1
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Edgar KS, Cunning C, Gardiner TA, McDonald DM. BH4 supplementation reduces retinal cell death in ischaemic retinopathy. Sci Rep 2023; 13:21292. [PMID: 38042898 PMCID: PMC10693630 DOI: 10.1038/s41598-023-48167-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 11/22/2023] [Indexed: 12/04/2023] Open
Abstract
Dysregulation of nitric oxide (NO) production can cause ischaemic retinal injury and result in blindness. How this dysregulation occurs is poorly understood but thought to be due to an impairment in NO synthase function (NOS) and nitro-oxidative stress. Here we investigated the possibility of correcting this defective NOS activity by supplementation with the cofactor tetrahydrobiopterin, BH4. Retinal ischaemia was examined using the oxygen-induced retinopathy model and BH4 deficient Hph-1 mice used to establish the relationship between NOS activity and BH4. Mice were treated with the stable BH4 precursor sepiapterin at the onset of hypoxia and their retinas assessed 48 h later. HPLC analysis confirmed elevated BH4 levels in all sepiapterin supplemented groups and increased NOS activity. Sepiapterin treatment caused a significant decrease in neuronal cell death in the inner nuclear layer that was most notable in WT animals and was associated with significantly diminished superoxide and local peroxynitrite formation. Interestingly, sepiapterin also increased inflammatory cytokine levels but not microglia cell number. BH4 supplementation by sepiapterin improved both redox state and neuronal survival during retinal ischaemia, in spite of a paradoxical increase in inflammatory cytokines. This implicates nitro-oxidative stress in retinal neurones as the cytotoxic element in ischaemia, rather than enhanced pro-inflammatory signalling.
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Affiliation(s)
- Kevin S Edgar
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, 97 Lisburn Road, BT9 7BL, UK
| | - Ciara Cunning
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, 97 Lisburn Road, BT9 7BL, UK
| | - Tom A Gardiner
- School of Medicine, Dentistry and Biomedical Sciences, Centre for Biomedical Sciences Education, Queen's University Belfast, Belfast, UK
| | - Denise M McDonald
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, 97 Lisburn Road, BT9 7BL, UK.
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2
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Meleady L, Towriss M, Kim J, Bacarac V, Dang V, Rowland ME, Ciernia AV. Histone deacetylase 3 regulates microglial function through histone deacetylation. Epigenetics 2023; 18:2241008. [PMID: 37506371 PMCID: PMC10392760 DOI: 10.1080/15592294.2023.2241008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
As the primary innate immune cells of the brain, microglia respond to damage and disease through pro-inflammatory release of cytokines and neuroinflammatory molecules. Histone acetylation is an activating transcriptional mark that regulates inflammatory gene expression. Inhibition of histone deacetylase 3 (Hdac3) has been utilized in pre-clinical models of depression, stroke, and spinal cord injury to improve recovery following injury, but the molecular mechanisms underlying Hdac3's regulation of inflammatory gene expression in microglia is not well understood. To address this lack of knowledge, we examined how pharmacological inhibition of Hdac3 in an immortalized microglial cell line (BV2) impacted histone acetylation and gene expression of pro- and anti-inflammatory genes in response to immune challenge with lipopolysaccharide (LPS). Flow cytometry and cleavage under tags & release using nuclease (CUT & RUN) revealed that Hdac3 inhibition increases global and promoter-specific histone acetylation, resulting in the release of gene repression at baseline and enhanced responses to LPS. Hdac3 inhibition enhanced neuroprotective functions of microglia in response to LPS through reduced nitric oxide release and increased phagocytosis. The findings suggest Hdac3 serves as a regulator of microglial inflammation, and that inhibition of Hdac3 facilitates the microglial response to inflammation and its subsequent clearing of debris or damaged cells. Together, this work provides new mechanistic insights into therapeutic applications of Hdac3 inhibition which mediate reduced neuroinflammatory insults through microglial response.
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Affiliation(s)
- Laura Meleady
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Morgan Towriss
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Jennifer Kim
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Vince Bacarac
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Vivien Dang
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Megan E. Rowland
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Annie Vogel Ciernia
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
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3
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Zaric BL, Macvanin MT, Isenovic ER. Free radicals: Relationship to Human Diseases and Potential Therapeutic applications. Int J Biochem Cell Biol 2023; 154:106346. [PMID: 36538984 DOI: 10.1016/j.biocel.2022.106346] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/06/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Reactive species are highly-reactive enzymatically, or non-enzymatically produced compounds with important roles in physiological and pathophysiological cellular processes. Although reactive species represent an extensively researched topic in biomedical sciences, many aspects of their roles and functions remain unclear. This review aims to systematically summarize findings regarding the biochemical characteristics of various types of reactive species and specify the localization and mechanisms of their production in cells. In addition, we discuss the specific roles of free radicals in cellular physiology, focusing on the current lines of research that aim to identify the reactive oxygen species-initiated cascades of reactions resulting in adaptive or pathological cellular responses. Finally, we present recent findings regarding the therapeutic modulations of intracellular levels of reactive oxygen species, which may have substantial significance in developing novel agents for treating several diseases.
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Affiliation(s)
- Bozidarka L Zaric
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia.
| | - Mirjana T Macvanin
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Esma R Isenovic
- Department of Radiobiology and Molecular Genetics, VINČA Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
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4
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Caruso G, Benatti C, Musso N, Fresta CG, Fidilio A, Spampinato G, Brunello N, Bucolo C, Drago F, Lunte SM, Peterson BR, Tascedda F, Caraci F. Carnosine Protects Macrophages against the Toxicity of Aβ1-42 Oligomers by Decreasing Oxidative Stress. Biomedicines 2021; 9:biomedicines9050477. [PMID: 33926064 PMCID: PMC8146816 DOI: 10.3390/biomedicines9050477] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/17/2021] [Accepted: 04/22/2021] [Indexed: 12/14/2022] Open
Abstract
Carnosine (β-alanyl-L-histidine) is a naturally occurring endogenous peptide widely distributed in excitable tissues such as the brain. This dipeptide has well-known antioxidant, anti-inflammatory, and anti-aggregation activities, and it may be useful for treatment of neurodegenerative disorders such as Alzheimer’s disease (AD). In this disease, peripheral infiltrating macrophages play a substantial role in the clearance of amyloid beta (Aβ) peptides from the brain. Correspondingly, in patients suffering from AD, defects in the capacity of peripheral macrophages to engulf Aβ have been reported. The effects of carnosine on macrophages and oxidative stress associated with AD are consequently of substantial interest for drug discovery in this field. In the present work, a model of stress induced by Aβ1-42 oligomers was investigated using a combination of methods including trypan blue exclusion, microchip electrophoresis with laser-induced fluorescence, flow cytometry, fluorescence microscopy, and high-throughput quantitative real-time PCR. These assays were used to assess the ability of carnosine to protect macrophage cells, modulate oxidative stress, and profile the expression of genes related to inflammation and pro- and antioxidant systems. We found that pre-treatment of RAW 264.7 macrophages with carnosine counteracted cell death and apoptosis induced by Aβ1-42 oligomers by decreasing oxidative stress as measured by levels of intracellular nitric oxide (NO)/reactive oxygen species (ROS) and production of peroxynitrite. This protective activity of carnosine was not mediated by modulation of the canonical inflammatory pathway but instead can be explained by the well-known antioxidant and free-radical scavenging activities of carnosine, enhanced macrophage phagocytic activity, and the rescue of fractalkine receptor CX3CR1. These new findings obtained with macrophages challenged with Aβ1-42 oligomers, along with the well-known multimodal mechanism of action of carnosine in vitro and in vivo, substantiate the therapeutic potential of this dipeptide in the context of AD pathology.
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Affiliation(s)
- Giuseppe Caruso
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (F.C.)
- Correspondence: ; Tel.: +39-095-7384265
| | - Cristina Benatti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (C.B.); (N.B.); (F.T.)
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Nicolò Musso
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (N.M.); (C.G.F.); (G.S.); (C.B.); (F.D.)
| | - Claudia G. Fresta
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (N.M.); (C.G.F.); (G.S.); (C.B.); (F.D.)
| | - Annamaria Fidilio
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (F.C.)
| | - Giorgia Spampinato
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (N.M.); (C.G.F.); (G.S.); (C.B.); (F.D.)
| | - Nicoletta Brunello
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (C.B.); (N.B.); (F.T.)
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (N.M.); (C.G.F.); (G.S.); (C.B.); (F.D.)
- Center for Research in Ocular Pharmacology-CERFO, University of Catania, 95125 Catania, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (N.M.); (C.G.F.); (G.S.); (C.B.); (F.D.)
| | - Susan M. Lunte
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA;
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
- Department of Chemistry, University of Kansas, Lawrence, KS 66047-1620, USA
| | - Blake R. Peterson
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA;
| | - Fabio Tascedda
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (C.B.); (N.B.); (F.T.)
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Filippo Caraci
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy; (A.F.); (F.C.)
- Department of Laboratories, Oasi Research Institute—IRCCS, 94018 Troina, Italy
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5
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Lowry JR, Marshall N, Wenzel TJ, Murray TE, Klegeris A. The dietary fatty acids α-linolenic acid (ALA) and linoleic acid (LA) selectively inhibit microglial nitric oxide production. Mol Cell Neurosci 2020; 109:103569. [PMID: 33161065 DOI: 10.1016/j.mcn.2020.103569] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder without a known cure or effective treatment. Research has identified several modifiable risk factors and suggested preventative measures to reduce the risk of developing AD, including alterations in diet. Polyunsaturated fatty acids (PUFAs) have been shown to regulate inflammatory responses in the central nervous system (CNS), the main site of inflammation in AD. In the CNS, microglia are immune cells responsible for the maintenance of homeostasis. However, in AD, microglia can become adversely activated, causing them to release increased levels of cytotoxins and inflammatory mediators, including nitric oxide (NO) and monocyte-chemoattractant protein (MCP)-1. We assessed the effects of two PUFAs, α-linolenic acid (ALA) and linoleic acid (LA), on select microglial immune functions, since the effects of these dietary fatty acids on neuroimmune responses are not well characterized. In BV-2 mouse microglia activated with lipopolysaccharide (LPS), exposure to LA reduced NO secretion and inducible nitric oxide synthase (iNOS) levels, whereas exposure to ALA reduced NO without a corresponding reduction of iNOS. Neither ALA nor LA altered MCP-1 levels or cytotoxins released by THP-1 human microglia-like cells stimulated with a combination of LPS and interferon (IFN)-γ. Specific receptor antagonists were used to demonstrate that the inhibitory effect of LA on NO secretion did not depend on the free fatty acid receptor (FFAR) 1 or FFAR4. Furthermore, gas chromatography with a flame ionization detector (GC-FID) revealed that exposure to LA or ALA did not alter the fatty acid composition of BV-2 microglia. Our data indicate that regulation of select microglial immune functions by ALA and LA could be one of the mechanisms underlying the observed link between certain dietary patterns and AD, such as reduced risk of cognitive decline and dementia associated with the Mediterranean diet.
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Affiliation(s)
- Jessica R Lowry
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Nick Marshall
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Tyler J Wenzel
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Taryn E Murray
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada.
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6
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Mandal M, Jaiswal P, Mishra A. Role of curcumin and its nanoformulations in neurotherapeutics: A comprehensive review. J Biochem Mol Toxicol 2020; 34:e22478. [PMID: 32124518 DOI: 10.1002/jbt.22478] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/26/2019] [Accepted: 02/14/2020] [Indexed: 01/11/2023]
Abstract
Curcumin, a dietary polyphenol and major constituent of Curcuma longa (Zingiberaceae), is extensively used as a spice in Asian countries. For ages, turmeric has been used in traditional medicine systems to treat various diseases, which was possible because of its anti-inflammatory, antioxidant, anticancerous, antiepileptic, antidepressant, immunomodulatory, neuroprotective, antiapoptotic, and antiproliferative effects. Curcumin has potent antioxidant, anti-inflammatory, antiapoptotic, neurotrophic activities, which support its plausible neuroprotective effects in neurodegenerative disease. However, there is limited information available regarding the clinical efficacy of curcumin in neurodegenerative cases. The low oral bioavailability of curcumin may be speculated as a plausible factor that limits its effects in humans. Therefore, utilization of several approaches for the enhancement of bioavailability may improve clinical outcomes. Furthermore, the use of nanotechnology and a targeted drug delivery system may improve the bioavailability of curcumin. The present review is designed to summarize the molecular mechanisms pertaining to the neuroprotective effects of curcumin and its nanoformulations.
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Affiliation(s)
- Mukesh Mandal
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research-Raebareli (NIPER-R), Bijnor-Sisendi Road, Sarojini Nagar, Near CRPF Base Camp, Lucknow, U.P., India
| | - Pawan Jaiswal
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research-Raebareli (NIPER-R), Bijnor-Sisendi Road, Sarojini Nagar, Near CRPF Base Camp, Lucknow, U.P., India
| | - Awanish Mishra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research-Raebareli (NIPER-R), Bijnor-Sisendi Road, Sarojini Nagar, Near CRPF Base Camp, Lucknow, U.P., India
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7
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Maksoud MJE, Tellios V, An D, Xiang Y, Lu W. Nitric oxide upregulates microglia phagocytosis and increases transient receptor potential vanilloid type 2 channel expression on the plasma membrane. Glia 2019; 67:2294-2311. [DOI: 10.1002/glia.23685] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/02/2019] [Accepted: 07/06/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Matthew J. E. Maksoud
- Graduate Program of Neuroscience The University of Western Ontario London Canada
- Department of Molecular Medicine Robarts Research Institute, The University of Western Ontario London Canada
| | - Vasiliki Tellios
- Graduate Program of Neuroscience The University of Western Ontario London Canada
- Department of Molecular Medicine Robarts Research Institute, The University of Western Ontario London Canada
| | - Dong An
- Department of Molecular Medicine Robarts Research Institute, The University of Western Ontario London Canada
| | - Yun‐Yan Xiang
- Department of Molecular Medicine Robarts Research Institute, The University of Western Ontario London Canada
| | - Wei‐Yang Lu
- Graduate Program of Neuroscience The University of Western Ontario London Canada
- Department of Molecular Medicine Robarts Research Institute, The University of Western Ontario London Canada
- Department of Physiology and Pharmacology The University of Western Ontario London Canada
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8
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Roy A, Banerjee S, Saqib U, Baig MS. NOS1-derived nitric oxide facilitates macrophage uptake of low-density lipoprotein. J Cell Biochem 2019; 120:11593-11603. [PMID: 30805961 DOI: 10.1002/jcb.28439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/29/2018] [Accepted: 12/06/2018] [Indexed: 01/24/2023]
Abstract
Foam cell formation is a hallmark event during atherosclerosis. The current paradigm is that lipid uptake by a scavenger receptor in macrophages initiates necrosis core formation that characterizes atherosclerosis. We report that NOS1-derived nitric oxide (NO) facilitates low-density lipoprotein (LDL) uptake by macrophages independent of the inflammatory response. LDL uptake could be dramatically suppressed by NOS1 specific inhibitor 1-(2-trifluoromethylphenyl) imidazole (TRIM). Importantly, the notion that NOS1 can mediate uptake of lipoproteins suggests that the foam cell formation is regulated by NOS1-derived NO-mediated mechanism. This is a novel study involving NOS1 as a critical player of foam cell formation and reveals much about the key molecular proteins involved in atherosclerosis. Targeting NOS1 would be a useful strategy in reducing LDL uptake by macrophages and hence dampening the atherosclerosis progression.
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Affiliation(s)
- Anjali Roy
- Discipline of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Sreeparna Banerjee
- Department of Biological Sciences, Orta Doğu Teknik Üniversitesi (ODTU/METU), Ankara, Turkey
| | - Uzma Saqib
- Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore (IITI), Indore, India
| | - Mirza S Baig
- Discipline of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
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9
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Teter B, Morihara T, Lim GP, Chu T, Jones MR, Zuo X, Paul RM, Frautschy SA, Cole GM. Curcumin restores innate immune Alzheimer's disease risk gene expression to ameliorate Alzheimer pathogenesis. Neurobiol Dis 2019; 127:432-448. [PMID: 30951849 PMCID: PMC8092921 DOI: 10.1016/j.nbd.2019.02.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 02/15/2019] [Accepted: 02/20/2019] [Indexed: 01/28/2023] Open
Abstract
Alzheimer's disease (AD) genetics implies a causal role for innate immune genes, TREM2 and CD33, products that oppose each other in the downstream Syk tyrosine kinase pathway, activating microglial phagocytosis of amyloid (Aβ). We report effects of low (Curc-lo) and high (Curc-hi) doses of curcumin on neuroinflammation in APPsw transgenic mice. Results showed that Curc-lo decreased CD33 and increased TREM2 expression (predicted to decrease AD risk) and also increased TyroBP, which controls a neuroinflammatory gene network implicated in AD as well as phagocytosis markers CD68 and Arg1. Curc-lo coordinately restored tightly correlated relationships between these genes' expression levels, and decreased expression of genes characteristic of toxic pro-inflammatory M1 microglia (CD11b, iNOS, COX-2, IL1β). In contrast, very high dose curcumin did not show these effects, failed to clear amyloid plaques, and dysregulated gene expression relationships. Curc-lo stimulated microglial migration to and phagocytosis of amyloid plaques both in vivo and in ex vivo assays of sections of human AD brain and of mouse brain. Curcumin also reduced levels of miR-155, a micro-RNA reported to drive a neurodegenerative microglial phenotype. In conditions without amyloid (human microglial cells in vitro, aged wild-type mice), Curc-lo similarly decreased CD33 and increased TREM2. Like curcumin, anti-Aβ antibody (also reported to engage the Syk pathway, increase CD68, and decrease amyloid burden in human and mouse brain) increased TREM2 in APPsw mice and decreased amyloid in human AD sections ex vivo. We conclude that curcumin is an immunomodulatory treatment capable of emulating anti-Aβ vaccine in stimulating phagocytic clearance of amyloid by reducing CD33 and increasing TREM2 and TyroBP, while restoring neuroinflammatory networks implicated in neurodegenerative diseases.
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Affiliation(s)
- B Teter
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America; Alzheimer's Translational Center, Veterans Administration (Research 151), Bldg. 114, Rm. 114-1, 11301 Wilshire Blvd, Los Angeles, CA 90073, United States of America.
| | - T Morihara
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America.
| | - G P Lim
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America
| | - T Chu
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America
| | - M R Jones
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America
| | - X Zuo
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America
| | - R M Paul
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Medicine, University of California, Los Angeles (UCLA), United States of America
| | - S A Frautschy
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Medicine, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America.
| | - G M Cole
- Departments of Neurology, Geriatric Research Education and Clinical Centerand, University of California, Los Angeles (UCLA), United States of America; Departments of Medicine, University of California, Los Angeles (UCLA), United States of America; Departments of Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research Education and Clinical Center, University of California, Los Angeles (UCLA), United States of America.
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10
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Lim SL, Tran DN, Zumkehr J, Chen C, Ghiaar S, Kieu Z, Villanueva E, Gallup V, Rodriguez-Ortiz CJ, Kitazawa M. Inhibition of hematopoietic cell kinase dysregulates microglial function and accelerates early stage Alzheimer's disease-like neuropathology. Glia 2018; 66:2700-2718. [PMID: 30277607 DOI: 10.1002/glia.23522] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 08/02/2018] [Accepted: 08/02/2018] [Indexed: 11/08/2022]
Abstract
Emerging evidence have posited that dysregulated microglia impair clearance and containment of amyloid-β (Aβ) species in the brain, resulting in aberrant buildup of Aβ and onset of Alzheimer's disease (AD). Hematopoietic cell kinase (Hck) is one of the key regulators of phagocytosis among the Src family tyrosine kinases (SFKs) in myeloid cells, and its expression is found to be significantly altered in AD brains. However, the role of Hck signaling in AD pathogenesis is unknown. We employed pharmacological inhibition and genetic ablation of Hck in BV2 microglial cells and J20 mouse model of AD, respectively, to evaluate the impact of Hck deficiency on Aβ-stimulated microglial phagocytosis, Aβ clearance, and resultant AD-like neuropathology. Our in vitro data reveal that pharmacological inhibition of SFKs/Hck in BV2 cells and genetic ablation of their downstream kinase, spleen tyrosine kinase (Syk), in primary microglia significantly attenuate Aβ oligomers-stimulated microglial phagocytosis. Whereas in Hck-deficient J20 mice, we observed exacerbated Aβ plaque burden, reduced microglial coverage, containment, and phagocytosis of Aβ plaques, and induced iNOS expression in plaque-associated microglial clusters. These multifactorial changes in microglial activities led to attenuated PSD95 levels in hippocampal DG and CA3 regions, but did not alter the postsynaptic dendritic spine morphology at the CA1 region nor cognitive function of the mice. Hck inhibition thus accelerates early stage AD-like neuropathology by dysregulating microglial function and inducing neuroinflammation. Our data implicate that Hck pathway plays a prominent role in regulating microglial neuroprotective function during the early stage of AD development.
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Affiliation(s)
- Siok Lam Lim
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Diana Nguyen Tran
- Molecular and Cell Biology, University of California, Merced, California
| | - Joannee Zumkehr
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Christine Chen
- Molecular and Cell Biology, University of California, Merced, California
| | - Sagar Ghiaar
- Molecular and Cell Biology, University of California, Merced, California
| | - Zanett Kieu
- Molecular and Cell Biology, University of California, Merced, California
| | | | - Victoria Gallup
- Molecular and Cell Biology, University of California, Merced, California
| | - Carlos J Rodriguez-Ortiz
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
| | - Masashi Kitazawa
- Center for Occupational and Environmental Health, Department of Medicine, University of California, Irvine, California.,Molecular and Cell Biology, University of California, Merced, California
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11
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Nacka-Aleksić M, Stojanović M, Simić L, Bufan B, Kotur-Stevuljević J, Stojić-Vukanić Z, Dimitrijević M, Ražić S, Leposavić G. Sex as a determinant of age-related changes in rat spinal cord inflammation-oxidation state. Biogerontology 2017; 18:821-839. [PMID: 28825141 DOI: 10.1007/s10522-017-9726-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/09/2017] [Indexed: 02/07/2023]
Abstract
To close the gap in our knowledge of sex influence on age-related changes in inflammation-oxidation state in spinal cord (SC) relevant to inflammation/oxidative-stress associated neuropathologies, 2-3 month-old (young) and 18-20 month-old (old) rats, exhibiting increased level of IL-6, a commonly used marker of inflamm-aging, were examined for inflammatory/redox status, and the underlying regulatory networks' molecules expression. With age, rat SC microglia became sensitized ("primed"), while SC tissue shifted towards mild inflammatory state, with increased levels of proinflammatory IL-1β (key marker of microglial systemic inflammation-induced neurotoxicity), which was more prominent in males. This, most likely, reflected age- and sex-related impairment in the expression of CX3CR1, the receptor for fractalkine (CX3CL1), the soluble factor which regulates microglial activation and diminishes production of IL-1β (central for fractalkine neuroprotection). Considering that (i) age-related changes in SC IL-1β expression were not followed by complementary changes in SC IL-6 expression, and (ii) the reversal in the direction of the sex bias in circulating IL-6 level and SC IL-1β expression, it seems obvious that there are tissue-specific differences in the proinflammatory cytokine profile. Additionally, old male rat SC exhibited greater oxidative damage than female, reflecting, most likely, their lower capacity to maintain the pro-oxidant-antioxidant balance. In conclusion, these findings, apart from highlighting the significance of sex for age-associated changes in SC inflammation-oxidation, may be relevant for understating sex differences in human inflammation/oxidative-stress related SC diseases, and consequently, for optimizing their prevention/therapy.
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Affiliation(s)
- Mirjana Nacka-Aleksić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Marija Stojanović
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Lidija Simić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Biljana Bufan
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | | | - Zorica Stojić-Vukanić
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Mirjana Dimitrijević
- Department of Immunology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia
| | - Slavica Ražić
- Department of Analytical Chemistry, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Gordana Leposavić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia.
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He GL, Luo Z, Shen TT, Li P, Yang J, Luo X, Chen CH, Gao P, Yang XS. Inhibition of STAT3- and MAPK-dependent PGE 2 synthesis ameliorates phagocytosis of fibrillar β-amyloid peptide (1-42) via EP2 receptor in EMF-stimulated N9 microglial cells. J Neuroinflammation 2016; 13:296. [PMID: 27871289 PMCID: PMC5117690 DOI: 10.1186/s12974-016-0762-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/09/2016] [Indexed: 12/16/2022] Open
Abstract
Background Prostaglandin E2 (PGE2)-involved neuroinflammatory processes are prevalent in several neurological conditions and diseases. Amyloid burden is correlated with the activation of E-prostanoid (EP) 2 receptors by PGE2 in Alzheimer’s disease. We previously demonstrated that electromagnetic field (EMF) exposure can induce pro-inflammatory responses and the depression of phagocytosis in microglial cells, but the signaling pathways involved in phagocytosis of fibrillar β-amyloid (fAβ) in microglial cells exposed to EMF are poorly understood. Given the important role of PGE2 in neural physiopathological processes, we investigated the PGE2-related signaling mechanism in the immunomodulatory phagocytosis of EMF-stimulated N9 microglial cells (N9 cells). Methods N9 cells were exposed to EMF with or without pretreatment with the selective inhibitors of cyclooxygenase-2 (COX-2), Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and mitogen-activated protein kinases (MAPKs) and antagonists of PG receptors EP1-4. The production of endogenous PGE2 was quantified by enzyme immunoassays. The phagocytic ability of N9 cells was evaluated based on the fluorescence intensity of the engulfed fluorescent-labeled fibrillar β-amyloid peptide (1-42) (fAβ42) measured using a flow cytometer and a fluorescence microscope. The effects of pharmacological agents on EMF-activated microglia were investigated based on the expressions of JAK2, STAT3, p38/ERK/JNK MAPKs, COX-2, microsomal prostaglandin E synthase-1 (mPGES-1), and EP2 using real-time PCR and/or western blotting. Results EMF exposure significantly increased the production of PGE2 and decreased the phagocytosis of fluorescent-labeled fAβ42 by N9 cells. The selective inhibitors of COX-2, JAK2, STAT3, and MAPKs clearly depressed PGE2 release and ameliorated microglial phagocytosis after EMF exposure. Pharmacological agents suppressed the phosphorylation of JAK2-STAT3 and MAPKs, leading to the amelioration of the phagocytic ability of EMF-stimulated N9 cells. Antagonist studies of EP1-4 receptors showed that EMF depressed the phagocytosis of fAβ42 through the PGE2 system, which is linked to EP2 receptors. Conclusions This study indicates that EMF exposure could induce phagocytic depression via JAK2-STAT3- and MAPK-dependent PGE2-EP2 receptor signaling pathways in microglia. Therefore, pharmacological inhibition of PGE2 synthesis and EP2 receptors may be a potential therapeutic strategy to combat the neurobiological deterioration that follows EMF exposure. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0762-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gen-Lin He
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Zhen Luo
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Ting-Ting Shen
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Ping Li
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Ju Yang
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Xue Luo
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China
| | - Chun-Hai Chen
- Key Laboratory of Medical Protection for Electromagnetic Radiation Ministry of Education, Third Military Medical University, Chongqing, 400038, People's Republic of China
| | - Peng Gao
- Key Laboratory of Medical Protection for Electromagnetic Radiation Ministry of Education, Third Military Medical University, Chongqing, 400038, People's Republic of China
| | - Xue-Sen Yang
- Department of Tropic Hygiene, Institute of Tropical Medicine, Third Military Medical University, 30 Gaotanyan Street, Chongqing, 400038, People's Republic of China.
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13
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Darvesh AS, Carroll RT, Bishayee A, Geldenhuys WJ, Van der Schyf CJ. Oxidative stress and Alzheimer’s disease: dietary polyphenols as potential therapeutic agents. Expert Rev Neurother 2014; 10:729-45. [DOI: 10.1586/ern.10.42] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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14
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Wang CC, Tsai YJ, Hsieh YC, Lin RJ, Lin CL. The aqueous extract from Toona sinensis leaves inhibits microglia-mediated neuroinflammation. Kaohsiung J Med Sci 2013; 30:73-81. [PMID: 24444536 PMCID: PMC7118447 DOI: 10.1016/j.kjms.2013.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 08/30/2013] [Indexed: 01/24/2023] Open
Abstract
The leaves of Toona sinensis, a well‐known traditional oriental medicine, have been prescribed for the treatment of enteritis and infection. Recently, aqueous extracts of Toona sinensis leaves (TSL‐1) have demonstrated many biological effects both in vitro and in vivo. In the central nervous system, microglial activation and their proinflammatory responses are considered an important therapeutic strategy for neuroinflammatory disorders such as cerebral ischemia, Alzheimer's disease, and Parkinson's disease. The present study attempted to validate the effect of TSL‐1 on microglia‐mediated neuroinflammation stimulated by lipopolysaccharide (LPS). As inflammatory parameters, the production of nitric oxide (NO), inducible NO synthase, and tumor necrosis factor‐α were evaluated. Our results demonstrate that TSL‐1 suppresses LPS‐induced NO production, tumor necrosis factor‐α secretion, and inducible NO synthase protein expression in a concentration‐dependent manner, without causing cytotoxicity. In addition, the inhibitory effects of TSL‐1 in LPS‐stimulated BV‐2 microglia were extended to post‐treatment suggesting the therapeutic potential of TSL‐1. Therefore, this work provides the future evaluation of the role of TSL‐1 in the treatment of neurodegenerative diseases by inhibition of inflammatory mediator production in activated microglia.
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Affiliation(s)
- Chao-Chuan Wang
- Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yee-Jean Tsai
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ya-Ching Hsieh
- Department of Medical Research, E-Da Hospital/I-Shou University, Kaohsiung, Taiwan
| | - Rong-Jyh Lin
- Department of Parasitology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Lung Lin
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Yarkoni O, Donlon L, Frankel D. Creating a bio-hybrid signal transduction pathway: opening a new channel of communication between cells and machines. BIOINSPIRATION & BIOMIMETICS 2012; 7:046017. [PMID: 23154675 DOI: 10.1088/1748-3182/7/4/046017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Manipulation of signal transduction pathways presents a viable mechanism to interface cells with electronics. In this work, we present a two-step signal transduction pathway involving cellular and electronic transduction elements. In order to circumvent many of the conventional difficulties encountered when harnessing chemical signalling for the purpose of electronics communication, gaseous nitric oxide (NO) was selected as the signalling molecule. By genetic engineering of the nitric oxide synthase protein eNOS and insertion of light-oxygen-voltage (LOV) domains, we have created a photoactive version of the protein. The novel chimeric eNOS was found to be capable of producing NO in response to excitation by visible light. By coupling these mutant cells to a surface modified platinum electrode, it was possible to convert an optical signal into a chemical one, followed by subsequent conversion of the chemical signal into an electrical output.
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Affiliation(s)
- Orr Yarkoni
- Department of Chemical Engineering, Newcastle University, Merz Court, Newcastle. NE1 7RU, UK
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16
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Darvesh AS, Carroll RT, Bishayee A, Novotny NA, Geldenhuys WJ, Van der Schyf CJ. Curcumin and neurodegenerative diseases: a perspective. Expert Opin Investig Drugs 2012; 21:1123-40. [DOI: 10.1517/13543784.2012.693479] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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17
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Brites D. The evolving landscape of neurotoxicity by unconjugated bilirubin: role of glial cells and inflammation. Front Pharmacol 2012; 3:88. [PMID: 22661946 PMCID: PMC3361682 DOI: 10.3389/fphar.2012.00088] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 04/23/2012] [Indexed: 12/13/2022] Open
Abstract
Unconjugated hyperbilirubinemia is a common condition in the first week of postnatal life. Although generally harmless, some neonates may develop very high levels of unconjugated bilirubin (UCB), which may surpass the protective mechanisms of the brain in preventing UCB accumulation. In this case, both short-term and long-term neurodevelopmental disabilities, such as acute and chronic UCB encephalopathy, known as kernicterus, or more subtle alterations defined as bilirubin-induced neurological dysfunction (BIND) may be produced. There is a tremendous variability in babies' vulnerability toward UCB for reasons not yet explained, but preterm birth, sepsis, hypoxia, and hemolytic disease are comprised as risk factors. Therefore, UCB levels and neurological abnormalities are not strictly correlated. Even nowadays, the mechanisms of UCB neurotoxicity are still unclear, as are specific biomarkers, and little is known about lasting sequelae attributable to hyperbilirubinemia. On autopsy, UCB was shown to be within neurons, neuronal processes, and microglia, and to produce loss of neurons, demyelination, and gliosis. In isolated cell cultures, UCB was shown to impair neuronal arborization and to induce the release of pro-inflammatory cytokines from microglia and astrocytes. However, cell dependent sensitivity to UCB toxicity and the role of each nerve cell type remains not fully understood. This review provides a comprehensive insight into cell susceptibilities and molecular targets of UCB in neurons, astrocytes, and oligodendrocytes, and on phenotypic and functional responses of microglia to UCB. Interplay among glia elements and cross-talk with neurons, with a special emphasis in the UCB-induced immunostimulation, and the role of sepsis in BIND pathogenesis are highlighted. New and interesting data on the anti-inflammatory and antioxidant activities of different pharmacological agents are also presented, as novel and promising additional therapeutic approaches to BIND.
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Affiliation(s)
- Dora Brites
- Neuron Glia Biology in Health and Disease Unit, Research Institute for Medicines and Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon Lisbon, Portugal
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Takata K, Kitamura Y. Molecular approaches to the treatment, prophylaxis, and diagnosis of Alzheimer's disease: tangle formation, amyloid-β, and microglia in Alzheimer's disease. J Pharmacol Sci 2012; 118:331-7. [PMID: 22382659 DOI: 10.1254/jphs.11r10fm] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Pathological hallmarks of Alzheimer's disease (AD) include senile plaques, neurofibrillary tangles (NFTs), synaptic loss, and neurodegeneration. Senile plaques are composed of amyloid-β (Aβ) and are surrounded by microglia, a primary immune effector cell in the central nervous system. NFTs are formed by the intraneuronal accumulation of hyperphosphorylated tau, and progressive synaptic and neuronal losses closely correlate with cognitive deficits in AD. Studies on responsible genes of familial AD and temporal patterns of pathological changes in brains of patients with Down's syndrome (Trisomy 21), who invariably develop neuropathology of AD, have suggested that Aβ accumulation is a primary event that influences other AD pathologies. Although details of the interaction between AD pathologies remain unclear, experimental evidences to discuss this issue have been accumulated. In this paper, we review and discuss recent findings that link the AD pathologies to each other. Further studies on the interaction between pathologies induced in AD brain may contribute to provide deep insight into the pathogenesis of AD and to develop novel therapeutic, prophylactic, and early diagnostic strategies for AD.
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Affiliation(s)
- Kazuyuki Takata
- Department of Neurobiology, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan.
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19
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Silva SL, Osório C, Vaz AR, Barateiro A, Falcão AS, Silva RFM, Brites D. Dynamics of neuron-glia interplay upon exposure to unconjugated bilirubin. J Neurochem 2011; 117:412-24. [PMID: 21275990 DOI: 10.1111/j.1471-4159.2011.07200.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Microglia are the main players of the brain immune response. They act as active sensors that rapidly respond to injurious insults by shifting into different activated states. Elevated levels of unconjugated bilirubin (UCB) induce cell death, immunostimulation and oxidative stress in both neurons and astrocytes. We recently reported that microglial phagocytic phenotype precedes the release of pro-inflammatory cytokines upon UCB exposure. We investigated whether and how microglia microenvironment influences the response to UCB. Our findings revealed that conditioned media derived from UCB-treated astrocytes reduce microglial inflammatory reaction and cell death, suggesting an attempt to curtail microglial over activation. Conditioned medium from UCB-challenged neurons, although down-regulating tumor necrosis factor-α and interleukin-1β promoted the release of interleukin-6 and nitric oxide, the activation of matrix metalloproteinase-9, and cell death, as compared with UCB-direct effects on microglia. Moreover, soluble factors released by UCB-treated neurons intensified the phagocytic properties manifested by microglia under direct exposure to UCB. Results from neuron-microglia mixed cultures incubated with UCB evidenced that sensitized microglia were able to prevent neurite outgrowth impairment and cell death. In conclusion, our data indicate that stressed neurons signal microglial clearance functions, but also overstimulate its inflammatory potential ultimately leading to microglia demise.
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Affiliation(s)
- Sandra L Silva
- Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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20
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Dibaj P, Nadrigny F, Steffens H, Scheller A, Hirrlinger J, Schomburg ED, Neusch C, Kirchhoff F. NO mediates microglial response to acute spinal cord injury under ATP control in vivo. Glia 2010; 58:1133-44. [PMID: 20468054 DOI: 10.1002/glia.20993] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To understand the pathomechanisms of spinal cord injuries will be a prerequisite to develop efficient therapies. By investigating acute lesions of spinal cord white matter in anesthetized mice with fluorescently labeled microglia and axons using in vivo two-photon laser-scanning microscopy (2P-LSM), we identified the messenger nitric oxide (NO) as a modulator of injury-activated microglia. Local tissue damages evoked by high-power laser pulses provoked an immediate attraction of microglial processes. Spinal superfusion with NO synthase and guanylate cyclase inhibitors blocked these extensions. Furthermore, local injection of the NO-donor spermine NONOate (SPNO) or the NO-dependent second messenger cGMP induced efficient migration of microglial cells toward the injection site. High-tissue levels of NO, achieved by uniform superfusion with SPNO and mimicking extended tissue damage, resulted in a fast conversion of the microglial shape from ramified to ameboid indicating cellular activation. When the spinal white matter was preconditioned by increased, ambient ATP (known as a microglial chemoattractant) levels, the attraction of microglial processes to local NO release was augmented, whereas it was abolished at low levels of tissue ATP. Because both signaling molecules, NO and ATP, mediate acute microglial reactions, coordinated pharmacological targeting of NO and purinergic pathways will be an effective mean to influence the innate immune processes after spinal cord injury.
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Affiliation(s)
- Payam Dibaj
- Department of Neurology, Georg August University of Göttingen, Germany
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21
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Saab CY, Hains BC. Remote neuroimmune signaling: a long-range mechanism of nociceptive network plasticity. Trends Neurosci 2009; 32:110-7. [PMID: 19135730 DOI: 10.1016/j.tins.2008.11.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 10/28/2008] [Accepted: 11/04/2008] [Indexed: 01/19/2023]
Abstract
Chronic pain secondary to neuronal injury is actively and continuously modulated at multiple locations along the sensory neuraxis. Here, we describe how nociceptive neurons of the spinal cord and thalamus process and communicate nociceptive information in terms of precisely calibrated firing patterns. We then discuss how several cell types with immunogenic properties (e.g. blood cells and glia) cause system-wide interference in nociceptive processing through novel signaling schema, thus contributing to nociceptive network plasticity and chronic pain.
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Affiliation(s)
- Carl Y Saab
- Department of Surgery, Rhode Island Hospital, Brown Alpert Medical School and Department of Neuroscience, Brown University, Providence, RI 02903, USA.
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23
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Notas G, Nifli AP, Kampa M, Vercauteren J, Kouroumalis E, Castanas E. Resveratrol exerts its antiproliferative effect on HepG2 hepatocellular carcinoma cells, by inducing cell cycle arrest, and NOS activation. Biochim Biophys Acta Gen Subj 2006; 1760:1657-66. [PMID: 17052855 DOI: 10.1016/j.bbagen.2006.09.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 08/25/2006] [Accepted: 09/15/2006] [Indexed: 01/17/2023]
Abstract
The stilbene resveratrol exerts antiproliferative and proapoptotic actions on a number of different cancer cell lines, through diverse mechanisms, including antioxidant effects, enzyme, growth factor and hormone receptor binding, and nucleic acid direct or indirect interactions. Although resveratrol accumulates in the liver, its effect on hepatocellular carcinoma has not been extensively studied. We have used the human hepatocyte-derived cancer cell line HepG2 to address the possible action of resveratrol on cell growth and to examine some possible mechanisms of action. Our results indicate that the stilbene inhibits potently cell proliferation, reduces the production of reactive oxygen species and induces apoptosis, through cell cycle arrest in G1 and G2/M phases. Furthermore it modulates the NO/NOS system, by increasing iNOS and eNOS expression, NOS activity and NO production. Inhibition of NOS enzymes attenuates its antiproliferative effect. These data could be of value in possible prevention or adjuvant treatment of hepatocellular carcinoma, through an increased consumption of resveratrol-rich foods and beverages.
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Affiliation(s)
- George Notas
- Laboratories of Gastroenterology, University of Crete School of Medicine, Heraklion, Greece
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Shariftabrizi A, Nifli AP, Ansari M, Saadat F, Ebrahimkhani MR, Alizadeh N, Nasseh A, Alexaki VI, Dehpour AR, Castanas E, Khorramizadeh MR. Matrix metalloproteinase 2 secretion in WEHI 164 fibrosarcoma cells is nitric oxide-related and modified by morphine. Eur J Pharmacol 2005; 530:33-9. [PMID: 16386243 DOI: 10.1016/j.ejphar.2005.11.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 11/17/2005] [Accepted: 11/22/2005] [Indexed: 10/25/2022]
Abstract
Matrix metalloproteinases (MMP) are ubiquitous enzymes involved in extracellular matrix remodeling, and as a consequence in a number of physiological and pathological states, including development, wound healing and cancer. A crucial feature of cancer progression and metastasis is the disruption of extracellular matrix, and spreading of proliferating cancer cells. Modulation of MMP is a main target of cancer research. Using the mouse fibrosarcoma cell line WEHI 164, producing high amounts of MMP-2, we investigated whether we could modulate its production. We report that MMP-2 is under the control of nitric oxide (NO)/nitric oxide synthase (NOS) system. In addition, we show that NOS activity is controlled by opioids in a non-opioid receptor-related manner. Finally, we provide evidence that morphine, when administrated at low, non-toxic concentrations (<10(-9) M) attenuates MMP-2 activity. We conclude that, as morphine is able to decrease metalloproteinase activity via the NO/NOS system, it may have a place in the treatment of several sarcomas including fibrosarcoma.
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Shen S, Yu S, Binek J, Chalimoniuk M, Zhang X, Lo SC, Hannink M, Wu J, Fritsche K, Donato R, Sun GY. Distinct signaling pathways for induction of type II NOS by IFNγ and LPS in BV-2 microglial cells. Neurochem Int 2005; 47:298-307. [PMID: 15955597 DOI: 10.1016/j.neuint.2005.03.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Revised: 03/30/2005] [Accepted: 03/30/2005] [Indexed: 11/30/2022]
Abstract
Nitric oxide (NO) release upon microglial cell activation has been implicated in the tissue injury and cell death in many neurodegenerative diseases. Recent studies have indicated the ability of interferon-gamma (IFNgamma) and lipopolysaccharides (LPS) to independently induce type II nitric oxide synthase (iNOS) expression and NO production in BV-2 microglial cells. However, a detailed comparison between the signaling pathways activating iNOS by these two agents has not been accomplished. Analysis of PKC isoforms revealed mainly the presence of PKCdelta, iota and lambda in BV-2 cells. Although both IFNgamma and LPS could specifically enhance the tyrosine phosphorylation of PKCdelta, treatment with IFNgamma induced a steady increase of phospho-PKCdelta for up to 1h, whereas treatment with LPS elevated phospho-PKCdelta levels only transiently, with peak activity at 5 min. Rottlerin, a specific inhibitor for PKCdelta, dose-dependently inhibited IFNgamma- and LPS-induced NO production. Despite the common involvement of PKCdelta, IFNgamma- but not LPS-induced NO production involved extracellular signal-regulated kinases (ERK1/2) cascade and IFNgamma-induced phosphorylation of ERK1/2 was mediated through PKC. On the other hand, LPS- but not IFNgamma-induced NO production was through stimulation of NF-kappaB activation and nuclear translocation to interact with DNA. These results demonstrated distinct signaling pathways for induction of iNOS by IFNgamma and LPS in BV-2 microglial cells.
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Affiliation(s)
- Siming Shen
- Department of Nutritional Sciences, University of Missouri, Columbia, MO 65212, USA
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Zabłocka A, Janusz M, Macała J, Lisowski J. A proline-rich polypeptide complex and its nonapeptide fragment inhibit nitric oxide production induced in mice. ACTA ACUST UNITED AC 2005; 125:35-9. [PMID: 15582711 DOI: 10.1016/j.regpep.2004.07.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2004] [Revised: 07/21/2004] [Accepted: 07/21/2004] [Indexed: 11/18/2022]
Abstract
A proline-rich polypeptide complex (PRP) isolated from ovine colostrum shows immunoregulatory and procognitive activities. It shows beneficial effects in Alzheimer's disease (AD) patients when orally administered in the form of tablets called Colostrinin. The mechanism of action of PRP/Colostrinin in AD has not been yet clarified. It is known that oxidative stress and overproduction of NO may enhance neurodegenerative processes. PRP regulates the secretion of cytokines, inhibits NO and O2- release in cell cultures. Since the results on isolated cells or cell lines frequently do not reflect the events in vivo, the effect of PRP and its nonapeptide fragment (NP) on the level of NO2- in sera of mice untreated or intraperitoneally treated with LPS was studied. PRP and NP did not induce production of NO. However, when applicated 6 h after LPS, they inhibited the release of NO induced by LPS in about 30-50%. The results in vivo presented in this paper confirm the results obtained in cell cultures and indicate that the beneficial effects of PRP/Colostrinin observed in AD patients may be, among others, due to an inhibition of overproduction of NO.
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Affiliation(s)
- Agnieszka Zabłocka
- Department of Immunochemistry, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 R. Weigla, 53-114 Wrocław, Poland
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de Almeida CJG, Chiarini LB, da Silva JP, E Silva PMR, Martins MA, Linden R. The cellular prion protein modulates phagocytosis and inflammatory response. J Leukoc Biol 2004; 77:238-46. [PMID: 15539455 DOI: 10.1189/jlb.1103531] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The cellular prion protein (PrPc) is a glycoprotein anchored by glycosylphosphatidylinositol (GPI) to the cell surface and is abundantly expressed in the central nervous system. It is also expressed in a variety of cell types of the immune system. We investigated the role of PrPc in the phagocytosis of apoptotic cells and other particles. Macrophages from mice with deletion of the Prnp gene showed higher rates of phagocytosis than wild-type macrophages in in vitro assays. The elimination of GPI-anchored proteins from the cell surface of macrophages from wild-type mice rendered these cells as efficient as macrophages derived from knockout mice. In situ detection of phagocytosis of apoptotic bodies within the retina indicated augmented phagocytotic activity in knockout mice. In an in vivo assay of acute peritonitis, knockout mice showed more efficient phagocytosis of zymosan particles than wild-type mice. In addition, leukocyte recruitment was altered in knockout mice, as compared with wild type. The data show that PrPc modulates phagocytosis in vitro and in vivo. This activity is described for the first time and may be important for normal macrophage functions as well as for the pathogenesis of prion diseases.
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Dudal S, Morissette C, Lacombe D, Tremblay P, Gervais F. Differences in the amyloid-beta-induced inflammatory response in microglia from C57BL/6 and A/J strains of mice. J Neuroimmunol 2004; 153:26-35. [PMID: 15265660 DOI: 10.1016/j.jneuroim.2004.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 03/01/2004] [Accepted: 04/21/2004] [Indexed: 11/24/2022]
Abstract
The microglial inflammatory response to Abeta(1-42) stimulation with or without IFN-gamma priming was investigated in low and high responder strains of mice, A/J and C57BL/6, respectively. A/J microglia showed moderate morphological changes upon stimulation with IFN-gamma alone or with Abeta(1-42). Conversely, C57BL/6 microglia showed major changes in their cellular morphology, which were accompanied by a decrease in NO release and a marked increase in TNF-alpha production. These results indicate that the magnitude of the microglial inflammatory response to Abeta is strongly influenced by genetic factors. Individual differences in the regulation of the microglial response may be a key player in the rate of development of the neuropathology of AD.
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Affiliation(s)
- Sherri Dudal
- Department of Experimental Medicine, McGill University, Montréal, Québec, Canada H3A 2T5
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Heneka MT, Gavrilyuk V, Landreth GE, O'Banion MK, Weinberg G, Feinstein DL. Noradrenergic depletion increases inflammatory responses in brain: effects on IkappaB and HSP70 expression. J Neurochem 2003; 85:387-98. [PMID: 12675915 DOI: 10.1046/j.1471-4159.2003.01694.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The inflammatory responses in many cell types are reduced by noradrenaline (NA) binding to beta-adrenergic receptors. We previously demonstrated that cortical inflammatory responses to aggregated amyloid beta (Abeta) are increased if NA levels were first depleted by lesioning locus ceruleus (LC) noradrenergic neurons, which replicates the loss of LC occurring in Alzheimer's disease. To examine the molecular basis for increased responses, we used the selective neurotoxin DSP4 to lesion the LC, and then examined levels of putative anti-inflammatory molecules. Inflammatory responses were achieved by injection of aggregated Abeta1-42 peptide and IL-1beta into frontal cortex, which induced neuronal inducible nitric oxide synthase (iNOS) and microglial IL-1beta expression. DSP4-treatment reduced basal levels of nuclear factor kappa B (NF-kappaB) inhibitory IkappaB proteins, and of heat shock protein (HSP)70. Inflammatory responses were prevented by co-injection (ibuprofen or ciglitzaone) or oral administration (pioglitazone) of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists. Treatment with PPARgamma agonists restored IkappaBalpha, IkappaBbeta, and HSP70 levels to values equal or above those observed in control animals, and reduced activation of cortical NF-kappaB. These results suggest that noradrenergic depletion reduces levels of anti-inflammatory molecules which normally limit cortical responses to Abeta, and that PPARgamma agonists can reverse that effect. These findings suggest one mechanism by which PPARgamma agonists could provide benefit in neurological diseases having an inflammatory component.
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Fiebich BL, Lieb K, Engels S, Heinrich M. Inhibition of LPS-induced p42/44 MAP kinase activation and iNOS/NO synthesis by parthenolide in rat primary microglial cells. J Neuroimmunol 2002; 132:18-24. [PMID: 12417429 DOI: 10.1016/s0165-5728(02)00279-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitric oxide (NO) has been implicated in the etiopathology of central nervous system (CNS) diseases such as multiple sclerosis (MS). Inhibition of NO synthesis has been proposed to be a possible mechanism of action of relevance in the treatment of multiple sclerosis and migraine. Here, we investigated the effect of parthenolide on inducible NO synthase (iNOS) synthesis and NO release using primary rat microglia. We found parthenolide to be an inhibitor of iNOS/NO synthesis. Investigating the molecular mechanisms by which parthenolide prevents iNOS/NO synthesis, we found that parthenolide inhibits the activation of p42/44 mitogen-activated protein kinase (MAPK), but not IkBalpha (IkappaBalpha) degradation or nuclear factor-kappaB (NF-kappaB) p65 activation. The data suggest that parthenolide might have a potential in the treatment of CNS diseases where NO is part of the pathophysiology.
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Affiliation(s)
- Bernd L Fiebich
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical School, D-79104 Freiburg, Germany.
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Rogers J, Strohmeyer R, Kovelowski CJ, Li R. Microglia and inflammatory mechanisms in the clearance of amyloid beta peptide. Glia 2002; 40:260-269. [PMID: 12379913 DOI: 10.1002/glia.10153] [Citation(s) in RCA: 288] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There is now abundant evidence that brain microglia, when activated, have the lineage, receptors, and synthetic capacity to participate in both potentially neurotoxic inflammatory responses and potentially beneficial phagocytic responses. Amyloid beta peptide (Abeta) forms highly insoluble, beta-pleated aggregates that are widely deposited in the Alzheimer's disease (AD) cortex and limbic system. Aggregated Abeta also activates the classical and alternative complement cascades. These properties make Abeta an excellent target for microglial phagocytosis, a view supported by multiple reports, through well established mechanisms of phagocyte clearance.
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Affiliation(s)
| | | | | | - Rena Li
- Sun Health Research Institute, Sun City, Arisona
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Mitrasinovic OM, Murphy GM. Accelerated phagocytosis of amyloid-beta by mouse and human microglia overexpressing the macrophage colony-stimulating factor receptor. J Biol Chem 2002; 277:29889-96. [PMID: 12032144 DOI: 10.1074/jbc.m200868200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microglia surrounding A beta plaques in Alzheimer's disease and in the APPV717F transgenic mouse model of Alzheimer's disease have enhanced immunoreactivity for the macrophage colony-stimulating factor receptor (M-CSFR), encoded by the proto-oncogene c-fms. Increased expression of M-CSFR on cultured microglia results in proliferation and release of pro-inflammatory cytokines and expression of inducible nitric-oxide synthase. We transfected mouse BV-2 and human SV-A3 microglia to overexpress M-CSFR and examined microglial phagocytosis of fluorescein-conjugated A beta. Flow cytometry and laser confocal microscopy showed accelerated phagocytosis of A beta in mouse and human microglia because of M-CSFR overexpression that was time- and concentration-dependent. In contrast, microglial uptake of 1-microm diameter polystyrene microspheres was not enhanced by M-CSFR overexpression. Microglial uptake of A beta was blocked by cytochalasin D, which inhibits phagocytosis. M-CSFR overexpression increased the mRNA for macrophage scavenger receptor A, and fucoidan blocking of macrophage scavenger receptors inhibited uptake of A beta. M-CSFR antibody blocking experiments demonstrated that increased A beta uptake depended on the interaction of the M-CSFR with its ligand. These results suggest that overexpression of M-CSFR in APPV717F mice may prime microglia for phagocytosis of A beta after immunization.
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Affiliation(s)
- Olivera M Mitrasinovic
- Neuroscience Research Laboratories, Department of Psychiatry & Behavioral Sciences, Stanford University School of Medicine, Stanford, California 94305-5485, USA
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Nakazawa T, Tomita H, Yamaguchi K, Sato Y, Shimura M, Kuwahara S, Tamai M. Neuroprotective effect of nipradilol on axotomized rat retinal ganglion cells. Curr Eye Res 2002; 24:114-22. [PMID: 12187483 DOI: 10.1076/ceyr.24.2.114.8162] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To determine whether nipradilol, a new anti-glaucoma drug, can protect retinal ganglion cells (RGCs) from secondary cell death caused by transection of the optic nerve (ON). METHODS The ON was transected 0.7 mm from its exit from the eye in Sprague Dawley rats. Nipradilol (1 x 10(-8) - 10(-3) M), timolol, prazosin, or sodium nitroprusside (SNP) (1 x 10(-6) - 10(-4) M) was injected intravitreally fifteen-minutes before the ON transection. Control eyes received the same amount of phosphate buffered (PB). The RGCs were labeled retrogradely by placing gelfoam soaked in fluoro-gold (FG) on the stump of ON. RGCs density was determined by counting the FG-labeled RGCs in flat-mounted retinas 3 to 14 days post-transection. To determine whether the neuroprotective action of nipradilol was due to its NO-donor property, carboxy-PTIO, a NO-scavenger, or KT5832, a protein kinase G inhibitor, was injected with the nipradilol. RESULTS After ON transection, the number of surviving RGCs after intravitreal injection of 1 x 10(-4) M nipradilol was significantly higher than that following PB injection. This protective activity was dose-dependent. Neither timolol nor prazosin had a neuroprotective effect but SNP protected RGCs in a dose-dependent manner. Carboxy-PTIO and KT5832 decreased the neuroprotective effect of nipradilol. CONCLUSIONS These results indicate that nipradilol has a possibility of neuroprotective effect on axotomized RGCs, and the effect depended mainly on its NO-donor property.
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Affiliation(s)
- Toru Nakazawa
- Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
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Rogers J, Lue LF. Microglial chemotaxis, activation, and phagocytosis of amyloid beta-peptide as linked phenomena in Alzheimer's disease. Neurochem Int 2001; 39:333-40. [PMID: 11578768 DOI: 10.1016/s0197-0186(01)00040-7] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microglia are widely held to play important pathophysiologic roles in Alzheimer's disease (AD). On exposure to amyloid beta peptide (A beta) they exhibit chemotactic, phagocytic, phenotypic and secretory responses consistent with scavenger cell activity in a localized inflammatory setting. Because AD microglial chemotaxis, phagocytosis, and secretory activity have common, tightly linked soluble intermediaries (e.g., cytokines, chemokines), cell surface intermediaries (e.g., receptors, opsonins), and stimuli (e.g., highly inert A beta deposits and exposed neurofibrilly tangles), the mechanisms for microglial clearance of A beta are necessarily coupled to localized inflammatory mechanisms that can be cytotoxic to nearby tissue. This presents a critical dilemma for strategies to remove A beta by enhancing micoglial activation--a dilemma that warrants substantial further investigation.
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Affiliation(s)
- J Rogers
- L.J. Roberts Center for Alzheimer's Research, Sun Health Research Institute, P.O. Box 1278, 10515 West Santa Fe Drive, Sun City, AZ 85372, USA.
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Harris-White ME, Chu T, Miller SA, Simmons M, Teter B, Nash D, Cole GM, Frautschy SA. Estrogen (E2) and glucocorticoid (Gc) effects on microglia and A beta clearance in vitro and in vivo. Neurochem Int 2001; 39:435-48. [PMID: 11578779 DOI: 10.1016/s0197-0186(01)00051-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The accumulation of fibrillar aggregates of beta Amyloid (A beta) in Alzheimer's Disease (AD) brain is associated with chronic brain inflammation. Although activated microglia (mu glia) can potentially clear toxic amyloid, chronic activation may lead to excessive production of neurotoxins. Recent epidemiological and clinical data have raised questions about the use of anti-inflammatory steroids (glucocorticoids, Gcs) and estrogens for treatment or prevention of AD. Since very little is known about steroid effects on mu glial interactions with amyloid, we investigated the effects of the synthetic Gc dexamethasone (DXM) and 17-beta estradiol (E2) in vitro in a murine mu glial-like N9 cell line on toxin production and intracellular A beta accumulation. To determine whether the steroid alterations of A beta uptake in vitro had relevance in vivo, we examined the effects of these steroids on A beta accumulation and mu glial responses to A beta infused into rat brain. Our in vitro data demonstrate for the first time that Gc dose-dependently enhanced mu glial A beta accumulation and support previous work showing that E2 enhances A beta uptake. Despite both steroids enhancing uptake, degradation was impeded, particularly with Gcs. Distinct differences between the two steroids were observed in their effect on toxin production and cell viability. Gc dose-dependently increased toxicity and potentiated A beta induction of nitric oxide, while E2 promoted cell viability and inhibited A beta induction of nitric oxide. The steroid enhancement of mu glial uptake and impedence of degradation observed in vitro were consistent with observations from in vivo studies. In the brains of A beta-infused rats, the mu glial staining in entorhinal cortex layer 3, not associated with A beta deposits was increased in response to A beta infusion and this effect was blocked by feeding rats prednisolone. In contrast, E2 enhanced mu glial staining in A beta-infused rats. A beta-immunoreactive (ir) deposits were quantitatively smaller, appeared denser, and were associated with robust mu glial responses. Despite the fact that steroid produced a smaller more focal deposit, total extracted A beta in cortical homogenate was elevated. Together, the in vivo and in vitro data support a role for steroids in plaque compaction. Our data are also consistent with the hypothesis that although E2 is less potent than Gc in impeding A beta degradation, long term exposure to both steroids could reduce A beta clearance and clinical utility. These data showing Gc potentiation of A beta-induced mu glial toxins may help explain the lack of epidemiological correlation for AD. The failure of both steroids to accelerate A beta degradation may explain their lack of efficacy for treatment of AD.
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Affiliation(s)
- M E Harris-White
- Department of Medicine, UCLA, C-128 RNRC, Los Angeles, CA 90095-1769, USA
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Kampa M, Hatzoglou A, Notas G, Niniraki M, Kouroumalis E, Castanas E. Opioids are non-competitive inhibitors of nitric oxide synthase in T47D human breast cancer cells. Cell Death Differ 2001; 8:943-52. [PMID: 11526449 DOI: 10.1038/sj.cdd.4400893] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2000] [Revised: 04/09/2001] [Accepted: 04/18/2001] [Indexed: 11/08/2022] Open
Abstract
Opioids and nitric oxide (NO) interact functionally in different systems. NO-generating agents decrease the activity of opioid agonists, prevent opioid tolerance, and are used in opioid withdrawal syndromes. There exist, however, few reports indicating a direct interaction of the two systems. T47D human breast cancer cells in culture express opioid receptors, and opioid agonists inhibit their growth, while they release high amounts of the NO-related molecules NO(2-)/NO(3-)to the culture medium. We have used this system to assay a possible direct interaction of opiergic and nitric oxide systems. Our results show that delta- or mu-acting opioid agonists do not modify the release of NO(2-)/NO(3-). In contrast, kappa-acting opioid agonists (ethylketocyclazocine, and alpha(S1)-casomorphine) decrease the release of NO(2-)/NO(3-), in a time- and dose-dependent manner. The general opioid antagonist diprenorphine (10(-6) M) produce a similar NO(2-)/NO(3-)release inhibition, indicating a possible non-opioid-receptor mediated phenomenon. In addition, ethylketocyclazocine, alpha(S1)-casomorphin and diprenorphine directly inhibit NOS activity: agonists, interact with both calcium-dependent and independent NOS-isoforms, while the antagonist diprenorphine modifies only the activity of the calcium-dependent fraction of the enzyme. Analysis of this interaction revealed that opioids modify the dimeric active form of NOS, through binding to the reductase part of the molecule, acting as non-competitive inhibitors of the enzyme. This interaction opens interesting new possibilities for tumor biology and breast cancer therapy.
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Affiliation(s)
- M Kampa
- Laboratory of Experimental Endocrinology, University of Crete, School of Medicine, PO Box 1393, Heraklion, GR-71110, Greece
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Sunohara JR, Ridgway ND, Cook HW, Byers DM. Regulation of MARCKS and MARCKS-related protein expression in BV-2 microglial cells in response to lipopolysaccharide. J Neurochem 2001; 78:664-72. [PMID: 11483670 DOI: 10.1046/j.1471-4159.2001.00458.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Myristoylated alanine-rich C kinase substrate (MARCKS) and MARCKS-related protein (MRP) have been implicated in membrane-cytoskeletal events underlying cell adhesion, migration, secretion, and phagocytosis. In BV-2 microglial cells, lipopolysaccharide (LPS) elicited a dose-dependent increase in mRNA of both MRP (sixfold) and MARCKS (threefold) with corresponding increases in [3H]myristoylated and immunoreactive protein levels. LPS also produced significant increases in protein kinase C (PKC)-beta twofold and PKC-epsilon (1.5-fold). Pro-inflammatory cytokines produced by activated microglia (IL-1beta, IL-6, TNF-alpha) did not mimic LPS effects on MARCKS or MRP expression when added individually or in combination. LPS and IFN-gamma produced a synergistic induction of iNOS but not MARCKS or MRP. Induction of MARCKS and MRP by LPS was completely blocked by inhibitors of NF-kappaB (PDTC) and protein tyrosine kinases (herbimycin A), partially blocked by the p38 kinase inhibitor SB203580, and unaffected by the MEK inhibitor PD98059. LPS induction of iNOS was considerably more sensitive to all these inhibitors. The Src kinase inhibitor PP2 had no effect, while the closely related inhibitor PP1 actually increased LPS induction of MARCKS and MRP. Our results suggest that MARCKS and MRP may play an important role in LPS-activated microglia, but are not part of the neuroinflammatory response produced by cytokines.
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Affiliation(s)
- J R Sunohara
- Atlantic Research Centre, Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
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