent dye BCECF to study intracellular pH (pHi) regulation in primary cultures of rat astrocytes and C6 glioma cells. Both cell types contain three pH-regulating transporters: (1) alkalinizing Na+/H+ exchange; (2) alkalinizing Na+ + HCO3 −/Cl−exchange; and (3) acidifying Cl−/HCO3− exchange. Na+/H+ exchange was most evident in the absence of CO2; recovery from acidification was Na+ dependent and amiloride sensitive. Exposure to CO2 caused a cell alkalinization that was inhibited by DIDS, dependent on external Na+, and inhibited 75% in the absence of Cl− (thus mediated by Na+ + HCO3−/Cl− exchange). When pHi was increased above the normal steady-state pHi, a DIDS-inhibitable and Na+ -independent acidifying recovery was evident, indicating the presence of Cl− /HCO3−exchange. Astrocytes, but not C6 cells, contain a fourth pH-regulating transporter, Na+ −HCO3− cotransport; in the presence of CO2, depolarization caused an alkalinization of 0.12 +− 0.01 (n
In recent literature, lymphokines have been reported to be able to promote both proliferation and maturation of some glial populations. In this paper, we compare the effect of rIL-1 on newborn and adult rat astroglial cells in vitro. In newborn, but not in adult astrocytes, 100 U/ml of rIL-1 beta increase [3H]thymidine incorporation with a maximal response by 3 days as compared to the control untreated culture. In contrast, rIL-1 beta induces an increase of GFAP immunoreactivity both in newborn and in adult astrocytes, as compared to the control untreated cells. These data indicate that, while both newborn and adult astroglial cells are capable of responding to rIL-1 beta, only newborn astrocytes can respond to this lymphokine with proliferation. Thus, it appears likely that different factors, other than rIL-1 beta, are needed by adult astrocytes to proliferate.
Blood-brain barrier (BBB) function is regulated by dynamic interactions among cell types within the neurovascular unit, including astrocytes and endothelial cells. Co-culture models of the BBB typically involve astrocytes seeded on two-dimensional (2D) surfaces, which recent studies indicate cause astrocytes to express a phenotype similar to that of reactive astrocytes in situ. We hypothesized that the culture conditions of astrocytes would differentially affect their ability to modulate BBB function in vitro. Brain endothelial cells were grown alone or in co-culture with astrocytes.
In this study, we investigated the role of the Arp2/3 complex and associated signaling in astrocytes. We demonstrate that the expansion of astrocytic cell bodies and processes is triggered by Arp2/3 inhibition in dissociated cultures and brain tissue. This phenomenon requires the activity of myosin II in conjunction with increased RhoA activity. Furthermore, we identified N-WASP and PICK1 as crucial Arp2/3 regulators in astrocyte morphological plasticity, and show that this mechanism underlies the rapid and drastic morphological changes exhibited by astrocytes under ischemic conditions.. In most studied cell types, inactivation of the Arp2/3 complex leads mainly to disappearance, outgrowth-inhibition or shrinkage of subcellular structures such as lamellipodia in fibroblasts and cancer cells (Steffen et al., 2006; Wu et al., 2012), or neurites and dendritic spines in neurons (Korobova and Svitkina, 2008; Hotulainen et al., 2009; Tahirovic et al., 2010; Nakamura et al., 2011; Yang et al., 2012). ...
Glutamate transporters (GluTs) maintain a low ambient level of glutamate in the central nervous system (CNS) and shape the activation of glutamate receptors at synapses. Nevertheless, the mechanisms that regulate the trafficking and localization of transporters near sites of glutamate release are poorly understood. Here, we examined the subcellular distribution and dynamic remodeling of the predominant GluT GLT-1 (excitatory amino acid transporter 2, EAAT2) in developing hippocampal astrocytes. Immunolabeling revealed that endogenous GLT-1 is concentrated into discrete clusters along branches of developing astrocytes that were apposed preferentially to synapsin-1 positive synapses. Green fluorescent protein (GFP)-GLT-1 fusion proteins expressed in astrocytes also formed distinct clusters that lined the edges of astrocyte processes, as well as the tips of filopodia and spine-like structures. Time-lapse three-dimensional confocal imaging in tissue slices revealed that GFP-GLT-1 clusters were ...
Astrocytes. Astrocytes are the most abundant cell type of the CNS, and exhibit broad morphological and functional heterogeneity. Astrocytes regulate ion and glutamate homeostasis, control the number and function of synapses, contribute to wound healing, form the blood-brain-barrier, and modulate cerebral blood flow. Astroglial cells also act as adult neural stem cells in the subventricular zone of the lateral ventricles lateral wall and in the subgranular layer of the dentate gyrus. GLAST is the most abundant glutamate transporter and a specific astrocyte marker in the developing and neonatal mammalian CNS. Radial glia and stem cells also express GLAST. The ACSA-2 antigen is specifically expressed on GLAST (ACSA-1)-positive astrocytes and is a second astrocyte-specific surface marker (PMID: 28317180). The antigen targeted by Anti-ACSA-2 is ATP1B2 (PMID: 28373281).. Oligodendrocytes. Oligodendrocytes form the myelin sheath around neuronal axons, which facilitates the fast saltatory propagation ...
The activation of those Ca2+ waves can be induced, as it has been said before, by neurotransmitters which are released into the synaptic space surrounded by astrocytes terminations. Evidence of this mechanisms has been provided by research into the role of mGluR5 in astrocytes in the nucleus accumbens. This type of glutamate receptor has a major role in regulating Ca2+ signaling in astrocytes and, as a consequence, the Ca2+ dependent release of excitatory transmitters from these glia: activation of mGluR5 induces Ca2+ oscillations in NAcc astrocytes with the correlated appearance of NMDA receptor-dependent slow inward currents detected in nucleus accumbens neurons. In other words, glutamatergic afferents cause the sustained activation of astrocytes, which in turn excite the surrounding through extrasynaptic NMDA receptors: this might be involved in amplificating neuronal signals (mGluR5 stimulates gliotransmission in the nucleus accumbens, 2007).. The release of gliotransmitters can be mediated ...
Purpose: While antiretroviral therapy (ART) has improved the quality of life and survival of HIV-1-infected patients, HIV-1-associated neurocognitive disorders (HAND) remain a major problem in over 30% of cases. All forms of HAND are associated with CNS inflammation. Astrocytes, the principal type of glial cells, are involved in signaling, homeostasis, and repair during CNS pathology. Some astrocytes become non-productively infected by HIV-1. The balance between matrix metalloproteinases (MMP) and their inhibitors must be tightly regulated during CNS inflammation. In the brain, tissue inhibitor of MMPs (TIMP)-1 protects human neurons from HIV-1-induced apoptosis and is mainly produced by astrocytes. Further, astrocyte TIMP-1 is differentially regulated during acute and chronic IL-1β-activation. However, the direct or indirect effects of astrocyte HIV-1 protein expression on TIMP-1 regulation are not well studied. Here, we investigated downstream effects of HIV-1 Tat and gp120 expression in astrocytes
An in-depth bioinformatic search for astrocyte-specific genes comprised three different methods: (i) a biased search for genes with an expression pattern similar to the best known astrocyte marker, GFAP, (ii) an unbiased search by a class prediction tool, recursive-supervised machine (R-SVM) analysis, and (iii) an empirical threshold approach to identify a common set of genes among complementary data sets. In the GFAP cluster analysis, GFAP captured a group of 393 genes that were differentially expressed by all in vitro astrocyte samples (Fig. 1 A ). Whereas this cluster likely represents a potential source of novel astrocyte genes (see Table 2 for a complete list), it is notable that no clear GFAP subcluster emerged, and correspondingly, a random sampling of genes among the GFAP cluster revealed their limited expression in CNS astrocytes by RNA ISH (see below). Next, to avoid the bias of so-called signature genes, R-SVM analysis was used to identify genes that "as a group" (unlike genes found ...
Cells and cell culture. Four GSCs were established and identified by our previous work, and were cultured in serum-free stem cell medium (SFM) (Neurobasal, Gibco, Thermo Fisher Scientific) containing 20 ng/mL basic fibroblast growth factor (bFGF; catalog 100-18B-50UG, PeproTech), 20 ng/mL epidermal growth factor (EGF; catalog AF-100-15-100UG, PeproTech), 10 μg/mL heparin (catalog 9041-08-1, Sigma-Aldrich), 2% B27 (Gibco, Thermo Fihser Scientific), and 2 mmol/L l-glutamine (catalog SH30034.01, HyClone). The induced human neural stem cells, H1-NSCs obtained from D.Q. Peis laboratory (Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China) and ReNcell-CX cells (ATCC), were cultured in medium as for the GSCs with the extra addition of 1% N-2 supplement (Gibco, Thermo Fisher Scientific). We purchased a normal human astrocyte cell line (HA) from ScienCell and cultured it using commercial astrocyte medium (catalog 1801, ScienCell) supplemented with 2% FBS ...
TY - JOUR. T1 - Computational Flux Balance Analysis Predicts that Stimulation of Energy Metabolism in Astrocytes and their Metabolic Interactions with Neurons Depend on Uptake of K+ Rather than Glutamate. AU - DiNuzzo, Mauro. AU - Giove, Federico. AU - Maraviglia, Bruno. AU - Mangia, Silvia. PY - 2017/1/1. Y1 - 2017/1/1. N2 - Brain activity involves essential functional and metabolic interactions between neurons and astrocytes. The importance of astrocytic functions to neuronal signaling is supported by many experiments reporting high rates of energy consumption and oxidative metabolism in these glial cells. In the brain, almost all energy is consumed by the Na+/K+ ATPase, which hydrolyzes 1 ATP to move 3 Na+ outside and 2 K+ inside the cells. Astrocytes are commonly thought to be primarily involved in transmitter glutamate cycling, a mechanism that however only accounts for few % of brain energy utilization. In order to examine the participation of astrocytic energy metabolism in brain ion ...
Astrocytes are largest class of glial cells, and are morphologically and physiologically adapted to play an integral part of central nervous system (CNS) activity. With emerging technologies, we have entered a new era of understanding how astrocytes participate in and modulate neuronal activity from the subcellular to mesoscale levels. However, fundamental questions about astrocytes remain. In particular, we have yet to fully understand: 1) how physiologically and molecularly heterogeneous are astrocytes, 2) how uniform or variable the astrocyte effects are on neurons at various synapses and circuits throughout the CNS, and 3) under what conditions and by what mechanisms do astrocytes modulate neuronal activity? Moreover, answers to these questions are needed to clarify some conflicting data that has arisen in past research. We are launching this Research Topic to explore recent advances in understanding how astrocytes listen and speak to neurons to shape cell-cell communication and physiological
When DArcy Wentworth Thompsons On Growth and Form was published 100 years ago, it raised the question of how biological forms arise during development and across evolution. In light of the advances in molecular and cellular biology since then, a succinct modern view of the question states: how do genes encode geometry? Our new special issue is packed with articles that use mathematical and physical approaches to gain insights into cell and tissue patterning, morphogenesis and dynamics, and that provide a physical framework to capture these processes operating across scales.. Read the Editorial by guest editors Thomas Lecuit and L. Mahadevan, as they provide a perspective on the influence of DArcy Thompsons work and an overview of the articles in this issue.. ...
Astrocytes are the major cell type in the human brain and in recent years have emerged as critical regulators of neural circuit development, function, plasticit...
Network analysis methods are increasingly applied to study biological processes at the -omic level. These techniques successfully combine Bayesian, graph theoretic and statistical inference approaches to identify key genetic modules. I will further develop these ideas and apply them to recent research in neuroscience, investigating signaling processes in neuron-astrocyte stem-cell co-cultures through combined analysis of transcriptomic and epigenetic changes. Novel methods will be developed to integrate and query omics data via network methodologies and machine learning classification. In addition to the mathematical and computational techniques thus developed, the results will contribute toward further research into neural co-cultures for disease study.. ...
Cell culture, transfection, treatments, and lentiviral transduction. MDA-MB-231, MCF7, HEK-293T, U937, NIH-3T3, 4T1, HBEC-5i, HUVEC, and HMEC cells obtained from ATCC were cultured under standard conditions. Parental BT474 (BT474-Par), MDA-MB-231 (231-Par), and HCC1954 (HCC1954-Par) and their brain metastatic derivatives (BT474-Br, 231-Br, and HCC1954-Br) were previously described (17). The lung and bone metastatic cell lines MDA-MB-231 LM2 and BoM-1833 were provided by Jianming Xu and Xiang Zhang (Baylor College of Medicine, Houston, Texas, USA), respectively. The γ-2A (JAK2-null) cell line was provided by George Stark (Cleveland Clinic, Cleveland, Ohio, USA). The BV2 cell line and the mouse astrocyte cell line were provided by Zhimin Lu and Isaiah J. Fidler (MD Anderson Cancer Center), respectively. siRNA and plasmid transfections were performed using DharmaFECT4 (GE Healthcare) and Lipofectamine 3000 (Invitrogen). Cells were serum-starved overnight followed by treatment with IL-6, IL-11, ...
A newly published study from a team of neuroscientists at MIT is latest in a growing body of evidence suggesting that astrocytes are critically important for processing sensory information.. A new study from MIT neuroscientists sheds light on a neural circuit that makes us likelier to remember what were seeing when our brains are in a more attentive state.. The team of neuroscientists found that this circuit depends on a type of brain cell long thought to play a supporting role, at most, in neural processing. When the brain is attentive, those cells, called astrocytes, relay messages alerting neurons of the visual cortex that they should respond strongly to whatever visual information they are receiving.. The findings, published this week in the online edition of the Proceedings of the National Academy of Sciences, are the latest in a growing body of evidence suggesting that astrocytes are critically important for processing sensory information, says Mriganka Sur, the Paul E. and Lilah Newton ...
S100A1 (Astrocyte Marker) Antibody - Without BSA and Azide, Mouse Monoclonal Antibody [Clone 4C4.9 ] validated in WB, IHC-P, IF, FC (AH10729-100), Abgent
Anti-S100 beta antibody - Astrocyte Marker (ab41548) has been cited in 16 publications. References for Mouse, Rat, Pig in Dot, IF, IHC - Wmt, WB
This is the first study to establish a co‐culture model, using BECs and astrocytes from two distinct developmental ages. Using this co‐culture model, we demonstrated that astrocytes enhance tight junction and P‐gp function in BECs. Moreover, postnatal astrocytes can dramatically upregulate P‐gp function in fetal BECs, while fetal astrocytes had no effect on P‐gp activity in postnatal BECs. Thus, the BBB‐inducing properties of astrocytes are dependent on developmental stage at which astrocytes were derived. We also found that ACM could mimic these effects on P‐gp function, suggesting a mechanism that involves soluble astrocyte‐derived factors. Using heat inactivation and protease treatment, we demonstrated that these astrocyte‐derived factors are dependent upon proteins. Fractionation of ACM indicated that these factors are in the molecular weight range of 3-100 kDa. Moreover, LC/MS‐MS identified 85 proteins that were significantly upregulated in PND14 ACM compared to GD50 ...
Image: Co-culture of embryonic mouse hippocampal neurons and astrocytes. Primary embryonic hippocampal neurons at 7 days in vitro, were stained with Microtubule Associated Protein-2 (MAP, green) to enable the visualization of the dendritic arbors. These neurons were cultured on top of a monolayer of primary cortical astrocytes, stained with an antibody directed against Glial Fibrillary Acidic Protein (GFAP, red). The cell nuclei were visualized by staining with 4,6-diamidino-2-phenylindole (DAPI, blue ...
TY - JOUR. T1 - CD38 regulation in activated astrocytes. T2 - Implications for neuroinflammation and HIV-1 brain infection. AU - Kou, Wei. AU - Banerjee, Sugato. AU - Eudy, James D. AU - Smith, Lynette M. AU - Persidsky, Raisa. AU - Borgmann, Kathleen. AU - Wu, Li. AU - Sakhuja, Namita. AU - Deshpande, Muralidhar S.. AU - Walseth, Timothy F.. AU - Ghorpade, Anuja. PY - 2009/8/1. Y1 - 2009/8/1. N2 - Reactive astrogliosis is a key pathological aspect of neuroinflammatory disorders including human immunodeficiency virus type 1 (HIV-1)-associated neurological disease. On the basis of previous data that showed astrocytes activated with interleukin (IL)-1b induce neuronal injury, we analyzed global gene changes in IL-1b-activated human astrocytes by gene microarray. Among the up-regulated genes, CD38, a 45- kDa type II single chain transmembrane glycoprotein, was a top candidate, with a 17.24-fold change that was validated by real-time polymerase chain reaction. Key functions of CD38 include enzymatic ...
One of the most coveted goals of science is to elucidate the cellular bases of complex brain functions. How does a piece of biological tissue produce accurate cognitive insights, or succumbs to a devastating neurological disease? Neurons and astrocytes are the most numerous cells in the brain, comprising >95% of the brain parenchyma, and are responsible for all aspects of rapid information processing in the mammalian brain. Monitoring of physiological changes at the individual cell level, as well as in cell populations, is essential (Popovic et al., 2015a;Nakajima et al., 2016). Early explorations of cellular physiology entailed metal (or glass and metal) electrodes. However, due to their highly invasive and tissue-harming nature, all electrodes, no matter how small, are limited experimental tools. While understanding brain circuits ultimately relies on the analyses of multiple and well identified cells and subcellular compartments, the required information at high spatial and temporal resolution is not
The long term goal of this laboratory is to enhance the ability of the human nervous system, particularly the retina and/or optic nerve, to regenerate. This pro...
Astrocytes (or glial cells), previously assumed to be passive players in brain physiology, may play a functional role in a number of complex behaviors. The central chemosensory control of breathing involves highly specialized neuronal populations in the brainstem, but what about astrocytes? Gourine et al. now present evidence that glial cells may help to control breathing. A number of techniques were used to reveal glial calcium rises in vitro that elicit a depolarization of neurons in the primary locus for central respiratory chemosensitivity. The depolarization in these neurons is evoked by vesicular release of ATP in neighboring astrocytes in response to the fall in extracellular pH. Thus, brainstem astrocytes have the ability to sense changes in blood and brain CO2, and pH directly, and may control the activity of the respiratory neuronal networks to regulate breathing.. A. V. Gourine, V. Kasymov, N. Marina, F. Tang, M. F. Figueiredo, S. Lane, A. G. Teschemacher, K. M. Spyer, K. Deisseroth, ...
TY - JOUR. T1 - βA3/A1-crystallin is required for proper astrocyte template formation and vascular remodeling in the retina. AU - Sinha, Debasish. AU - Valapala, Mallika. AU - Bhutto, Imran. AU - Patek, Bonnie. AU - Zhang, Cheng. AU - Hose, Stacey. AU - Yang, Fang. AU - Cano, Marisol. AU - Stark, Walter J.. AU - Lutty, Gerard A.. AU - Zigler, J. Samuel. AU - Wawrousek, Eric F.. PY - 2012/9/1. Y1 - 2012/9/1. N2 - Nuc1 is a spontaneous rat mutant resulting from a mutation in the Cryba1 gene, coding for βA3/A1-crystallin. Our earlier studies with Nuc1 provided novel evidence that astrocytes, which express βA3/A1-crystallin, have a pivotal role in retinal remodeling. The role of astrocytes in the retina is only beginning to be explored. One of the limitations in the field is the lack of appropriate animal models to better investigate the function of astrocytes in retinal health and disease. We have now established transgenic mice that overexpress the Nuc1 mutant form of Cryba1, specifically in ...
Alcohol (EtOH) abuse and HIV-1 remain significant public health problems. Globally, drinkers have approximately 70-77% higher risk of HIV-infection than non-drinkers. The prevalence of alcohol abuse among HIV-positive individuals has been estimated to be between 29-60% in the United States. Many studies showed that neurodegeneration in alcohol abusers include exacerbated neuroinflammation and oxidative damage. However, how EtOH regulates HIV-1-induced astrocyte neuroinflammation is unknown. Thus, we explored mechanism(s) involved in alcohol-mediated activation of human astrocytes with HIV-1 and subsquent alterations in their inflammatory functions. Alcohol exposure altered the morphology of astrocytes, proinflammatory responses and induced cytotoxicity in a dose-dependent manner. Time-depended changes were also evaluated. Alcohol and HIV-1 co-treatment decreased cell viability and proliferation, while increasing apoptosis and mitochondrial depolarization. Alcohol and HIV-1 together increased the levels
Höytö A, Juutilainen J, Naarala J (2007).. Murine L929 fibroblasts, rat C6 glioblastoma cells, human SH-SY5Y neuroblastoma cells and rat primary astrocytes were exposed to RFR at 872 MHz. The cells were exposed for 2,8, or 24 hours to continuous wave (CW) RFR or to a GSM type signal pulse modulated at 217 Hz, at SARs of 1.5, 2.5, or 6.0 W/kg (except in the case of the primary astrocytes, which were not exposed at 2.5 W/kg). Cellular ODC levels were determined.. ODC activity was reduced in primary astrocytes at a statistically significant level, at both 1.5 and 6.0 W/kg SAR, and in both CW and GSM modulated exposure. In the secondary cell lines ODC activity was generally unaffected, except in two instances that may have been related to accidental temperature increase in the cell medium.. The authors point out that decrease in ODC activity leads to impaired polyamine synthesis, which results in decreased proliferation.. ...
Reliable, high throughput, in vitro preliminary screening batteries have the potential to greatly accelerate the rate at which regulatory neurotoxicity data is generated. This study evaluated the importance of astrocytes when predicting acute toxic potential using a neuronal screening battery of pure neuronal (NT2.N) and astrocytic (NT2.A) and integrated neuronal/astrocytic (NT2.N/A) cell systems derived from the human NT2.D1 cell line, using biochemical endpoints (mitochondrial membrane potential (MMP) depolarisation and ATP and GSH depletion). Following exposure for 72 h, the known acute human neurotoxicants trimethyltin-chloride, chloroquine and 6-hydroxydopamine were frequently capable of disrupting biochemical processes in all of the cell systems at non-cytotoxic concentrations. Astrocytes provide key metabolic and protective support to neurons during toxic challenge in vivo and generally the astrocyte containing cell systems showed increased tolerance to toxicant insult compared with the ...
This lesson is going to define the term astrocyte. Youll learn what the two main types of astrocytes are and the many functions of astrocytes in...
Background: Astrocytes, which comprise ~90% of overall brain mass, are involved in brain immunity. These cells represent the non-professional class of CNS-resident APCs and may promote or inhibit CNS inflammation depending on the cytokines they secrete. IL-10 family of cytokines and their receptors, IL-20R1 and IL-20R2, may have a role in shifting astrocytes to a neuroprotective or neurodegenerative function. Objective: To address the expression of IL-20R1 and IL-20R2 cytokine receptors in astrocytes and brain cortex of C57BL/6 mice. Methods: We investigated the expression of IL-20R1 and IL-20R2 in C57BL/6 mice astroglial cells and brain cortex in response to lipopolysaccharide (LPS), using reverse-transcription polymerase chain reaction (RTPCR) method. Results: Astrocytes were able to express IL-20R1 and IL-20R2 mRNA not only in response to LPS stimulation but also in the absence of LPS. Furthermore, we found the expression of IL-20R1 and IL-20R2 mRNA in the cortex of adult C57BL/6 mice. Conclusions:
How is oligodendrocyte/type-2 astrocyte abbreviated? O/2A stands for oligodendrocyte/type-2 astrocyte. O/2A is defined as oligodendrocyte/type-2 astrocyte rarely.
BACKGROUND: Elevated levels of oncostatin M (OSM), an interleukin-6 cytokine family member, have been observed in HIV-1-associated neurocognitive disorders (HAND) and Alzheimers disease. However, the function of OSM in these disease conditions is unclear. Since deficient glutamate uptake by astrocytes is instrumental in HAND-associated neurotoxicity, we hypothesized that OSM impairs glutamate uptake in astrocytes and thereby promotes neuronal excitotoxicity. METHODS: Primary cultures of mouse cortical astrocytes, neurons, microglia, and BV2 cell line were used. The expression of glutamate transporters (GLAST/EAAT1 and GLT-1/EAAT2) was investigated using real-time PCR and Western blot, and their activity was assessed by measuring (3)H-D-aspartate uptake. Neuronal toxicity was measured using the colorimetric MTT (3-(4,5-dimethylthiazol-2-yl-) 2,5-diphenyltetrazolium bromide) assay and immunocytochemistry. A chimeric HIV-1 that infects murine cells (EcoHIV/NL4-3-GFP virus (EcoHIV)) was used to ...
The production of a certain kind of brain cell that had been considered an impediment to healing may actually be needed to staunch bleeding and promote repair after a stroke or head trauma, researchers at Duke Medicine report.
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To further reveal the relationship between Atg5 and the JAK‐STAT signaling pathway, a series of experiments were performed to investigate changes of inhibitors of JAK/STAT including SOCS1, SOCS2, SOCS3, and SHP‐2 [31], [32]. The greatest decrease of SOCS2 (the suppressor of cytokine signaling 2, a member of STAT‐induced STAT inhibitors) was observed when Atg5 was overexpressed (Supplementary Fig S4D). Next, we observed that Atg5 knockdown elevated the expression of SOCS2 (Fig 5C), and Atg5 overexpression decreased SOCS2 (Supplementary Fig S4F). We further found that SOCS2 knockdown (Supplementary Fig S4E) resulted in the increased expression of pSTAT3 and could restore decreased pSTAT3 levels to normal caused by Atg5 knockdown (Fig 5D). To further analyze the relationship between SOCS2 and Atg5 in vivo, we investigated whether SOCS2 downregulation could rescue astrocyte differentiation defects caused by Atg5 loss. Our data show that SOCS2 knockdown restored the number of GFAP‐positive ...
Astrocytes are secretory cells highly, participating in quick brain communication by releasing glutamate. of such component is sustained by autocrine/paracrine action of PGE2. 1. Intro The morphology and the location of astrocytes place them in a unique position to be able to listen and respond to neuronal activity [1C5]. Astrocytes communicate a wide variety of practical neurotransmitter receptors essential for sensing neuronal activity [6]. Many of these receptors are G-protein-coupled receptors (GPCRs) that, upon activation, stimulate phospholipase C and form inositol (1,4,5)-triphosphate (IP3) which increases the intracellular calcium (Ca2+) concentration through the release of Ca2+ from intracellular stores [6]. The intracellular cascade resulting in Ca2+ rise in astrocytes is the main mechanism these cells use to transduce synaptic activity. It is well established the GPCR- mediated Ca2+ variations in astrocytes can result in launch of chemical substances [7, 8] such as excitatory amino ...
HIV-associated neurological disorders (HAND) are estimated to affect 60% of the HIV infected population. HIV-encephalitis (HIVE), the pathological correlate of the most severe form of HAND is often characterized by glial activation, cytokine/chemokine dysregulation, and neuronal damage and loss. However, the severity of HIVE correlates better with glial activation rather than viral load. One of the characteristic features of HIVE is the increased amount of the neurotoxic chemokine, CXCL10. This chemokine can be released from astroglia activated with the pro-inflammatory cytokines IFN-γ and TNF-α, in conjunction with HIV-1 Tat, all of which are elevated in HIVE. In an effort to understand the pathogenesis of HAND, this study was aimed at exploring the regulation of CXCL10 by cellular and viral factors during astrocyte activation. Specifically, the data herein demonstrate that the combined actions of HIV-1 Tat and the pro-inflammatory cytokines, IFN-γ and TNF-α, result in the induction of CXCL10 at
We found eNOS immunoreactivity in the PVN to be largely localized in astrocyte cell bodies and processes. Given that eNOS did not colocalize with nNOS, which is exclusively expressed in neurons,5,11 our studies support a cellular segregation between these 2 isoforms. Still, the precise cellular distribution of eNOS in the CNS remains controversial. Although eNOS was reported both in astrocytic cultures29 and brain tissue,30,31 including recently in the nucleus tractus solitarius,17 others failed to detect eNOS in astrocytes.16 In addition, although we found eNOS staining in close association with the local microvasculature, it did not overlap with endothelial cells but rather with processes in contact with the abluminal side of the microvessels. These processes were immunoreactive for the glial-specific marker GFAP, likely representing astrocytic endfeet.32 This result is somewhat inconsistent with previous studies showing eNOS in brain endothelium.16 Thus, methodological dissimilarities, ...
Epilepsy, characterized by recurrent seizures, affects 1% of the general population. Interestingly, 25% of diabetics develop seizures with a yet unknown mechanism. Hyperglycemia downregulates inwardly rectifying potassium channel 4.1 (Kir4.1) in cultured astrocytes. Therefore, the present study aims to determine if downregulation of functional astrocytic Kir4.1 channels occurs in brains of type 2 diabetic mice and could influence hippocampal neuronal hyperexcitability. Using whole-cell patch clamp recording in hippocampal brain slices from male mice, we determined the electrophysiological properties of stratum radiatum astrocytes and CA1 pyramidal neurons. In diabetic mice, astrocytic Kir4.1 channels were functionally downregulated as evidenced by multiple characteristics including depolarized membrane potential, reduced barium-sensitive Kir currents and impaired potassium uptake capabilities of hippocampal astrocytes. Furthermore, CA1 pyramidal neurons from diabetic mice displayed increased spontaneous
Background Production of the chemokine CCL2 by cells of the neurovascular unit (NVU) drives critical aspects of neuroinflammation. Suppression of CCL2 therefore holds promise in treating neuroinflammatory disease. Accordingly, we sought to determine if the compound bindarit, which inhibits CCL2 synthesis, could repress the three NVU sources of CCL2 most commonly reported in neuroinflammation - astrocytes, microglia and brain microvascular endothelial cells (BMEC) - as well as modify the clinical course of neuroinflammatory disease. Methods The effect of bindarit on CCL2 expression by cultured murine astrocytes, microglia and BMEC was examined by quantitative reverse transcription polymerase chain reaction (qRTPCR). Bindarit action on mouse brain and spinal cord in vivo was similarly investigated by qRT-PCR following LPS injection in mice. And to further gauge the potential remedial effects of bindarit on neuroinflammatory disease, its impact on the clinical course of experimental autoimmune
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Anna Orr, who works in the lab of Lennart Mucke, Gladstone Institute of Neurological Disease, San Francisco, claimed that astrocytes in AD mouse models also overproduce the A2A receptor. Expressed by neurons and astroglia, the A2A receptor couples to Gs proteins that raise the levels of the second messenger cAMP in the cytosol. Previous studies suggested that A2A renders neurons more susceptibility to AD pathology, and that A2A antagonists prevented Aβ-induced cognitive deficits in mouse models of the disease (see Rahman, 2009, and DallIgna et al., 2007). However, scientists know little about how A2A expression changes in Alzheimers.. Orr and colleagues expected to find A2A in microglia, because they had previously found that these cells ramped up its expression upon inflammation (see Orr et al., 2009). To their surprise, they found that astrocytes, not microglia, tested positive for A2A in postmortem tissue from people with AD. The hippocampus expressed the receptor most strongly, and levels ...
Video articles in JoVE about neural pathways include An Introduction to Neuroanatomy, Revealing Neural Circuit Topography in Multi-Color, Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling, A Proboscis Extension Response Protocol for Investigating Behavioral Plasticity in Insects: Application to Basic, Biomedical, and Agricultural Research, The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration, Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle, Structured Motor Rehabilitation After Selective Nerve Transfers, Frame-by-Frame Video Analysis of Idiosyncratic Reach-to-Grasp Movements in Humans, Investigating the Function of Deep Cortical and Subcortical Structures Using Stereotactic Electroencephalography: Lessons from the Anterior Cingulate Cortex, Visualizing Protein Kinase A Activity
The interaction between hetero- and homosynaptic conditioning indicated that the homosynaptic PBD consists of two separable components (Figure 2). One component is shared with the tHeSD and should then be expressed as a depression of "resting Pves" and an increased PPR, possibly related to reversal of Rab3-dependent "superpriming" at high-Pr synapses. The other component is then specific for recently active synapses and seems to involve depletion of vesicles, contributing to further depression, and facilitation/augmentation, counteracting the depression.. That the conditioning burst causes depletion of vesicles available for release by the subsequent test stimulation was indicated by the analysis of the cumulative test train response (Figure 3). Another analysis, based on changes in PPR (Figure 4), supported this conclusion. This analysis was based on the premises that facilitation/augmentation is associated with decreased PPR [18] whereas depletion is associated with no, or very small, changes ...
Astrocytes are intimately related to neuronal synapses, and are increasingly implicated in neurodevelopment and disease. Our lab studies astrocyte-neuron interactions at the molecular level by identifying novel astrocyte-encoded genes and studying their functional role in circuit and synapse formation during development. The finding that astrocytes are heterogeneous based on their location in the central nervous system provides a powerful tool to begin to identify novel astrocyte-encoded genes based on regional heterogeneity, and explore their functions in the developing nervous system. Using circuits in the developing spinal cord and other CNS regions, we study the role of specific astrocyte-encoded proteins on neuronal positioning, neuronal survival, and synapse formation. We are also interested in how astrocytes communicate with microglia to regulate synapse number and circuit function throughout the lifespan, and may serve as regulators of the innate immune system in the brain. These types ...
Single computed slice through a tomographic reconstruction of the cell body of a protoplasmic astrocyte in a 0.5 um thick section from the hippocampus...
In this report, we demonstrate that MSCs migrate throughout the forebrain and cerebellum after transplantation into neonatal mouse brains. These events occur in a manner consistent with the ongoing developmental processes that occur in early postnatal life, and they suggest that MSCs mimic the behavior of neural progenitor cells. This is supported further by the finding that some MSCs differentiated into astrocytes whereas others may have differentiated into neurons, as indicated by expression of neurofilament. Therefore, MSCs can produce differentiated progeny of a different dermal origin.. We believe the most significant factor contributing to this behavior of MSCs is their exposure to the neonatal brain microenvironment. Early in postnatal life, the brain continues to undergo extensive development. For example, in forebrain, the process of gliogenesis coincides with a dramatic expansion of the subventricular zone. This germinal zone forms adjacent to the lateral ventricle during embryogenesis ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
The journal focuses on neuroimmunology and neuroinflammation, and the coverage extends to other basic and clinical studies related to neuroscience including molecular biology, psychology, pathology, physiology, endocrinology, pharmacology, oncology, etc.
The Aquaporin-4 (AQP4) water channel contributes to brain water homeostasis in perivascular astrocyte endfeet where it is concentrated. We postulated that AQP4 is tethered at this site by binding of the AQP4 C terminus to ...
Injection into the nucleus basalis of the rat of preaggregated A(1-42) produced a congophylic deposit and microglial and astrocyte activation and infiltration and caused a strong inflammatory reaction characterized by IL-1 production, increased inducible cyclooxygenase (COX-2), and inducible nitric oxide synthase (iNOS) expression. Many phospho-p38MAPK-positive cells were observed around the deposit at 7 days after A injection. Phospho-p38MAPK colocalized with activated microglial cells, but not astrocytes. The inflammatory reaction was accompanied by cholinergic hypofunction. We investigated the protective effect of the selective COX-2 inhibitor rofecoxib in attenuating the inflammatory response and neurodegeneration evoked by A(1-42). Rofecoxib (3 mg/kg/day, 7 days) reduced microglia and astrocyte activation, iNOS induction, and p38MAPK activation to control levels. Cholinergic hypofunction was also significantly attenuated by treatment with rofecoxib. We show here for the first time in vivo ...
Tumor selective targeting of SapC-DOPS-CVM in co-cultured astrocytes and tumor cells(A) Normal human astrocytes and MDA-MB-231-luc-D3H2LN co-culture. Astrocytes
Rathke-Hartlieb, S, Budde, P, Ewert, S, Schlomann, U, Staege, MS, Jockusch, Harald, Bartsch, JW, and Frey, Jürgen. 2000. "Elevated expression of membrane type I metalloproteinase (MT1-MMP) in reactive astrocytes following neurodegeneration in mouse central nervous system". FEBS LETTERS 481 (3): 227-234 ...
MG400 profile in microglia vs. astrocytes, oligodendrocytes and neurons(a) Dendogram of unsupervised hierarchical clustering (Pearson correlation; average linka
Click to launch & play an online audio visual presentation by Prof. Vladimir Parpura on Mechanisms of glutamate release from astrocytes, part of a collection of online lectures.
Genomatix Software GmbH, Munich, Germany. The chemokine RANTES is produced by a variety of cell types in response to diverse stimuli. The molecular mechanisms involved in transcriptional control of RANTES can vary significantly between the various cells that express the gene and the specific activating stimuli used. For example, T cells strongly induce RANTES "late" (i.e. 3 to 7 days) after activation through their T cell receptor. Monocytes do not upregulate RANTES in response to TNF-alpha, IL-1beta or gamma-IFN, but quickly and transiently induce RANTES following stimulation with lipopolysaccaride (LPS) (maximal expression by 6 to 9 hours. By contrast, fibroblasts and astrocytes produce RANTES in response to TNF-alpha, IL-1 beta and gamma-IFN with the initial expression seen by 6 hours and maximal expression by 48 hours. The promoter region that regulates these diverse modes of expression may act as an enhancesome. It is compact, highly conserved over evolution, and can be efficiently studied ...
Dynamic Changes of CD44 Expression from Progenitors to Subpopulations of Astrocytes and Neurons in Developing Cerebellum. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
A study from Columbia University and Harvard University has uncovered a complex interplay between neurons and support cells known as astrocytes that contributes to the pathology of ALS. Such an intricate interplay complicates regenerative therapies for this disease. In the spinal cord, a group of neurons called motor neurons extend their axons to skeletal muscles…
In new research a team at MITs Picower Institute for Learning and Memory is working to uncover the likely crucial role of a supporting cast member with a stellar-sounding name: the astrocyte. The work could ultimately provide insight into many brain disorders.
Research over the past decade has given us novel insights into the diverse roles played by astrocytes in the functioning of numerous processes within the central nervous system (CNS) that have been...
mTOR/S6 kinase pathway contributes to astrocyte survival during ischemia. - María Dolores Pastor, Isaac García-Yébenes, Noelia Fradejas, José Manuel Pérez-Ortiz, Silvia Mora-Lee, Pedro Tranque, María Angeles Moro, Mario Pende, Soledad Calvo
Glial cells are increasingly recognized as active players that profoundly influence neuronal synaptic transmission by specialized signaling (...)
A) Schematic representation of Laconic (LACtate Optical Nano-Indicator from CECs) used this study. B) Mammalian cells expressing Laconic in the cytosol. C) Modulation of the intracellular concentration of glucose by nitric oxide, an effect enhanced by low oxygen concentration. Signal detected with a fluorescent nanosensor for glucose expressed in astrocytes. Articles original image.. Astrocytes are crucial cells in the brain that are intimately coupled with neural metabolism and nitric oxide (NO), an intercellular messenger involved in multiple body functions and whose prolonged exposure, irreversibly inhibits some of these processes. However, the speed and potency of the NO metabolic effects in physiological concentrations have been incompletely characterized until now.. The team lead by Felipe Barros, set out to investigate the metabolic effects of NO in astrocytes via the utilization of the spatio-temporal high resolution provided by genetically coded optical sensors, developed at the Center ...
An electrodiffusive formalism was developed for computing the dynamics of the membrane potential and ion concentrations in the intra- and extracellular space in a one-dimensional geometry (cable). This (general) formalism was implemented in a model of astrocytes exchanging K+, Na+ and Cl- ions with the extracellular space (ECS). A limited region (0, x,l/10 where l is the astrocyte length) of the ECS was exposed to an increase in the local K+ concentration. The model is used to explore how astrocytes contribute in transporting K+ out from high-concentration regions via a mechanism known as spatial buffering, which involves local uptake from high concentration regions, intracellular transport, and release of K+ in regions with lower ECS concentrations ...
In a single set of ex periments, extracellular Ca2 was replaced with Ca2 totally free PSS to avoid influx of Ca2 as being a contributing mechan ism for alterations in i. A normal astrocytic response induced by ATP in Ca2 no cost PSS is presented in Figure 2C. It showed just one declining phase with no professional longed element of decay. The absence of the delayed phase of i in Ca2 no cost option is consistent with influx of extracellular Ca2 mediating this part of response. In 3 additional experiments, the secondary slow phase of response was absent in Ca2 totally free alternative. Total effects yielded a single time program of decay in Ca2 free of charge PSS was 28. 9 one. eight s. This decay time program was not appreciably diverse from your rapid time program of your con trol response evoked by one mM ATP.. The prolonged phase of i elicited by selleck ATP in standard PSS and its absence in Ca2 free PSS could reflect entry of Ca2 by way of SOC following the original release in the divalent ...
TY - JOUR. T1 - Glutamate transporter function of rat hippocampal astrocytes is impaired following the global ischemia. AU - Yeh, Tu Hsueh. AU - Hwang, Hwa Min. AU - Chen, Jin Jung. AU - Wu, Tony. AU - Li, Allen Hon Lun. AU - Wang, Hung Li. PY - 2005/4. Y1 - 2005/4. N2 - Astroglial glutamate transporters, GLT-1 and GLAST, play an essential role in removing released glutamate from the extracellular space and are essential for maintaining a low concentration of extracellular glutamate in the brain. It was hypothesized that impaired function of glial glutamate transporters induced by transient global ischemia may lead to an elevated level of extracellular glutamate and subsequent excitotoxic neuronal death. To test this hypothesis, in the present study, we performed whole-cell patch-clamp recording of hippocampal CA1 astrocytes in control or postischemic slices, and measured glutamate transporter activity by recording glutamate-evoked transporter currents. Six to 24 h after global ischemia, maximal ...
As a response to central nervous system injury, astrocytes become reactive. Two cellular hallmarks of reactive gliosis are hypertrophy of astrocyte processes and upregulation of intermediate filament (nanofilament) proteins glial fibrillary acidic protein (GFAP), vimentin, nestin, and synemin. Astrocytes in mice devoid of GFAP and vimentin (GFAP (-/-) Vim (-/-)) do not form cytoplasmic intermediate filaments. GFAP (-/-) Vim (-/-) mice develop larger infarcts after ischemic stroke (Li et al. in J Cereb Blood Flow Metab 28(3):468-481, 2008). Here, we attempted to analyze the underlying mechanisms using oxygen-glucose deprivation (OGD), an in vitro ischemia model, examining a potential link between astrocyte intermediate filaments and reactive oxygen species (ROS). We observed a reorganization of the intermediate filament network in astrocytes exposed to OGD. ROS accumulation was higher in GFAP (-/-) Vim (-/-) than wild-type astrocytes when exposed to OGD followed by reperfusion or when exposed to ...
This study aims to investigate the roles of the Notch-Hes1 pathway in the advanced glycation end product (AGE)-mediated differentiation of neural stem cells (NSCs). We prepared pLentiLox3.7 lentiviral vectors that express short hairpin RNA (shRNA) against Notch1 and transfected it into NSCs. Cell differentiation was analyzed under confocal laser-scanning microscopy. The percentage of neurons and astrocytes was quantified by normalizing the total number of TUJ1+ (Neuron-specific class III β-tubulin) and GFAP+ (Glial fibrillary acidic protein) cells to the total number of Hoechst 33342-labeled cell nuclei. The protein and gene expression of Notch-Hes1 pathway components was examined via western blot analysis and real-time PCR. After 1 week of incubation, we found that AGE-bovine serum albumin (BSA) (400 μg/mL) induced the astrocytic differentiation of cultured neurospheres and inhibited neuronal formation. The expression of Notch-Hes1 pathway components was upregulated in the cells in the AGE-BSA
Canine distemper virus (CDV) causes a fatal demyelinating leukoencephalitis in young dogs resembling human multiple sclerosis. Astrocytes are the main cellular target of CDV and undergo reactive changes already in pre-demyelinating brain lesions. Based on their broad range of beneficial and detrimental effects in the injured brain reactive astrogliosis is in need of intensive investigation. The aim of the study was to characterize astrocyte plasticity during the course of CDV-induced demyelinating leukoencephalitis by the aid of immunohistochemistry, immunofluorescence and gene expression analysis. Immunohistochemistry revealed the presence of reactive glial fibrillary acidic protein (GFAP)+ astrocytes with increased survivin and reduced aquaporin 4, and glutamine synthetase protein levels, indicating disturbed blood brain barrier function, glutamate homeostasis and astrocyte maladaptation, respectively. Gene expression analysis revealed 81 differentially expressed astrocyte-related genes with a
Astrocytes extend highly branched processes that form functionally isolated microdomains, facilitating local homeostasis by redistributing ions, removing neurotransmitters, and releasing factors to influence blood flow and neuronal activity. Microdomains exhibit spontaneous increases in calcium (Ca2+), but the mechanisms and functional significance of this localized signaling are unknown. By developing conditional, membrane-anchored GCaMP3 mice, we found that microdomain activity that occurs in the absence of inositol triphosphate (IP3)-dependent release from endoplasmic reticulum arises through Ca2+ efflux from mitochondria during brief openings of the mitochondrial permeability transition pore. These microdomain Ca2+ transients were facilitated by the production of reactive oxygen species during oxidative phosphorylation and were enhanced by expression of a mutant form of superoxide dismutase 1 (SOD1 G93A) that causes astrocyte dysfunction and neurodegeneration in amyotrophic lateral sclerosis ...
Abstract: Treatment of rat cerebellar astrocyte-enriched primary cultures with dexamethasone enhances the nitric oxide-dependent cyclic GMP formation induced by noradrenaline in a time-(,6 h) and concentration-dependent manner (half-maximal effect at 1 nM). Stimulation of cyclic GMP formation by the calcium ionophore A23187 is similarly enhanced. In contrast, cyclic GMP accumulation in cells treated with lipopolysaccharide is inhibited by dexamethasone. The potentiating effect of dexamethasone is prevented by the protein synthesis inhibitor cycloheximide and is not due to increased soluble guanylate cyclase activity. Agonist stimulation of [3H]arginine to [3H]citrulline conversion is enhanced by dexamethasone in astrocytes but not in cerebellar granule cells. These results indicate that glucocorticoids may up-regulate astroglial calcium-dependent nitric oxide synthase while preventing expression of inducible nitric oxide synthase and are the first report of a differential long-term regulation of ...
Astrocytes are the site of early dysfunction and damage in Mn neurotoxicity. Astrocytes are the most abundant CNS cells (~50% by volume), and they perform numerous essential functions for normal neuronal activity, such as glutamate uptake, glutamine release, K+ and H+ buffering and volume regulation [36, 75, 76]. Astrocytes accumulate up to 50-fold higher Mn concentrations compared to neurons, thus serving as the main homeostatic and storage site for this metal [75, 77]. The intracellular concentration of Mn in astrocytes is ~50-75 μM where it is an essential cofactor for the astrocyte-specific enzyme glutamine synthetase, which catalyzes the conversion of glutamate to glutamine [78, 79]. The excessive accumulation of Mn in astrocytes mediates neurotoxicity primarily by oxidative stress and impairment of glutamate transporters [80, 81]. Mn toxicity has been shown to cause astrocytic alterations in primate models, and exposure of pathophysiologically relevant Mn concentrations in astrocytes in ...
TY - JOUR. T1 - Testosterone treatment attenuates the effects of facial nerve transection on glial fibrillary acidic protein (GFAP) levels in the hamster facial motor nucleus. AU - Coers, Susanna. AU - Tanzer, Lisa. AU - Jones, Kathryn. PY - 2002. Y1 - 2002. N2 - Testosterone propionate (TP) administration coincident with facial nerve injury accelerates the recovery rate from facial muscle paralysis in the hamster. One mechanism by which TP could augment peripheral nerve regeneration is through glial fibrillary acidic protein (GFAP) regulation in the facial motor nucleus. In a previous study, axotomy alone induces increases in GFAP mRNA, with TP significantly attenuating the axotomy-induced increases in GFAP mRNA. In the present study, immunoblotting techniques were used to extend our previous GFAP mRNA studies to the protein level. Castrated male hamsters were subjected to a right facial nerve transection, with half of the animals receiving subcutaneous implants of 100% crystalline TP. The left ...
TY - JOUR. T1 - αB-crystallin and 27-kd heat shock protein are regulated by stress conditions in the central nervous system and accumulate in Rosenthal fibers. AU - Iwaki, T.. AU - Iwaki, A.. AU - Tateishi, J.. AU - Sakaki, Y.. AU - Goldman, J. E.. PY - 1993/12/1. Y1 - 1993/12/1. N2 - To understand the significance of the accumulation of αB-crystallin in Rosenthal fibers within astrocytes, the expression and metabolism of αB- crystallin in glioma cell lines were examined under the conditions of heat and oxidative stress, αB-crystallin mRNA was increased after both stresses, and αB-crystallin protein moved from a detergent-soluble form. In addition, Western blotting of Alexanders disease brain homogenates revealed that the 27-kd heat shock protein (HSP27), which is related to αB-crystallin, accumulates along with αB-crystallin. The presence of HSP27 in Rosenthal fibers was directly demonstrated by immunohistochemistry. Our results suggest that astrocytes in Alexanders disease may be ...

Binding and Uptake of A beta 1-42 by Primary Human Astrocytes In VitroBinding and Uptake of A beta 1-42 by Primary Human Astrocytes In Vitro

Thus, primary human astrocytes derived from different sources can bind and internalize A beta 1-42, and fetal astrocytes were ... Thus, primary human astrocytes derived from different sources can bind and internalize A beta 1-42, and fetal astrocytes were ... In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta ... In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta ...
more infohttps://lup.lub.lu.se/search/publication/1443637

Infection of primary human fetal astrocytes by human herpesvirus 6<...Infection of primary human fetal astrocytes by human herpesvirus 6<...

Jun HE, McCarthy M, Zhou YI, Chandran B, Wood C. Infection of primary human fetal astrocytes by human herpesvirus 6. Journal of ... Jun, H. E., McCarthy, M., Zhou, Y. I., Chandran, B., & Wood, C. (1996). Infection of primary human fetal astrocytes by human ... Infection of primary human fetal astrocytes by human herpesvirus 6. H. E. Jun, Micheline McCarthy, Y. I. Zhou, Bala Chandran, ... Jun, HE, McCarthy, M, Zhou, YI, Chandran, B & Wood, C 1996, Infection of primary human fetal astrocytes by human herpesvirus 6 ...
more infohttps://miami.pure.elsevier.com/en/publications/infection-of-primary-human-fetal-astrocytes-by-human-herpesvirus-

Glutamate transporter function of rat hippocampal astrocytes is impaired following the global ischemia<...Glutamate transporter function of rat hippocampal astrocytes is impaired following the global ischemia<...

Yeh, TH, Hwang, HM, Chen, JJ, Wu, T, Li, AHL & Wang, HL 2005, Glutamate transporter function of rat hippocampal astrocytes is ... Glutamate transporter function of rat hippocampal astrocytes is impaired following the global ischemia. / Yeh, Tu Hsueh; Hwang ... To test this hypothesis, in the present study, we performed whole-cell patch-clamp recording of hippocampal CA1 astrocytes in ... To test this hypothesis, in the present study, we performed whole-cell patch-clamp recording of hippocampal CA1 astrocytes in ...
more infohttps://tmu.pure.elsevier.com/en/publications/glutamate-transporter-function-of-rat-hippocampal-astrocytes-is-i

Intermediate filaments of zebrafish retinal and optic nerve astrocytes and Müller glia: differential distribution of...Intermediate filaments of zebrafish retinal and optic nerve astrocytes and Müller glia: differential distribution of...

Studies of astrocyte function during ONR in zebrafish cannot solely rely on GFAP as an astrocyte marker or indicator of ... studies of the role astrocytes may play during ONR in zebrafish cannot rely on GFAP as an marker for astrocytes or an indicator ... Cytokeratin labeling of astrocytes was observed throughout the optic nerve and less intensely in cells in the retinal inner ... As part of an ongoing study of ONR in zebrafish [5], we examined intermediate filament (IF) expression of astrocytes in the ...
more infohttps://bmcresnotes.biomedcentral.com/articles/10.1186/1756-0500-3-50

Intermediate filaments are important for astrocyte response to oxidative stress induced by oxygen-glucose deprivation and...Intermediate filaments are important for astrocyte response to oxidative stress induced by oxygen-glucose deprivation and...

Compared to wild-type astrocytes, GFAP (-/-) Vim (-/-) astrocytes exposed to OGD and reperfusion exhibited increased cell death ... Astrocytes in mice devoid of GFAP and vimentin (GFAP (-/-) Vim (-/-)) do not form cytoplasmic intermediate filaments. GFAP ... ROS accumulation was higher in GFAP (-/-) Vim (-/-) than wild-type astrocytes when exposed to OGD followed by reperfusion or ... We conclude that the astrocyte intermediate filament system is important for the cell response to oxidative stress induced by ...
more infohttps://scholars.latrobe.edu.au/display/publication452121

101555 | Dayton Childrens101555 | Dayton Children's

Astrocytes are the most common type of cell in the central nervous system. They perform many essential roles and make up the ... An astrocytoma (as-troh-sy-TOE-muh) is a brain tumor that originates from a star-shaped brain cell known as an astrocyte. ... When there is a defect in an astrocyte that causes it to grow out of control, the brain tumor that forms is called an ...
more infohttps://www.childrensdayton.org/kidshealth/a/101555

Astrocyte - WikipediaAstrocyte - Wikipedia

After astrocyte specification has occurred in the developing CNS, it is believed that astrocyte precursors migrate to their ... When in proximity to the pia mater, all three forms of astrocytes send out processes to form the pia-glial membrane. Astrocytes ... Gömöri-positive astrocytes. These are a subset of protoplasmic astrocytes that contain numerous cytoplasmic inclusions, or ... Because of this ability of astrocytes to communicate with their neighbors, changes in the activity of one astrocyte can have ...
more infohttps://en.wikipedia.org/wiki/Astrocyte

Alzheimer type II astrocyte - WikipediaAlzheimer type II astrocyte - Wikipedia

Although these astrocytes are present in this disease, it has not yet been determined if Alzheimer type II astrocytes are a ... Like other astrocytes, it is a non-neuronal glial cell. They are not associated with Alzheimers disease. Astrocytes belong to ... Alzheimer type II astrocytes are visually characterized by an enlarged size and lack of cytoplasm. These astrocytes appear to ... For example, astrocytes have many transporters and ion channels that allow for ion balance and static pH levels in order to ...
more infohttps://en.wikipedia.org/wiki/Alzheimer_type_II_astrocyte

Astrocyte - WikipediaAstrocyte - Wikipedia

The astrocytes next to neurons in the frontal cortex and hippocampus store and release glucose. Thus, astrocytes can fuel ... Astrocytes are depicted in red. Cell nuclei are depicted in blue. Astrocytes were obtained from brains of newborn mice ... Astrocytes are macroglial cells in the central nervous system. Astrocytes are derived from heterogeneous populations of ... Gömöri-positive astrocytes. These are a subset of protoplasmic astrocytes that contain numerous cytoplasmic inclusions, or ...
more infohttps://en.wikipedia.org/wiki/Astrocytes

Lifeboat Foundation News Blog: AstrocytesLifeboat Foundation News Blog: Astrocytes

Archive for the Astrocytes tag. Jun 26, 2018. Experimental Drug Injection Causes the Brain to Grow New Neurons Posted by ... What this cocktail does when injected into the brain is it hijacks the astrocytes into behaving like new neurons. This is ... Tags: Alzheimers Disease, Astrocytes, Brain, Brain Damage, cognitive, Cognitive Function, Experimental Drug, health, ... Another important detail is that there are 10 times more astrocytes in the brain than neurons. That means that there are 1 ...
more infohttps://lifeboat.com/blog/tag/astrocytes

Direct Reprogramming of RESTing Astrocytes.  - PubMed - NCBIDirect Reprogramming of RESTing Astrocytes. - PubMed - NCBI

Direct Reprogramming of RESTing Astrocytes.. Wang C1, Fong H1, Huang Y2. ... Transcriptional Mechanisms of Proneural Factors and REST in Regulating Neuronal Reprogramming of Astrocytes. [Cell Stem Cell. ... 2015) use neuronal conversion of astrocytes to dissect transcriptional mechanisms of fate determination and identify circuits ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/26140600

Metabolic Interactions between Neurons and Astrocytes | SpringerLinkMetabolic Interactions between Neurons and Astrocytes | SpringerLink

Hertz, L. and Schousboe, A., Role of astrocytes in compartmentation of amino acid and energy metabolism. In:Astrocytes, ... Walz, W. and Hinks, E., A transmembrane sodium cycle in astrocytes, Brain Res. 368: 226-232 (1986).PubMedCrossRefGoogle Scholar ... Code, W.E., White, H.S. and Hertz, L., The effect of midazolam on calcium signaling in astrocytes, Ann. N.Y. Acad. Sci. 625: ... Yu, A.C.H., Gregory, G.A. and Chan, P.H., Hypoxia-induced dysfunction and injury of astrocytes in primary cell cultures, J. ...
more infohttps://link.springer.com/chapter/10.1007/978-1-4757-9486-1_1

Astrocytes Control Appetite | Science SignalingAstrocytes Control Appetite | Science Signaling

Astrocytes respond to a hormone that signals satiety to control synaptic plasticity of neurons that regulate eating. ... Astrocytes respond to a hormone that signals satiety to control synaptic plasticity of neurons that regulate eating. ... Thus, leptin signaling in astrocytes in the region of the brain that controls appetite is necessary for the neuronal response ... created mice with knockout of the leptin receptor in astrocytes of adults and investigated the effects in the hypothalamic ...
more infohttps://stke.sciencemag.org/content/7/333/ec186

Astrocytes and Vasculature - WebvisionAstrocytes and Vasculature - Webvision

Astrocytes and Vasculature. This laser confocal image shows a GFP transgenic mouse retina under the control of the GFAP ... These labels not only show the spatial relationship of individual astrocytes to one another, but also the vasculature. Image ...
more infohttps://webvision.med.utah.edu/2012/07/astrocytes-and-vasculature/

Why are Astrocytes Important? | SpringerLinkWhy are Astrocytes Important? | SpringerLink

Astrocytes, which populate the grey and white mater of the brain and the spinal cord are highly heterogeneous in their ... Astrocytes Glutamate Astroglial cradle Glymphatic system Astrogliopathology Neurological disorders Special Issue: In honor of ... Astrocytes, which populate the grey and white mater of the brain and the spinal cord are highly heterogeneous in their ... Hazell AS (2009) Astrocytes are a major target in thiamine deficiency and Wernickes encephalopathy. Neurochem Int 55:129-135 ...
more infohttps://link.springer.com/article/10.1007%2Fs11064-014-1403-2

Heterogeneity of reactive astrocytesHeterogeneity of reactive astrocytes

Astrocytes respond to injury and disease in the central nervous system (CNS) with a process referred to as reactive astrogl … ... Astrocytes respond to injury and disease in the central nervous system (CNS) with a process referred to as reactive ... It is noteworthy that different stimuli of astrocyte reactivity can lead to similar degrees of GFAP upregulation while causing ... Structural and functional changes are regulated in reactive astrocytes by many different potential signaling events that occur ...
more infohttps://www.wingsforlife.com/de/aktuelles/heterogeneity-of-reactive-astrocytes-1072/

astrocyte | Journal of Neuroscienceastrocyte | Journal of Neuroscience

Astrocytes Regulate GLP-1 Receptor-Mediated Effects on Energy Balance David J. Reiner, Elizabeth G. Mietlicki-Baase, Lauren E. ... Dysfunctional Calcium and Glutamate Signaling in Striatal Astrocytes from Huntingtons Disease Model Mice Ruotian Jiang, Blanca ... FGF-1 Triggers Pannexin-1 Hemichannel Opening in Spinal Astrocytes of Rodents and Promotes Inflammatory Responses in Acute ...
more infohttps://www.jneurosci.org/keyword/astrocyte?page=2

Astrocytes going live: advances and challenges.  - PubMed - NCBIAstrocytes going live: advances and challenges. - PubMed - NCBI

A, two-photon fluorescence image of astrocytes (green) and blood vessels (red) in rat neocortex, stained using the astrocyte- ... Astrocytes going live: advances and challenges.. Nimmerjahn A1.. Author information. 1. Department of Biology, James H. Clark ... C and D, spontaneous calcium transients in two astrocytes (C) and one neuron (D) from a single recording measured as relative ... Astrocytes are one of the most numerous cell types in the CNS. They have emerged as sophisticated cells participating in a ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/19204050?dopt=Abstract

Astrocytes help separate man from mouseAstrocytes help separate man from mouse

... fibrous astrocytes »human brain »information processing »interlaminar astrocytes »protoplasmic astrocytes »spinal cord injury » ... fibrous astrocytes , human brain , information processing , interlaminar astrocytes , protoplasmic astrocytes , spinal cord ... Alzheimers »Calcium »Epilepsy »Human astrocytes »astrocytes »blood flow »blood vessel »brain cell »brain function and sensory ... Further reports about: , Alzheimers , Calcium , Epilepsy , Human astrocytes , astrocytes , blood flow , blood vessel , brain ...
more infohttp://www.innovations-report.com/html/reports/life-sciences/astrocytes-separate-man-mouse-129901.html

A role for astrocytes in learning and memory?A role for astrocytes in learning and memory?

Astrocytes, once thought little more than passive, structurally supportive brain cells, are increasingly recognized as having a ... have found that individual star-shaped glial cells called astrocytes release a specific signalling molecule, called D-serine, ... Long-term potentiation depends on release of D-serine from astrocytes. Nature ( doi:10.1038/nature08673).. ...
more infohttp://www.ucl.ac.uk/ion/articles/archive-2010/Rusakov

Astrocyte-Synapse Structural PlasticityAstrocyte-Synapse Structural Plasticity

... Yann Bernardinelli, Dominique Muller, and Irina Nikonenko Department of Neuroscience, ... Yann Bernardinelli, Dominique Muller, and Irina Nikonenko, "Astrocyte-Synapse Structural Plasticity," Neural Plasticity, vol. ...
more infohttps://www.hindawi.com/journals/np/2014/232105/cta/

Relaxin Protects Astrocytes from Hypoxia In VitroRelaxin Protects Astrocytes from Hypoxia In Vitro

Astrocytes that were treated with relaxin-2 and relaxin-3 showed a marked decrease in ROS production when compared to control ... Next, to test whether relaxin reduced the production of reactive oxygen species (ROS) astrocytes were exposed to the same ... Mitochondrial membrane potential was higher in astrocytes that were treated with relaxin-2 and relaxin-3 compared to untreated ... Taken together, these data present novel findings that show relaxin protects astrocytes from ischemic conditions through the ...
more infohttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0090864

Astrocyte - WikipediaAstrocyte - Wikipedia

The astrocytes next to neurons in the frontal cortex and hippocampus store and release glucose. Thus, astrocytes can fuel ... Astrocytes are depicted in red. Cell nuclei are depicted in blue. Astrocytes were obtained from brains of newborn mice ... Astrocytes are macroglial cells in the central nervous system. Astrocytes are derived from heterogeneous populations of ... Gömöri-positive astrocytes. These are a subset of protoplasmic astrocytes that contain numerous cytoplasmic inclusions, or ...
more infohttps://en.m.wikipedia.org/wiki/Astroglial_cell

Astrocytes: Wiring the Brain, 1st Edition (Paperback) - RoutledgeAstrocytes: Wiring the Brain, 1st Edition (Paperback) - Routledge

... and the connections that the astrocyte makes with other cells of the brain are essential for a variety of important neural ... Astrocytes play diverse roles in central nervous system (CNS) function and dysfunction, ... Astrocytes in Epilepsy; C. Steinhäuser and G. Seifert. Astrocyte Involvement in the Acquired Demyelinating Diseases; S. E. Lutz ... Astrocytes play diverse roles in central nervous system (CNS) function and dysfunction, and the connections that the astrocyte ...
more infohttps://www.routledge.com/Astrocytes-Wiring-the-Brain-1st-Edition/Scemes-Spray/p/book/9781138374300

astrocyte | Definition, Function, & Facts | Britannica.comastrocyte | Definition, Function, & Facts | Britannica.com

Astrocytes can be subdivided into fibrous and protoplasmic types. Learn more about astrocytes, including their structure and ... Astrocyte, star-shaped cell that is a type of neuroglia found in the nervous system in both invertebrates and vertebrates. ... Unlike fibrous astrocytes, protoplasmic astrocytes occur in the gray matter of the central nervous system. They have fewer ... Astrocytes divide after injury to the nervous system and occupy the spaces left by injured neurons. Astrocytes also are thought ...
more infohttps://www.britannica.com/science/astrocyte
  • In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta clearance is sparse. (lu.se)
  • Therefore, by means of flow cytometry and confocal laser scanning microscopy (CLSM), we evaluated the binding and internalization of A beta 1-42 by primary human fetal astrocytes and adult astrocytes, isolated from nondemented subjects (n = 8) and AD subjects (n = 6). (lu.se)
  • Upon over night exposure of astrocytes to FAM-labeled A beta 1-42 (10 mu M) preparations, (80.7 +/- 17.7)% fetal and (52.9 +/- 20.9)% adult A beta-positive astrocytes (P = 0.018) were observed. (lu.se)
  • Thus, primary human astrocytes derived from different sources can bind and internalize A beta 1-42, and fetal astrocytes were more efficient in A beta 1-42 uptake than adult astrocytes. (lu.se)
  • Furthermore, we analyzed whether alpha 1-antichymotrypsin (ACT), which is found in amyloid plaques and can influence A beta fibrillogenesis, affects the A beta uptake by human astrocytes. (lu.se)
  • No significant difference was found in A beta 1-42 uptake between AD and non-AD astrocytes, and no influence of ApoE genotype on A beta 1-42 uptake was observed in any group. (lu.se)
  • Under these conditions, there was no increase in cellular release of the proinflammatory chemokine monocyte-chemoattractant protein 1, as compared with nontreated control astrocytes. (lu.se)
  • There is now compelling evidence that reactive astrocytes exhibit a substantial potential for heterogeneity at multiple levels, including gene expression, cell morphology, topography (distance from lesions), CNS regions, local (among neighboring cells), cell signaling and cell function. (wingsforlife.com)
  • Structural and functional changes are regulated in reactive astrocytes by many different potential signaling events that occur in a context dependent manner. (wingsforlife.com)
  • The resulting expression profile overlapped with that of reactive astrocytes, although the magnitude of the changes was smaller in the aged astrocytes. (alzforum.org)
  • Platelet-derived growth factor stimulated synthesis of TSP in a human glial cell line ( 28 ) and transforming growth factor-β1 induced TSP-1 mRNA in astrocytes ( 29 ), but the potential role of extracellular ATP and P2 receptor signaling in TSP-1 expression and release in astrocytes has not been investigated. (pnas.org)
  • In this study, we show that extracellular ATP, through the activation of P2Y 4 receptors, stimulates TSP-1 expression and release in astrocytes and that this nucleotide-induced increase is mediated by protein kinase signaling pathways. (pnas.org)
  • For example, astrocytes have many transporters and ion channels that allow for ion balance and static pH levels in order to achieve homeostasis. (wikipedia.org)
  • Recent evidence has shifted the focus on astrocytes from primarily a passive role involved in homeostasis to a more active role in a number of key physiological and pathological interactions with neurons ( 1 - 4 ). (pnas.org)
  • Astrocyte involvement in neuron homeostasis may also extend to trophic support ( 8 ), antioxidant functions, and production of critical substrates for neuron membrane synthesis. (pnas.org)
  • The aim of the study was to characterize astrocyte plasticity during the course of CDV-induced demyelinating leukoencephalitis by the aid of immunohistochemistry, immunofluorescence and gene expression analysis. (nature.com)
  • However, the functional relevance of astrocyte plasticity in canine distemper remains to be determined. (nature.com)
  • The astrocyte represents the most abundant yet least understood cell type of the CNS. (pnas.org)
  • Within the CNS astrocytes are the most abundant cell type. (nature.com)
  • Studies carried out by Hochstim and colleagues have demonstrated that three distinct populations of astrocytes arise from the p1, p2 and p3 domains. (wikipedia.org)
  • The three populations of astrocyte subtypes which have been identified are 1) dorsally located VA1 astrocytes, derived from p1 domain, express PAX6 and reelin 2) ventrally located VA3 astrocytes, derived from p3, express NKX6.1 and SLIT1 and 3) and intermediate white-matter located VA2 astrocyte, derived from the p2 domain, which express PAX6, NKX6.1, reelin and SLIT1. (wikipedia.org)
  • This suggests that manganism, a neurological disorder with Parkinson's-like symptoms, is caused by the development of these astrocytes through manganese poisoning. (wikipedia.org)
  • Given that we found diverse astrocyte subpopulations, we wondered whether these subpopulations could also explain astrocyte contributions to a host of different neurological diseases," Deneen said. (medindia.net)
  • Astrocyte expression of mRNA encoding cytokines IP-10 and JE/MCP-1 in experimental autoimmune encephalomyelitis," FASEB Journal , vol. 7, no. 6, pp. 592-600, 1993. (hindawi.com)
  • The main processes exit the cell in a radial direction (hence the name astrocyte , meaning "star-shaped cell"), forming expansions and end feet at the surfaces of vascular capillaries . (britannica.com)
  • Experiments with mice have shown that exposure to manganese leads to the development of Alzheimer's type II astrocytes. (wikipedia.org)
  • The hope is that the cocktail will cause the astrocytes to behave as neurons and help the mice recover. (lifeboat.com)
  • created mice with knockout of the leptin receptor in astrocytes of adults and investigated the effects in the hypothalamic circuits involved in the regulation of eating and compared them with control mice. (sciencemag.org)
  • Coverage and direct contacts between the astrocytes and neurons in the hypothalamus of the knockout mice, including the POMC and AgRP neurons involved in the regulation of feeding, were reduced. (sciencemag.org)
  • In mice genetically engineered to carry human stuttering mutations, vocalization defects are derived from abnormalities in astrocytes in the corpus callosum. (neurosciencenews.com)
  • In this study, we have defined the mature astrocyte on the molecular level through an exhaustive and integrated transcriptional analysis of many distinct astrocyte-rich cultures and CNS tissues by using standard and nonstandard bioinformatic approaches. (pnas.org)
  • These subtypes of astrocytes can be identified on the basis of their expression of different transcription factors (PAX6, NKX6.1) and cell surface markers (reelin and SLIT1). (wikipedia.org)
  • Instead, it is necessary to recognize the considerable potential for heterogeneity and determine the functional implications of astrocyte reactivity in a context specific manner as regulated by specific signaling events. (wingsforlife.com)
  • This review will summarize some of their most intriguing findings, discuss some of their implications, and look ahead at some of the challenges we face in studying astrocyte function in vivo. (nih.gov)
  • This has big implications for how our brains process information," said first author Nancy Ann Oberheim, Ph.D., a medical student who recently completed her doctoral thesis on astrocytes. (innovations-report.com)
  • After astrocyte specification has occurred in the developing CNS, it is believed that astrocyte precursors migrate to their final positions within the nervous system before the process of terminal differentiation occurs. (wikipedia.org)
  • Astrocytes respond to injury and disease in the central nervous system (CNS) with a process referred to as reactive astrogliosis. (wingsforlife.com)
  • Astrocytes divide after injury to the nervous system and occupy the spaces left by injured neurons. (britannica.com)
  • If our central nervous system were a city, then some astrocytes work in the public water department. (study.com)
  • So astrocytes store and release sources of nutrition for the nervous system, especially when the city is starving, so to speak. (study.com)
  • Other functions attributed to astrocytes include the repair of the nervous system and general structural support for the nervous system. (study.com)
  • Alzheimer type II astrocytes are visually characterized by an enlarged size and lack of cytoplasm. (wikipedia.org)
  • Gene expression analysis revealed 81 differentially expressed astrocyte-related genes with a dominance of genes associated with neurotoxic A1-polarized astrocytes. (nature.com)
  • Further studies showed that each subpopulation of astrocytes expressed distinct sets of genes. (medindia.net)
  • Shiga toxin 1-induced inflammatory response in lipopolysaccharide-sensitized astrocytes is mediated by endogenous tumor necrosis factor alpha," Infection and Immunity , vol. 78, no. 3, pp. 1193-1201, 2010. (hindawi.com)
  • Her team has discovered what might be called the secret lives of astrocytes and has made a series of startling discoveries. (innovations-report.com)
  • Observed findings indicate an astrocyte polarization towards a neurotoxic phenotype likely contributing to lesion initiation and progression in canine distemper leukoencephalitis. (nature.com)
  • If astrocytes were important, scientists thought, it was most likely because they help create a healthy environment for the neurons. (innovations-report.com)
  • Rather than realizing their tools were incomplete, scientists assumed that astrocytes were silent. (innovations-report.com)
  • Astrocytes, in contrast, send slower signals whose function is still being worked out by scientists. (innovations-report.com)
  • As if that weren't enough, scientists described an instance where astrocytes made the ultimate sacrifice: by leaving their identity behind and becoming something else entirely. (alzforum.org)
  • Astrocytes express both P2Y and P2X receptors ( 13 - 18 ), and these receptors are coupled to protein kinase cascades, including mitogen-activated protein kinases (MAPKs) and protein kinase B/Akt ( 14 , 15 , 19 , 20 ), that mediate gene expression ( 21 , 22 ). (pnas.org)