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Agusti A, Hernández-Rabaza V, Balzano T, Taoro-Gonzalez L, Ibañez-Grau A, Cabrera-Pastor A, Fustero S, Llansola M, Montoliu C, Felipo V. Sildenafil reduces neuroinflammation in cerebellum, restores GABAergic tone, and improves motor in-coordination in rats with hepatic encephalopathy. CNS Neurosci Ther 2017; 23:386-394. [PMID: 28296282 DOI: 10.1111/cns.12688] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 01/23/2017] [Accepted: 02/09/2017] [Indexed: 12/31/2022] Open
Abstract
AIMS Patients with liver disease may develop hepatic encephalopathy (HE), with cognitive impairment and motor in-coordination. Rats with HE due to portacaval shunts (PCS) show motor in-coordination. We hypothesized that in PCS rats: (i) Motor in-coordination would be due to enhanced GABAergic tone in cerebellum; (ii) increased GABAergic tone would be due to neuroinflammation; (iii) increasing cGMP would reduce neuroinflammation and GABAergic tone and restore motor coordination. To assess these hypotheses, we assessed if (i) treatment with sildenafil reduces neuroinflammation; (ii) reduced neuroinflammation is associated with reduced GABAergic tone and restored motor coordination. METHODS Rats were treated with sildenafil to increase cGMP. Microglia and astrocytes activation were analyzed by immunohistochemistry, extracellular GABA by microdialysis, and motor coordination in the beam walking. RESULTS PCS rats show neuroinflammation in cerebellum, with microglia and astrocytes activation, increased IL-1b and TNF-a and reduced YM-1 and IL-4. Membrane expression of the GABA transporter GAT1 is reduced, while GAT3 is increased. Extracellular GABA and motor in-coordination are increased. Sildenafil treatment eliminates neuroinflammation, microglia and astrocytes activation; changes in membrane expression of GABA transporters; and restores motor coordination. CONCLUSIONS This study supports an interplay between cGMP-neuroinflammation and GABAergic neurotransmission in impairing motor coordination in PCS rats.
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Affiliation(s)
- Ana Agusti
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | | | - Tiziano Balzano
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Lucas Taoro-Gonzalez
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Andrea Ibañez-Grau
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Andrea Cabrera-Pastor
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Santos Fustero
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Marta Llansola
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Carmina Montoliu
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
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Kikuchi S, Nishihara T, Kawasaki S, Abe N, Kuwabara J, Choudhury ME, Takahashi H, Yano H, Nagaro T, Watanabe Y, Aibiki M, Tanaka J. The ameliorative effects of a hypnotic bromvalerylurea in sepsis. Biochem Biophys Res Commun 2015; 459:319-326. [PMID: 25732089 DOI: 10.1016/j.bbrc.2015.02.111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/19/2015] [Indexed: 12/30/2022]
Abstract
Sepsis is a severe pathologic event, frequently causing death in critically ill patients. However, there are no approved drugs to treat sepsis, despite clinical trials of many agents that have distinct targets. Therefore, a novel effective treatment should be developed based on the pathogenesis of sepsis. We recently observed that an old hypnotic drug, bromvalerylurea (BU) suppressed expression of many kinds of pro- and anti-inflammatory mediators in LPS- or interferon-γ activated alveolar and peritoneal macrophages (AMs and PMs). Taken the anti-inflammatory effects of BU on macrophages, we challenged it to septic rats that had been subjected to cecum-ligation and puncture (CLP). BU was subcutaneously administered to septic rats twice per day. Seven days after CLP treatment, 85% of septic rats administrated vehicle had died, whereas administration of BU reduce the rate to 50%. Septic rats showed symptoms of multi-organ failure; respiratory, circulatory and renal system failures as revealed by histopathological analyses, blood gas test and others. BU ameliorated these symptoms. BU also prevented elevated serum-IL-6 level as well as IL-6 mRNA expression in septic rats. Collectively, BU might be a novel agent to ameliorate sepsis by preventing the onset of MOF.
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Affiliation(s)
- Satoshi Kikuchi
- Department of Emergency Medicine, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan; Department of Gastrointestinal Surgery and Surgical Oncology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Tasuku Nishihara
- Department of Anesthesiology and Resuscitology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Shun Kawasaki
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan; Department of Anesthesiology and Resuscitology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Naoki Abe
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan; Department of Anesthesiology and Resuscitology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Jun Kuwabara
- Department of Gastrointestinal Surgery and Surgical Oncology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Mohammed E Choudhury
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Hisaaki Takahashi
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Hajime Yano
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Takumi Nagaro
- Department of Anesthesiology and Resuscitology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Yuji Watanabe
- Department of Gastrointestinal Surgery and Surgical Oncology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Mayuki Aibiki
- Department of Emergency Medicine, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan.
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Bordt EA, Polster BM. NADPH oxidase- and mitochondria-derived reactive oxygen species in proinflammatory microglial activation: a bipartisan affair? Free Radic Biol Med 2014; 76:34-46. [PMID: 25091898 PMCID: PMC4252610 DOI: 10.1016/j.freeradbiomed.2014.07.033] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/19/2014] [Accepted: 07/24/2014] [Indexed: 12/18/2022]
Abstract
Microglia are the resident immune cells of the brain and play major roles in central nervous system development, maintenance, and disease. Brain insults cause microglia to proliferate, migrate, and transform into one or more activated states. Classical M1 activation triggers the production of proinflammatory factors such as tumor necrosis factor-α, interleukin-1β (IL-1β), nitric oxide, and reactive oxygen species (ROS), which, in excess, can exacerbate brain injury. The mechanisms underlying microglial activation are not fully understood, yet reactive oxygen species are increasingly implicated as mediators of microglial activation. In this review, we highlight studies linking reactive oxygen species, in particular hydrogen peroxide derived from NADPH oxidase-generated superoxide, to the classical activation of microglia. In addition, we critically evaluate controversial evidence suggesting a specific role for mitochondrial reactive oxygen species in the activation of the NLRP3 inflammasome, a multiprotein complex that mediates the production of IL-1β and IL-18. Finally, the limitations of common techniques used to implicate mitochondrial ROS in microglial and inflammasome activation, such as the use of the mitochondrially targeted ROS indicator MitoSOX and the mitochondrially targeted antioxidant MitoTEMPO, are also discussed.
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Affiliation(s)
- Evan A Bordt
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research, and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Brian M Polster
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research, and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Smirkin A, Matsumoto H, Takahashi H, Inoue A, Tagawa M, Ohue S, Watanabe H, Yano H, Kumon Y, Ohnishi T, Tanaka J. Iba1(+)/NG2(+) macrophage-like cells expressing a variety of neuroprotective factors ameliorate ischemic damage of the brain. J Cereb Blood Flow Metab 2010; 30:603-15. [PMID: 19861972 PMCID: PMC2949149 DOI: 10.1038/jcbfm.2009.233] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In a transient 90-min middle cerebral artery occlusion (MCAO) model of rats, a large ischemic lesion is formed where macrophage-like cells massively accumulate, many of which express a macrophage marker, Iba1, and an oligodendrocyte progenitor cell marker, NG2 chondroitin sulfate proteoglycan (NG2); therefore, the cells were termed BINCs (Brain Iba1(+)/NG2(+) Cells). A bone marrow transplantation experiment using green-fluorescent protein-transgenic rats showed that BINCs were derived from bone marrow. 5-Fluorouracil (5FU) injection at 2 days post reperfusion (2 dpr) markedly reduced the number of BINCs at 7 dpr, causing enlargement of necrotic volumes and frequent death of the rats. When isolated BINCs were transplanted into 5FU-aggravated ischemic lesion, the volume of the lesion was much reduced. Quantitative real-time RT-PCR showed that BINCs expressed mRNAs encoding bFGF, BMP2, BMP4, BMP7, GDNF, HGF, IGF-1, PDGF-A, and VEGF. In particular, BINCs expressed IGF-1 mRNA at a very high level. Immunohistochemical staining showed that IGF-1-expressing BINCs were found not only in rat but also human ischemic brain lesions. These results suggest that bone marrow-derived BINCs play a beneficial role in ischemic brain lesions, at least in part, through secretion of neuroprotective factors.
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Affiliation(s)
- Anna Smirkin
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime 791-0295, Japan
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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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Salimi K, Humpel C. Down-regulation of complement receptor 3 and major histocompatibility complex I and II antigen-like immunoreactivity accompanies ramification in isolated rat microglia. Brain Res 2002; 946:283-9. [PMID: 12137932 DOI: 10.1016/s0006-8993(02)02896-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Isolated primary microglia are highly activated in conventional culture systems. This has restricted studies to the use of late stage measures of activation rather than highly sensitive immunophenotypic and morphological criteria that mark even very early stages of microglial activation in vivo. In the present study, serum-free, serine- and glycine-free medium and poly-L-lysine coated surfaces have been used to demonstrate for the first time isolated rat microglia which (i) downregulate their immunoreactivity for antibodies recognizing complement receptor 3 and major histocompatibility complex antigens while differentiating into ramified cells, and (ii) respond to a subset of modulators with upregulation of complement receptor 3-like immunoreactivity. During 2 weeks of culturing under basal conditions, ramification was accompanied by strong downregulation of OX-42, OX-18 and OX-6 immunoreactivity (antibodies recognizing complement receptor 3 and major histocompatibility complex class I and II antigens, respectively). Ramified cells had lower level immunoreactivity for all three markers than non-ramified cells. High OX-42 immunoreactivity was also associated with morphological signs of activation previously described in vivo. Enhanced OX-42 immunoreactivity was induced by applying either serine and glycine or lipopolysaccharide (LPS) while granulocyte macrophage-colony stimulating factor increased cell number without affecting OX-42 immunoreactivity. LPS induced alterations were apparent within 24 h, were transient, and did not include changes in OX-18 or OX-6 immunoreactivity, cell number or proportion of ramified cells. The results attest to the special efficacy of this culture method for the investigation of the early microglial reaction by use of highly sensitive immunophenotypic criteria.
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Affiliation(s)
- Kayvon Salimi
- Laboratory of Psychiatry, Clinic of Psychiatry, University Hospital Innsbruck, Anichstr. 35, Austria.
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Cuadros MA, Navascués J. Early origin and colonization of the developing central nervous system by microglial precursors. PROGRESS IN BRAIN RESEARCH 2001; 132:51-9. [PMID: 11545016 DOI: 10.1016/s0079-6123(01)32065-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- M A Cuadros
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
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Smith ME. Phagocytic properties of microglia in vitro: implications for a role in multiple sclerosis and EAE. Microsc Res Tech 2001; 54:81-94. [PMID: 11455615 DOI: 10.1002/jemt.1123] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The microglial cell, after many years of neglect, has become recognized as the sole representative cell of the immune system that resides in the normal central nervous system. While normally dormant, microglia can be activated by secretory substances or signals associated with disease or injury, and becomes a phagocytic cell, which also produces its own injurious molecules. In the activating process, its morphology is changed from a resting process-bearing cell, into a rounded amoebic form, and displays new or increased amounts of functional markers, such as receptors and Class I and Class II MHC molecules. Microglia prepared from newborn mice or rats for tissue culture are already activated, and can be used for studies of their phagocytic properties. Although they can phagocytize foreign substances, their uptake and metabolism of myelin are emphasized here, in keeping with their role in demyelinating diseases. A number of receptors have been implicated and appear to be important in the attachment to, and ingestion of, myelin particles in vitro, including the Fc, complement, macrophage scavenger, and the Galectin-3/MAC-2 receptors, although the alpha2-macroglobulin/low-density lipoprotein receptor and mannose receptors have also been suggested as participants in myelin phagocytosis. Certain cytokines and adhesion molecules also regulate the phagocytic activity of microglia. Comparative in vitro studies of phagocytosis by peritoneal macrophages and microglia have shown that the two kinds of cells respond differently to regulatory molecules, and it is concluded that they have different innate properties. The role of microglia in the demyelinative diseases experimental autoimmune encephalomyelitis and multiple sclerosis is emphasized here, and the possible means of intervention in the process leading to myelin destruction is discussed. Published 2001 Wiley-Liss, Inc.
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Affiliation(s)
- M E Smith
- Department of Neurology, VA Health Care Center, Palo Alto, California 94304, USA.
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