1
|
Xue YJ, Cui SS, Guo DC, Liu JS, Yang MF, Kang HT, Jiang Q, Qu LD. Development of a method for the isolation and culture of astrocytes from the canine cerebral cortex. J Neurosci Methods 2022; 370:109476. [PMID: 35007653 DOI: 10.1016/j.jneumeth.2022.109476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Astrocytes are considered key players in neuroimmunopathological processes, and they play a certain role in neuroinflammation. Rodent primary astrocyte cultures are commonly used in the study of human neuroinflammation. However, gene sequence homologies are closer between humans and dogs than between humans and rodents. NEW METHOD We established protocols to isolate astrocytes from the canine forebrain. Cerebral hemispheres of 3-4-week-old dogs were used. The isolation procedure included the use of the Neural Tissue Dissociation Kit P, demyelination by the magnetic bead method, and separation and preparation by differential adhesion. RESULTS We found a 96% astrocyte purification rate after isolation by differential adhesion. Purified canine astrocytes increased the secretion of interleukin-1β, interleukin-6, and tumor necrosis factor-alpha, and increased the expression of glial fibrillary acidic protein after lipopolysaccharide stimulation. We sequenced the transcriptome of the purified canine astrocytes and analyzed the differentially expressed genes among the rodent, human, and canine astrocytes. Transcriptome profiling and gene ontology analysis of the genes co-expressed in humans and canines indicate that human and canine astrocytes may be different from their rodent counterparts in terms of mediated interactions with metals. COMPARED WITH THE EXISTING METHODS The cells prepared by our method allow for the rapid separation of astrocytes with a relatively small resource scheme. The method also retains the cell phenotype and has an in vitro culture lifetime of approximately 2 to 3 months. CONCLUSION We established a method for preparing canine astrocytes with high purity, which can be used to study the biological function of astrocytes in vitro.
Collapse
Affiliation(s)
- Yu-Jia Xue
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Sai-Sai Cui
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Dong-Chun Guo
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Jia-Sen Liu
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Ming-Fa Yang
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Hong-Tao Kang
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China
| | - Qian Jiang
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China.
| | - Lian-Dong Qu
- Division of Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678 Haping Road, Xiangfang District, Harbin, Heilongjiang 150069, China.
| |
Collapse
|
2
|
Shan L, Zhang T, Fan K, Cai W, Liu H. Astrocyte-Neuron Signaling in Synaptogenesis. Front Cell Dev Biol 2021; 9:680301. [PMID: 34277621 PMCID: PMC8284252 DOI: 10.3389/fcell.2021.680301] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 06/14/2021] [Indexed: 01/10/2023] Open
Abstract
Astrocytes are the key component of the central nervous system (CNS), serving as pivotal regulators of neuronal synapse formation and maturation through their ability to dynamically and bidirectionally communicate with synapses throughout life. In the past 20 years, numerous astrocyte-derived molecules promoting synaptogenesis have been discovered. However, our understanding of the cell biological basis underlying intra-neuron processes and astrocyte-mediated synaptogenesis is still in its infancy. Here, we provide a comprehensive overview of the various ways astrocytes talk to neurons, and highlight astrocytes’ heterogeneity that allow them to displays regional-specific capabilities in boosting synaptogenesis. Finally, we conclude with promises and future directions on how organoids generated from human induced pluripotent stem cells (hiPSCs) effectively address the signaling pathways astrocytes employ in synaptic development.
Collapse
Affiliation(s)
- Lili Shan
- Guangzhou Laboratory, Guangzhou, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Tongran Zhang
- Guangzhou Laboratory, Guangzhou, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Kevin Fan
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States
| | - Weibo Cai
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States
| | - Huisheng Liu
- Guangzhou Laboratory, Guangzhou, China.,Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| |
Collapse
|
3
|
Testen A, Sepulveda-Orengo MT, Gaines CH, Reissner KJ. Region-Specific Reductions in Morphometric Properties and Synaptic Colocalization of Astrocytes Following Cocaine Self-Administration and Extinction. Front Cell Neurosci 2018; 12:246. [PMID: 30147645 PMCID: PMC6096402 DOI: 10.3389/fncel.2018.00246] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 07/18/2018] [Indexed: 12/23/2022] Open
Abstract
While much is known about the effects of cocaine use on the cellular structure and function of neurons and synapses within the brain’s reward circuitry, relatively little is known about the effects of cocaine on astrocytes. Given the significant role that astrocytes play in modulating neuronal and synaptic function, this lack of knowledge regarding the role of astroglial adaptations in the neuropathology of drug abuse represents an important investigative need. We recently showed that astrocytes within the nucleus accumbens (NAc) core exhibit decreased volume, surface area, and synaptic colocalization following cocaine self-administration and extinction, compared to NAc astrocytes from saline-administering animals (Scofield et al., 2016b). However, it is unknown whether these cocaine-dependent changes in astrocytes are ubiquitous throughout the brain’s reward circuitry, or represent specific adaptations within the NAc. It is also not known whether the extinction period is necessary for the retracted phenotype, or whether self-administration alone is sufficient to drive these changes. In the current study, we have extended our assessment of the effects of cocaine self-administration on morphometric properties and synaptic colocalization of astrocyte peripheral processes in the prelimbic region of the medial prefrontal cortex (PL) and basolateral nucleus of the amygdala (BLA), both known to also contribute significantly to motivated behaviors. In addition, in order to pinpoint the temporal dimension of previously observed effects, we also examined astrocytes within the NAc following the last self-administration session. While a reduction of astrocyte size and synaptic colocalization was observed in the NAc core of cocaine-extinguished rats as previously shown, no differences in PL or BLA astrocytes were observed between saline- and cocaine-extinguished rats. Moreover, decreased synaptic colocalization of peripheral processes in the NAc was observed with a post-synaptic marker, instead of a presynaptic marker as used previously. In contrast, no significant changes were found in NAc astrocytes after self-administration alone. These results provide insights into the influence of cocaine use on astrocytes within the brain reward circuitry, and inform both regional heterogeneity as well as temporal dynamics of astrocyte responsiveness to cocaine self-administration.
Collapse
Affiliation(s)
- Anze Testen
- Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Marian T Sepulveda-Orengo
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Christiann H Gaines
- Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kathryn J Reissner
- Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| |
Collapse
|
4
|
Cho CH. Commentary: Identification of diverse astrocyte populations and their malignant analogs. Front Mol Neurosci 2017; 10:193. [PMID: 28659761 PMCID: PMC5468430 DOI: 10.3389/fnmol.2017.00193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/30/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Chang-Hoon Cho
- College of Public Health, Korea UniversitySeoul, South Korea
| |
Collapse
|
5
|
|
6
|
Beardsley PM, Hauser KF. Glial modulators as potential treatments of psychostimulant abuse. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 69:1-69. [PMID: 24484974 DOI: 10.1016/b978-0-12-420118-7.00001-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glia (including astrocytes, microglia, and oligodendrocytes), which constitute the majority of cells in the brain, have many of the same receptors as neurons, secrete neurotransmitters and neurotrophic and neuroinflammatory factors, control clearance of neurotransmitters from synaptic clefts, and are intimately involved in synaptic plasticity. Despite their prevalence and spectrum of functions, appreciation of their potential general importance has been elusive since their identification in the mid-1800s, and only relatively recently have they been gaining their due respect. This development of appreciation has been nurtured by the growing awareness that drugs of abuse, including the psychostimulants, affect glial activity, and glial activity, in turn, has been found to modulate the effects of the psychostimulants. This developing awareness has begun to illuminate novel pharmacotherapeutic targets for treating psychostimulant abuse, for which targeting more conventional neuronal targets has not yet resulted in a single, approved medication. In this chapter, we discuss the molecular pharmacology, physiology, and functional relationships that the glia have especially in the light in which they present themselves as targets for pharmacotherapeutics intended to treat psychostimulant abuse disorders. We then review a cross section of preclinical studies that have manipulated glial processes whose behavioral effects have been supportive of considering the glia as drug targets for psychostimulant-abuse medications. We then close with comments regarding the current clinical evaluation of relevant compounds for treating psychostimulant abuse, as well as the likelihood of future prospects.
Collapse
Affiliation(s)
| | - Kurt F Hauser
- Virginia Commonwealth University, Richmond, Virginia, USA
| |
Collapse
|
7
|
Astrocyte regulation of CNS inflammation and remyelination. Brain Sci 2013; 3:1109-27. [PMID: 24961523 PMCID: PMC4061872 DOI: 10.3390/brainsci3031109] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/12/2013] [Accepted: 07/12/2013] [Indexed: 01/17/2023] Open
Abstract
Astrocytes regulate fundamentally important functions to maintain central nervous system (CNS) homeostasis. Altered astrocytic function is now recognized as a primary contributing factor to an increasing number of neurological diseases. In this review, we provide an overview of our rapidly developing understanding of the basal and inflammatory functions of astrocytes as mediators of CNS responsiveness to inflammation and injury. Specifically, we elaborate on ways that astrocytes actively participate in the pathogenesis of demyelinating diseases of the CNS through their immunomodulatory roles as CNS antigen presenting cells, modulators of blood brain barrier function and as a source of chemokines and cytokines. We also outline how changes in the extracellular matrix can modulate astrocytes phenotypically, resulting in dysregulation of astrocytic responses during inflammatory injury. We also relate recent studies describing newly identified roles for astrocytes in leukodystrophies. Finally, we describe recent advances in how adapting this increasing breadth of knowledge on astrocytes has fostered new ways of thinking about human diseases, which offer potential to modulate astrocytic heterogeneity and plasticity towards therapeutic gain. In summary, recent studies have provided improved insight in a wide variety of neuroinflammatory and demyelinating diseases, and future research on astrocyte pathophysiology is expected to provide new perspectives on these diseases, for which new treatment modalities are increasingly necessary.
Collapse
|
8
|
EMSLEY JASONG, MACKLIS JEFFREYD. Astroglial heterogeneity closely reflects the neuronal-defined anatomy of the adult murine CNS. ACTA ACUST UNITED AC 2012; 2:175-86. [PMID: 17356684 PMCID: PMC1820889 DOI: 10.1017/s1740925x06000202] [Citation(s) in RCA: 209] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Astroglia comprise an extremely morphologically diverse cell type that have crucial roles in neural development and function. Nonetheless, distinct regions of the CNS have traditionally been defined by the phenotypic characteristics and connectivity of neuros. In a complementary fashion, we present evidence that discrete regions of the adult CNS can be delineated based solely on the morphology, density and proliferation rates of astroglia. We used transgenic hGFAP-GFP mice in which robust expression of GFP in adult astroglia enables detailed morphological characterization of this diversely heterogeneous cell population with 3D confocal microscopy. By using three complementary methods for labeling adult astroglia (hGFAP-GFP expression, and GFAP and S100beta immunostaining), we find that there is a remarkably diverse, regionally stereotypical array of astroglial morphology throughout the CNS, and that discrete anatomical regions can be defined solely on the morphology of astroglia within that region. Second, we find that the density of astroglia varies dramatically across the CNS, and that astroglial density effectively delineates even the sub-regions of complex structures, such as the thalamus. We also find that regional astroglial density varies depending on how astroglia are labeled. To quantify and illustrate these broad differences in astroglial density, we generated an anatomical density atlas of the CNS. Third, the proliferation rate, or mitotic index, of astroglia in the adult CNS also effectively defines anatomical regions. These differences are present regardless of the astroglial-labeling method used. To supplement our atlas of astroglial density we generated an atlas of proliferation density for the adult CNS. Together, these studies demonstrate that the morphology, density and proliferation rate of astroglia can independently define the discrete cytoarchitecture of the adult mammalian CNS, and support the concept that regional astroglial heterogeneity reflects important molecular and functional differences between distinct classes of astroglia, much like the long-accepted heterogeneity of neuronal populations.
Collapse
Affiliation(s)
| | - JEFFREY D. MACKLIS
- Correspondence should be addressed to: Jeffrey D. Macklis, MGH-HMS Center for Nervous System Repair, Massachusetts General Hospital, Edwards 4 (EDR 410), 50 Blossom Street, Boston MA USA 02114, phone: +1 617 724 0678, fax: +1 617 726 2310,
| |
Collapse
|
9
|
Emsley JG, Menezes JRL, Madeiro Da Costa RF, Martinez AMB, Macklis JD. Identification of radial glia-like cells in the adult mouse olfactory bulb. Exp Neurol 2012; 236:283-97. [PMID: 22634209 DOI: 10.1016/j.expneurol.2012.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 04/18/2012] [Accepted: 05/12/2012] [Indexed: 01/08/2023]
Abstract
Immature neurons migrate tangentially within the rostral migratory stream (RMS) to the adult olfactory bulb (OB), then radially to their final positions as granule and periglomerular neurons; the controls over this transition are not well understood. Using adult transgenic mice with the human GFAP promoter driving expression of enhanced GFP, we identified a population of radial glia-like cells that we term adult olfactory radial glia-like cells (AORGs). AORGs have large, round somas and simple, radially oriented processes. Confocal reconstructions indicate that AORGs variably express typical radial glial markers, only rarely express mouse GFAP, and do not express astroglial, oligodendroglial, neuronal, or tanycyte markers. Electron microscopy provides further supporting evidence that AORGs are not immature neurons. Developmental analyses indicate that AORGs are present as early as P1, and are generated through adulthood. Tracing studies show that AORGs are not born in the SVZa, suggesting that they are born either in the RMS or the OB. Migrating immature neurons from the adult SVZa are closely apposed to AORGs during radial migration in vivo and in vitro. Taken together, these data indicate a newly-identified population of radial glia-like cells in the adult OB that might function uniquely in neuronal radial migration during adult OB neurogenesis.
Collapse
Affiliation(s)
- Jason G Emsley
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | | | | | | | | |
Collapse
|
10
|
Pyka M, Busse C, Seidenbecher C, Gundelfinger ED, Faissner A. Astrocytes are crucial for survival and maturation of embryonic hippocampal neurons in a neuron-glia cell-insert coculture assay. Synapse 2011; 65:41-53. [PMID: 20506382 DOI: 10.1002/syn.20816] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Synapses represent specialized cell-cell contact sites between nerve cells. These structures mediate the rapid and efficient transmission of signals between neurons and are surrounded by glial cells. Previous investigations have shown that astrocytes are important for the formation, maintenance, and function of CNS synapses. To study effects of glial-derived molecules on synaptogenesis, we have established an in vitro cell-insert coculture system for E18 rat hippocampal neurons and various glial cell types. Neurons were cultured without direct contact with glial cells for distinct time periods. First, it was confirmed that astrocytes are essential to promote survival of E18 hippocampal neurons. Beginning with 10 days in culture, the concurrent expression of pre- and postsynaptic proteins was observed. Moreover, the colocalization of the presynaptic marker Bassoon and the postsynaptic protein ProSAP1/Shank2 indicated the formation of synapses. A technique was developed that permits the semiautomated quantitative determination of the number of synaptic puncta per neuron. The culture system was used to assess effects of pharmacological treatments on synapse formation by applying blockers and activators of small GTPases. In particular, treatment with lysophosphatidic acid enhanced synaptogenesis in the coculture system.
Collapse
Affiliation(s)
- Martin Pyka
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University, D-44780 Bochum, Germany
| | | | | | | | | |
Collapse
|
11
|
Vermeiren C, Najimi M, Vanhoutte N, Tilleux S, de Hemptinne I, Maloteaux JM, Hermans E. Acute up-regulation of glutamate uptake mediated by mGluR5a in reactive astrocytes. J Neurochem 2005; 94:405-16. [PMID: 15998291 DOI: 10.1111/j.1471-4159.2005.03216.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Excitatory transmission in the CNS necessitates the existence of dynamic controls of the glutamate uptake achieved by astrocytes, both in physiological conditions and under pathological circumstances characterized by gliosis. In this context, this study was aimed at evaluating the involvement of group I metabotropic glutamate receptors (mGluR) in the regulation of glutamate transport in a model of rat astrocytes undergoing in vitro activation using a cocktail of growth factors (G5 supplement). The vast majority of the cells were found to take up aspartate, mainly through the glutamate/aspartate transporter (GLAST), and at least 60% expressed functional mGluR5a. When exposed for 15 s to the selective group I mGluR agonist (S)-3,5-dihydroxyphenylglycine, reactive astrocytes showed a significant increase in their capacity to take up aspartate. This effect was confirmed at the single-cell level, since activation of mGluRs significantly increased the initial slope of aspartate-dependent Na+ entry associated with the activity of glutamate transporters. This up-regulation was inhibited by an antagonist of mGluR5 and, more importantly, was sensitive to a specific glutamate transporter 1 (GLT-1) blocker. The acute influence of mGluR5 on aspartate uptake was phospholipase C- and protein kinase C-dependent, and was mimicked by phorbol esters. We conclude that mGluR5a contributes to a dynamic control of GLT-1 function in activated astrocytes, acting as a glial sensor of the extracellular glutamate concentration in order to acutely regulate the excitatory transmission.
Collapse
Affiliation(s)
- Céline Vermeiren
- Laboratoire de Pharmacologie Expérimentale, Université catholique de Louvain, Brussels, Belgium
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
The present review article deals with the pathogenesis of toxoplasmosis. The article briefly highlights some important aspects such as different strains, mode of infection and clinical characteristics, entry into host cell, immune response, host parasite interaction, tissue cyst formation and disease recurrence.
Collapse
Affiliation(s)
- G M Bhopale
- Parasitology and Immunodiagnostic Laboratory, Research and Development Division, Hindustan Antibiotics Ltd, Pimpri, 411018, Pune, India
| |
Collapse
|
13
|
Abstract
Patch-clamp recordings were obtained in brain slices from 283 rat astrocytes. The expression of voltage-activated whole-cell currents was compared in four different CNS regions (hippocampus, cerebral cortex, spinal cord, and cerebellum). Our data show that CNS astrocytes do not show significant regional differences in their ion channel complement. With the exception of cerebellar Bergmann glial cells, essentially all astrocytes express a combination of delayed rectifying outward K(+) currents, transient A-type K(+) currents, and small Na(+) currents. Developmentally, an increasing percentage of astrocytes and Bergmann glial cells express inwardly rectifying K(+) currents. We did not observe cells that were passive, i.e., lacking voltage-activated currents. A few cells that appeared "passive" in initial recordings showed voltage-activated K(+) currents after off-line leak subtraction. The heterogeneity observed in the ion channel complement was found to be identical when cell-to-cell variations observed within a given CNS region and between various CNS regions were compared, suggesting a common and fairly stereotypical complement of ion channels in CNS astrocytes. Ion channel expression in Bergmann glial cells differed from that of all other CNS regions studied. These cells typically showed very low input resistances attributable to a significant time- and voltage-independent resting K(+) conductance. However, as with electrophysiologically "passive"-appearing astrocytes, Bergmann glial cells showed expression of delayed rectifying K(+) currents after off-line leak subtraction. Inwardly rectifying K(+) currents were observed in Bergmann glial cells after postnatal day 17. Collectively, our data suggest that all astrocytes contain voltage-gated ion channels that display a common pattern of expression during development.
Collapse
Affiliation(s)
- A Bordey
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | | |
Collapse
|
14
|
Stephenson D, Rash K, Smalstig B, Roberts E, Johnstone E, Sharp J, Panetta J, Little S, Kramer R, Clemens J. Cytosolic phospholipase A2 is induced in reactive glia following different forms of neurodegeneration. Glia 1999; 27:110-28. [PMID: 10417811 DOI: 10.1002/(sici)1098-1136(199908)27:2<110::aid-glia2>3.0.co;2-c] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Many recent studies have emphasized the deleterious role of inflammation in CNS injury. Increases in free fatty acids, eicosanoids, and products of lipid peroxidation are known to occur in various conditions of acute and chronic CNS injury, including cerebral ischemia, traumatic brain injury, and Alzheimer's disease. Although an inflammatory response can be induced by many different means, phospholipases, such as cytosolic phospholipase A(2) (cPLA(2)), may play an important role in the production of inflammatory mediators and in the production of other potential second messengers. cPLA(2) hydrolyzes membrane phospholipids and its activity liberates free fatty acids leading directly to the production of eicosanoids. We investigated the cellular localization of cytosolic phospholipase A(2) in the CNS following: (1) focal and global cerebral ischemia, (2) facial nerve axotomy, (3) human cases of Alzheimer's disease, (4) transgenic mice overexpressing mutant superoxide dismutase, a mouse model of amyotrophic lateral sclerosis, and (5) transgenic mice overexpressing mutant amyloid precursor protein, which exhibits age-related amyloid deposition characteristic of Alzheimer's disease. We show that in every condition evaluated, cytosolic phospholipase A(2) is present in reactive glial cells within the precise region of neuron loss. In conditions where neurons did not degenerate or are protected from death, cytosolic phospholipase A(2) is not observed. Both astrocytes and microglial cells are immunoreactive for cytosolic phospholipase A(2) following injury, with astrocytes being the most consistent cell type expressing cytosolic phospholipase A(2). The presence of cytosolic phospholipase A(2) does not merely overlap with reactive astroglia, as reactive astrocytes were observed that did not exhibit cytosolic phospholipase A(2) immunoreactivity. In most conditions evaluated, inflammatory processes have been postulated to play a pivotal role and may even participate in neuronal cell death. These results suggest that cytosolic phospholipase A(2) may prove an attractive therapeutic target for neurodegeneration.
Collapse
Affiliation(s)
- D Stephenson
- Graduate Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Stephenson D, Rash K, Smalstig B, Roberts E, Johnstone E, Sharp J, Panetta J, Little S, Kramer R, Clemens J. Cytosolic phospholipase A2 is induced in reactive glia following different forms of neurodegeneration. Glia 1999. [DOI: 10.1002/(sici)1098-1136(199908)27:2%3c110::aid-glia2%3e3.0.co;2-c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
16
|
Cullen KM, Halliday GM, Double KL, Brooks WS, Creasey H, Broe GA. Cell loss in the nucleus basalis is related to regional cortical atrophy in Alzheimer's disease. Neuroscience 1997; 78:641-52. [PMID: 9153647 DOI: 10.1016/s0306-4522(96)00569-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cortical atrophy and cell loss in the cholinergic nucleus basalis is a well-established characteristic of Alzheimer's disease; however, previous studies not have analysed cholinergic cell loss and cortical atrophy in concert. In autopsy brains from eight patients with Alzheimer's disease and 12 control subjects, the numbers of nucleus basalis neurons were determined from 50-microm serial Nissl-stained sections. Volumes of the cerebrum, cortical gray matter (total, lobar and subregional), white matter and deep gray structures were computed by point counting on black and white photographs of gapless 3-mm coronal slices of formalin-fixed brains. Cell loss in the nucleus basalis was found to range between 89% and 42% in Alzheimer's disease compared with controls. White matter volume was unchanged in absolute terms in Alzheimer's disease patients compared with controls, while cortical volume was significantly reduced. Gray matter atrophy was most prominent in temporal and frontal cortices. A highly significant linear relationship was found between cortical volume and nucleus basalis cell number in controls and Alzheimer's disease patients, with values for both groups on a single regression line. Whole brain and cerebral volumes were also highly correlated to nucleus basalis cell numbers in both groups. A quantitative analysis of plaque and tangle burden in cortical target areas of the nucleus basalis was performed. In contrast to the relationship with cortical volume, nucleus basalis cell number and neurofibrillary tangle number were not significantly correlated to the density of cortical histopathology. These results suggest that the volume of cortical gray matter is coupled to the number of nucleus basalis neurons. Compromised viability of nucleus basalis neurons may precede cortical volume loss as large numbers of neurofibrillary tangles, detected with nickel peroxidase staining, were found in this nucleus in all Alzheimer's disease cases, including those with minimal cell loss.
Collapse
Affiliation(s)
- K M Cullen
- School of Biological Sciences and Department of Pathology, University of Sydney, Australia
| | | | | | | | | | | |
Collapse
|
17
|
Kobayashi K, Kobayashi H, Ueda M, Honda Y. Monoclonal antibody, KK1, recognizes human retinal astrocytes and distinguishes a subtype of astrocytes in mouse brain. Brain Res 1996; 740:57-65. [PMID: 8973798 DOI: 10.1016/s0006-8993(96)00852-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Astrocytes exhibit a diverse morphology and numerous functions in the central nervous system as well as in the retina. In order to obtain markers for the analysis of astrocytes, we prepared monoclonal antibodies that recognized antigens specific to astrocytes. Monoclonal antibody (mAb), designated KK1, reacted with the processes of astrocytes in the nerve fiber layer and the ganglion cell layer in the human retina as detected by indirect immunofluorescence. Normal Müller cells, whose processes are localized vertically in retina, were not labeled by KK1 mAb. In mouse brain, KK1 mAb reacted specifically with astrocytes in the white matter, but not with those in the gray matter. Studies employing a high-resolution confocal laser scanning microscope and double-labeling with KK1 mAb and commercially available anti-glial fibrillary acidic protein (GFAP) mAb (GA5) revealed that KK1 mAb visualized the processes that were not recognized by anti-GFAP mAb (GA5) in both human retina and mouse brain. In cultured mouse astrocytes, KK1 mAb reacted only with anti-GFAP mAb (GA5)-positive cells, but a small percentage of anti-GFAP mAb (GA5)-positive cells were labeled with KK1 mAb. In addition, the subcellular distribution of the KK1 antigen in cultured astrocytes apparently differed from that of GFAP labeled by anti-GFAP mAb (GA5). The antigen that was purified from the normal mouse brain by KK1 mAb-conjugated beads reacted with anti-GFAP mAb(GA5) in immunoblotting. No reactivity of KK1 mAb was observed in immunohistochemical analysis in GFAP -/- mutant mouse brain. These results demonstrate that KK1 mAb specifically recognized an epitope of GFAP that did not react with other anti-GFAP mAb (GA5). Retinal astrocytes and a subtype of astrocytes in the white matter of mouse brain shared the epitope that was recognized by KK1 mAb. KK1 mAb might be a powerful tool to investigate a subtype of astrocytes.
Collapse
Affiliation(s)
- K Kobayashi
- Department of Ophthalmology, Faculty of Medicine, Kyoto University, Japan
| | | | | | | |
Collapse
|
18
|
|
19
|
Brodie C. Functional PAF receptors in glia cells: binding parameters and regulation of expression. Int J Dev Neurosci 1994; 12:631-40. [PMID: 7900545 DOI: 10.1016/0736-5748(94)90015-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Platelet activating factor is a unique phosphoglycerine which possesses a variety of biological functions exerting its biological effects via specific surface receptors. In the central nervous system, platelet activating factor has been suggested to play a role during injury especially in conditions of ischemia and trauma-induced neuronal damage. The specific cell populations expressing platelet activating factor receptor, however, have not been identified. In this study, the binding properties of platelet activating factor receptors in C6 glioma cells and primary cultures of astrocytes and oligodendrocytes were characterized by using the ligand [3H]WEB 2086. Early-passage glial cells which exhibit oligodendrocytic phenotype, expressed lower levels of [3H]WEB 2086 binding than either late-passage cells which exhibit astrocytic phenotypes or primary astroglia cells. No specific binding was observed in primary cultures of oligodendrocytes. The Bmax (136 +/- 15.3 fmol/mg protein) and Kd (29 +/- 3.2 nM) levels obtained for primary astroglia cells were similar to those described for other cell types. The expression of platelet activating factor receptor in early-passage glia cells was up-regulated by treatment with insulin which induces astrocytic differentiation. In contrast, db-cyclic AMP exerted an inhibitory effect on the level of platelet activating factor receptor in both early- and late-passage cells. The level of functional platelet activating factor receptor in C6 cells as measured by the ability of platelet activating factor to induce 45Ca2+ influx was increased in cells expressing astrocytic phenotypes and was decreased in db-cyclic AMP-treated cells. In accordance with lack of specific [3H]WEB 2086 binding, platelet activating factor did not induce a detectable response of Ca2+ influx in cultures of oligodendrocytes. This report provides the first direct demonstration of selective expression of functional platelet activating factor receptors and their properties in astroglia cells. The findings support the suggestion that platelet activating factor may play an important role as a mediator of injury and immune responses in the nervous system.
Collapse
Affiliation(s)
- C Brodie
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| |
Collapse
|
20
|
Junier MP, Suzuki F, Onteniente B, Peschanski M. Target-deprived CNS neurons express the NGF gene while reactive glia around their axonal terminals contain low and high affinity NGF receptors. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1994; 24:247-60. [PMID: 7968364 DOI: 10.1016/0169-328x(94)90138-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Reactive gliosis is part of the response of central nervous system to injury and neurodegeneration. Cellular components of the reactive gliosis have the capability to synthesize neurotrophic factors, and thus are capable of affecting the fate of neuronal populations in the injured tissue. In this study, we explored the putative involvement of reactive glia-derived neurotrophins in sustaining the axonal projections of target-deprived neurons. Neuronal targets of the dorsal column nuclei neurons were suppressed through excitotoxic lesion of the ventrobasal complex of the rat thalamus (VB). Despite the development of reactive gliosis, neither up-regulation of NGF, nor BDNF or NT3 mRNA could be detected by solution hybridization in the lesioned site at all times tested. In contrast, expression of the LNGFR gene increased progressively up to 90 days post-lesion. Immunocytochemical studies localized the LNGFR protein in a subset of small cells with ramified processes resembling microglia at 7 and 20 days post-lesion. At longer times, double immunolabelling studies revealed that a substantial part of LNGFR-immunoreactive cells filling the area of neuronal loss were neither microglial cells nor astrocytes although presence of LNGFR in a subset of microglial cells could not be excluded. Previous ultrastructural studies of the kainate-lesioned VB suggest that these LNGFR-immunoreactive cells correspond to oligodendrocytes and/or Schwann cells. At 2 months post-lesion, when LNGFR expression was maximal, increased levels of trkA mRNA were detected in the lesioned site. Immunocytochemical studies revealed the presence of numerous trkA-immunoreactive astrocytes. TrkB mRNA, encoding the full-length high-affinity receptor for BDNF, remained undetectable by non-isotopic in situ hybridization. In contrast to the lack of neurotrophin gene expression by glial components of the lesioned VB, dorsal column nuclei neurons contained NGF mRNA as revealed by in situ hybridization studies at 10 days--prior to enhanced LNGFR expression in the lesion--and 2 months post-lesion. In addition, the number and the staining intensity of NGF mRNA-positive neurons was increased in the target-deprived neurons, as compared with the contra-lateral nucleus projecting to intact targets. These results show that glial cells present in a reactive gliosis which develops in the kainic acid-lesioned thalamus, do not synthesize neurotrophins but instead produce high levels of both low- and high-affinity NGF receptors, LNGFR by Schwann cells/oligodendrocytes and possibly a subset of microglial cells, and trkA by reactive astrocytes.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- M P Junier
- INSERM CJF 91-02, Faculté Médecine, Créteil, France
| | | | | | | |
Collapse
|
21
|
Abstract
Astrocytes, once relegated to a mere supportive role in the central nervous system, are now recognized as a heterogeneous class of cells with many important and diverse functions. Major astrocyte functions can be grouped into three categories: guidance and support of neuronal migration during development, maintenance of the neural microenvironment, and modulation of immune reactions by serving as antigen-presenting cells. The concept of astrocytic heterogeneity is critical to understanding the functions and reactions of these cells in disease. Astrocytes from different regions of the brain have diverse biochemical characteristics and may respond in different ways to a variety of injuries. Astrocytic swelling and hypertrophy-hyperplasia are two common reactions to injury. This review covers the morphologic and pathophysiologic findings, time course, and determinants of these two responses. In addition to these common reactions, astrocytes may play a primary role in certain diseases, including epilepsy, neurological dysfunction in liver disease, neurodegenerative disorders such as Parkinson's and Huntington's diseases, and demyelination. Evidence supporting primary involvement of astrocytes in these diseases will be considered.
Collapse
Affiliation(s)
- D L Montgomery
- Texas A&M Veterinary Medical Diagnostic Laboratory, Amarillo
| |
Collapse
|
22
|
Peterson PK, Gekker G, Hu S, Anderson WR, Kravitz F, Portoghese PS, Balfour HH, Chao CC. Morphine amplifies HIV-1 expression in chronically infected promonocytes cocultured with human brain cells. J Neuroimmunol 1994; 50:167-75. [PMID: 8120138 DOI: 10.1016/0165-5728(94)90043-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Previous studies have shown that morphine promotes the replication of human immunodeficiency virus (HIV)-1 in peripheral blood mononuclear cell cocultures. In the present study, we tested the hypothesis that morphine would amplify HIV-1 expression in the chronically infected promonocytic clone U1 when cocultured with lipopolysaccharide-stimulated human fetal brain cells. Marked upregulation of HIV-1 expression was observed in these cocultures (quantified by measurement of HIV-1 p24 antigen levels in supernatants), and treatment of brain cells with morphine resulted in a bell-shaped dose-dependent enhancement of viral expression. The mechanism of morphine's amplifying effect appears to be opioid receptor-mediated and to involve enhanced production of tumor necrosis factor-alpha by microglial cells.
Collapse
Affiliation(s)
- P K Peterson
- Neuroimmunobiology and Host Defense Laboratory, Minneapolis Medical Research Foundation, MN 55404
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Forsyth RJ, Bartlett K, Burchell A, Scott HM, Eyre JA. Astrocytic glucose-6-phosphatase and the permeability of brain microsomes to glucose 6-phosphate. Biochem J 1993; 294 ( Pt 1):145-51. [PMID: 8395816 PMCID: PMC1134577 DOI: 10.1042/bj2940145] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cells from primary rat astrocyte cultures express a 36.5 kDa protein that cross-reacts with polyclonal antibodies to the catalytic subunit of rat hepatic glucose-6-phosphatase on Western blotting. Glucose-6-phosphate-hydrolysing activity of the order of 10 nmol/min per mg of total cellular protein can be demonstrated in cell homogenates. This activity shows latency, and is localized to the microsomal fraction. Kinetic analysis shows a Km of 15 mM and a Vmax. of 30 nmol/min per mg of microsomal protein in disrupted microsomes. Approx. 40% of the total phosphohydrolase activity is specific glucose-6-phosphatase, as judged by sensitivity to exposure to pH 5 at 37 degrees C. Previous reports that the brain microsomal glucose-6-phosphatase system does not distinguish glucose 6-phosphate and mannose 6-phosphate are confirmed in astrocyte microsomes. However, we demonstrate significant phosphomannose isomerase activity in brain microsomes, allowing for ready interconversion between mannose 6-phosphate and glucose 6-phosphate (Vmax. 15 nmol/min per mg of microsomal protein; apparent Km < 1 mM; pH optimum 5-6 for the two-step conversion). This finding invalidates the past inference from the failure of brain microsomes to distinguish mannose 6-phosphate and glucose 6-phosphate that the cerebral glucose-6-phosphatase system lacks a 'glucose 6-phosphate translocase' [Fishman and Karnovsky (1986) J. Neurochem. 46, 371-378]. Furthermore, light-scattering experiments confirm that a proportion of whole brain microsomes is readily permeable to glucose 6-phosphate.
Collapse
Affiliation(s)
- R J Forsyth
- Department of Child Health, Medical School, University of Newcastle upon Tyne, U.K
| | | | | | | | | |
Collapse
|
24
|
Eddleston M, Mucke L. Molecular profile of reactive astrocytes--implications for their role in neurologic disease. Neuroscience 1993; 54:15-36. [PMID: 8515840 PMCID: PMC7130906 DOI: 10.1016/0306-4522(93)90380-x] [Citation(s) in RCA: 1114] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/1992] [Indexed: 01/31/2023]
Abstract
The central nervous system responds to diverse neurologic injuries with a vigorous activation of astrocytes. While this phenomenon is found in many different species, its function is obscure. Understanding the molecular profile characteristic of reactive astrocytes should help define their function. The purpose of this review is to provide a summary of molecules whose levels of expression differentiate activated from resting astrocytes and to use the molecular profile of reactive astrocytes as the basis for speculations on the functions of these cells. At present, reactive astrocytosis is defined primarily as an increase in the number and size of cells expressing glial fibrillary acidic protein. In vivo, this increase in glial fibrillary acidic protein-positive cells reflects predominantly phenotypic changes of resident astroglia rather than migration or proliferation of such cells. Upon activation, astrocytes upmodulate the expression of a large number of molecules. From this molecular profile it becomes apparent that reactive astrocytes may benefit the injured nervous system by participating in diverse biological processes. For example, upregulation of proteases and protease inhibitors could help remodel the extracellular matrix, regulate the concentration of different proteins in the neuropil and clear up debris from degenerating cells. Cytokines are key mediators of immunity and inflammation and could play a critical role in the regulation of the blood-central nervous system interface. Neurotrophic factors, transporter molecules and enzymes involved in the metabolism of excitotoxic amino acids or in the antioxidant pathway may help protect neurons and other brain cells by controlling neurotoxin levels and contributing to homeostasis within the central nervous system. Therefore, an impairment of astroglial performance has the potential to exacerbate neuronal dysfunction. Based on the synopsis of studies presented, a number of issues become apparent that deserve a more extensive analysis. Among them are the relative contribution of microglia and astrocytes to early wound repair, the characterization of astroglial subpopulations, the specificity of the astroglial response in different diseases as well as the analysis of reactive astrocytes with techniques that can resolve fast physiologic processes. Differences between reactive astrocytes in vivo and primary astrocytes in culture are discussed and underline the need for the development and exploitation of models that will allow the analysis of reactive astrocytes in the intact organism.
Collapse
Affiliation(s)
- M Eddleston
- Department of Neuropharmacology, Scripps Research Institute
| | | |
Collapse
|
25
|
Bailey MS, Shipley MT. Astrocyte subtypes in the rat olfactory bulb: morphological heterogeneity and differential laminar distribution. J Comp Neurol 1993; 328:501-26. [PMID: 8429132 DOI: 10.1002/cne.903280405] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Despite increased recognition of the importance and heterogeneity of astrocyte functions throughout the central nervous system (CNS) relatively little attention has been paid to morphological diversity among astrocytes. Recent studies have indicated that subsets of astrocytes are involved in glial-axonal interactions critical to both development and reinnervation of the rat olfactory bulb. Here, we have characterized the morphologies and distribution of astrocytes within anatomically and functionally distinct layers of the adult main olfactory bulb (MOB). Using a known immunohistochemical marker for astrocytes, glial fibrillary acidic protein (GFAP), and the classic gold sublimate method, we identified six astrocyte subtypes based on their morphology and distribution: (1) unipolar, (2) irregular, (3) wedge-shape, (4) circular, (5) semicircular, and (6) elongate. Unipolar, irregular and wedge-shape astrocytes have not been previously described in the CNS. The unipolar and irregular types are located exclusively in the olfactory nerve layer. Wedge-shape astrocytes are unique to, and are the major subtype in, the glomerular layer. These three morphologically unique astrocyte subtypes may correspond to olfactory nerve layer (ONL) and glomerular layer (GL) astrocytes, which express molecules that regulate axonal growth or synaptogenesis during development and/or regeneration of the olfactory nerve. In the glomerular layer, astrocytes are highly organized with respect to the glomeruli. Individual astrocytes are loyal to a single glomerulus. In the external plexiform layer, astrocytes are spaced relatively uniformly. In the granule cell layer, astrocytes appear to compartmentalize granule cell aggregates, recently shown to be coupled by tight junctions. The distribution and patterns of astrocyte processes and the density of GFAP immunoreactivity are distinctive for each of the layers of the olfactory bulb. The spacing of astrocytes and the organization of their processes may be important to compartmentalization of neuronal functions. High levels of GFAP immunoreactivity correlated with layers of high neuronal plasticity. The morphological diversity and differential distribution of astrocytes in the olfactory bulb reported here support growing evidence for functional diversity of astrocytes and important interactions among specific astrocyte and neuron subtypes. It is reasonable to hypothesize, therefore, that as for neurons, morphologically distinctive astrocyte subtypes may correspond to functionally specific classes.
Collapse
Affiliation(s)
- M S Bailey
- Department of Anatomy and Cell Biology, University of Cincinnati College of Medicine, Ohio 45267-0521
| | | |
Collapse
|
26
|
Rouget M, Araud D, Seite R, Prochiantz A, Autillo-Touati A. Astrocyte-regulated synaptogenesis: an in vitro ultrastructural study. Neurosci Lett 1993; 150:85-8. [PMID: 8097027 DOI: 10.1016/0304-3940(93)90114-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Striatal neurons from E15 rat embryos were dissociated, plated at low cell density on polyornithine or on astrocyte monolayers derived from the striatum (homotopic) or mesencephalon (heterotopic), and cultured in a chemically defined medium. Dendrites developing in homotopic co-cultures could reach a state of maturation allowing the establishment of synapses with axons from mesencephalic explants. This culture system thus partially reproduces the in vivo conditions in which striatal neurons developing in an homotopic glial environment can serve as synaptic targets for afferent mesencephalic axons.
Collapse
Affiliation(s)
- M Rouget
- Laboratoire de Biologie Cellulaire, Faculté de Médecine, Marseille, France
| | | | | | | | | |
Collapse
|
27
|
Vogelweid CM, Johnson GC, Besch-Williford CL, Basler J, Walker SE. Inflammatory central nervous system disease in lupus-prone MRL/lpr mice: comparative histologic and immunohistochemical findings. J Neuroimmunol 1991; 35:89-99. [PMID: 1955574 DOI: 10.1016/0165-5728(91)90164-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The brains of pathogen-free autoimmune MRL/lpr, NZBWF1 and NZB mice were examined for central nervous system (CNS) inflammation in premoribund 8-week-old animals and at ages when active systemic lupus erythematosus (SLE) was present. CNS inflammation was observed only in MRL/lpr mice. Immunohistochemical studies of brains from young MRL/lpr mice found that infiltrates were composed primarily of CD4+ cells. Older MRL/lpr mice (22 and 26 weeks of age) had CD4+ cells predominantly, but CD8+ and B220+ cells were also present. Perivascular leakage of IgG was a prominent and unexpected finding in the MRL/lpr model. Congenic MRL/+ mice with late-onset autoimmunity had no inflammatory cells in brain tissue, and there was no perivascular staining with IgG or albumin. Our findings suggest that MRL/lpr mice are a useful model for studies of lupus-associated CNS inflammatory disease, and perivascular leakage may be a primary mechanism for entry of IgG into the brain.
Collapse
Affiliation(s)
- C M Vogelweid
- Department of Pathology, College of Veterinary Medicine, University of Missouri, Columbia 65212
| | | | | | | | | |
Collapse
|
28
|
Abstract
Brain macrophages are transiently present in different regions of the central nervous system during development or in the course of tissue remodelling following various types of injuries. To investigate the influence of these phagocytes on neuronal growth and survival, brain macrophages stemming from the cerebral cortex of rat embryos were added to neuronal primary cultures. A neurotoxic effect of brain macrophages was demonstrated by the reduction of the number of neurons bearing neurites within two days of contact between the two cell types. Neuronal death and phagocytosis were also directly observed in video recordings of living cultures. This toxicity involved the production by brain macrophages of reactive oxygen intermediates, as shown by the protective effect of catalase, a scavenger of H2O2. In addition, the respiratory bursts of brain macrophages were stimulated in the presence of neurons. These results suggest that brain macrophages could favour the appearance of neuroregressive events which occur either during neurogenesis or in neurodegenerative diseases, implying intracerebral recruitment of mononuclear phagocytes.
Collapse
Affiliation(s)
- Clotilde Théry
- INSERM U.114, Chaire de Neuropharmacologie, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | | | | |
Collapse
|
29
|
Abstract
The nervous system, through the production of neuroregulators (neurotransmitters, neuromodulators and neuropeptides) can regulate specific immune system functions, while the immune system, through the production of immunoregulators (immunomodulators and immunopeptides) can regulate specific nervous system functions. This indicates a reciprocal communication between the nervous and immune systems. The presence of immunoregulators in the brain and cerebrospinal fluid is the result of local synthesis--by intrinsic and blood-derived macrophages, activated T-lymphocytes that cross the blood-brain barrier, endothelial cells of the cerebrovasculature, microglia, astrocytes, and neuronal components--and/or uptake from the peripheral blood through the blood-brain barrier (in specific cases) and circumventricular organs. Acute and chronic pathological processes (infection, inflammation, immunological reactions, malignancy, necrosis) stimulate the synthesis and release of immunoregulators in various cell systems. These immunoregulators have pivotal roles in the coordination of the host defense mechanisms and repair, and induce a series of immunological, endocrinological, metabolical and neurological responses. This review summarizes studies concerning immunoregulators--such as interleukins, tumor necrosis factor, interferons, transforming growth factors, thymic peptides, tuftsin, platelet activating factor, neuro-immunoregulators--in the nervous system. It also describes the monitoring of immunoregulators by the central nervous system (CNS) as part of the regulatory factors that induce neurological manifestations (e.g., fever, somnolence, appetite suppression, neuroendocrine alterations) frequently accompanying acute and chronic pathological processes.
Collapse
Affiliation(s)
- C R Plata-Salamán
- School of Life and Health Sciences, University of Delaware, Newark 19716
| |
Collapse
|