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Minamihata T, Takano K, Moriyama M, Nakamura Y. Lysophosphatidylinositol, an Endogenous Ligand for G Protein-Coupled Receptor 55, Has Anti-inflammatory Effects in Cultured Microglia. Inflammation 2021; 43:1971-1987. [PMID: 32519268 DOI: 10.1007/s10753-020-01271-4] [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: 01/04/2023]
Abstract
Lysophosphatidylinositol (LysoPI), an endogenous ligand for G protein-coupled receptor (GPR) 55, has been known to show various functions in several tissues and cells; however, its roles in the central nervous system (CNS) are not well known. In particular, the detailed effects of LysoPI on microglial inflammatory responses remain unknown. Microglia is the immune cell that has important functions in maintaining immune homeostasis of the CNS. In this study, we explored the effects of LysoPI on inflammatory responses using the mouse microglial cell line BV-2, which was stimulated with lipopolysaccharide (LPS), and some results were confirmed also in rat primary microglia. LysoPI was found to reduce LPS-induced nitric oxide (NO) production and inducible NO synthase protein expression without affecting cell viability in BV-2 cells. LysoPI also suppressed intracellular generation of reactive oxygen species both in BV-2 cells and primary microglia and cytokine release in BV-2 cells. In addition, LysoPI treatment decreased phagocytic activity of LPS-stimulated BV-2 cells and primary microglia. The GPR55 antagonist CID16020046 completely inhibited LysoPI-induced downregulation of phagocytosis in BV-2 microglia, but did not affect the LysoPI-induced decrease in NO production. Our results suggest that LysoPI suppresses microglial phagocytosis via a GPR55-dependent pathway and NO production via a GPR55-independent pathway. LysoPI may contribute to neuroprotection in pathological conditions such as brain injury or neurodegenerative diseases, through its suppressive role in the microglial inflammatory response.
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Affiliation(s)
- Tomoki Minamihata
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
| | - Katsura Takano
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
| | - Mitsuaki Moriyama
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan.
| | - Yoichi Nakamura
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
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Olivier E, Wakx A, Fouyet S, Dutot M, Rat P. JEG-3 placental cells in toxicology studies: a promising tool to reveal pregnancy disorders. Anat Cell Biol 2021; 54:83-92. [PMID: 33281121 PMCID: PMC8017447 DOI: 10.5115/acb.20.234] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/16/2020] [Accepted: 11/03/2020] [Indexed: 01/08/2023] Open
Abstract
Placental alterations are responsible for adverse pregnancy outcomes like preeclampsia and intrauterine growth restriction. And yet, placenta toxicology has not become a fully-fledged toxicology field. Because placenta is very often seen only as a barrier between the mother and the fetus, there is a lack and therefore a need for an experimental human model with technical recommendations to study placenta toxicology. In vitro approaches are recommended in experimental toxicology as they focus on a specific biological process and yield high-throughput screening methods. In the present study, we first established incubation conditions to preserve signatures of the human JEG-3 cell line identity while enabling toxicity detection. JEG-3 cells prepared in our incubation conditions were renamed JEG-Tox cells. As placental alterations are mainly triggered by uncontrolled apoptosis, we second used known apoptotic agents pregnant women are exposed to, to check that JEG-Tox cells can trigger apoptosis. Ethanol, bisphenol F, quinalphos, 4,4'-DDT, benzalkonium chloride, phenoxyethanol, propylparaben, and perfluorooctanic acid all induced chromatin condensation in JEG-Tox cells. Our incubation conditions allow JEG-Tox cells to keep placental cell identity and to respond to toxic chemicals. JEG-Tox cells are a pertinent model for placenta toxicology and could be used to better understand pregnancy alterations.
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Affiliation(s)
- Elodie Olivier
- UMR CNRS 8038 CiTCoM, Laboratoire de Chimie-Toxicologie Analytique et Cellulaire, Université de Paris, Faculté de Pharmacie de Paris, Paris, France
| | - Anaïs Wakx
- UMR CNRS 8038 CiTCoM, Laboratoire de Chimie-Toxicologie Analytique et Cellulaire, Université de Paris, Faculté de Pharmacie de Paris, Paris, France
| | - Sophie Fouyet
- UMR CNRS 8038 CiTCoM, Laboratoire de Chimie-Toxicologie Analytique et Cellulaire, Université de Paris, Faculté de Pharmacie de Paris, Paris, France
| | - Mélody Dutot
- UMR CNRS 8038 CiTCoM, Laboratoire de Chimie-Toxicologie Analytique et Cellulaire, Université de Paris, Faculté de Pharmacie de Paris, Paris, France.,Recherche & Développement, YSLAB, Quimper, France
| | - Patrice Rat
- UMR CNRS 8038 CiTCoM, Laboratoire de Chimie-Toxicologie Analytique et Cellulaire, Université de Paris, Faculté de Pharmacie de Paris, Paris, France
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Yao Y, Fu KY. Serum-deprivation leads to activation-like changes in primary microglia and BV-2 cells but not astrocytes. Biomed Rep 2020; 13:51. [PMID: 32974017 DOI: 10.3892/br.2020.1358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/28/2020] [Indexed: 12/22/2022] Open
Abstract
The aim of the present study was to determine the effect of serum deprivation on primary microglia, BV-2 cells and primary astrocytes. Cell morphology combined with the expression of phospho-(p-)38 and p-extracellular signal-regulated kinase (ERK) were assessed. Serum deprivation resulted in various alterations in the three cell cultures. Primary microglia and BV-2 cells exhibited alterations indicative of activation under serum treatment, as well as lipopolysaccharide (LPS) treatment. However, astrocytes did not react as fast. Regarding morphology, the processes present on the primary microglia and BV-2 cells became shorter and the cell bodies became larger, and more transparent vesicles were observed within the cell bodies, which indicated their increased phagocytic ability. At the protein level, p-p38 expression increased quickly within 1 h in the primary microglia culture in response to LPS treatment. Furthermore, the expression levels of p-p38 and p-ERK were elevated in both primary microglia and BV-2 cells under serum deprivation, as well as under LPS treatment, which was not observed in the primary astrocytes. These results suggest that serum deprivation may result in similar changes to cell morphology and the expression levels of p-p38 and p-ERK as LPS treatment in primary microglia and BV-2 cells. These observations suggest that primary microglia and BV-2 cells may become activated under serum deprivation, at least to a certain degree.
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Affiliation(s)
- Yao Yao
- Department of Oral and Maxillofacial Surgery, Beijing Stomatological Hospital and School of Stomatology, Capital Medical University, Beijing 100050, P.R. China
| | - Kai-Yuan Fu
- Center for TMD and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing 100081, P.R. China
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Rabenstein M, Vay SU, Flitsch LJ, Fink GR, Schroeter M, Rueger MA. Osteopontin directly modulates cytokine expression of primary microglia and increases their survival. J Neuroimmunol 2016; 299:130-138. [DOI: 10.1016/j.jneuroim.2016.09.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 12/19/2022]
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Yao Y, Tan YH, Light AR, Mao J, Yu ACH, Fu KY. Alendronate Attenuates Spinal Microglial Activation and Neuropathic Pain. THE JOURNAL OF PAIN 2016; 17:889-903. [PMID: 27063783 DOI: 10.1016/j.jpain.2016.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 03/03/2016] [Accepted: 03/15/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED Many derivatives of bisphosphonates, which are inhibitors of bone resorption, have been developed as promising agents for painful pathologies in patients with bone resorption-related diseases. The mechanism for pain relief by bisphosphonates remains uncertain. Studies have reported that bisphosphonates could reduce central neurochemical changes involved in the generation and maintenance of bone cancer pain. In this study, we hypothesized that bisphosphonates would inhibit spinal microglial activation and prevent the development of hyperalgesia caused by peripheral tissue injury. We investigated the effects of alendronate (a nitrogen-containing bisphosphonate) on the development of neuropathic pain and its role in modulating microglial activation in vivo and in vitro. Intrathecal and intraperitoneal administration of alendronate relieved neuropathic pain behaviors induced by chronic constriction sciatic nerve injury. Alendronate also significantly attenuated spinal microglial activation and p38 mitogen-activated protein kinase (MAPK) phosphorylation without affecting astrocytes. In vitro, alendronate downregulated phosphorylated p38 and phosphorylated extracellular signal regulated kinase expression in lipopolysaccharide-stimulated primary microglia within 1 hour, and pretreatment with alendronate for 12 and 24 hours decreased the expression of inflammatory cytokines (tumor necrosis factor α, and interleukins 1β and 6). These findings indicate that alendronate could effectively relieve chronic constriction sciatic nerve injury-induced neuropathic pain by at least partially inhibiting the activation of spinal microglia and the p38 MAPK signaling pathway. PERSPECTIVE Alendronate could relieve neuropathic pain behaviors in animals by inhibiting the activation of spinal cord microglia and the p38 MAPK cell signaling pathway. Therapeutic applications of alendronate may be extended beyond bone metabolism-related disease.
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Affiliation(s)
- Yao Yao
- Center for TMD and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yong-Hui Tan
- Center for TMD and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China
| | - Alan R Light
- Department of Anesthesiology and Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah
| | - Jianren Mao
- Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Albert Cheung Hoi Yu
- Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science Center, Beijing, China
| | - Kai-Yuan Fu
- Center for TMD and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China.
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Gilthorpe JD, Oozeer F, Nash J, Calvo M, Bennett DL, Lumsden A, Pini A. Extracellular histone H1 is neurotoxic and drives a pro-inflammatory response in microglia. F1000Res 2013; 2:148. [PMID: 24358859 PMCID: PMC3782347 DOI: 10.12688/f1000research.2-148.v1] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/28/2013] [Indexed: 01/23/2023] Open
Abstract
In neurodegenerative conditions and following brain trauma it is not understood why neurons die while astrocytes and microglia survive and adopt pro-inflammatory phenotypes. We show here that the damaged adult brain releases diffusible factors that can kill cortical neurons and we have identified histone H1 as a major extracellular candidate that causes neurotoxicity and activation of the innate immune system. Extracellular core histones H2A, H2B H3 and H4 were not neurotoxic. Innate immunity in the central nervous system is mediated through microglial cells and we show here for the first time that histone H1 promotes their survival, up-regulates MHC class II antigen expression and is a powerful microglial chemoattractant. We propose that when the central nervous system is degenerating, histone H1 drives a positive feedback loop that drives further degeneration and activation of immune defences which can themselves be damaging. We suggest that histone H1 acts as an antimicrobial peptide and kills neurons through mitochondrial damage and apoptosis.
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Affiliation(s)
- Jonathan D Gilthorpe
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK ; Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, S-901 87, Sweden
| | - Fazal Oozeer
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Julia Nash
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Margarita Calvo
- Wolfson Centre for Age Related Diseases, King's College London, London, SE1 1UL, UK
| | - David Lh Bennett
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Andrew Lumsden
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Adrian Pini
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
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Neuregulin-ErbB signaling promotes microglial proliferation and chemotaxis contributing to microgliosis and pain after peripheral nerve injury. J Neurosci 2010; 30:5437-50. [PMID: 20392965 DOI: 10.1523/jneurosci.5169-09.2010] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A key component in the response of the nervous system to injury is the proliferation and switch to a "proinflammatory" phenotype by microglia (microgliosis). In situations where the blood-brain barrier is intact, microglial numbers increase via the proliferation and chemotaxis of resident microglia; however, there is limited knowledge regarding the factors mediating this response. After peripheral nerve injury, a dorsal horn microgliosis develops, which directly contributes to the development of neuropathic pain. Neuregulin-1 (NRG-1) is a growth and differentiation factor with a well characterized role in neural and cardiac development. Microglia express the NRG1 receptors erbB2, 3, and 4, and NRG1 signaling via the erbB2 receptor stimulated microglial proliferation, chemotaxis, and survival, as well as interleukin-1beta release in vitro. Intrathecal treatment with NRG1 resulted in microglial proliferation within the dorsal horn, and these cells developed an activated morphology. This microglial response was associated with the development of both mechanical and cold pain-related hypersensitivity. Primary afferents express NRG1, and after spinal nerve ligation (SNL) we observed both an increase in NRG1 within the dorsal horn as well as activation of erbB2 specifically within microglia. Blockade of the erbB2 receptor or sequestration of endogenous NRG after SNL reduced the proliferation, the number of microglia with an activated morphology, and the expression of phospho-P38 by microglia. Furthermore, consequent to such changes, the mechanical pain-related hypersensitivity and cold allodynia were reduced. NRG1-erbB signaling therefore represents a novel pathway regulating the injury response of microglia.
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Svoboda N, Zierler S, Kerschbaum HH. cAMP mediates ammonia-induced programmed cell death in the microglial cell line BV-2. Eur J Neurosci 2007; 25:2285-95. [PMID: 17445227 DOI: 10.1111/j.1460-9568.2007.05452.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although ammonia is a well-known neuropathogenic factor, the cellular mechanisms of ammonia toxicity are less characterized. Up to now, the main focus of ammonia toxicity has been on astrocytes and neurons. Despite the significance of microglia in neurodegenerative diseases, little is known about their responsiveness to ammonia. In the present study, we found that ammonia triggered mitosis at concentrations between 30 microm and 3.0 mm but apoptosis at concentrations >or= 1.0 mm in the murine microglial cell line BV-2. Most apoptotic cells showed an accumulation of condensed chromatin at the nuclear envelope, blebbing of the plasma membrane, formation of apoptotic bodies and an increase in caspase 3/7 activity. Blockade of caspase 3/7 activity by Ac-DEVD-CHO suppressed ammonia-induced apoptosis. Surprisingly, some BV-2 cells exposed to ammonia displayed clear signs of mitotic catastrophe, a type of cell death occurring during mitosis. In a further series of experiments, we found that cyclic adenosine 3',5'-monophosphate (cAMP) mediated the apoptogenic effects of ammonia, because (i) ammonia dose-dependently elevated the intracellular cAMP level, (ii) blockade of the adenylyl cyclase by SQ-22536 suppressed ammonia-induced apoptosis, (iii) inhibition of phosphodiesterases (PDEs) by the nonselective PDE inhibitor IBMX, or by the PDE4-selective inhibitor rolipram, increased the relative number of apoptotic cells, and (iv) the cAMP analogues 8-bromoadenosine cAMP and Sp-cAMP mimicked the effect of ammonia and triggered apoptosis. Taken together, our results indicate that distinct concentrations of ammonia trigger opposite signalling pathways in microglial cells.
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Affiliation(s)
- Nina Svoboda
- Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
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Koyama Y, Kiyo-oka M, Osakada M, Horiguchi N, Shintani N, Ago Y, Kakuda M, Baba A, Matsuda T. Expression of prokineticin receptors in mouse cultured astrocytes and involvement in cell proliferation. Brain Res 2006; 1112:65-9. [PMID: 16901473 DOI: 10.1016/j.brainres.2006.07.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Revised: 06/30/2006] [Accepted: 07/04/2006] [Indexed: 11/30/2022]
Abstract
Effects of prokineticins (PKs), a novel family of bioactive peptides with a mitogenic action to endothelial cells of the endocrine gland and testis, on astrocytic functions were examined. Mouse cultured astrocytes expressed PK-R1 type PK receptors, while there was little expression of the PK-R2 type. PKs caused increases in astrocytic cytosolic Ca2+ levels and BrdU incorporation. Increases in Ca2+ levels by PK-2 were diminished by U73122 (a phospholipase C inhibitor). PK-induced BrdU incorporation was inhibited by U73122, GF109203 (a protein kinase C inhibitor) and PD98059 (a MEK/ERK inhibitor). These results indicate that PK receptors are expressed in astrocytes and regulate astrocytic proliferation.
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Affiliation(s)
- Yutaka Koyama
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-Oka 1-6 Suita, Osaka 565-0871, Japan.
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Yoshioka Y, Yamamuro A, Maeda S. Nitric oxide/cGMP signaling pathway protects RAW264 cells against nitric oxide-induced apoptosis by inhibiting the activation of p38 mitogen-activated protein kinase. J Pharmacol Sci 2006; 101:126-34. [PMID: 16778361 DOI: 10.1254/jphs.fpj06001x] [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: 10/24/2022] Open
Abstract
Nitric oxide (NO) induces apoptosis in various cells lines, while activation of the NO/cGMP signaling pathway prevents apoptosis induced by diverse stimuli, including NO. Here, we report the cytoprotective mechanisms of the NO/cGMP signaling pathway against NO-induced apoptosis in a mouse macrophage-like cell line, RAW264. Treatment with sodium nitroprusside (SNP), an NO donor, at a high-toxic concentration (4 mM) stimulated the N-terminal conformational change of Bax and its translocation to mitochondria followed by cytochrome c release and nuclear fragmentation in RAW264 cells. These changes of Bax were attenuated by pretreatment with SNP at a low-nontoxic concentration (100 microM) or dibutyryl cGMP (DBcGMP), a cell-permeable cGMP analogue. SB203580, a p38 mitogen-activated protein kinase (MAP kinase) inhibitor, blocked the effects of 4 mM SNP on Bax translocation and cell viability. Treatment with 4 mM SNP activated p38 MAP kinase and this effect was prevented by pretreatment with 100 microM SNP or DBcGMP. These findings suggest that the NO/cGMP signaling pathway inhibits NO-induced apoptosis of macrophages by suppressing the p38 MAP kinase activation, which results in N-terminal conformational change of Bax and its translocation to mitochondria.
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Affiliation(s)
- Yasuhiro Yoshioka
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
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Yoshioka Y, Kitao T, Kishino T, Yamamuro A, Maeda S. Nitric oxide protects macrophages from hydrogen peroxide-induced apoptosis by inducing the formation of catalase. THE JOURNAL OF IMMUNOLOGY 2006; 176:4675-81. [PMID: 16585560 DOI: 10.4049/jimmunol.176.8.4675] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigated the cytoprotective effect of NO on H2O2-induced cell death in mouse macrophage-like cell line RAW264. H2O2-treated cells showed apoptotic features, such as activation of caspase-9 and caspase-3, nuclear fragmentation, and DNA fragmentation. These apoptotic features were significantly inhibited by pretreatment for 24 h with NO donors, sodium nitroprusside and 1-hydroxy-2-oxo-3,3-bis-(2-aminoethyl)-1-triazene, at a low nontoxic concentration. The cytoprotective effect of NO was abrogated by the catalase inhibitor 3-amino-1,2,4-triazole but was not affected by a glutathione synthesis inhibitor, L-buthionine-(S,R)-sulfoximine. NO donors increased the level of catalase and its activity in a concentration-dependent manner. Cycloheximide, a protein synthesis inhibitor, inhibited both the NO-induced increase in the catalase level and the cytoprotective effect of NO. These results indicate that NO at a low concentration protects macrophages from H2O2-induced apoptosis by inducing the production of catalase.
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Affiliation(s)
- Yasuhiro Yoshioka
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
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Chock VY, Giffard RG. Development of neonatal murine microglia in vitro: changes in response to lipopolysaccharide and ischemia-like injury. Pediatr Res 2005; 57:475-80. [PMID: 15718374 DOI: 10.1203/01.pdr.0000155758.79523.44] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hypoxic/ischemic brain injury in the neonate can activate an inflammatory cascade, which potentiates cellular injury. The role of microglia in this inflammatory response has not been studied extensively. We used an in vitro model of murine microglia to investigate changes in microglial cytokine release and injury during early development. Isolated microglia were subjected to lipopolysaccharide (LPS) activation or injury by glucose deprivation (GD), serum deprivation (SD), or combined oxygen-glucose deprivation (OGD) for varying durations. The extent and the type of cell death were determined by trypan blue, terminal deoxynucleotidyl end-nick labeling, and annexin staining. Early-culture microglia (2-3 d in purified culture) showed significantly more apoptotic cell death after SD, GD, and OGD compared with microglia maintained in culture for 14-17 d. Measurements of tumor necrosis factor-alpha (TNF-alpha) and IL-1beta in culture media demonstrated that OGD induced greater release of both TNF-alpha and IL-1beta than LPS activation, with early-culture microglia producing more TNF-alpha compared with late-culture microglia. Microglia that are cultured for a short time are more sensitive to ischemia-like injury in vitro than those that are cultured for longer durations and may contribute to worsening brain injury by increased release of inflammatory cytokines. Inhibition of microglial activation and decreasing proinflammatory cytokine release may be targets for reduction of neonatal hypoxic/ischemic brain injury.
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Affiliation(s)
- Valerie Y Chock
- Department of Neonatology, Stanford University School of Medicine, Stanford, California 94305, USA
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Higuchi A, Shimmura S, Ishii M, Aburatani H, Tsubota K. Serum- and serum deprivation-induced transcriptional profiles of cultured conjunctival epithelial cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 506:673-6. [PMID: 12613976 DOI: 10.1007/978-1-4615-0717-8_94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- Akihiro Higuchi
- Department of Ophthalmology, Tokyo Dental College, Chiba, Japan
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Yoshioka Y, Yamamuro A, Maeda S. Nitric oxide at a low concentration protects murine macrophage RAW264 cells against nitric oxide-induced death via cGMP signaling pathway. Br J Pharmacol 2003; 139:28-34. [PMID: 12746220 PMCID: PMC1573816 DOI: 10.1038/sj.bjp.0705206] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. We investigated the cytoprotective effect of low-dose nitric oxide (NO) on NO-induced cell death in mouse macrophage-like cell line RAW264. 2. Sodium nitroprusside (SNP), an NO donor, at a high concentration (4 mM) released cytochrome c from mitochondria and induced death in RAW264 cells. Acetyl-L-aspartyl-L-glutamyl-L-valyl-L-aspart-1-al (Ac-DEVD-CHO, 100-200 microM), a caspase-3 inhibitor, attenuated the SNP-induced cell death in a concentration-dependent manner. 3. Pretreatment with 100 microM SNP for 24 h, which had no effect on cell viability, attenuated the cell death and reduced cytochrome c release from mitochondria to the cytosol induced by 4 mM SNP. 4. LY83583 (1-3 microM) and 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 30-100 microM), soluble guanylate cyclase inhibitors, negated the protective effect of the 100 microM SNP pretreatment. 5. Pretreatment with 1 mM dibutylyl guanosine-3',5'-cyclic monophosphate (DBcGMP), a cell-permeable guanosine-3',5'-cyclic monophosphate (cGMP) analogue, for 24 h inhibited both cytochrome c release and cell death induced by SNP. 6. Protein kinase G inhibitor KT5823 (10 microM) significantly reduced the cytoprotective effects of low-dose SNP and DBcGMP. 7. These results indicate that low-dose NO protects RAW264 cells from NO-induced apoptosis through cGMP production and activation of protein kinase G.
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Affiliation(s)
- Y Yoshioka
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan
| | - A Yamamuro
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan
| | - S Maeda
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan
- Author for correspondence:
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Abstract
Microglia, residential macrophages in the central nervous system, can release a variety of factors including cytokines, chemokines, etc. to regulate the communication among neuronal and other types of glial cells. Microglia play immunological roles in mechanisms underlying the phagocytosis of invading microorganisms and removal of dead or damaged cells. When microglia are hyperactivated due to a certain pathological imbalance, they may cause neuronal degeneration. Pathological activation of microglia has been reported in a wide range of conditions such as cerebral ischemia, Alzheimer's disease, prion diseases, multiple sclerosis, AIDS dementia, and others. Nearly 5000 papers on microglia can be retrieved on the Web site PubMed at present (November 2001) and half of them were published within the past 5 years. Although it is not possible to read each paper in detail, as many factors as possible affecting microglial functions in in vitro culture systems are presented in this review. The factors are separated into "activators" and "inhibitors," although it is difficult to classify many of them. An overview on these factors may help in the development of a new strategy for the treatment of various neurodegenerative diseases.
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Affiliation(s)
- Yoichi Nakamura
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University; Sakai, Japan.
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