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Errede M, Annese T, Petrosino V, Longo G, Girolamo F, de Trizio I, d'Amati A, Uccelli A, Kerlero de Rosbo N, Virgintino D. Microglia-derived CCL2 has a prime role in neocortex neuroinflammation. Fluids Barriers CNS 2022; 19:68. [PMID: 36042496 PMCID: PMC9429625 DOI: 10.1186/s12987-022-00365-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/03/2022] [Indexed: 11/12/2022] Open
Abstract
Background In myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), several areas of demyelination are detectable in mouse cerebral cortex, where neuroinflammation events are associated with scarce inflammatory infiltrates and blood–brain barrier (BBB) impairment. In this condition, the administration of mesenchymal stem cells (MSCs) controls neuroinflammation, attenuating astrogliosis and promoting the acquisition of stem cell traits by astrocytes. To contribute to the understanding of the mechanisms involved in the pathogenesis of EAE in gray matter and in the reverting effects of MSC treatment, the neocortex of EAE-affected mice was investigated by analyzing the cellular source(s) of chemokine CCL2, a molecule involved in immune cell recruitment and BBB-microvessel leakage. Methods The study was carried out by immunohistochemistry (IHC) and dual RNAscope IHC/in situ hybridization methods, using astrocyte, NG2-glia, macrophage/microglia, and microglia elective markers combined with CCL2. Results The results showed that in EAE-affected mice, hypertrophic microglia are the primary source of CCL2, surround the cortex neurons and the damaged BBB microvessels. In EAE-affected mice treated with MSCs, microgliosis appeared diminished very soon (6 h) after treatment, an observation that was long-lasting (tested after 10 days). This was associated with a reduced CCL2 expression and with apparently preserved/restored BBB features. In conclusion, the hallmark of EAE in the mouse neocortex is a condition of microgliosis characterized by high levels of CCL2 expression. Conclusions This finding supports relevant pathogenetic and clinical aspects of the human disease, while the demonstrated early control of neuroinflammation and BBB permeability exerted by treatment with MSCs may have important therapeutic implications. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-022-00365-5.
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Affiliation(s)
- Mariella Errede
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy.,Department of Medicine and Surgery, LUM University, Casamassima Bari, Italy
| | - Valentina Petrosino
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Giovanna Longo
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy
| | - Francesco Girolamo
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy
| | - Ignazio de Trizio
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy
| | - Antonio d'Amati
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy.,Department of Emergency and Organ Transplantation, Pathology Section, University of Bari School of Medicine, Bari, Italy
| | - Antonio Uccelli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Nicole Kerlero de Rosbo
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy.,TomaLab, Institute of Nanotechnology, Consiglio Nazionale Delle Ricerche (CNR), Rome, Italy
| | - Daniela Virgintino
- Department of Basic Medical Sciences, Neuroscience, and Sensory Organs, University of Bari School of Medicine, Piazza Giulio Cesare, Policlinics, 70124, Bari, Italy.
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2
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Dehhaghi M, Kazemi Shariat Panahi H, Braidy N, Guillemin GJ. Herpetosiphon Secondary Metabolites Inhibit Amyloid-β Toxicity in Human Primary Astrocytes. J Alzheimers Dis 2021; 76:423-433. [PMID: 32474470 DOI: 10.3233/jad-200116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The accumulation of extracellular plaques containing amyloid-β protein (Aβ) in the brain is one of the main pathological hallmarks of Alzheimer's disease (AD). Aβ peptide can promote the production of highly volatile free radicals and reactive oxygen species (ROS) that can induce oxidative damage to neurons and astrocytes. At present, numerous studies have investigated the neuroprotective and glioprotective effects of natural products derived from plants, animals, and microorganisms. OBJECTIVE We investigated the glioprotective effect of secondary metabolites obtained from Herpetosiphon sp. HM 1988 against Aβ40-induced toxicity in human primary astrocytes. METHODS The protective effect of bacterial secondary metabolites against Aβ40-induced inducible nitric oxide synthase (iNOS) activity was evaluated using the citrulline assay. To confirm the iNOS activity, nitrite production was assessed using the fluorometric Griess diazotization assay. Intracellular NAD+ depletion and lactate dehydrogenase (LDH) release in human primary astrocytes were also examined using well-established spectrophotometric assays. RESULTS Our results indicate that Aβ40 can induce elevation in iNOS and LDH activities, nitrite production, and cellular energy depletion. Importantly, extract of Herpetosiphon sp. HM 1988 decreased iNOS activity, nitrite production, and LDH release. In addition, metabolites of the strain were able to restore cellular energy deficits through inhibition of NAD+ depletion mediated by Aβ40. CONCLUSION These findings suggest that Herpetosiphon metabolites may represent a promising, novel source for the prevention of Aβ toxicity in AD.
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Affiliation(s)
- Mona Dehhaghi
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | | | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Faculty of Medicine, Sydney, Australia
| | - Gilles J Guillemin
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
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3
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Dulka K, Nacsa K, Lajkó N, Gulya K. Quantitative morphometric and cell-type-specific population analysis of microglia-enriched cultures subcloned to high purity from newborn rat brains. IBRO Neurosci Rep 2021; 10:119-129. [PMID: 33842918 PMCID: PMC8019997 DOI: 10.1016/j.ibneur.2021.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/30/2021] [Indexed: 12/27/2022] Open
Abstract
Morphological and functional characterizations of cultured microglia are essential for the improved understanding of their roles in neuronal health and disease. Although some studies (phenotype analysis, phagocytosis) can be carried out in mixed or microglia-enriched cultures, in others (gene expression) pure microglia must be used. If the use of genetically modified microglial cells is not feasible, isolation of resident microglia from nervous tissue must be carried out. In this study, mixed primary cultures were established from the forebrains of newborn rats. Secondary microglia-enriched cultures were then prepared by shaking off these cells from the primary cultures, which were subsequently used to establish tertiary cultures by further shaking off the easily detachable microglia. The composition of these cultures was quantitatively analyzed by immunocytochemistry of microglia-, astrocyte-, oligodendrocyte- and neuron-specific markers to determine yield and purity. Microglia were quantitatively characterized regarding morphological and proliferation aspects. Secondary and tertiary cultures typically exhibited 73.3% ± 17.8% and 93.1% ± 6.0% purity for microglia, respectively, although the total number of microglia in the latter was much smaller. One in seven attempts of culturing the tertiary cultures had ~99% purity for microglia. The overall yield from the number of cells plated at DIV0 to the Iba1-positive microglia in tertiary cultures was ~1%. Astrocytic and neuronal contamination progressively decreased during subcloning, while oligodendrocytes were found sporadically throughout culturing. Although the tertiary microglia cultures had a low yield, they produced consistently high purity for microglia; after validation, such cultures are suitable for purity-sensitive functional screenings (gene/protein expression).
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Key Words
- ANOVA, One-way analysis of variance
- CNPase, 2′,3′-Cyclic nucleotide 3′-phosphodiesterase
- CNS, Central nervous system
- Cell yield
- DIV, Day(s) in vitro
- DMEM, Dulbecco’s Modified Eagle’s Medium
- Differential adherence
- FBS, Fetal bovine serum
- FITC, Fluorescein isothiocyanate
- GFAP, Glial fibrillary acidic protein
- Iba1, Ionized calcium-binding adapter molecule 1
- Immunocytochemistry
- Ki67, Proliferation marker antigen identified by the monoclonal antibody Ki67
- PBS, Phosphate buffered saline
- PI, Proliferation index
- PVP, Polyvinylpyrrolidone
- Proliferation
- Purity of culture
- RT, Room temperature
- Rpm, Revolutions per minute
- S.D., Standard deviation
- S1, S2, Secondary subcultures
- Secondary/tertiary culture
- T1, T2, Tertiary subcultures
- TI, Transformation index
- subDIV, Subcloned day(s) in vitro
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Affiliation(s)
- Karolina Dulka
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Kálmán Nacsa
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Noémi Lajkó
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Karoly Gulya
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
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Engel M, Gee YS, Cross D, Maccarone A, Heng B, Hulme A, Smith G, Guillemin GJ, Stringer BW, Hyland CJT, Ooi L. Novel dual-action prodrug triggers apoptosis in glioblastoma cells by releasing a glutathione quencher and lysine-specific histone demethylase 1A inhibitor. J Neurochem 2019; 149:535-550. [PMID: 30592774 PMCID: PMC6590141 DOI: 10.1111/jnc.14655] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/04/2018] [Accepted: 12/19/2018] [Indexed: 02/04/2023]
Abstract
Targeting epigenetic mechanisms has shown promise against several cancers but has so far been unsuccessful against glioblastoma (GBM). Altered histone 3 lysine 4 methylation and increased lysine‐specific histone demethylase 1A (LSD1) expression in GBM tumours nonetheless suggest that epigenetic mechanisms are involved in GBM. We engineered a dual‐action prodrug, which is activated by the high hydrogen peroxide levels associated with GBM cells. This quinone methide phenylaminecyclopropane prodrug releases the LSD1 inhibitor 2‐phenylcyclopropylamine with the glutathione scavenger para‐quinone methide to trigger apoptosis in GBM cells. Quinone methide phenylaminocyclopropane impaired GBM cell behaviours in two‐dimensional and three‐dimensional assays, and triggered cell apoptosis in several primary and immortal GBM cell cultures. These results support our double‐hit hypothesis of potentially targeting LSD1 and quenching glutathione, in order to impair and kill GBM cells but not healthy astrocytes. Our data suggest this strategy is effective at selectively targeting GBM and potentially other types of cancers. Open science badges
This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. ![]()
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Affiliation(s)
- Martin Engel
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Yi Sing Gee
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Dale Cross
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Alan Maccarone
- Mass Spectrometry User Resource and Research Facility, School of Chemistry, University of Wollongong, Wollongong, New South Wales, Australia
| | - Benjamin Heng
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Amy Hulme
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Grady Smith
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Gilles J Guillemin
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Brett W Stringer
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Christopher J T Hyland
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
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Dehhaghi M, Tan V, Heng B, Mohammadipanah F, Guillemin GJ. Protective Effects of Myxobacterial Extracts on Hydrogen Peroxide-induced Toxicity on Human Primary Astrocytes. Neuroscience 2018; 399:1-11. [PMID: 30496822 DOI: 10.1016/j.neuroscience.2018.11.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 12/19/2022]
Abstract
Astrocytes, the main non-neuronal cells in the brain, have significant roles in the maintenance and survival of neurons. Oxidative stress has been implicated in various neurodegenerative disorders such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Myxobacteria produce a wide range of bioactive metabolites with notable structures and modes of action, which introduce them as potent natural product producers. In the present study, we evaluated the effects of myxobacterial extracts on hydrogen peroxide (H2O2)-mediated toxicity on primary human astrocytes. We showed that myxobacterial extracts could decrease the formation of reactive oxygen species (ROS), nitric oxide (NO) production, and cell death assessed by the release of lactate dehydrogenase (LDH). Myxobacterial extracts were also able to reduce the nitric oxide synthase (NOS) activity. The extracts reduced the oxidative effect of H2O2 on over-activation of poly (ADP-ribose) polymerase (PARP1), therefore preventing the cell death by restoring the NAD+ levels. In addition, myxobacterial extracts ameliorated the oxidative stress by increasing the glutathione level in cells. The overall results showed myxobacterial extracts, especially from the strains Archangium sp. UTMC 4070 and Cystobacter sp. UTMC 4073, were able to protect human primary astrocytes from oxidative stress.
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Affiliation(s)
- Mona Dehhaghi
- Departmentof Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran; NeuroinflammationGroup, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | - Vanessa Tan
- NeuroinflammationGroup, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | - Benjamin Heng
- NeuroinflammationGroup, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | - Fatemeh Mohammadipanah
- Departmentof Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.
| | - Gilles J Guillemin
- NeuroinflammationGroup, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia.
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6
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Dehhaghi M, Tan V, Heng B, Braidy N, Mohammadipanah F, Guillemin GJ. Neuroprotective Effect of Myxobacterial Extracts on Quinolinic Acid-Induced Toxicity in Primary Human Neurons. Neurotox Res 2018; 35:281-290. [PMID: 30267267 DOI: 10.1007/s12640-018-9945-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 07/30/2018] [Accepted: 08/03/2018] [Indexed: 12/14/2022]
Abstract
Quinolinic acid (QUIN) is a neurotoxin, gliotoxin, and proinflammatory molecule involved in the pathogenesis of several neurological diseases. Myxobacteria have been known as a rich source of secondary metabolites with diverse structures and mode of actions. In this study, we examined the potential neuroprotective effects of myxobacterial extracts on QUIN-induced excitotoxicity in primary human neurons. For this purpose, primary cultures of human neurons were pre-incubated with myxobacterial extracts and subsequently treated with QUIN at a pathophysiological concentration of 550 nM. The results showed that some myxobacterial extracts can significantly attenuate formation of reactive oxygen species (ROS), nitric oxide (NO) production, and extracellular lactate dehydrogenase (LDH) activity of human neurons. Moreover, myxobacterial extracts were also able to reduce neuronal nitric oxide synthase (nNOS) activity. Some extracts prevented cell death by reducing the activation of poly (ADP-ribose) polymerase (PARP1) by QUIN, therefore by maintaining NAD+ levels. In addition, myxobacterial extracts ameliorated oxidative stress by increasing the intracellular levels of glutathione after treatment with QUIN. The results showed that extracts of Stigmatella sp. UTMC 4072 and Archangium sp. UTMC 4070 and were the most effective in reducing QUIN-induced excitotoxicity in primary human neurons. Due to their antioxidative activity, myxobacterial extracts represent an underexplored source of potential new drugs for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Mona Dehhaghi
- Department of Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.,Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Vanessa Tan
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Benjamin Heng
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Fatemeh Mohammadipanah
- Department of Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.
| | - Gilles J Guillemin
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
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7
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Facci L, Barbierato M, Zusso M, Skaper SD, Giusti P. Serum amyloid A primes microglia for ATP-dependent interleukin-1β release. J Neuroinflammation 2018; 15:164. [PMID: 29803222 PMCID: PMC5970445 DOI: 10.1186/s12974-018-1205-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/15/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Acute-phase response is a systemic reaction to environmental/inflammatory insults and involves production of acute-phase proteins, including serum amyloid A (SAA). Interleukin-1β (IL-1β), a master regulator of neuroinflammation produced by activated inflammatory cells of the myeloid lineage, in particular microglia, plays a key role in the pathogenesis of acute and chronic diseases of the peripheral nervous system and CNS. IL-1β release is promoted by ATP acting at the purinergic P2X7 receptor (P2X7R) in cells primed with toll-like receptor (TLR) ligands. METHODS Purified (> 99%) microglia cultured from neonatal rat cortex and cerebellum were first primed with the putative TLR4/TLR2 agonist SAA (recombinant human Apo-SAA) or the established TLR4 agonist lipopolysaccharide (LPS) followed by addition of ATP. Expression of genes for the NLRP3 inflammasome, IL-1β, tumor necrosis factor-α (TNF-α), and SAA1 was measured by quantitative real-time polymerase chain reaction (q-PCR). Intracellular and extracellular amounts of IL-1β were determined by ELISA. RESULTS Apo-SAA stimulated, in a time-dependent manner, the expression of NLRP3, IL-1β, and TNF-α in cortical microglia, and produced a concentration-dependent increase in the intracellular content of IL-1β in these cells. A 2-h 'priming' of the microglia with Apo-SAA followed by addition of ATP for 1 h, resulting in a robust release of IL-1β into the culture medium, with a concomitant reduction in its intracellular content. The selective P2X7R antagonist A740003 blocked ATP-dependent release of IL-1β. Microglia prepared from rat cerebellum displayed similar behaviors. As with LPS, Apo-SAA upregulated SAA1 and TLR2 mRNA, and downregulated that of TLR4. LPS was less efficacious than Apo-SAA, perhaps reflecting an action of the latter at TLR4 and TLR2. The TLR4 antagonist CLI-095 fully blocked the action of LPS, but only partially that of Apo-SAA. Although the TLR2 antagonist CU-CPT22 was inactive against Apo-SAA, it also failed to block the TLR2 agonist Pam3CSK4. CONCLUSIONS Microglia are central to the inflammatory process and a major source of IL-1β when activated. P2X7R-triggered IL-1β maturation and export is thus likely to represent an important contributor to this cytokine pool. Given that SAA is detected in Alzheimer disease and multiple sclerosis brain, together with IL-1β-immunopositive microglia, these findings propose a link between P2X7R, SAA, and IL-1β in CNS pathophysiology.
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Affiliation(s)
- Laura Facci
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy
| | - Massimo Barbierato
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy
| | - Morena Zusso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy
| | - Stephen D Skaper
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Pietro Giusti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy
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Expression and Differential Responsiveness of Central Nervous System Glial Cell Populations to the Acute Phase Protein Serum Amyloid A. Sci Rep 2017; 7:12158. [PMID: 28939905 PMCID: PMC5610307 DOI: 10.1038/s41598-017-12529-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/12/2017] [Indexed: 02/07/2023] Open
Abstract
Acute-phase response is a systemic reaction to environmental/inflammatory insults and involves hepatic production of acute-phase proteins, including serum amyloid A (SAA). Extrahepatically, SAA immunoreactivity is found in axonal myelin sheaths of cortex in Alzheimer's disease and multiple sclerosis (MS), although its cellular origin is unclear. We examined the responses of cultured rat cortical astrocytes, microglia and oligodendrocyte precursor cells (OPCs) to master pro-inflammatory cytokine tumour necrosis factor (TNF)-α and lipopolysaccaride (LPS). TNF-α time-dependently increased Saa1 (but not Saa3) mRNA expression in purified microglia, enriched astrocytes, and OPCs (as did LPS for microglia and astrocytes). Astrocytes depleted of microglia were markedly less responsive to TNF-α and LPS, even after re-addition of microglia. Microglia and enriched astrocytes showed complementary Saa1 expression profiles following TNF-α or LPS challenge, being higher in microglia with TNF-α and higher in astrocytes with LPS. Recombinant human apo-SAA stimulated production of both inflammatory mediators and its own mRNA in microglia and enriched, but not microglia-depleted astrocytes. Co-ultramicronized palmitoylethanolamide/luteolin, an established anti-inflammatory/ neuroprotective agent, reduced Saa1 expression in OPCs subjected to TNF-α treatment. These last data, together with past findings suggest that co-ultramicronized palmitoylethanolamide/luteolin may be a novel approach in the treatment of inflammatory demyelinating disorders like MS.
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9
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Sun X, Hu X, Wang D, Yuan Y, Qin S, Tan Z, Gu Y, Huang X, He C, Su Z. Establishment and characterization of primary astrocyte culture from adult mouse brain. Brain Res Bull 2017; 132:10-19. [DOI: 10.1016/j.brainresbull.2017.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/05/2017] [Indexed: 01/06/2023]
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10
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Chandrasekaran A, Avci HX, Leist M, Kobolák J, Dinnyés A. Astrocyte Differentiation of Human Pluripotent Stem Cells: New Tools for Neurological Disorder Research. Front Cell Neurosci 2016; 10:215. [PMID: 27725795 PMCID: PMC5035736 DOI: 10.3389/fncel.2016.00215] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/30/2016] [Indexed: 12/22/2022] Open
Abstract
Astrocytes have a central role in brain development and function, and so have gained increasing attention over the past two decades. Consequently, our knowledge about their origin, differentiation and function has increased significantly, with new research showing that astrocytes cultured alone or co-cultured with neurons have the potential to improve our understanding of various central nervous system diseases, such as amyotrophic lateral sclerosis, Alzheimer’s disease, or Alexander disease. The generation of astrocytes derived from pluripotent stem cells (PSCs) opens up a new area for studying neurologic diseases in vitro; these models could be exploited to identify and validate potential drugs by detecting adverse effects in the early stages of drug development. However, as it is now known that a range of astrocyte populations exist in the brain, it will be important in vitro to develop standardized protocols for the in vitro generation of astrocyte subsets with defined maturity status and phenotypic properties. This will then open new possibilities for co-cultures with neurons and the generation of neural organoids for research purposes. The aim of this review article is to compare and summarize the currently available protocols and their strategies to generate human astrocytes from PSCs. Furthermore, we discuss the potential role of human-induced PSCs derived astrocytes in disease modeling.
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Affiliation(s)
| | - Hasan X Avci
- BioTalentum LtdGödöllő, Hungary; Department of Medical Chemistry, University of SzegedSzeged, Hungary
| | - Marcel Leist
- Dorenkamp-Zbinden Chair, Faculty of Mathematics and Sciences, University of Konstanz Konstanz, Germany
| | | | - Andras Dinnyés
- BioTalentum LtdGödöllő, Hungary; Molecular Animal Biotechnology Laboratory, Szent Istvan UniversityGödöllő, Hungary
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Braidy N, Rossez H, Lim CK, Jugder BE, Brew BJ, Guillemin GJ. Characterization of the Kynurenine Pathway in CD8 + Human Primary Monocyte-Derived Dendritic Cells. Neurotox Res 2016; 30:620-632. [PMID: 27510585 DOI: 10.1007/s12640-016-9657-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/06/2016] [Accepted: 07/29/2016] [Indexed: 12/27/2022]
Abstract
The kynurenine (KYN) pathway (KP) is a major degradative pathway of the amino acid, L-tryptophan (TRP), that ultimately leads to the anabolism of the essential pyridine nucleotide, nicotinamide adenine dinucleotide. TRP catabolism results in the production of several important metabolites, including the major immune tolerance-inducing metabolite KYN, and the neurotoxin and excitotoxin quinolinic acid. Dendritic cells (DCs) have been shown to mediate immunoregulatory roles that mediated by TRP catabolism. However, characterization of the KP in human DCs has so far only been partly delineated. It is critical to understand which KP enzymes are expressed and which KP metabolites are produced to be able to understand their regulatory effects on the immune response. In this study, we characterized the KP in human monocyte-derived DCs (MDDCs) in comparison with the human primary macrophages using RT-PCR, high-pressure gas chromatography, mass spectrometry, and immunocytochemistry. Our results show that the KP is entirely expressed in human MDDC. Following activation of the KP using interferon gamma, MDDCs can mediate apoptosis of T h cells in vitro. Understanding the molecular mechanisms regulating KP metabolism in MDDCs may provide renewed insight for the development of novel therapeutics aimed at modulating immunological effects and peripheral tolerance.
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Affiliation(s)
- Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia.
| | - Helene Rossez
- St Vincent's Centre for Applied Medical Research, Sydney, Australia
| | - Chai K Lim
- Neuropharmacology Group, MND and Neurodegenerative Diseases Research Centre, Macquarie University, Sydney, NSW, 2109, Australia
| | - Bat-Erdene Jugder
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Bruce J Brew
- St Vincent's Centre for Applied Medical Research, Sydney, Australia.,Department of Neurology and HIV Medicine, St Vincent's Hospital, Sydney, Australia
| | - Gilles J Guillemin
- Neuropharmacology Group, MND and Neurodegenerative Diseases Research Centre, Macquarie University, Sydney, NSW, 2109, Australia.
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Valekova I, Jarkovska K, Kotrcova E, Bucci J, Ellederova Z, Juhas S, Motlik J, Gadher SJ, Kovarova H. Revelation of the IFNα, IL-10, IL-8 and IL-1β as promising biomarkers reflecting immuno-pathological mechanisms in porcine Huntington's disease model. J Neuroimmunol 2016; 293:71-81. [PMID: 27049565 DOI: 10.1016/j.jneuroim.2016.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 02/12/2016] [Accepted: 02/17/2016] [Indexed: 12/25/2022]
Abstract
Studies on Huntington's disease (HD) demonstrated altered immune response in HD gene carriers. Using multiplexing immunoassay, we simultaneously investigated seven cytokines in secretomes of microglia and blood monocytes, cerebrospinal fluid (CSF) and serum collected from transgenic HD minipigs at pre-symptomatic disease stage. Decline in IFNα and IL-10 was observed in CSF and secretome of microglia whilst elevated IL-8 and IL-1β levels were secreted by microglia. Additionally, IL-8 was increased in serum. The proportion of mutant huntingtin in microglia may have causative impact on cytokine production. IFNα, IL-10, IL-8 and IL-1β represent promising biomarkers reflecting immuno-pathological mechanisms in porcine HD model.
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Affiliation(s)
- Ivona Valekova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic; Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, 128 43 Prague, Czech Republic
| | - Karla Jarkovska
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic
| | - Eva Kotrcova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic; Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, 128 43 Prague, Czech Republic
| | - John Bucci
- Thermo Fisher Scientific, 5791 Van Allen Way, Carlsbad, CA 92008, USA
| | - Zdenka Ellederova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic
| | - Stefan Juhas
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic
| | - Suresh Jivan Gadher
- Thermo Fisher Scientific - Life Science Solutions, 7335 Executive Way, Frederick, MD 21704, USA
| | - Hana Kovarova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, v.v.i., Rumburska 89, 277 21 Libechov, Czech Republic; Research Center PIGMOD, Rumburska 89, 277 21 Libechov, Czech Republic.
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13
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Marinelli C, Di Liddo R, Facci L, Bertalot T, Conconi MT, Zusso M, Skaper SD, Giusti P. Ligand engagement of Toll-like receptors regulates their expression in cortical microglia and astrocytes. J Neuroinflammation 2015; 12:244. [PMID: 26714634 PMCID: PMC4696218 DOI: 10.1186/s12974-015-0458-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/15/2015] [Indexed: 12/13/2022] Open
Abstract
Background Toll-like receptor (TLR) activation on microglia and astrocytes are key elements in neuroinflammation which accompanies a number of neurological disorders. While TLR activation on glia is well-established to up-regulate pro-inflammatory mediator expression, much less is known about how ligand engagement of one TLR may affect expression of other TLRs on microglia and astrocytes. Methods In the present study, we evaluated the effects of agonists for TLR2 (zymosan), TLR3 (polyinosinic-polycytidylic acid (poly(I:C)), a synthetic analogue of double-stranded RNA) and TLR4 (lipopolysaccaride (LPS)) in influencing expression of their cognate receptor as well as that of the other TLRs in cultures of rat cortical purified microglia (>99.5 %) and nominally microglia-free astrocytes. Elimination of residual microglia (a common contaminant of astrocyte cultures) was achieved by incubation with the lysosomotropic agent l-leucyl-l-leucine methyl ester (L-LME). Results Flow cytometric analysis confirmed the purity (essentially 100 %) of the obtained microglia, and up to 5 % microglia contamination of astrocytes. L-LME treatment effectively removed microglia from the latter (real-time polymerase chain reaction). The three TLR ligands robustly up-regulated gene expression for pro-inflammatory markers (interleukin-1 and interleukin-6, tumor necrosis factor) in microglia and enriched, but not purified, astrocytes, confirming cellular functionality. LPS, zymosan and poly(I:C) all down-regulated TLR4 messenger RNA (mRNA) and up-regulated TLR2 mRNA at 6 and 24 h. In spite of their inability to elaborate pro-inflammatory mediator output, the nominally microglia-free astrocytes (>99 % purity) also showed similar behaviours to those of microglia, as well as changes in TLR3 gene expression. LPS interaction with TLR4 activates downstream mitogen-activated protein kinase and nuclear factor-κB signalling pathways and subsequently causes inflammatory mediator production. The effects of LPS on TLR2 mRNA in both cell populations were antagonized by a nuclear factor-κB inhibitor. Conclusions TLR2 and TLR4 activation in particular, in concert with microglia and astrocytes, comprise key elements in the initiation and maintenance of neuropathic pain. The finding that both homologous (zymosan) and heterologous (LPS, poly(I:C)) TLR ligands are capable of regulating TLR2 gene expression, in particular, may have important implications in understanding the relative contributions of different TLRs in neurological disorders associated with neuroinflammation. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0458-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carla Marinelli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Rosa Di Liddo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Laura Facci
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Thomas Bertalot
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Maria Teresa Conconi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Morena Zusso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Stephen D Skaper
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Pietro Giusti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
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Jebelli J, Piers T, Pocock J. Selective Depletion of Microglia from Cerebellar Granule Cell Cultures Using L-leucine Methyl Ester. J Vis Exp 2015:e52983. [PMID: 26275019 DOI: 10.3791/52983] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Microglia, the resident immunocompetent cells of the CNS, play multifaceted roles in modulating and controlling neuronal function, as well as mediating innate immunity. Primary rodent cell culture models have greatly advanced our understanding of neuronal-glial interactions, but only recently have methods to specifically eliminate microglia from mixed cultures been utilized. One such technique - described here - is the use of L-leucine methyl ester, a lysomotropic agent that is internalized by macrophages and microglia, wherein it causes lysosomal disruption and subsequent apoptosis(13,14). Experiments using L-leucine methyl ester have the power to identify the contribution of microglia to the surrounding cellular environment under diverse culture conditions. Using a protocol optimized in our laboratory, we describe how to eliminate microglia from P5 rodent cerebellar granule cell culture. This approach allows one to assess the relative impact of microglia on experimental data, as well as determine whether microglia are playing a neuroprotective or neurotoxic role in culture models of neurological conditions, such as stroke, Alzheimer's or Parkinson's disease.
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Affiliation(s)
| | - Thomas Piers
- Therapeutic Innovation Group, School of Life and Medical Sciences, University College London
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15
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Cell transcriptional state alters genomic patterns of DNA double-strand break repair in human astrocytes. Nat Commun 2014; 5:5799. [PMID: 25517576 DOI: 10.1038/ncomms6799] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/07/2014] [Indexed: 01/11/2023] Open
Abstract
The misrepair of DNA double-strand breaks in close spatial proximity within the nucleus can result in chromosomal rearrangements that are important in the pathogenesis of haematopoietic and solid malignancies. It is unknown why certain epigenetic states, such as those found in stem or progenitor cells, appear to facilitate neoplastic transformation. Here we show that altering the transcriptional state of human astrocytes alters patterns of DNA damage repair from ionizing radiation at a gene locus-specific and genome-wide level. Astrocytes induced into a reactive state exhibit increased DNA repair, compared with non-reactive cells, in actively transcribed chromatin after irradiation. In mapping these repair sites, we identify misrepair events and repair hotspots that are unique to each state. The precise characterization of genomic regions susceptible to mutation in specific transcriptional states provides new opportunities for addressing clonal evolution in solid cancers, in particular those where double-strand break induction is a cornerstone of clinical intervention.
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16
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Toll-like receptors 2, -3 and -4 prime microglia but not astrocytes across central nervous system regions for ATP-dependent interleukin-1β release. Sci Rep 2014; 4:6824. [PMID: 25351234 PMCID: PMC5381369 DOI: 10.1038/srep06824] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/09/2014] [Indexed: 12/13/2022] Open
Abstract
Interleukin-1β (IL-1β) is a crucial mediator in the pathogenesis of inflammatory diseases at the periphery and in the central nervous system (CNS). Produced as an unprocessed and inactive pro-form which accumulates intracellularly, release of the processed cytokine is strongly promoted by ATP acting at the purinergic P2X7 receptor (P2X7R) in cells primed with lipopolysaccharide (LPS), a Toll-like receptor (TLR) 4 ligand. Microglia are central to the inflammatory process and a major source of IL-1β when activated. Here we show that purified (>99%) microglia cultured from rat cortex, spinal cord and cerebellum respond robustly to ATP-dependent IL-1β release, upon priming with a number of TLR isoform ligands (zymosan and Pam3CSK4 for TLR2, poly(I:C) for TLR3). Cytokine release was prevented by a P2X7R antagonist and inhibitors of stress-activated protein kinases. Enriched astrocytes (≤5% microglia) from these CNS regions displayed responses qualitatively similar to microglia but became unresponsive upon eradication of residual microglia with the lysosomotropic agent Leu-Leu-OMe. Activation of multiple TLR isoforms in nervous system pathology, coupled with elevated extracellular ATP levels and subsequent P2X7R activation may represent an important route for microglia-derived IL-1β. This phenomenon may have important consequences for neuroinflammation and its position to the common pathology of CNS diseases.
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17
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Pan Y, Chen XY, Zhang QY, Kong LD. Microglial NLRP3 inflammasome activation mediates IL-1β-related inflammation in prefrontal cortex of depressive rats. Brain Behav Immun 2014; 41:90-100. [PMID: 24859041 DOI: 10.1016/j.bbi.2014.04.007] [Citation(s) in RCA: 319] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/02/2014] [Accepted: 04/15/2014] [Indexed: 12/27/2022] Open
Abstract
Depression is an inflammatory disorder. Pro-inflammatory cytokine interleukin-1 beta (IL-1β) may play a pivotal role in the central nervous system (CNS) inflammation of depression. Here, we investigated IL-1β alteration in serum, cerebrospinal fluid (CSF) and prefrontal cortex (PFC) of chronic unpredictable mild stress (CUMS)-exposed rats, a well-documented model of depression, and further explored the molecular mechanism by which CUMS procedure induced IL-1β-related CNS inflammation. We showed that 12-week CUMS procedure remarkably increased PFC IL-1β mRNA and protein levels in depressive-like behavior of rats, without significant alteration of serum and CSF IL-1β levels. We found that CUMS procedure significantly caused PFC nuclear factor kappa B (NF-κB) inflammatory pathway activation in rats. The intriguing finding in this study was the induced activation of nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome with the increased IL-1β maturation in PFC of CUMS rats, suggesting a new grade of regulatory mechanism for IL-1β-related CNS inflammation. Moreover, microglial activation and astrocytic function impairment were observed in PFC of CUMS rats. The increased co-location of NLRP3 and ionized calcium binding adaptor molecule 1 (Iba1) protein expression supported that microglia in glial cells was the primary contributor for CUMS-induced PFC NLRP3 inflammasome activation in rats. These alterations in CUMS rats were restored by chronic treatment of the antidepressant fluoxetine, indicating that fluoxetine-mediated rat PFC IL-1β reduction involves both transcriptional and post-transcriptional regulatory mechanisms. These findings provide in vivo evidence that microglial NLRP3 inflammasome activation is a mediator of IL-1β-related CNS inflammation during chronic stress, and suggest a new therapeutic target for the prevention and treatment of depression.
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Affiliation(s)
- Ying Pan
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, PR China
| | - Xu-Yang Chen
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, PR China
| | - Qing-Yu Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, PR China
| | - Ling-Dong Kong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, PR China.
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18
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Tosi G, Vilella A, Chhabra R, Schmeisser MJ, Boeckers TM, Ruozi B, Vandelli MA, Forni F, Zoli M, Grabrucker AM. Insight on the fate of CNS-targeted nanoparticles. Part II: Intercellular neuronal cell-to-cell transport. J Control Release 2014; 177:96-107. [DOI: 10.1016/j.jconrel.2014.01.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 12/23/2013] [Accepted: 01/02/2014] [Indexed: 01/01/2023]
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19
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Hinojosa AE, Caso JR, García-Bueno B, Leza JC, Madrigal JLM. Dual effects of noradrenaline on astroglial production of chemokines and pro-inflammatory mediators. J Neuroinflammation 2013; 10:81. [PMID: 23837880 PMCID: PMC3708781 DOI: 10.1186/1742-2094-10-81] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/29/2013] [Indexed: 11/23/2022] Open
Abstract
Background Noradrenaline (NA) is known to limit neuroinflammation. However, the previously described induction by NA of a chemokine involved in the progression of immune/inflammatory processes, such as chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein-1 (MCP-1), apparently contradicts NA anti-inflammatory actions. In the current study we analyzed NA regulation of astroglial chemokine (C-X3-C motif) ligand 1 (CX3CL1), also known as fractalkine, another chemokine to which both neuroprotective and neurodegenerative actions have been attributed. In addition, NA effects on other chemokines and pro-inflammatory mediators were also analyzed. Methods Primary astrocyte-enriched cultures were obtained from neonatal Wistar rats. These cells were incubated for different time durations with combinations of NA and lipopolysaccharide (LPS). The expression and synthesis of different proteins was measured by RT-PCR and enzyme-linked immunosorbent assay (ELISA) or enzyme immunoassays. Data were analyzed by one-way analysis of variance (ANOVA), followed by Newman-Keuls multiple comparison tests. Results The data presented here show that in control conditions, NA induces the production of CX3CL1 in rat cultured astrocytes, but in the presence of an inflammatory stimulus, such as LPS, NA has the opposite effect inhibiting CX3CL1 production. This inversion of NA effect was also observed for MCP-1. Based on the observation of this dual action, NA regulation of different chemokines and pro-inflammatory cytokines was also analyzed, observing that in most cases NA exerts an inhibitory effect in the presence of LPS. One characteristic exception was the induction of cyclooxygenase-2 (COX-2), where a summative effect was detected for both LPS and NA. Conclusion These data suggest that NA effects on astrocytes can adapt to the presence of an inflammatory agent reducing the production of certain cytokines, while in basal conditions NA may have the opposite effect and help to maintain moderate levels of these cytokines.
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Affiliation(s)
- Ara E Hinojosa
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Centro de Investigación Biomédica en Red de Salud Mental, Instituto de Investigación Hospital 12 de Octubre, Avenida Complutense s/n, Madrid, Spain
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20
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Renner NA, Sansing HA, Inglis FM, Mehra S, Kaushal D, Lackner AA, Maclean AG. Transient acidification and subsequent proinflammatory cytokine stimulation of astrocytes induce distinct activation phenotypes. J Cell Physiol 2013; 228:1284-94. [PMID: 23154943 DOI: 10.1002/jcp.24283] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 11/02/2012] [Indexed: 01/18/2023]
Abstract
The foot processes of astrocytes cover over 60% of the surface of brain microvascular endothelial cells, regulating tight junction integrity. Retraction of astrocyte foot processes has been postulated to be a key mechanism in pathology. Therefore, movement of an astrocyte in response to a proinflammatory cytokine or even limited retraction of processes would result in leaky junctions between endothelial cells. Astrocytes lie at the gateway to the CNS and are instrumental in controlling leukocyte entry. Cultured astrocytes typically have a polygonal morphology until stimulated. We hypothesized that cultured astrocytes which were induced to stellate would have an activated phenotype compared with polygonal cells. We investigated the activation of astrocytes derived from adult macaques to the cytokine TNF-α under resting and stellated conditions by four parameters: morphology, intermediate filament expression, adhesion, and cytokine secretion. Astrocytes were stellated following transient acidification; resulting in increased expression of GFAP and vimentin. Stellation was accompanied by decreased adhesion that could be recovered with proinflammatory cytokine treatment. Surprisingly, there was decreased secretion of proinflammatory cytokines by stellated astrocytes compared with polygonal cells. These results suggest that astrocytes are capable of multiple phenotypes depending on the stimulus and the order stimuli are applied.
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Affiliation(s)
- Nicole A Renner
- Program in Neuroscience, Tulane University, New Orleans, LA, USA
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21
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Szabo M, Gulya K. Development of the microglial phenotype in culture. Neuroscience 2013; 241:280-95. [PMID: 23535251 DOI: 10.1016/j.neuroscience.2013.03.033] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 01/01/2023]
Abstract
Selected morphological, molecular and functional aspects of various microglial cell populations were characterized in cell cultures established from the forebrains of E18 rat embryos. The mixed primary cortical cultures were maintained for up to 28days using routine culturing techniques when the microglial cells in the culture were not stimulated or immunologically challenged. During culturing, expansion of the microglial cell populations was observed, as evidenced by quantitative assessment of selected monocyte/macrophage/microglial cell-specific markers (human leukocyte antigen (HLA) DP, DQ, DR, CD11b/c and Iba1) via immunocyto- and histochemistry and Western blot analysis. The Iba1 immunoreactivity in Western blots steadily increased about 750-fold, and the number of Iba1-immunoreactive cells rose at least 67-fold between one day in vitro (DIV1) and DIV28. Morphometric analysis on binary (digital) silhouettes of the microglia revealed their evolving morphology during culturing. Microglial cells were mainly ameboid in the early stages of in vitro differentiation, while mixed populations of ameboid and ramified cell morphologies were characteristic of older cultures as the average transformation index (TI) increased from 1.96 (DIV1) to 15.17 (DIV28). Multiple immunofluorescence labeling of selected biomarkers revealed different microglial phenotypes during culturing. For example, while HLA DP, DQ, DR immunoreactivity was present exclusively in ameboid microglia (TI<3) between DIV1 and DIV10, CD11b/c- and Iba1-positive microglial cells were moderately (TI<13) and progressively (TI<81) more ramified, respectively, and always present throughout culturing. Regardless of the age of the cultures, proliferating microglia were Ki67-positive and characterized by low TI values (TI<3). The microglial function was assessed by an in vitro phagocytosis assay. Unstimulated microglia with low TI values were significantly more active in phagocytosing fluorescent microspheres than the ramified forms. In vitro studies on microglial population dynamics combined with phenotypic characterization can be of importance when different in vivo pathophysiological situations are modeled in vitro.
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Affiliation(s)
- M Szabo
- Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
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22
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Kumamaru H, Saiwai H, Kobayakawa K, Kubota K, van Rooijen N, Inoue K, Iwamoto Y, Okada S. Liposomal clodronate selectively eliminates microglia from primary astrocyte cultures. J Neuroinflammation 2012; 9:116. [PMID: 22651847 PMCID: PMC3419615 DOI: 10.1186/1742-2094-9-116] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 05/31/2012] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND There is increasing interest in astrocyte biology because astrocytes have been demonstrated to play prominent roles in physiological and pathological conditions of the central nervous system, including neuroinflammation. To understand astrocyte biology, primary astrocyte cultures are most commonly used because of the direct accessibility of astrocytes in this system. However, this advantage can be hindered by microglial contamination. Although several authors have warned regarding microglial contamination in this system, complete microglial elimination has never been achieved. METHODS The number and proliferative potential of contaminating microglia in primary astrocyte cultures were quantitatively assessed by immunocytologic and flow cytometric analyses. To examine the utility of clodronate for microglial elimination, primary astrocyte cultures or MG-5 cells were exposed to liposomal or free clodronate, and then immunocytologic, flow cytometric, and gene expression analyses were performed. The gene expression profiles of microglia-eliminated and microglia-contaminated cultures were compared after interleukin-6 (IL-6) stimulation. RESULTS The percentage of contaminating microglia exceeded 15% and continued to increase because of their high proliferative activity in conventional primary astrocyte cultures. These contaminating microglia were selectively eliminated low concentration of liposomal clodronate. Although primary microglia and MG-5 cells were killed by both liposomal and free clodronate, free clodronate significantly affected the viability of astrocytes. In contrast, liposomal clodronate selectively eliminated microglia without affecting the viability, proliferation or activation of astrocytes. The efficacy of liposomal clodronate was much higher than that of previously reported methods used for decreasing microglial contamination. Furthermore, we observed rapid tumor necrosis factor-α and IL-1b gene induction in conventional primary astrocyte cultures after IL-6 stimulation, which was due to the activation of the Janus kinase/signal transducer and activator of the transcription pathway in contaminating microglia. CONCLUSIONS Because contaminating microglia could result in erroneous data regarding the pro-inflammatory properties of astrocytes, astrocyte biology should be studied in the absence of microglial contamination. Our simple method will be widely applicable to experimental studies of astrocyte biology and provide clues for understanding the role of astrocytes in neural development, function and disease.
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Affiliation(s)
- Hiromi Kumamaru
- Department of Orthopedic Surgery, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Uliasz TF, Hamby ME, Jackman NA, Hewett JA, Hewett SJ. Generation of primary astrocyte cultures devoid of contaminating microglia. Methods Mol Biol 2012; 814:61-79. [PMID: 22144300 DOI: 10.1007/978-1-61779-452-0_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Microglia, resident phagocytic cells of the central nervous system, are frequent contaminants of astrocyte cultures. Unfortunately and not always fully appreciated, contamination by microglia can confound results of studies designed to elucidate the molecular mechanisms underlying astrocyte-specific responses. The paradigm described herein employs the mitotic inhibitor, cytosine β-D: -arabinofuranoside, followed by the lysosomotropic agent, leucine methylester, to maximally deplete microglia, thereby generating highly enriched astrocyte monolayers that remain viable and functional. Successful removal of microglia from confluent monolayers of primary astrocyte cultures is achieved without the need for cell passage and successful reduction is confirmed by depletion of microglial-specific markers.
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Affiliation(s)
- Tracy F Uliasz
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
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24
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Microglial carbohydrate-binding receptors for neural repair. Cell Tissue Res 2012; 349:215-27. [DOI: 10.1007/s00441-012-1342-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 01/25/2012] [Indexed: 01/04/2023]
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Lee MC, Ting KK, Adams S, Brew BJ, Chung R, Guillemin GJ. Characterisation of the expression of NMDA receptors in human astrocytes. PLoS One 2010; 5:e14123. [PMID: 21152063 PMCID: PMC2994931 DOI: 10.1371/journal.pone.0014123] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 10/26/2010] [Indexed: 12/14/2022] Open
Abstract
Astrocytes have long been perceived only as structural and supporting cells within the central nervous system (CNS). However, the discovery that these glial cells may potentially express receptors capable of responding to endogenous neurotransmitters has resulted in the need to reassess astrocytic physiology. The aim of the current study was to characterise the expression of NMDA receptors (NMDARs) in primary human astrocytes, and investigate their response to physiological and excitotoxic concentrations of the known endogenous NMDAR agonists, glutamate and quinolinic acid (QUIN). Primary cultures of human astrocytes were used to examine expression of these receptors at the mRNA level using RT-PCR and qPCR, and at the protein level using immunocytochemistry. The functionality role of the receptors was assessed using intracellular calcium influx experiments and measuring extracellular lactate dehydrogenase (LDH) activity in primary cultures of human astrocytes treated with glutamate and QUIN. We found that all seven currently known NMDAR subunits (NR1, NR2A, NR2B, NR2C, NR2D, NR3A and NR3B) are expressed in astrocytes, but at different levels. Calcium influx studies revealed that both glutamate and QUIN could activate astrocytic NMDARs, which stimulates Ca2+ influx into the cell and can result in dysfunction and death of astrocytes. Our data also show that the NMDAR ion channel blockers, MK801, and memantine can attenuate glutamate and QUIN mediated cell excitotoxicity. This suggests that the mechanism of glutamate and QUIN gliotoxicity is at least partially mediated by excessive stimulation of NMDARs. The present study is the first to provide definitive evidence for the existence of functional NMDAR expression in human primary astrocytes. This discovery has significant implications for redefining the cellular interaction between glia and neurons in both physiological processes and pathological conditions.
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Affiliation(s)
- Ming-Chak Lee
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Ka Ka Ting
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Seray Adams
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Bruce J. Brew
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
- Departments of Neurology and HIV Medicine, St. Vincent's Hospital, Sydney, Australia
| | - Roger Chung
- NeuroRepair Group, Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia
| | - Gilles J. Guillemin
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
- * E-mail:
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26
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Sbai O, Ould-Yahoui A, Ferhat L, Gueye Y, Bernard A, Charrat E, Mehanna A, Risso JJ, Chauvin JP, Fenouillet E, Rivera S, Khrestchatisky M. Differential vesicular distribution and trafficking of MMP-2, MMP-9, and their inhibitors in astrocytes. Glia 2010; 58:344-66. [PMID: 19780201 DOI: 10.1002/glia.20927] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes play an active role in the central nervous system and are critically involved in astrogliosis, a homotypic response of these cells to disease, injury, and associated neuroinflammation. Among the numerous molecules involved in these processes are the matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, secreted or membrane-bound, that regulate by proteolytic cleavage the extracellular matrix, cytokines, chemokines, cell adhesion molecules, and plasma membrane receptors. MMP activity is tightly regulated by the tissue inhibitors of MMPs (TIMPs), a family of secreted multifunctional proteins. Astrogliosis in vivo and astrocyte reactivity induced in vitro by proinflammatory cues are associated with modulation of expression and/or activity of members of the MMP/TIMP system. However, nothing is known concerning the intracellular distribution and secretory pathways of MMPs and TIMPs in astrocytes. Using a combination of cell biology, biochemistry, fluorescence and electron microscopy approaches, we investigated in cultured reactive astrocytes the intracellular distribution, transport, and secretion of MMP-2, MMP-9, TIMP-1, and TIMP-2. MMP-2 and MMP-9 demonstrate nuclear localization, differential intracellular vesicular distribution relative to the myosin V and kinesin molecular motors, and LAMP-2-labeled lysosomal compartment, and we show vesicular secretion for MMP-2, MMP-9, and their inhibitors. Our results suggest that these proteinases and their inhibitors use different pathways for trafficking and secretion for distinct astrocytic functions.
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Affiliation(s)
- Oualid Sbai
- Neurobiologie des Interactions Cellulaires et Neurophysiopathologie, UMR 6184 CNRS--Université de la Méditerranée, Faculté de Médecine, 51 Boulevard Pierre Dramard, Marseille Cedex 15, France
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27
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Moussaud S, Draheim HJ. A new method to isolate microglia from adult mice and culture them for an extended period of time. J Neurosci Methods 2010; 187:243-53. [DOI: 10.1016/j.jneumeth.2010.01.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 01/14/2010] [Accepted: 01/15/2010] [Indexed: 12/25/2022]
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28
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Ting KK, Brew BJ, Guillemin GJ. Effect of quinolinic acid on human astrocytes morphology and functions: implications in Alzheimer's disease. J Neuroinflammation 2009; 6:36. [PMID: 20003262 PMCID: PMC2797503 DOI: 10.1186/1742-2094-6-36] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/10/2009] [Indexed: 02/06/2023] Open
Abstract
The excitotoxin quinolinic acid (QUIN) is synthesized through the kynurenine pathway (KP) by activated monocyte lineage cells. QUIN is likely to play a role in the pathogenesis of several major neuroinflammatory diseases including Alzheimer's disease (AD). The presence of reactive astrocytes, astrogliosis, increased oxidative stress and inflammatory cytokines are important pathological hallmarks of AD. We assessed the stimulatory effects of QUIN at low physiological to high excitotoxic concentrations in comparison with the cytokines commonly associated with AD including IFN-γ and TNF-α on primary human astrocytes. We found that QUIN induces IL-1β expression, a key mediator in AD pathogenesis, in human astrocytes. We also explored the effect of QUIN on astrocyte morphology and functions. At low concentrations, QUIN treatment induced concomitantly a marked increase in glial fibrillary acid protein levels and reduction in vimentin levels compared to controls; features consistent with astrogliosis. At pathophysiological concentrations QUIN induced a switch between structural protein expressions in a dose dependent manner, increasing VIM and concomitantly decreasing GFAP expression. Glutamine synthetase (GS) activity was used as a functional metabolic test for astrocytes. We found a significant dose-dependent reduction in GS activity following QUIN treatment. All together, this study showed that QUIN is an important factor for astroglial activation, dysregulation and cell death with potential relevance to AD and other neuroinflammatory diseases.
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Affiliation(s)
- Ka Ka Ting
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
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29
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Shah VB, Ozment-Skelton TR, Williams DL, Keshvara L. Vav1 and PI3K are required for phagocytosis of β-glucan and subsequent superoxide generation by microglia. Mol Immunol 2009; 46:1845-53. [DOI: 10.1016/j.molimm.2009.01.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2008] [Accepted: 01/07/2009] [Indexed: 12/28/2022]
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30
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Orlando EA, Imbschweiler I, Gerhauser I, Baumgärtner W, Wewetzer K. In vitro characterization and preferential infection by canine distemper virus of glial precursors with Schwann cell characteristics from adult canine brain. Neuropathol Appl Neurobiol 2009; 34:621-37. [PMID: 19076697 DOI: 10.1111/j.1365-2990.2008.00958.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS Canine distemper virus (CDV)-induced demyelinating leukoencephalomyelitis is a naturally occurring model for multiple sclerosis. The aim of this study was to establish primary glial cell cultures from adult canine brain for the analysis of CDV spread and cell tropism. METHODS Cultures were inoculated with the CDV-R252 and a CDV-Onderstepoort strain expressing the green fluorescent protein (CDV-OndeGFP). CDV antigen expression was studied using cell type-specific antibodies at different days post infection. Glial cells expressing p75(NTR) were purified using antibody-based techniques and characterized with regard to antigen expression and proliferation. RESULTS Three weeks after seeding, cultures contained spindle-shaped cells expressing p75(NTR), oligodendrocytic cells, astrocytes, microglia and fibroblasts. Both CDV strains induced a mild to moderate cytopathic effect that consisted of single necrotic and few syncytial giant cells, but displayed in part a differential cell tropism. Whereas CDV-OndeGFP expression in microglia and astrocytes did not exceed 1% and 50%, respectively, CDV-R252 infected 100% and 80% of both cell types, respectively. The cells most early infected by both CDV strains expressed p75(NTR) and may correlate to cells previously identified as aldynoglia. Treatment of p75(NTR+) cells with Schwann cell mitogens and serum deprivation increased proliferation and A2B5 expression, respectively, indicating common properties compared with Schwann cells and oligodendrocyte precursors. CONCLUSIONS Infection of adult canine astrocytes and microglia revealed CDV strain-specific cell tropism. Moreover, this is the first identification of a glial cell type with Schwann cell-like properties in adult canine brain and, more importantly, these cells displayed a high susceptibility to CDV infection.
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Affiliation(s)
- E A Orlando
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
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31
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Tambuyzer BR, Ponsaerts P, Nouwen EJ. Microglia: gatekeepers of central nervous system immunology. J Leukoc Biol 2008; 85:352-70. [DOI: 10.1189/jlb.0608385] [Citation(s) in RCA: 238] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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32
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Abstract
The kynurenine pathway is a major route of L-tryptophan catabolism producing neuroactive metabolites implicated in neurodegeneration and immune tolerance. We characterized the kynurenine pathway in human neurons and the human SK-N-SH neuroblastoma cell line and found that the kynurenine pathway enzymes were variably expressed. Picolinic carboxylase was expressed only in primary and some adult neurons but not in SK-N-SH cells. Because of this difference, SK-N-SH cells were able to produce the excitotoxin quinolinic acid, whereas human neurons produced the neuroprotectant picolinic acid. The net result of kynurenine pathway induction in human neurons is therefore predicted to result in neuroprotection, immune regulation, and tumor inhibition, whereas in SK-N-SH cells, it may result in neurotoxicity, immune tolerance, and tumor promotion. This study represents the first comprehensive characterization of the kynurenine pathway in neurons and the first description of the involvement of the kynurenine pathway as a mechanism for controlling both tumor cell neurotoxicity and persistence.
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33
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Ting KK, Brew BJ, Guillemin GJ. Effect of quinolinic acid on gene expression in human astrocytes: Implications for Alzheimer's disease. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.ics.2007.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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34
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Nakajima K, Graeber MB, Sonoda M, Tohyama Y, Kohsaka S, Kurihara T. In vitro proliferation of axotomized rat facial nucleus-derived activated microglia in an autocrine fashion. J Neurosci Res 2006; 84:348-59. [PMID: 16673407 DOI: 10.1002/jnr.20882] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Transection of rat adult facial nerve leads to an increase in the number of activated microglia in the facial nucleus (FN), with a peak in proliferation 3 days after transection. To investigate the characteristics of these activated microglia, we isolated the cells with high purity from axotomized FN (axFN) 3 days after transection according to the previously reported procedure for explant culture. The isolated microglia exhibited immunocytochemical properties similar to those in vivo, and their numbers increased approximately five- to sevenfold over a period of 10 days without the addition of any mitogens, suggesting that self-reproduction was occurring. Actually, the microglia actively incorporated bromodeoxyuridine (BrdU) and strongly expressed an S-phase-specific protein marker, proliferating cell nuclear antigen (PCNA). To examine the mechanism underlying this proliferation, the expression of the mitogens and specific receptors of the microglia were analyzed in conditioned medium (CM) and cells. Macrophage-colony stimulating factor (M-CSF) and granulocyte macrophage-CSF (GM-CSF) were detected in the CM as well as in the cells. Their specific receptor proteins, c-Fms and GMCSFRalpha, were also detected in the cell homogenate. These proliferating microglia were not found to produce deleterious factors for neurons. In summary, the microglia isolated from the axFN were found to be proliferative in an autocrine fashion and to have some cellular properties in common with those observed in vivo.
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Affiliation(s)
- Kazuyuki Nakajima
- Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan.
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35
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Hamby ME, Uliasz TF, Hewett SJ, Hewett JA. Characterization of an improved procedure for the removal of microglia from confluent monolayers of primary astrocytes. J Neurosci Methods 2005; 150:128-37. [PMID: 16105687 DOI: 10.1016/j.jneumeth.2005.06.016] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Revised: 06/15/2005] [Accepted: 06/15/2005] [Indexed: 11/26/2022]
Abstract
Cultures of astrocytes can be readily established and are widely used to study the biological functions of these glial cells in isolation. Unfortunately, contamination by microglia can confound results from such studies. Herein, a simple and highly effective modification of a common procedure to remove microglia from astrocyte cultures is described. After becoming confluent, astrocytes were exposed to a mitotic inhibitor for 5-6 days then treated with 50-75 mM l-leucine methyl ester (LME) for 60-90 min. Unlike previous protocols that employed lower LME concentrations on subconfluent cultures or during passage of astrocytes, this protocol effectively depleted microglia from high-density astrocyte monolayers. This was evidenced by the selective depletion of microglial-specific markers. Purified monolayers appeared morphologically normal 24h after LME treatment and expressed nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2) proteins upon stimulation with LPS plus IFNgamma, albeit to a lower level than unpurified monolayers. This difference could be attributed to removal of contaminating microglia from monolayers and not to astrocyte dysfunction, since LME treatment did not alter global protein synthesis and a reactive phenotype could be induced in the purified monolayers. Thus, this modified protocol selectively depletes microglia from high-density primary astrocyte monolayers without compromising their functional integrity.
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Affiliation(s)
- Mary E Hamby
- Department of Neuroscience MC 3401, University of Connecticut Health Center, 263 Farmington Avenue, CT 06030-3401, USA
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36
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Guillemin GJ, Wang L, Brew BJ. Quinolinic acid selectively induces apoptosis of human astrocytes: potential role in AIDS dementia complex. J Neuroinflammation 2005; 2:16. [PMID: 16042813 PMCID: PMC1187916 DOI: 10.1186/1742-2094-2-16] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Accepted: 07/26/2005] [Indexed: 12/30/2022] Open
Abstract
There is evidence that the kynurenine pathway (KP) and particularly one of its end products, quinolinic acid (QUIN) play a role in the pathogenesis of several major neuroinflammatory diseases, and more particularly AIDS dementia complex (ADC). We hypothesized that QUIN may be involved in astrocyte apoptosis because: 1) apoptotic astrocytes have been observed in the brains of ADC patients, 2) ADC patients have elevated cerebrospinal fluid QUIN concentrations, and 3) QUIN can induce astrocyte death. Primary cultures of human fetal astrocytes were treated with three pathophysiological concentrations of QUIN. Numeration of apoptotic cells was assessed using double immunocytochemistry for expression of active caspase 3 and for nucleus condensation. We found that treatment of human astrocytes with QUIN induced morphological (cell body shrinking) and biochemical changes (nucleus condensation and over-expression of active caspase 3) of apoptosis. After 24 hours of treatment with QUIN 500 nM and 1200 nM respectively 10 and 14% of astrocytes were undergoing apoptosis. This would be expected to lead to a relative lack of trophic support factors with consequent neuronal dysfunction and possibly death. Astroglial apoptosis induced by QUIN provides another potential mechanism for the neurotoxicity of QUIN during ADC.
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Affiliation(s)
- Gilles J Guillemin
- Centre for Immunology, St Vincent's Hospital, Sydney, Australia
- University of New South Wales, Faculty of Medicine, Sydney, Australia
| | - Lily Wang
- Centre for Immunology, St Vincent's Hospital, Sydney, Australia
| | - Bruce J Brew
- Centre for Immunology, St Vincent's Hospital, Sydney, Australia
- Department of Neurology, St Vincent's Hospital, Sydney, Australia
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37
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Rosin C, Colombo S, Calver AA, Bates TE, Skaper SD. Dopamine D2 and D3 receptor agonists limit oligodendrocyte injury caused by glutamate oxidative stress and oxygen/glucose deprivation. Glia 2005; 52:336-43. [PMID: 16078234 DOI: 10.1002/glia.20250] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dopamine receptor activation is thought to contribute adversely to several neuropathological disorders, including Parkinson's disease and schizophrenia. In addition, dopamine may have a neuroprotective role: dopamine receptor agonists are reported to protect nerve cells by virtue of their antioxidant properties as well as by receptor-mediated mechanisms. White matter injury can also be a significant factor in neurological disorders. Using real-time RT-PCR, we show that differentiated rat cortical oligodendrocytes express dopamine D2 receptor and D3 receptor mRNA. Oligodendrocytes were vulnerable to oxidative glutamate toxicity and to oxygen/glucose deprivation injury. Agonists for dopamine D2 and D3 receptors provided significant protection of oligodendrocytes against these two forms of injury, and the protective effect was diminished by D2 and D3 antagonists. Levels of oligodendrocyte D2 receptor and D3 receptor protein, as measured by Western blotting, appeared to increase following combined oxygen and glucose deprivation. Our results suggest that dopamine D2 and D3 receptor activation may play an important role in oligodendrocyte protection against oxidative glutamate toxicity and oxygen-glucose deprivation injury.
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MESH Headings
- Animals
- Cell Death/drug effects
- Cell Death/physiology
- Cells, Cultured
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Glucose/metabolism
- Glutamic Acid/metabolism
- Hypoxia-Ischemia, Brain/metabolism
- Hypoxia-Ischemia, Brain/physiopathology
- Hypoxia-Ischemia, Brain/prevention & control
- Oligodendroglia/drug effects
- Oligodendroglia/metabolism
- Oxidative Stress/drug effects
- Oxidative Stress/physiology
- Oxygen/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine/genetics
- Receptors, Dopamine/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Receptors, Dopamine D3/genetics
- Receptors, Dopamine D3/metabolism
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Affiliation(s)
- Claudia Rosin
- Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development Limited, Harlow, United Kingdom
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38
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Guillemin GJ, Smith DG, Smythe GA, Armati PJ, Brew BJ. Expression of the kynurenine pathway enzymes in human microglia and macrophages. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 527:105-12. [PMID: 15206722 DOI: 10.1007/978-1-4615-0135-0_12] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There is good evidence that the kynurenine pathway (KP) and one of its products, quinolinic acid (QUIN) play a role in the pathogenesis of neurological diseases. Monocytic cells are known to be the major producers of QUIN. However, macrophages have the ability to produce approximately 20 to 30-fold more QUIN than microglia. The molecular origin of this difference has not been clarified yet. Using unstimulated and IFN-gamma-stimulated cultures of human fcetal microglia and adult macrophages, we assayed mRNA expression of 8 key enzymes of the KP using RT-PCR and QUIN production using GC-MS. We found that after stimulation with IFN-gamma microglia produced de novo 20-fold less QUIN than macrophages. This quantitative difference in the ability to produce QUIN appears to be associated with a lower expression of 3 important enzymes of the KP in microglia: indoleamine 2,3-dioxygenase (IDO), kynureninase (KYNase) and kynurenine hydroxylase (KYN(OH)ase). These results suggest that activated infiltrating macrophages are the most potent QUIN producers during brain inflammatory diseases with playing a lesser role.
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39
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Lévêque T, Le Pavec G, Boutet A, Tardieu M, Dormont D, Gras G. Differential regulation of gelatinase A and B and TIMP-1 and -2 by TNFalpha and HIV virions in astrocytes. Microbes Infect 2004; 6:157-63. [PMID: 14998513 DOI: 10.1016/j.micinf.2003.11.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Accepted: 11/05/2003] [Indexed: 11/28/2022]
Abstract
Changes in the fine balance between matrix metalloproteinases and their tissue inhibitors, which drives extracellular matrix turnover, may be critical to central nervous system inflammation in HIV infection as well as in neurotoxicity. Although they do not produce virus when infected by HIV, astrocytes may be directly affected by the virion, because some viral proteins are known to transduce signaling in brain cells and are also sensitive to the major proinflammatory cytokine TNFalpha. We therefore studied the effects of HIV and TNFalpha on MMP-2, MMP-9 and their inhibitors, TIMP-1 and TIMP-2, in astrocytes, by zymography and ELISA, respectively, or by RT-PCR for both of them. HIV slightly increased the production of pro-MMP-2 and pro-MMP-9 by astrocytes, in a dose-dependent manner. TNFalpha strongly induced pro-MMP-9. TIMP-1 and TIMP-2 levels were affected only slightly, if at all, by HIV and TNFalpha. Thus, astrocyte/HIV contact may lead to extracellular matrix activation, which may be strongly amplified by the inflammatory response. Our data strongly suggest that, besides their physiological production of MMP-2, astrocytes would be a major source of MMP-9 in the inflamed brain.
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Affiliation(s)
- Thierry Lévêque
- Laboratoire de Neuro-Immuno-Virologie, Service de Neurovirologie, Commissariat à l'Energie Atomique and Université Paris-Sud, Centre de Recherches du Service de Santé des Armées, Institut Paris-Sud Cytokines, Ecole Pratique des Hautes Etudes, France
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40
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Guillemin GJ, Smythe GA, Veas LA, Takikawa O, Brew BJ. A beta 1-42 induces production of quinolinic acid by human macrophages and microglia. Neuroreport 2004; 14:2311-5. [PMID: 14663182 DOI: 10.1097/00001756-200312190-00005] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We hypothesized that the tryptophan catabolites produced through the kynurenine pathway (KP), and more particularly the excitotoxin quinolinic acid (QUIN), may play an important role in the pathogenesis of Alzheimer's disease (AD). In this study, we demonstrated that aggregated amyloid peptide A beta 1-42 induced indoleamine 2,3-dioxygenase (IDO) expression and resulted in a significant increase in production of QUIN by human primary macrophages and microglia. In contrast, A beta 1-40 and prion peptide (PrP) 106-126 did not induce any significant increase in QUIN production. These data imply that local QUIN production may be one of the factors involved in the pathogenesis of neuronal damage in AD.
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Affiliation(s)
- Gilles J Guillemin
- Centre for Immunology, St. Vincent's Hospital, Darlinghurst, NSW 2010, Australia.
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41
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Guillemin GJ, Smythe G, Takikawa O, Brew BJ. Expression of indoleamine 2,3-dioxygenase and production of quinolinic acid by human microglia, astrocytes, and neurons. Glia 2004; 49:15-23. [PMID: 15390107 DOI: 10.1002/glia.20090] [Citation(s) in RCA: 363] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
There is good evidence that the kynurenine pathway (KP) and one of its end products, quinolinic acid (QUIN) play a role in the pathogenesis of several major neurological diseases. While QUIN has been shown to be produced in neurotoxic concentrations by macrophages and microglia, the capacity of astrocytes and neurons to produce QUIN is controversial. Using interferon gamma (IFN-gamma)-stimulated primary cultures of human mixed brain cells, we assayed expression of the KP regulatory enzyme indoleamine 2,3-dioxygenase (IDO) and QUIN production by immunocytochemistry. Using IFN-gamma-stimulated purified cultures of neurons, astrocytes, microglia and macrophages, we studied IDO expression by RT-PCR and production of QUIN using mass spectrometry. We found that astrocytes, neurons, and microglia expressed IDO but only microglia were able to produce detectable amounts of QUIN. However, astrocytes and neurons had the ability to catabolize QUIN. This study also provides the first evidence of IDO expression and lack of production of QUIN in culture of primary human neurons.
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42
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Houalla T, Levine RL. The isolation and culture of microglia-like cells from the goldfish brain. J Neurosci Methods 2003; 131:121-31. [PMID: 14659832 DOI: 10.1016/j.jneumeth.2003.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have developed a method for isolating goldfish microglia. Cells were identified as microglia immunohistochemically with NN-2, a monoclonal antibody (MAb) raised against teleost retinal microglial cells, and by their phagocytic abilities. Morphological characterization of the cells identified round, phase-bright cells as well as flattened macrophage-like cells. Ramified cells were also seen but they were rare. Fusion of macrophage-like cells occurred in high density cultures and resulted in the formation of giant cells that disintegrated a few days later. Immunohistochemical studies demonstrated that virtually all of the cells in our cultures were NN-2+ and did not label with either antiGFAP (an astrocyte marker) or MAb 6D2 (an oligodendrocyte marker). Cells identified as microglia were intensely phagocytic and ingested latex microspheres, DiIAcLDL and goldfish myelin in vitro. In addition, we labelled microglial cells in vivo with intracranial injections of fluorescent dextran and found that microglia isolated from these animals contained the dextran and phagocytosed microspheres. We also studied the effect of myelin on microsphere uptake and compared the effect of myelin and opsonized myelin on the phagocytic activity of the cells. Our results showed a clear increase in the phagocytic activity of microglia when incubated with myelin, with an enhanced effect of opsonized myelin.
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Affiliation(s)
- T Houalla
- Department of Biology, McGill University, Montréal, Qué, Canada H3A 1B1
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43
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Tham CS, Lin FF, Rao TS, Yu N, Webb M. Microglial activation state and lysophospholipid acid receptor expression. Int J Dev Neurosci 2003; 21:431-43. [PMID: 14659994 DOI: 10.1016/j.ijdevneu.2003.09.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
We used a simple commercial magnetic immunobead method for the preparation of acutely isolated microglial cells from postnatal days 1-3 rat brain. With the exception of a 15 min enzyme incubation, all stages are carried out at 4 degrees C, minimizing the opportunity for changes in gene expression during the isolation to be reflected in changes in accumulated mRNA. The composition of the isolated cells was compared with that of microglial cultures prepared by conventional tissue culture methods, and the purity of microglia was comparable between the two preparations. RT-PCR analysis of several genes related to inflammatory products indicated that the acutely prepared cells were in a less activated condition than the conventionally tissue cultured cells. We examined the pattern of expression of receptors for lysophosphatidic acid (lpa) and sphingosine-1-phosphate (S1P) using quantitative real-time PCR (TaqMan PCR) techniques. mRNA for LPA1, S1P1, S1P2, S1P3 and S1P5 was detected in these preparations, but the levels of the different receptor mRNAs varied according to the state of activation of the cells. mRNA for LPA3 was only detected significantly in cultured cell after lipopolysaccharide (LPS) stimulation, being almost absent in cultured microglia and undetectable in the acutely isolated preparations. The levels of mRNA of LPA1 and S1P receptors was reduced by overnight exposure to S1P, while the same treatment significantly up-regulated the level of LPA3 mRNA.
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MESH Headings
- Animals
- Animals, Newborn
- Astrocytes/metabolism
- Base Sequence
- Blotting, Northern
- CD11b Antigen/genetics
- CD11b Antigen/metabolism
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cells, Cultured
- Cyclooxygenase 2
- Dose-Response Relationship, Drug
- Drug Interactions
- Enzyme Inhibitors/pharmacology
- Enzyme-Linked Immunosorbent Assay
- Fluorescent Antibody Technique/methods
- Gene Expression/drug effects
- Glial Fibrillary Acidic Protein/metabolism
- Imidazoles/pharmacology
- Indoles/metabolism
- Interleukin-6/genetics
- Interleukin-6/metabolism
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Lectins/metabolism
- Lysophospholipids/pharmacology
- Microglia/metabolism
- Myelin Basic Protein/metabolism
- Nitric Oxide Synthase/genetics
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type II
- Oligodendroglia/metabolism
- Osteopontin
- Prostaglandin-Endoperoxide Synthases/genetics
- Prostaglandin-Endoperoxide Synthases/metabolism
- Pyridines/pharmacology
- RNA, Messenger/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Receptors, G-Protein-Coupled/biosynthesis
- Receptors, G-Protein-Coupled/genetics
- Receptors, Lipoprotein/biosynthesis
- Receptors, Lipoprotein/drug effects
- Receptors, Lipoprotein/genetics
- Receptors, Lysophospholipid
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Sialoglycoproteins/genetics
- Sialoglycoproteins/metabolism
- Tumor Necrosis Factor-alpha/metabolism
- p38 Mitogen-Activated Protein Kinases
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Affiliation(s)
- Chui-Se Tham
- Molecular Neuroscience Laboratory, Merck Research Laboratories, 3535 General Atomics Court, San Diego, CA 92121, USA
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44
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Guillemin GJ, Brew BJ. Microglia, macrophages, perivascular macrophages, and pericytes: a review of function and identification. J Leukoc Biol 2003; 75:388-97. [PMID: 14612429 DOI: 10.1189/jlb.0303114] [Citation(s) in RCA: 406] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The phenotypic differentiation of systemic macrophages that have infiltrated the central nervous system, pericytes, perivascular macrophages, and the "real" resident microglial cells is a major immunocytochemical and immunohistochemical concern for all users of cultures of brain cells and brain sections. It is not only important in assessing the purity of cell cultures; it is also of fundamental importance in the assessment of the pathogenetic significance of perivascular inflammatory phenomena within the brain. The lack of a single membranous and/or biochemical marker allowing conclusive identification of these cells is still a major problem in neurobiology. This review briefly discusses the functions of these cells and catalogs a large number of membranous and biochemical markers, which can assist in the identification of these cells.
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Affiliation(s)
- Gilles J Guillemin
- Centre for Immunology, Neuroimmunology Department, St. Vincent's Hospital, Sydney, NSW, Australia.
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45
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Abstract
Traditionally, the primary function of oligodendrocytes (OLGs) in the CNS has been considered to be myelination. Here, we investigated whether OLGs may play a trophic role, particularly during development. Neurotrophin expression was assessed in postnatal day 7 basal forebrain (BF) OLGs, using in situ hybridization and detection of myelin basic protein. Nerve growth factor, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) mRNAs were revealed in OLGs in vivo and in culture. To determine whether OLGs support nearby neurons, we examined the influence of OLGs on BF cholinergic neurons. Neuronal function was enhanced by cocultured OLGs and OLG conditioned medium. Moreover, trophic effects of OLG conditioned medium were partially blocked by K252a, a trk tyrosine kinase inhibitor, and by neutralizing anti-BDNF or anti-NT-3 antisera, indicating that neurotrophins may mediate these effects, perhaps in concert with other signals. Our studies support a novel role for OLGs in providing local trophic support for neurons in the CNS.
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46
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Overholser ED, Coleman GD, Bennett JL, Casaday RJ, Zink MC, Barber SA, Clements JE. Expression of simian immunodeficiency virus (SIV) nef in astrocytes during acute and terminal infection and requirement of nef for optimal replication of neurovirulent SIV in vitro. J Virol 2003; 77:6855-66. [PMID: 12768005 PMCID: PMC156169 DOI: 10.1128/jvi.77.12.6855-6866.2003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2002] [Accepted: 03/18/2003] [Indexed: 01/24/2023] Open
Abstract
As the most numerous cells in the brain, astrocytes play a critical role in maintaining central nervous system homeostasis, and therefore, infection of astrocytes by human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) in vivo could have important consequences for the development of HIV encephalitis. In this study, we establish that astrocytes are infected in macaques during acute SIV infection (10 days postinoculation) and during terminal infection when there is evidence of SIV-induced encephalitis. Additionally, with primary adult rhesus macaque astrocytes in vitro, we demonstrate that the macrophage-tropic, neurovirulent viruses SIV/17E-Br and SIV/17E-Fr replicate efficiently in astrocytes, while the lymphocyte-tropic, nonneurovirulent virus SIV(mac)239 open-nef does not establish productive infection. Furthermore, aminoxypentane-RANTES abolishes virus replication, suggesting that these SIV strains utilize the chemokine receptor CCR5 for entry into astrocytes. Importantly, we show that SIV Nef is required for optimal replication in primary rhesus macaque astrocytes and that normalizing input virus by particle number rather than by infectivity reveals a disparity between the ability of a Nef-deficient virus and a virus encoding a nonmyristoylated form of Nef to replicate in these central nervous system cells. Since the myristoylated form of Nef has been implicated in functions such as CD4 and major histocompatibility complex I downregulation, kinase association, and enhancement of virion infectivity, these data suggest that an as yet unidentified function of Nef may exist to facilitate SIV replication in astrocytes that may have important implications for in vivo pathogenesis.
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Affiliation(s)
- Emily D Overholser
- Department of Comparative Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287, USA
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47
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Croitoru-Lamoury J, Guillemin GJ, Boussin FD, Mognetti B, Gigout LI, Chéret A, Vaslin B, Le Grand R, Brew BJ, Dormont D. Expression of chemokines and their receptors in human and simian astrocytes: evidence for a central role of TNF alpha and IFN gamma in CXCR4 and CCR5 modulation. Glia 2003; 41:354-70. [PMID: 12555203 DOI: 10.1002/glia.10181] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chemokines are key mediators of the selective migration of leukocytes that occurs in neurodegenerative diseases and related inflammatory processes. Astrocytes, the most abundant cell type in the CNS, have an active role in brain inflammation. To ascertain the role of astrocytes during neuropathological processes, we have investigated in two models of primary cells (human fetal and simian adult astrocytes) the repertoire of chemokines and their receptors expressed in response to inflammatory stimuli. We demonstrated that, in the absence of any stimulation, human fetal and simian adult astrocytes express mRNA for receptors APJ, BOB/GPR15, Bonzo/CXCR6, CCR2, CCR3, CCR5, CCR8, ChemR23, CXCR3/GPR9, CXCR4, GPR1, and V28/CX3CR1. Moreover, TNFalpha and IL-1beta significantly increase BOB/GPR15, CCR2, and V28/CX3CR1 mRNA levels in both models. Furthermore, TNFalpha and IFNgamma act synergistically to induce expression of the major coreceptors for HIV infection, CXCR4 and CCR5, at both the mRNA and protein levels in human and simian astrocytes, whereas CCR3 expression was not affected by cytokine treatment. Finally, TNFalpha/IFNgamma was the most significant cytokine combination in leading to a pronounced upregulation in a comparable, time-dependent manner of the production of chemokines IP-10/CXCL10, RANTES/CCL5, MIG/CXCL9, MCP-1/CCL2, and IL-8/CXCL8. In summary, these data suggest that astrocytes serve as an important source of chemokines under the dependence of a complex cytokine regulation, and TNFalpha and IFNgamma are important modulators of chemokines and chemokine receptor expression in human as well as simian astrocytes. Finally, with the conditions we used, there was no difference between species or age of tissue.
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48
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Guillemin GJ, Croitoru-Lamoury J, Dormont D, Armati PJ, Brew BJ. Quinolinic acid upregulates chemokine production and chemokine receptor expression in astrocytes. Glia 2003; 41:371-81. [PMID: 12555204 DOI: 10.1002/glia.10175] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Within the brain, quinolinic acid (QUIN) is an important neurotoxin, especially in AIDS dementia complex (ADC). Its production by monocytic lineage cells is increased in the context of inflammation. However, it is not known whether QUIN promotes inflammation. Astrocytes are important in immunoregulation within the brain and so we chose to examine the effects of QUIN on the astrocyte. Using purified primary human fetal astrocyte cultures, we determined chemokine production using ELISA assays and RT-PCR and chemokine receptor expression using immunocytochemistry and RT-PCR with QUIN in comparison to TNFalpha, IL-1beta, and IFNgamma. We found that QUIN induces astrocytes to produce large quantities of MCP-1 (CCL2) and lesser amounts of RANTES (CCL5) and IL-8 (CXCL8). QUIN also increases SDF-1alpha (CXCL12), HuMIG (CXCL9), and fractalkine (CX(3)CL1) mRNA expression. Moreover, QUIN leads to upregulation of the chemokine receptor expression of CXCR4, CCR5, and CCR3 in human fetal astrocytes. Most of these effects were comparable to those induced by TNFalpha, IL-1beta, and IFNgamma. The present work represents the first evidence that QUIN induces chemokine and chemokine receptor expression in astrocytes and is at least as potent as classical mediators such as inflammatory cytokines. These results suggest that QUIN may be critical in the amplification of brain inflammation, particularly in ADC.
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49
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Nikonenko I, Toni N, Moosmayer M, Shigeri Y, Muller D, Sargent Jones L. Integrins are involved in synaptogenesis, cell spreading, and adhesion in the postnatal brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2003; 140:185-94. [PMID: 12586424 DOI: 10.1016/s0165-3806(02)00590-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Integrins are a major family of heterodimeric surface glycoproteins that act as adhesion molecules, have a spectrum of extracellular matrix (ECM) molecules as their ligands, and regulate a variety of cellular functions. Integrins are known to be critical to embryonic brain development, and recent studies have indicated their essential role in adult brain function, although their role in postnatal brain development and function has not been examined. Here, we used the organotypic slice culture system to investigate the role of integrins in postnatal hippocampal development by exposing the tissue to either an integrin competitive antagonist, the peptide GRGDSP containing Arg-Gly-Asp (RGD) attachment site, or to function-blocking beta(1)-integrin antibodies to disrupt integrin interactions. These experiments revealed that beta(1)-integrin antibodies interfered with spreading of the culture, resulting in a rapid and marked diminution of slice area. beta(1)-integrin antibodies and RGD peptide disrupted cell adhesion, causing cell detachment and migration of glial cells from the explant. The majority of the detached cells were of macroglial origin and switched to expression of the intermediate filament proteins vimentin and nestin, suggesting a developmental regression. The organotypic organization of slice cultures was not affected, although exposure to either integrin antagonist or antibody resulted in a statistically significant reduction in the number of synapses measured in the apical dendrites of CA1 pyramidal neurons. The results demonstrate that integrins markedly affect postnatal CNS development, in both ultrastructural construction and organizational processes.
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Affiliation(s)
- Irina Nikonenko
- Department of Pharmacology, Centre Médical Universitaire, 1211 4, Geneva, Switzerland.
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50
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Guillemin GJ, Williams KR, Smith DG, Smythe GA, Croitoru-Lamoury J, Brew BJ. QUINOLINIC ACID IN THE PATHOGENESIS OF ALZHEIMER’S DISEASE. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 527:167-76. [PMID: 15206729 DOI: 10.1007/978-1-4615-0135-0_19] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
We propose that the tryptophan catabolites produced through the kynurenine pathway (KP), and more particularly quinolinic acid (QUIN), may play an important role in the pathogenesis of Alzheimer's disease (AD). In this study, we demonstrated that after 72 hours amyloid peptide (Abeta) 1-42 induced indoleamine 2,3-dioxygenase (IDO) expression and in a significant increase in production of QUIN by human macrophages and microglia. In contrast, Abeta11-40 and Prion peptide (PrP) 106-126 did not induce any significant increase in QUIN production. We also investigated the potential modulatory effect of QUIN and kynurenic acid (KYNA) on Abeta11-42 and Abeta1-40 aggregation. After 24 and 120 hours, we did not observe any significant difference in the level of aggregation compared to the control (Abeta alone). Abeta has been shown to induce IL1-beta mRNA expression by human foetal astrocytes and macrophages. We demonstrate that QUIN has the same effect. Interestingly, IL-1beta has been found in association with plaques in AD. All together these data imply that QUIN may be, locally, one of the factors involved in the pathogenesis of neuronal damage in AD.
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