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Li Q, Qi S, Liang J, Tian Y, He S, Liao Q, Xing S, Han L, Chen X. Review of triazole scaffolds for treatment and diagnosis of Alzheimer's disease. Chem Biol Interact 2023; 382:110623. [PMID: 37451665 DOI: 10.1016/j.cbi.2023.110623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/28/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
Triazole scaffolds, a series of 5-membered heterocycles, are well known for their high efficacy, low toxicity, and superior pharmacokinetics. Alzheimer's disease (AD) is the first neurodegenerative disorder with complex pathological mechanisms. Triazole, as an aromatic group with three nitrogen atoms, forms polar and non-polar interactions with diverse key residues in the receptor-ligand binding procedure, and has been widely used in the molecular design in the development of anti-AD agents. Moreover, considering the simple synthesis approaches, triazole scaffolds are commonly used to link two pharmacodynamic groups in one chemical molecule, forming multi-target directed ligands (MTDLs). Furthermore, the click reaction between azide- and cyano-modified enzyme and ligand provides feasibility for the new modulator discovery, compound tissue distribution evaluation, enzyme localization, and pharmacological mechanism study, promoting the diagnosis of AD course.
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Affiliation(s)
- Qi Li
- Department of Medical Pharmacy, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong, PR China.
| | - Shulei Qi
- Department of Medical Pharmacy, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong, PR China
| | - Jinxin Liang
- Department of Medical Pharmacy, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong, PR China
| | - Yuqing Tian
- Department of Medical Pharmacy, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong, PR China
| | - Siyu He
- Guizhou Medical University, Guiyang, 550025, Guizhou, PR China
| | - Qinghong Liao
- Shandong Junrong Technology Transfer Co., Ltd, Qingdao, 266071, Shandong, PR China
| | - Shuaishuai Xing
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, Jiangsu, PR China
| | - Lingfei Han
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, Jiangsu, PR China
| | - Xuehong Chen
- Department of Medical Pharmacy, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong, PR China.
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Stachowicz K, Pańczyszyn-Trzewik P, Sowa-Kućma M, Misztak P. Changes in working memory induced by lipopolysaccharide administration in mice are associated with metabotropic glutamate receptors 5 and contrast with changes induced by cyclooxygenase-2: Involvement of postsynaptic density protein 95 and down syndrome cell adhesion molecule. Neuropeptides 2023; 100:102347. [PMID: 37182274 DOI: 10.1016/j.npep.2023.102347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/27/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
The strength and quality of the signal propagated by the glutamate synapse (Glu) depend, among other things, on the structure of the postsynaptic part and the quality of adhesion between the interacting components of the synapse. Postsynaptic density protein 95 (PSD95), mammalian target of rapamycin (mTOR), and Down syndrome cell adhesion molecule (DSCAM) are components of the proper functioning of an excitatory synapse. PSD95 is a member of the membrane-associated guanylate kinases protein family, mainly located at the postsynaptic density of the excitatory synapse. PSD95, via direct interaction, regulates the clustering and functionality of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartic acid (NMDA) receptors at a synapse. Here, the effects of treatment with an antagonist of mGluR5 (MTEP) and NS398 (cyclooxygenase-2, COX-2 inhibitor) on PSD95, mTOR, and DSCAM in the hippocampus (HC) of C57B1/6 J mice using Western blots in the context of learning were examined. Moreover, the sensitivity of selected proteins to lipopolysaccharide (LPS) was monitored. MTEP injected for seven days induced upregulation of PSD95 in HC of mice. The observed effect was regulated by a COX-2 inhibitor and concurrently by LPS. Accompanying alterations in DSCAM protein were found, suggesting changes in adhesion strength after modulation of glutamatergic (Glu) synapse via tested compounds.
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Affiliation(s)
- Katarzyna Stachowicz
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland.
| | - Patrycja Pańczyszyn-Trzewik
- Department of Human Physiology, Institute of Medical Sciences, Medical College of Rzeszów University, Kopisto Street 2a, 35-310 Rzeszow, Poland
| | - Magdalena Sowa-Kućma
- Department of Human Physiology, Institute of Medical Sciences, Medical College of Rzeszów University, Kopisto Street 2a, 35-310 Rzeszow, Poland
| | - Paulina Misztak
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
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Guo KM, Li W, Wang ZH, He LC, Feng Y, Liu HS. Low-dose aspirin inhibits trophoblast cell apoptosis by activating the CREB/Bcl-2 pathway in pre-eclampsia. Cell Cycle 2022; 21:2223-2238. [PMID: 35792905 PMCID: PMC9586659 DOI: 10.1080/15384101.2022.2092814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 11/03/2022] Open
Abstract
Excessive apoptosis of placental trophoblast cells is considered a major cause of pre-eclampsia (PE) pathogenesis. Phosphorylation of the widely expressed cAMP response element binding protein (CREB) regulates apoptosis and may be involved in PE incidence. Low-dose aspirin (LDA) is an effective approach for preventing PE with unclear mechanisms. Thus we examined whether LDA protects against PE by inhibiting trophoblast cell apoptosis through CREB. The effects of LDA on human PE placenta, PE model rat placenta, and hydrogen peroxide (H2O2)-induced HTR-8/SVneo cell apoptosis were analyzed. TUNEL assay, immunohistochemistry, Cell Counting Assay Kit-8 (CCK-8) assay, western blot, and flow cytometry assay were performed. In the placenta of human PE and rat PE models, the TUNEL index increased and was partially corrected with LDA pre-treatment. Meanwhile, decreased Bcl-2 and increased Bax expression were significantly reversed by LDA pre-treatment. In HTR-8/SVneo cells, H2O2 decreased cell viability, promoted apoptosis, reduced the Bcl-2/Bax ratio, aggravated loss of mitochondrial membrane potential (MMP), increased cytoplasmic cytochrome c release, and simultaneously activated caspase-9 and caspase-3. These effects were effectively restored by LDA pre-treatment in the cells. Moreover, LDA promoted CREB phosphorylation in trophoblast cells. CREB interference further promoted apoptosis, reduced the Bcl-2/Bax ratio, and increased MMP loss. CREB interference also reversed the inhibitory effect of LDA on H2O2-induced apoptosis in HTR-8/SVneo cells. Thus, LDA was shown to inhibit trophoblast cell mitochondrial apoptosis by activating the CREB/Bcl-2 pathway, providing novel evidence for the protective mechanism of LDA in PE.Abbreviations; PE: Pre-eclampsia; LDA: low-dose aspirin; CREB: cAMP response element binding protein; ROS: reactive oxygen species; H2O2: hydrogen peroxide; PBS: Phosphate-buffered saline; Bcl-2: B-cell lymphoma-2; MMP: Mitochondrial membrane potential; Cyt-c: CytochromeC.
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Affiliation(s)
- Kai-Min Guo
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wei Li
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xi’an Medical University, Xi’an, China
| | - Zhao-Hua Wang
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
- Department of Histology and Embryology, Guangzhou Medical University, Guangzhou, China
| | - Lang-Chi He
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yan Feng
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Hui-Shu Liu
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
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López DE, Ballaz SJ. The Role of Brain Cyclooxygenase-2 (Cox-2) Beyond Neuroinflammation: Neuronal Homeostasis in Memory and Anxiety. Mol Neurobiol 2020; 57:5167-5176. [PMID: 32860157 DOI: 10.1007/s12035-020-02087-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 08/24/2020] [Indexed: 12/13/2022]
Abstract
Cyclooxygenases are a group of heme-containing isozymes (namely Cox-1 and Cox-2) that catalyze the conversion of arachidonic acid to largely bioactive prostaglandins (PGs). Cox-1 is the ubiquitous housekeeping enzyme, and the mitogen-inducible Cox-2 is activated to cause inflammation. Interestingly, Cox-2 is constitutively expressed in the brain at the postsynaptic dendrites and excitatory terminals of the cortical and spinal cord neurons. Neuronal Cox-2 is activated in response to synaptic excitation to yield PGE2, the predominant Cox-2 metabolite in the brain, which in turn stimulates the release of glutamate and neuronal firing in a retrograde fashion. Cox-2 is also engaged in the metabolism of new endocannabinoids from 2-arachidonoyl-glycerol to modulate their actions at presynaptic terminals. In addition to these interactions, the induction of neuronal Cox-2 is coupled to the trans-synaptic activation of the dopaminergic mesolimbic system and some serotoninergic receptors, which might contribute to the development of emotional behavior. Although much of the focus regarding the induction of Cox-2 in the brain has been centered on neuroinflammation-related neurodegenerative and psychiatric disorders, some evidence also suggests that Cox-2 release during neuronal signaling may be pivotal for the fine tuning of cortical networks to regulate behavior. This review compiles the evidence supporting the homeostatic role of neuronal Cox-2 in synaptic transmission and plasticity, since neuroinflammation is originally triggered by the induction of glial Cox-2 expression. The goal is to provide perspective on the roles of Cox-2 beyond neuroinflammation, such as those played in memory and anxiety, and whose evidence is still scant.
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Affiliation(s)
- Diana E López
- Biomedical Sciences Graduate Program, Yachay Tech University, Urcuquí, Ecuador
| | - Santiago J Ballaz
- School of Biological Sciences and Engineering, Yachay Tech University, Hacienda San José s/n, San Miguel de Urcuquí, Ecuador.
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Singh P, Shrestha S, Cortes-Salva MY, Jenko KJ, Zoghbi SS, Morse CL, Innis RB, Pike VW. 3-Substituted 1,5-Diaryl-1 H-1,2,4-triazoles as Prospective PET Radioligands for Imaging Brain COX-1 in Monkey. Part 1: Synthesis and Pharmacology. ACS Chem Neurosci 2018; 9:2610-2619. [PMID: 29678105 DOI: 10.1021/acschemneuro.8b00102] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cyclooxygenase-1 (COX-1) is a key enzyme in the biosynthesis of proinflammatory thromboxanes and prostaglandins and is found in glial and neuronal cells within brain. COX-1 expression is implicated in numerous neuroinflammatory states. We aim to find a direct-acting positron emission tomography (PET) radioligand for imaging COX-1 in human brain as a potential biomarker of neuroinflammation and for serving as a tool in drug development. Seventeen 3-substituted 1,5-diaryl-1 H-1,2,4-triazoles were prepared as prospective COX-1 PET radioligands. From this set, three 1,5-(4-methoxyphenyl)-1 H-1,2,4-triazoles, carrying a 3-methoxy (5), 3-(1,1,1-trifluoroethoxy) (20), or 3-fluoromethoxy substituent (6), were selected for radioligand development, based mainly on their high affinities and selectivities for inhibiting human COX-1, absence of carboxyl group, moderate computed lipophilicities, and scope for radiolabeling with carbon-11 ( t1/2 = 20.4 min) or fluorine-18 ( t1/2 = 109.8 min). Methods were developed for producing [11C]5, [11C]20, and [ d2-18F]6 from hydroxy precursors in a form ready for intravenous injection for prospective evaluation in monkey with PET.
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Affiliation(s)
- Prachi Singh
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Stal Shrestha
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Michelle Y. Cortes-Salva
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Kimberly J. Jenko
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Sami S. Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Cheryl L. Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Robert B. Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
| | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892, United States
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6
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Bortolanza M, Padovan-Neto FE, Cavalcanti-Kiwiatkoski R, Dos Santos-Pereira M, Mitkovski M, Raisman-Vozari R, Del-Bel E. Are cyclooxygenase-2 and nitric oxide involved in the dyskinesia of Parkinson's disease induced by L-DOPA? Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0190. [PMID: 26009769 DOI: 10.1098/rstb.2014.0190] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Inflammatory mechanisms are proposed to play a role in L-DOPA-induced dyskinesia. Cyclooxygenase-2 (COX2) contributes to inflammation pathways in the periphery and is constitutively expressed in the central nervous system. Considering that inhibition of nitric oxide (NO) formation attenuates L-DOPA-induced dyskinesia, this study aimed at investigating if a NO synthase (NOS) inhibitor would change COX2 brain expression in animals with L-DOPA-induced dyskinesia. To this aim, male Wistar rats received unilateral 6-hydroxydopamine microinjection into the medial forebrain bundle were treated daily with L-DOPA (21 days) combined with 7-nitroindazole or vehicle. All hemi-Parkinsonian rats receiving l-DOPA showed dyskinesia. They also presented increased neuronal COX2 immunoreactivity in the dopamine-depleted dorsal striatum that was directly correlated with dyskinesia severity. Striatal COX2 co-localized with choline-acetyltransferase, calbindin and DARPP-32 (dopamine-cAMP-regulated phosphoprotein-32), neuronal markers of GABAergic neurons. NOS inhibition prevented L-DOPA-induced dyskinesia and COX2 increased expression in the dorsal striatum. These results suggest that increased COX2 expression after L-DOPA long-term treatment in Parkinsonian-like rats could contribute to the development of dyskinesia.
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Affiliation(s)
- Mariza Bortolanza
- School of Odontology of Ribeirão Preto, Department of Morphology, University of São Paulo (USP), Physiology and Basic Pathology, Av. Café S/N, 14040-904, Ribeirão Preto, São Paulo, Brazil Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of Sao Paulo, São Paulo, Brazil
| | - Fernando E Padovan-Neto
- Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of Sao Paulo, São Paulo, Brazil Department of Behavioural Neurosciences, Av. Bandeirantes 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Roberta Cavalcanti-Kiwiatkoski
- Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of Sao Paulo, São Paulo, Brazil Medical School, Department of Physiology, University of Sao Paulo, São Paulo, Brazil
| | - Maurício Dos Santos-Pereira
- Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of Sao Paulo, São Paulo, Brazil Medical School, Department of Physiology, University of Sao Paulo, São Paulo, Brazil
| | - Miso Mitkovski
- Light Microscopy Facility, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Rita Raisman-Vozari
- Institut de Cerveau et de la Moelle Epinière, Sorbonne Université UPMC UM75 INSERM U1127, CNRS UMR 7225, Paris, France
| | - Elaine Del-Bel
- School of Odontology of Ribeirão Preto, Department of Morphology, University of São Paulo (USP), Physiology and Basic Pathology, Av. Café S/N, 14040-904, Ribeirão Preto, São Paulo, Brazil Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of Sao Paulo, São Paulo, Brazil Department of Behavioural Neurosciences, Av. Bandeirantes 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil Medical School, Department of Physiology, University of Sao Paulo, São Paulo, Brazil
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7
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Altinbas B, Topuz BB, İlhan T, Yilmaz MS, Erdost H, Yalcin M. Activation of the central histaminergic system mediates arachidonic-acid-induced cardiovascular effects. Can J Physiol Pharmacol 2014; 92:645-54. [DOI: 10.1139/cjpp-2014-0043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to explain the involvement of the central histaminergic system in arachidonic acid (AA)-induced cardiovascular effects in normotensive rats using hemodynamic, immunohistochemistry, and microdialysis studies. Intracerebroventricularly (i.c.v.) administered AA (0.25, 0.5, and 1.0 μmol) induced dose- and time-dependent increases in mean arterial pressure and decreased heart rate in conscious normotensive Sprague–Dawley rats. Central injection of AA (0.5 μmol) also increased posterior hypothalamic extracellular histamine levels and produced strong COX-1 but not COX-2 immunoreactivity in the posterior hypothalamus of rats. Moreover, the cardiovascular effects and COX-1 immunoreactivity in the posterior hypothalamus induced by AA (0.5 μmol; i.c.v.) were almost completely blocked by the H2 receptor antagonist ranitidine (50 and 100 nmol; i.c.v.) and partially blocked by the H1 receptor blocker chlorpheniramine (100 nmol; i.c.v.) and the H3–H4 receptor antagonist thioperamide (50 and 100 nmol; i.c.v.). In conclusion, these results indicate that centrally administered AA induces pressor and bradycardic responses in conscious rats. Moreover, we suggest that AA may activate histaminergic neurons and increase extracellular histamine levels, particularly in the posterior hypothalamus. Acting as a neurotransmitter, histamine is potentially involved in AA-induced cardiovascular effects under normotensive conditions.
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Affiliation(s)
- Burcin Altinbas
- Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey
| | - Bora Burak Topuz
- Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey
| | - Tuncay İlhan
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey
| | - Mustafa Sertac Yilmaz
- Department of Medical Pharmacology, Faculty of Medicine, Uludag University, Bursa 16059, Turkey
| | - Hatice Erdost
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey
| | - Murat Yalcin
- Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey
- Department of Physiology, Faculty of Veterinary Medicine, Near East University, Nicosia, Cyprus
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Montori S, DosAnjos S, Poole A, Regueiro-Purriños MM, Llorente IL, Darlison MG, Fernández-López A, Martínez-Villayandre B. Differential effect of transient global ischaemia on the levels of γ-aminobutyric acid type A (GABAA) receptor subunit mRNAs in young and older rats. Neuropathol Appl Neurobiol 2012; 38:710-22. [DOI: 10.1111/j.1365-2990.2012.01254.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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9
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Russo I, Caracciolo L, Tweedie D, Choi SH, Greig NH, Barlati S, Bosetti F. 3,6'-Dithiothalidomide, a new TNF-α synthesis inhibitor, attenuates the effect of Aβ1-42 intracerebroventricular injection on hippocampal neurogenesis and memory deficit. J Neurochem 2012; 122:1181-92. [PMID: 22731394 DOI: 10.1111/j.1471-4159.2012.07846.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Evidence indicates altered neurogenesis in neurodegenerative diseases associated with inflammation, including Alzheimer's disease (AD). Neuroinflammation and its propagation have a critical role in the degeneration of hippocampal neurons, cognitive impairment, and altered neurogenesis. Particularly, tumor necrosis factor (TNF)-α plays a central role in initiating and regulating the cytokine cascade during an inflammatory response and is up-regulated in brain of AD patients. In this study, we investigated the effects of a novel thalidomide-based TNF-α lowering drug, 3,6'-dithiothalidomide, on hippocampal progenitor cell proliferation, neurogenesis and, memory tasks after intracerebroventricular injection of β-amyloid (Aß)(1-42) peptide. Seven days after Aβ(1-42) injection, a significant proliferation of hippocampal progenitor cells and memory impairment were evident. Four weeks after Aβ(1-42) peptide injection, elevated numbers of surviving 5-bromo-2'-deoxyuridine cells and newly formed neurons were detected. Treatment with 3,6'-dithiothalidomide attenuated these Aβ(1-42) provoked effects. Our data indicate that although treatment with 3,6'-dithiothalidomide in part attenuated the increase in hippocampal neurogenesis caused by Aβ(1-42) -induced neuroinflammation, the drug prevented memory deficits associated with increased numbers of activated microglial cells and inflammatory response. Therefore, 3,6'-dithiothalidomide treatment likely reduced neuronal tissue damage induced by neuroinflammation following Aβ(1-42) injection. Understanding the modulation of neurogenesis, and its relationship with memory function could open new therapeutic interventions for AD and other neurodegenerative disorders with an inflammatory component.
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Affiliation(s)
- Isabella Russo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, NIH, Bethesda, MD, USA
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Palumbo S, Toscano CD, Parente L, Weigert R, Bosetti F. The cyclooxygenase-2 pathway via the PGE₂ EP2 receptor contributes to oligodendrocytes apoptosis in cuprizone-induced demyelination. J Neurochem 2011; 121:418-27. [PMID: 21699540 DOI: 10.1111/j.1471-4159.2011.07363.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclooxygenases (COX)-1 and -2 are key enzymes required for the conversion of arachidonic acid to eicosanoids, potent mediators of inflammation. In patients with multiple sclerosis, COX-2 derived prostaglandins (PGs) are elevated in the CSF and COX-2 is up-regulated in demyelinating plaques. However, it is not known whether COX-2 activity contributes to oligodendrocyte death. In cuprizone-induced demyelination, oligodendrocyte apoptosis and a concomitant increase in the gene expression of COX-2 and PGE₂-EP2 receptor precede histological demyelination. COX-2 and EP2 receptor were expressed by oligodendrocytes, suggesting a causative role for the COX-2/EP2 pathway in the initiation of oligodendrocyte death and demyelination. COX-2 gene deletion, chronic treatment with the COX-2 selective inhibitor celecoxib, or with the EP2 receptor antagonist AH6809 reduced cuprizone-induced oligodendrocyte apoptosis, the degree of demyelination and motor dysfunction. These data indicate that the PGE₂ EP2 receptor contributes to oligodendrocyte apoptosis and open possible new therapeutic approaches for multiple sclerosis.
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Affiliation(s)
- Sara Palumbo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, Bethesda, Maryland, USA
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11
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Palumbo S, Toscano CD, Parente L, Weigert R, Bosetti F. Time-dependent changes in the brain arachidonic acid cascade during cuprizone-induced demyelination and remyelination. Prostaglandins Leukot Essent Fatty Acids 2011; 85:29-35. [PMID: 21530210 PMCID: PMC3109126 DOI: 10.1016/j.plefa.2011.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 03/30/2011] [Accepted: 04/04/2011] [Indexed: 12/21/2022]
Abstract
Phospholipases A(2) (PLA(2)) are the enzymatic keys for the activation of the arachidonic acid (AA) cascade and the subsequent synthesis of pro-inflammatory prostanoids (prostaglandins and tromboxanes). Prostanoids play critical roles in the initiation and modulation of inflammation and their levels have been reported increased in several neurological and neurodegenerative disorders, including multiple sclerosis (MS). Here, we aimed to determine whether brain expression PLA(2) enzymes and the terminal prostagland in levels are changed during cuprizone-induced demyelination and in the subsequent remyelination phase. Mice were given the neurotoxicant cuprizone through the diet for six weeks to induce brain demyelination. Then, cuprizone was withdrawn and mice were returned to a normal diet for 6 weeks to allow spontaneous remyelination. We found that after 4-6 weeks of cuprizone, sPLA(2)(V) and cPLA(2), but not iPLA(2)(VI), gene expression was upregulated in the cortex, concomitant with an increase in the expression of astrocyte and microglia markers. Cyclooxygenase (COX)-2 gene expression was consistently upregulated during all the demyelination period, whereas COX-1 sporadically increased only at week 5 of cuprizone exposure. However, we found that at the protein level only sPLA(2)(V) and COX-1 were elevated during demyelination, with COX-1 selectively expressed by activated and infiltrated microglia/macrophages and astrocytes. Levels of PGE(2), PGD(2), PGI(2) and TXB(2) were also increased during demyelination. During remyelination, none of the PLA(2) isoforms was significantly changed, whereas COX-1 and -2 were sporadically upregulated only at the gene expression level. PGE(2), PGI(2) and PGD(2) levels returned to normal, whereas TXB(2) was still upregulated after 3 weeks of cuprizone withdrawal. Our study characterizes for the first time time-dependent changes in the AA metabolic pathway during cuprizone-induced demyelination and the subsequent remyelination and suggests that sPLA(2)(V) is the major isoform contributing to AA release.
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Affiliation(s)
- S Palumbo
- National Institute on Aging, National Institutes of Health, Brain Physiology and Metabolism Section, Bethesda, MD 20892-0947, USA
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12
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Yoshikawa K, Palumbo S, Toscano CD, Bosetti F. Inhibition of 5-lipoxygenase activity in mice during cuprizone-induced demyelination attenuates neuroinflammation, motor dysfunction and axonal damage. Prostaglandins Leukot Essent Fatty Acids 2011; 85:43-52. [PMID: 21555210 PMCID: PMC3109232 DOI: 10.1016/j.plefa.2011.04.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/06/2011] [Accepted: 04/12/2011] [Indexed: 11/20/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Increased expression of 5-lipoxygenase (5-LO), a key enzyme in the biosynthesis of leukotrienes (LTs), has been reported in MS lesions and LT levels are elevated in the cerebrospinal fluid of MS patients. To determine whether pharmacological inhibition of 5-LO attenuates demyelination, MK886, a 5-LO inhibitor, was given to mice fed with cuprizone. Gene and protein expression of 5-LO were increased at the peak of cuprizone-induced demyelination. Although MK886 did not attenuate cuprizone-induced demyelination in the corpus callosum or in the cortex, it attenuated cuprizone-induced axonal damage and motor deficits and reduced microglial activation and IL-6 production. These data suggest that during cuprizone-induced demyelination, the 5-LO pathway contributes to microglial activation and neuroinflammation and to axonal damage resulting in motor dysfunction. Thus, 5-LO inhibition may be a useful therapeutic treatment in demyelinating diseases of the CNS.
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Affiliation(s)
| | | | | | - F. Bosetti
- Corresponding author: Francesca Bosetti, Pharm.D., Ph.D., 9 Memorial Drive, Rm. 1S126 MSC 0947, Bethesda MD 20892-0947, Phone: (301) 594-5077, Fax: (301) 402-0074,
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Caracciolo L, Barbon A, Palumbo S, Mora C, Toscano CD, Bosetti F, Barlati S. Altered mRNA editing and expression of ionotropic glutamate receptors after kainic acid exposure in cyclooxygenase-2 deficient mice. PLoS One 2011; 6:e19398. [PMID: 21589914 PMCID: PMC3093380 DOI: 10.1371/journal.pone.0019398] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 04/04/2011] [Indexed: 12/31/2022] Open
Abstract
Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2(-/-)) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2(-/-) mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2(-/-) mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2(-/-) mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2(-/-) compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2(-/-) mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2(-/-) mice. After KA exposure, COX-2(-/-) mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2(-/-) mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the glutamatergic system.
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Affiliation(s)
- Luca Caracciolo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Alessandro Barbon
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Sara Palumbo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Cristina Mora
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Christopher D. Toscano
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Francesca Bosetti
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Sergio Barlati
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
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Manev H, Chen H, Dzitoyeva S, Manev R. Cyclooxygenases and 5-lipoxygenase in Alzheimer's disease. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:315-9. [PMID: 20691748 PMCID: PMC3033490 DOI: 10.1016/j.pnpbp.2010.07.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 07/20/2010] [Accepted: 07/29/2010] [Indexed: 11/26/2022]
Abstract
Typically, cyclooxygenases (COXs) and 5-lipoxygenase (5-LOX), enzymes that generate biologically active lipid molecules termed eicosanoids, are considered inflammatory. Hence, their putative role in Alzheimer's disease (AD) has been explored in the framework of possible inflammatory mechanisms of AD pathobiology. More recent data indicate that these enzymes and the biologically active lipid molecules they generate could influence the functioning of the central nervous system and the pathobiology of neurodegenerative disorders such as AD via mechanisms different from classical inflammation. These mechanisms include the cell-specific localization of COXs and 5-LOX in the brain, the type of lipid molecules generated by the activity of these enzymes, the type and the localization of receptors selective for a type of lipid molecule, and the putative interactions of the COXs and 5-LOX pathways with intracellular components relevant for AD such as the gamma-secretase complex. Considering the importance of these multiple and not necessarily inflammatory mechanisms may help us delineate the exact nature of the involvement of the brain COXs and 5-LOX in AD and would reinvigorate the search for novel targets for AD therapy.
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Affiliation(s)
- Hari Manev
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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KPNA6 (Importin {alpha}7)-mediated nuclear import of Keap1 represses the Nrf2-dependent antioxidant response. Mol Cell Biol 2011; 31:1800-11. [PMID: 21383067 DOI: 10.1128/mcb.05036-11] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The transcription factor Nrf2 has emerged as a master regulator of cellular redox homeostasis. As an adaptive response to oxidative stress, Nrf2 activates the transcription of a battery of genes encoding antioxidants, detoxification enzymes, and xenobiotic transporters by binding the cis-antioxidant response element in the promoter regions of genes. The magnitude and duration of inducible Nrf2 signaling is delicately controlled at multiple levels by Keap1, which targets Nrf2 for redox-sensitive ubiquitin-mediated degradation in the cytoplasm and exports Nrf2 from the nucleus. However, it is not clear how Keap1 gains access to the nucleus. In this study, we show that Keap1 is constantly shuttling between the nucleus and the cytoplasm under physiological conditions. The nuclear import of Keap1 requires its C-terminal Kelch domain and is independent of Nrf1 and Nrf2. We have determined that importin α7, also known as karyopherin α6 (KPNA6), directly interacts with the Kelch domain of Keap1. Overexpression of KPNA6 facilitates Keap1 nuclear import and attenuates Nrf2 signaling, whereas knockdown of KPNA6 slows down Keap1 nuclear import and enhances the Nrf2-mediated adaptive response induced by oxidative stress. Furthermore, KPNA6 accelerates the clearance of Nrf2 protein from the nucleus during the postinduction phase, therefore promoting restoration of the Nrf2 protein to basal levels. These findings demonstrate that KPNA6-mediated Keap1 nuclear import plays an essential role in modulating the Nrf2-dependent antioxidant response and maintaining cellular redox homeostasis.
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Cyclooxygenase-1 and -2 differentially modulate lipopolysaccharide-induced blood-brain barrier disruption through matrix metalloproteinase activity. J Cereb Blood Flow Metab 2010; 30:370-80. [PMID: 19844242 PMCID: PMC2818570 DOI: 10.1038/jcbfm.2009.223] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cyclooxygenases (COX) -1 and -2 are key regulators of innate immune responses. We recently demonstrated that the expression of proinflammatory cytokines and chemokines is reduced in COX-1 null ((-/-)), and increased in COX-2(-/-) mice compared with their respective wild type controls during lipopolysaccharide (LPS)-induced innate immune activation. As chemokines are involved in leukocyte recruitment into the inflamed brain, we hypothesized that COX-1 and COX-2 deletion will differentially modulate blood-brain barrier (BBB) permeability in response to LPS. In the present study, using quantitative magnetic resonance imaging, we found that LPS-induced BBB disruption was exacerbated in COX-2(-/-) versus COX-2(+/+) mice. In the hippocampus and cortex of LPS-treated mice, matrix metalloproteinase (MMP)-3 activity was significantly decreased in COX-1(-/-) mice, whereas in COX-2(-/-) mice the activity of both MMP-9 and MMP-3, known to mediate BBB breakdown, was increased. Brain mRNA expression of the leukocyte attracting chemokine Cxcl10, the intercellular interaction molecule Icam-1, the pan-leukocyte marker Cd45 was increased in COX-2(-/-) versus COX-2(+/+) mice, whereas Cxcl10 and Cd45 mRNA expression was decreased in COX-1(-/-) versus COX-1(+/+) mice after LPS. Altogether, these results indicate that COX-2 activity modulates MMP-9 and-3 activities and is necessary to maintain BBB integrity during toll-like receptor 4-dependent innate immune activation.
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Ahmad M, Rose ME, Vagni V, Griffith RP, Dixon CE, Kochanek PM, Hickey RW, Graham SH. Genetic disruption of cyclooxygenase-2 does not improve histological or behavioral outcome after traumatic brain injury in mice. J Neurosci Res 2009; 86:3605-12. [PMID: 18711748 DOI: 10.1002/jnr.21809] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Increasing evidence suggests a role for cyclooxygenase-2 (COX-2) in traumatic brain injury (TBI). In the present study, the role of COX-2 in TBI was investigated using COX-2 gene-disrupted (COX-2 null) mice and wild-type (WT) controls that were subjected to the controlled cortical impact (CCI) model of TBI. There was increased expression of COX-2 in ipsilateral hippocampus in WT mice subjected to CCI. CCI resulted in a significant increase in prostaglandin E(2) concentrations in WT compared with COX-2 null hippocampi. There was a significant increase in TUNEL staining of CA1 neurons 24 hr after CCI in WT, but not in COX-2 null mice, compared with sham-operated controls, which is consistent with a protective role for COX-2 in the early phase of injury after TBI. However, there was no difference in lesion volume 21 days after CCI in COX-2 null and WT mice. COX-2 gene disruption did not alter Morris water maze performance. Taken together, these results suggest only a minor role for COX-2 activity in determining outcome after TBI in mouse.
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Affiliation(s)
- Muzamil Ahmad
- Geriatric Research Educational and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
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18
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Choi SH, Bosetti F. Cyclooxygenase-1 null mice show reduced neuroinflammation in response to beta-amyloid. Aging (Albany NY) 2009; 1:234-44. [PMID: 20157512 PMCID: PMC2806008 DOI: 10.18632/aging.100021] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 02/10/2009] [Indexed: 11/25/2022]
Abstract
Several independent
epidemiological studies indicate that chronic use of non-steroidal
anti-inflammatory drugs can reduce the risk of developing Alzheimer's
disease (AD), supporting the inflammatory cascade hypothesis. Although the
first clinical trial with indomethacin, a preferential cyclooxygenase
(COX)-1 inhibitor, showed beneficial effects, subsequent large clinical
trials, mostly using COX-2 inhibitors, failed to show any beneficial effect
in AD patients with mild to severe cognitive impairment. These combined
data suggest that either an early treatment is crucial to stop the
mechanisms underlying the disease before the onset of the symptoms, or that
preferential COX-1 inhibition, rather than COX-2, is beneficial. Therefore,
a full understanding of the physiological, pathological, and/or
neuroprotective role of COX isoforms may help to develop better therapeutic
strategies for the prevention or treatment of AD. In this study, we
examined the effect of COX-1 genetic deletion on the inflammatory response
and neurodegeneration induced by β-amyloid. β-amyloid (Aβ1-42)
was centrally injected in the lateral ventricle of COX-1-deficient (COX-1-/-)
and their respective wild-type (WT) mice. In COX-1-/-
mice, Aβ1-42-induced inflammatory response and neuronal
damage were attenuated compared to WT mice, as shown by Fluoro-Jade B and
nitrotyrosine staining. These results indicate that inhibition of COX-1
activity may be valid therapeutic strategy to reduce brain inflammatory
response and neurodegeneration.
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Affiliation(s)
- Sang-Ho Choi
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA
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Toscano CD, Kingsley PJ, Marnett LJ, Bosetti F. NMDA-induced seizure intensity is enhanced in COX-2 deficient mice. Neurotoxicology 2008; 29:1114-20. [PMID: 18834901 DOI: 10.1016/j.neuro.2008.08.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 08/30/2008] [Indexed: 12/25/2022]
Abstract
Pharmacological inhibition or genetic deletion of cyclooxygenase (COX)-2, but not COX-1, has been shown to increase susceptibility to kainic acid (KA)-induced excitotoxicity. However, it is unclear if susceptibility to excitotoxins that act through other neurotransmitter receptors is altered by COX-2 inhibition. To further understand the involvement of COX-2 in regulating susceptibility to excitotoxicity, we investigated the effect of COX-2 deletion on excitotoxicity induced by peripheral injection of N-methyl-d-aspartate (NMDA, a specific agonist of the NMDA receptors) or lindane (a GABA(A) receptor antagonist). COX-2(-/-) mice injected intraperitoneally with NMDA (50-100mg/kg) exhibited significantly increased median seizure intensity when compared to COX-2(+/+) mice. Further, COX-2(-/-) mice exposed to NMDA showed neuronal damage, detected by Fluoro Jade B (FJB) staining, in the CA3 region of the hippocampus. There was no FJB staining nor any significant difference in median or maximal seizure intensity in COX-2(+/+) and COX-2(-/-) mice exposed to lindane. LC-MS/MS analysis of brain prostaglandin profile in COX-2(-/-) mice demonstrated a significant increase in PGF(2alpha), TXB(2), PGE(2) and PGD(2) expression 1h after administration of an excitotoxic dose of KA, but not of NMDA. Our findings demonstrate that COX-2 regulates susceptibility to KA and NMDA excitotoxicity, which directly activate glutamatergic neurotransmission, but not to lindane, which indirectly alters glutamatergic neurotransmission. Furthermore, increased levels of prostaglandins after seizures are associated with consistent manifestation of neuronal damage.
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Affiliation(s)
- Christopher D Toscano
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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Pinent M, Hackl H, Burkard TR, Prokesch A, Papak C, Scheideler M, Hämmerle G, Zechner R, Trajanoski Z, Strauss JG. Differential transcriptional modulation of biological processes in adipocyte triglyceride lipase and hormone-sensitive lipase-deficient mice. Genomics 2008; 92:26-32. [DOI: 10.1016/j.ygeno.2008.03.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 03/07/2008] [Indexed: 10/21/2022]
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Aid S, Langenbach R, Bosetti F. Neuroinflammatory response to lipopolysaccharide is exacerbated in mice genetically deficient in cyclooxygenase-2. J Neuroinflammation 2008; 5:17. [PMID: 18489773 PMCID: PMC2409311 DOI: 10.1186/1742-2094-5-17] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Accepted: 05/19/2008] [Indexed: 11/21/2022] Open
Abstract
Background Cyclooxygenases (COX) -1 and -2 are key mediators of the inflammatory response in the central nervous system. Since COX-2 is inducible by inflammatory stimuli, it has been traditionally considered as the most appropriate target for anti-inflammatory drugs. However, the specific roles of COX-1 and COX-2 in modulating a neuroinflammatory response are unclear. Recently, we demonstrated that COX-1 deficient mice show decreased neuroinflammatory response and neuronal damage in response to lipopolysaccharide (LPS). Methods In this study, we investigated the role of COX-2 in the neuroinflammatory response to intracerebroventricular-injected LPS (5 μg), a model of direct activation of innate immunity, using COX-2 deficient (COX-2-/-) and wild type (COX-2+/+) mice, as well as COX-2+/+ mice pretreated for 6 weeks with celecoxib, a COX-2 selective inhibitor. Results Twenty-four hours after LPS injection, COX-2-/- mice showed increased neuronal damage, glial cell activation, mRNA and protein expression of markers of inflammation and oxidative stress, such as cytokines, chemokines, iNOS and NADPH oxidase. Brain protein levels of IL-1β, NADPH oxidase subunit p67phox, and phosphorylated-signal transducer and activator of transcription 3 (STAT3) were higher in COX-2-/- and in celecoxib-treated mice, compared to COX-2+/+ mice. The increased neuroinflammatory response in COX-2-/- mice was likely mediated by the upregulation of STAT3 and suppressor of cytokine signaling 3 (SOCS3). Conclusion These results show that inhibiting COX-2 activity can exacerbate the inflammatory response to LPS, possibly by increasing glial cells activation and upregulating the STAT3 and SOCS3 pathways in the brain.
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Affiliation(s)
- Saba Aid
- Brain Physiology and Metabolism Section, National Institute on Aging, NIH, 9000 Memorial Drive, Bldg 9 Room 1S126, Bethesda, MD 20892, USA.
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Toscano CD, Ueda Y, Tomita YA, Vicini S, Bosetti F. Altered GABAergic neurotransmission is associated with increased kainate-induced seizure in prostaglandin-endoperoxide synthase-2 deficient mice. Brain Res Bull 2007; 75:598-609. [PMID: 18355636 DOI: 10.1016/j.brainresbull.2007.10.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 10/12/2007] [Accepted: 10/15/2007] [Indexed: 11/19/2022]
Abstract
Excitotoxicity involves over activation of brain excitatory glutamate receptors and has been implicated in neurological, neurodegenerative and neuropsychiatric diseases. Metabolism of arachidonic acid (AA) through the phospholipase A(2) (PLA(2))/prostaglandin-endoperoxide synthase (PTGS) pathway is increased after excitotoxic stimulation. However, the individual roles of the PTGS isoforms in this process are not well established. We assessed the role of the PTGS isoforms in the process of excitotoxicity by exposing mice deficient in either PTGS-1 (PTGS-1(-/-)) or PTGS-2 (PTGS-2(-/-)) to the prototypic excitotoxin, kainic acid (KA). Seizure intensity and neuronal damage were significantly elevated in KA-exposed PTGS-2(-/-), but not in PTGS-1(-/-), mice. The increased susceptibility was not associated with an alteration in KA receptor binding activity or mediated through the CB1 endocannabinoid receptor. The frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) was decreased in the CA1 pyramidal neurons of PTGS-2(-/-) mice, suggesting an alteration of GABAergic function. In wild-type mice, six weeks treatment with the PTGS-2 selective inhibitor celecoxib recapitulated the increased susceptibility to KA-induced excitotoxicity observed in PTGS-2(-/-) mice, further supporting the role of PTGS-2 in the excitotoxic process. The increased susceptibility to KA was also associated with decreased brain levels of PGE(2), a biomarker of PTGS-2 activity. Our results suggest that PTGS-2 activity and its specific products may modulate neuronal excitability by affecting GABAergic neurotransmission. Further, inhibition of PTGS-2, but not PTGS-1, may increase the susceptibility to seizures.
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Affiliation(s)
- Christopher D Toscano
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, 9 Memorial Drive, Bethesda, MD 20892, USA
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Bosetti F. Arachidonic acid metabolism in brain physiology and pathology: lessons from genetically altered mouse models. J Neurochem 2007; 102:577-86. [PMID: 17403135 PMCID: PMC2084377 DOI: 10.1111/j.1471-4159.2007.04558.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The arachidonic acid (AA) cascade involves the release of AA from the membrane phospholipids by a phospholipase A(2), followed by its subsequent metabolism to bioactive prostanoids by cyclooxygenases coupled with terminal synthases. Altered brain AA metabolism has been implicated in neurological, neurodegenerative, and psychiatric disorders. The development of genetically altered mice lacking specific enzymes of the AA cascade has helped to elucidate the individual roles of these enzymes in brain physiology and pathology. The roles of AA and its metabolites in brain physiology, with a particular emphasis on the phospholipase A(2)/cyclooxygenases pathway, are summarized, and the specific phenotypes of genetically altered mice relevant to brain physiology and neurotoxic models are discussed.
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Affiliation(s)
- Francesca Bosetti
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA.
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