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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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Moyano P, Sanjuan J, García JM, Anadon MJ, Naval MV, Sola E, García J, Frejo MT, Pino JD. Dysregulation of prostaglandine E2 and BDNF signaling mediated by estrogenic dysfunction induces primary hippocampal neuronal cell death after single and repeated paraquat treatment. Food Chem Toxicol 2020; 144:111611. [PMID: 32738378 DOI: 10.1016/j.fct.2020.111611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/05/2020] [Accepted: 07/13/2020] [Indexed: 01/01/2023]
Abstract
Paraquat (PQ) produces hippocampal neuronal cell death and cognitive dysfunctions after unique and continued exposure, but the mechanisms are not understood. Primary hippocampal wildtype or βAPP-Tau silenced cells were co-treated with PQ with or without E2, N-acetylcysteine (NAC), NS-398 (cyclooxygenase-2 inhibitor), MF63 (PGES-1 inhibitor) and/or recombinant brain-derived neurotrophic factor (BDNF) during one- and fourteen-days to studied PQ effect on prostaglandin E2 (PGE2) and BDNF signaling and their involvement in hyperphosphorylated Tau (pTau) and amyloid-beta (Aβ) protein formation, and oxidative stress generation, that lead to neuronal cell loss through estrogenic disruption, as a possible mechanism of cognitive dysfunctions produced by PQ. Our results indicate that PQ overexpressed cyclooxygenase-2 that leads to an increase of PGE2 and alters the expression of EP1-3 receptor subtypes. PQ induced also a decrease of proBDNF and mature BDNF levels and altered P75NTR and tropomyosin receptor kinase B (TrkB) expression. PQ induced PGE2 and BDNF signaling dysfunction, mediated through estrogenic disruption, leading to Aβ and pTau proteins synthesis, oxidative stress generation and finally to cell death. Our research provides relevant information to explain PQ hippocampal neurotoxic effects, indicating a probable explanation of the cognitive dysfunction observed and suggests new therapeutic strategies to protect against PQ toxic effects.
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Affiliation(s)
- Paula Moyano
- Department of Pharmacology and Toxicology, Veterinary School, Complutense University of Madrid, 28040, Madrid, Spain
| | - Javier Sanjuan
- Department of Pharmacology and Toxicology, Veterinary School, Complutense University of Madrid, 28040, Madrid, Spain
| | - José Manuel García
- Department of Pharmacology and Toxicology, Veterinary School, Complutense University of Madrid, 28040, Madrid, Spain
| | - María José Anadon
- Department of Legal Medicine, Psychiatry and Pathology, Medical School, Complutense University of Madrid, 28041, Madrid, Spain
| | - Maria Victoria Naval
- Department of Pharmacology, Pharmacognosy and Botany, Pharmacy School, Complutense University of Madrid, 28041, Madrid, Spain
| | - Emma Sola
- Department of Legal Medicine, Psychiatry and Pathology, Medical School, Complutense University of Madrid, 28041, Madrid, Spain
| | - Jimena García
- Department of Pharmacology, Health Sciences School, Alfonso X University, 28691, Madrid, Spain
| | - María Teresa Frejo
- Department of Pharmacology and Toxicology, Veterinary School, Complutense University of Madrid, 28040, Madrid, Spain
| | - Javier Del Pino
- Department of Pharmacology and Toxicology, Veterinary School, Complutense University of Madrid, 28040, Madrid, Spain.
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Quinolinic Acid-Induced Huntington Disease-Like Symptoms Mitigated by Potent Free Radical Scavenger Edaravone-a Pilot Study on Neurobehavioral, Biochemical, and Histological Approach in Male Wistar Rats. J Mol Neurosci 2018; 66:322-341. [PMID: 30284227 DOI: 10.1007/s12031-018-1168-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/28/2018] [Indexed: 12/14/2022]
Abstract
In this study, we demonstrated for the first time the neuroprotective role of edaravone (Eda) (5 and 10 mg/kg b.w.), a potent free radical scavenger against the unilateral stereotaxic induction of quinolinic acid (QA) (300 nm/4 μl saline)-induced Huntington disease (HD)-like symptoms in behavioral, biochemical, and histological features in male Wistar rats striatum. QA induction, which mimics the early stage of HD, commonly causes oxidative stress to the cell and decreases the antioxidant defense mechanism by altering the level of lipid peroxidation (LPO), protein carbonyls, and nitrate concentration (NO) and the activities of glutathione family enzymes (GPx, GST, GR) and acetyl choline esterase concentration (AChE) which was found to be ameliorated by Eda treatment in both the tested doses 5 and 10 mg/kg b.w. in the significance of P < 0.05 and P < 0.01, respectively. Finally histopathological analysis by hematoxylin and eosin stain concluded the promising neurodefensive role of Eda in rat striatum at the dosage of 10 mg/kg b.w., with the decreased tissue damage and the number of damaged granular cells when compared to QA-induced groups.
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Kumar A, Rani A, Scheinert RB, Ormerod BK, Foster TC. Nonsteroidal anti-inflammatory drug, indomethacin improves spatial memory and NMDA receptor function in aged animals. Neurobiol Aging 2018; 70:184-193. [PMID: 30031231 DOI: 10.1016/j.neurobiolaging.2018.06.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 06/04/2018] [Accepted: 06/19/2018] [Indexed: 11/17/2022]
Abstract
A redox-mediated decrease in N-methyl-D-aspartate (NMDA) receptor function contributes to psychiatric diseases and impaired cognition during aging. Inflammation provides a potential source of reactive oxygen species for inducing NMDA receptor hypofunction. The present study tested the hypothesis that the nonsteroidal anti-inflammatory drug indomethacin, which improves spatial episodic memory in aging rats, would enhance NMDA receptor function through a shift in the redox state. Male F344 young and aged rats were prescreened using a 1-day version of the water maze task. Animals were then treated with the indomethacin or vehicle, delivered in a frozen milk treat (orally, twice per day, 18 days), and retested on the water maze. Indomethacin treatment enhanced water maze performance. Hippocampal slices were prepared for examination of CA3-CA1 synaptic responses, long-term potentiation, and NMDA receptor-mediated synaptic responses. No effect of treatment was observed for the total synaptic response. Long-term potentiation magnitude and NMDA receptor input-output curves were enhanced for aged indomethacin-treated animals. To examine redox regulation of NMDA receptors, a second group of aged animals was treated with indomethacin or vehicle, and the effect of the reducing agent, dithiothreitol ([DTT], 0.5 mM) on NMDA receptor-mediated synaptic responses was evaluated. As expected, DTT increased the NMDA receptor response and the effect of DTT was reduced by indomethacin treatment. The results indicate that indomethacin acted to diminish the age-related and redox-mediated NMDA receptor hypofunction and suggest that inflammation contributes to cognitive impairment through an increase in redox stress.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Rachel B Scheinert
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Department of Biomedical Engineering, J. Crayton Pruitt Family, University of Florida, Gainesville, FL, USA
| | - Brandi K Ormerod
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Department of Biomedical Engineering, J. Crayton Pruitt Family, University of Florida, Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
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The use of quetiapine in the treatment of major depressive disorder: Evidence from clinical and experimental studies. Neurosci Biobehav Rev 2018; 86:36-50. [DOI: 10.1016/j.neubiorev.2017.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/24/2017] [Accepted: 12/24/2017] [Indexed: 12/19/2022]
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Kondo F, Tachi M, Gosho M, Fukayama M, Yoshikawa K, Okada S. Changes in hypothalamic neurotransmitter and prostanoid levels in response to NMDA, CRF, and GLP-1 stimulation. Anal Bioanal Chem 2015; 407:5261-72. [PMID: 25633219 DOI: 10.1007/s00216-015-8496-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 01/13/2015] [Accepted: 01/14/2015] [Indexed: 11/25/2022]
Abstract
Determination of neuroactive substances, such as neurotransmitters and prostanoids, in the extracellular space of the living brain is a very important technique in neuroscience. The hypothalamic paraventricular nucleus (PVN) is one of the most important autonomic control centers in the brain. Recently, we demonstrated that thromboxane (Tx) A2 in the PVN may play an important role in adrenomedullary outflow evoked by N-methyl-D-aspartate (NMDA), corticotrophin-releasing factor (CRF), and glucagon-like peptide-1 (GLP-1) stimulation using microdialysis sampling and liquid chromatography-ion trap tandem mass spectrometry (LC-ITMS(n)). In the present study, we investigated whether centrally administered NMDA, CRF, and GLP-1 can release five neurotransmitters, acetylcholine (ACh), histamine, glutamate (Glu), γ-aminobutyric acid (GABA), and serotonin (5-HT), along with six prostanoids, TxB2, prostaglandin (PG) E2, PGD2, 15-deoxy-∆(12,14) (15d)-PGJ2, 6-keto-PGF1α, and PGF2α in rat PVN microdialysates after optimization of LC-ITMS(n) conditions . All stimulations increased the levels of 5-HT, TxB2, PGE2, and PGF2α (except for 5-HT stimulated with GLP-1). Only NMDA increased the levels of ACh, Glu, and GABA. Treatment with dizocilpine maleate (MK-801), a noncompetitive NMDA receptor antagonist, attenuated the NMDA-induced increase in the levels of neuroactive substances except for Glu. This is the first study to use LC-ITMS(n) to analyze neurotransmitters and prostanoids in the same microdialysates from rat PVN.
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Affiliation(s)
- Fumio Kondo
- Department of Pharmacology, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan,
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Effect of Licofelone—A Dual COX/5-LOX Inhibitor in Intracerebroventricular Streptozotocin-Induced Behavioral and Biochemical Abnormalities in Rats. J Mol Neurosci 2014; 55:749-59. [DOI: 10.1007/s12031-014-0414-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 08/21/2014] [Indexed: 12/25/2022]
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Akanuma SI, Higuchi T, Higashi H, Ozeki G, Tachikawa M, Kubo Y, Hosoya KI. Transporter-mediated prostaglandin E₂ elimination across the rat blood-brain barrier and its attenuation by the activation of N-methyl-D-aspartate receptors. Drug Metab Pharmacokinet 2014; 29:387-93. [PMID: 24717839 DOI: 10.2133/dmpk.dmpk-14-rg-004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Prostaglandin (PG) E2 is involved in neuroinflammation and neurotoxicity, and the cerebral PGE2 concentration is increased in neurodegenerative diseases. Because the intracerebral concentration of L-glutamate (L-Glu) is reported to be also elevated in neurodegenerative diseases, it has been proposed that L-Glu affects PGE2 dynamics in the brain, and thus exacerbates neural excitotoxicity. The purpose of this study was to investigate the effect of intracerebral L-Glu on PGE2 elimination across the blood-brain barrier (BBB) in rats by using the intracerebral microinjection technique. [(3)H]PGE2 injected into the cerebral cortex was eliminated from the brain in rats, and the apparent brain-to-blood [(3)H]PGE2 efflux clearance was found to be 60.1 µL/(min·g brain). Intracerebral pre-administration of 50 mM L-Glu significantly inhibited [(3)H]PGE2 elimination across the BBB and this L-Glu-induced inhibition was abolished by co-administration of an intracellular Ca(2+) chelator. The intracellular Ca(2+) concentration is reported to be increased via N-methyl-d-aspartate (NMDA)-type L-Glu receptors (NMDAR) and [(3)H]PGE2 elimination was attenuated by intracerebral pre-administration of a mixture of NMDA and D-serine. Moreover, the co-administration of antagonists of NMDAR with L-Glu abolished the attenuation of PGE2 elimination induced by intracerebral L-Glu administration. These results suggest that L-Glu attenuates BBB-mediated PGE2 elimination via NMDAR-mediated processes.
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Affiliation(s)
- Shin-ichi Akanuma
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
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Rehni AK, Singh TG. Selenium induced anticonvulsant effect: a potential role of prostaglandin E(1) receptor activation linked mechanism. J Trace Elem Med Biol 2013; 27:31-9. [PMID: 22748695 DOI: 10.1016/j.jtemb.2012.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 01/11/2012] [Accepted: 05/06/2012] [Indexed: 11/26/2022]
Abstract
PROJECT Selenium deficiency has been associated with enhanced propensity of seizures in man and laboratory animals. Therefore, the present study has been designed to investigate the anti-convulsant effect of sodium selenite and seleno-dl-methionine on pentylenetetrazole induced seizures in mice and the role of prostaglandin receptor activation in the proposed anticonvulsant effect of sodium selenite. PROCEDURE Sodium selenite (1, 3 and 10 mg kg(-1), i.p.) and seleno-dl-methionine (0.3, 1 and 3 mg kg(-1), i.p.) was used to evaluate the potential effect on pentylenetetrazole induced seizures in mice. Pentylenetetrazole induced seizures were assessed in terms of onset time of straub's tail phenomenon, jerky movements of the whole body and convulsions. Additionally, an isobolographic study design was used to examine the interaction between sodium selenite and celecoxib (a cyclooxygenase-2 inhibitor). Sodium selenite and seleno-dl-methionine significantly attenuated pentylenetetrazole induced seizures in mice. RESULTS Prior administration of misoprostol (a selective agonist of prostaglandin E(1) receptors) markedly attenuated the anticonvulsant effect of sodium selenite as well as seleno-dl-methionine in mice. However, the administration of misoprostol per se did not produce any behavioral changes. Further, sodium selenite was observed to exert a synergistic interaction with celecoxib. CONCLUSIONS Selenium induced reduction in seizure like behavior might be ascribed to the activation of a prostaglandin E(1) receptor activation linked mechanism. It is further proposed that sodium selenite exerts a synergistic anti-convulsant effect with celecoxib indicating the therapeutic usefulness of combining the two agents to treat epilepsy.
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Affiliation(s)
- Ashish K Rehni
- Chitkara College of Pharmacy, Chandigarh-Patiala National Highway, Rajpura 140401, Patiala, Punjab, India.
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Ramadan E, Basselin M, Rao JS, Chang L, Chen M, Ma K, Rapoport SI. Lamotrigine blocks NMDA receptor-initiated arachidonic acid signalling in rat brain: implications for its efficacy in bipolar disorder. Int J Neuropsychopharmacol 2012; 15:931-43. [PMID: 21733229 PMCID: PMC3204186 DOI: 10.1017/s1461145711001003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
An up-regulated brain arachidonic acid (AA) cascade and a hyperglutamatergic state characterize bipolar disorder (BD). Lamotrigine (LTG), a mood stabilizer approved for treating BD, is reported to interfere with glutamatergic neurotransmission involving N-methyl-d-aspartate receptors (NMDARs). NMDARs allow extracellular calcium into the cell, thereby stimulating calcium-dependent cytosolic phospholipase A2 (cPLA2) to release AA from membrane phospholipid. We hypothesized that LTG, like other approved mood stabilizers, would reduce NMDAR-mediated AA signalling in rat brain. An acute subconvulsant dose of NMDA (25 mg/kg) or saline was administered intraperitoneally to unanaesthetized rats that had been treated p.o. daily for 42 d with vehicle or a therapeutically relevant dose of LTG (10 mg/kg.d). Regional brain AA incorporation coefficients k* and rates J in, and AA signals, were measured using quantitative autoradiography after intravenous [1-14C]AA infusion, as were other AA cascade markers. In chronic vehicle-treated rats, acute NMDA compared to saline increased k* and J in in widespread regions of the brain, as well as prostaglandin (PG)E2 and thromboxane B2 concentrations. Chronic LTG treatment compared to vehicle reduced brain cyclooxygenase (COX) activity, PGE2 concentration, and DNA-binding activity of the COX-2 transcription factor, NF-κB. Pretreatment with chronic LTG blocked the acute NMDA effects on AA cascade markers. In summary, chronic LTG like other mood stabilizers blocks NMDA-mediated signalling involving the AA metabolic cascade. Since markers of the AA cascade and of NMDAR signalling are up-regulated in the post-mortem BD brain, mood stabilizers generally may be effective in BD by dampening NMDAR signalling and the AA cascade.
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Affiliation(s)
- Epolia Ramadan
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
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Ibrahim B, Sowemimo A, van Rooyen A, Van de Venter M. Antiinflammatory, analgesic and antioxidant activities of Cyathula prostrata (Linn.) Blume (Amaranthaceae). JOURNAL OF ETHNOPHARMACOLOGY 2012; 141:282-289. [PMID: 22387161 DOI: 10.1016/j.jep.2012.02.032] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 02/13/2012] [Accepted: 02/14/2012] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Cyathula prostrata (Linn) Blume (Amaranthaceae) is an annual herb widely used traditionally in the treatment of various inflammatory and pain related health disorders in Nigeria. The aim of this study is to evaluate the anti-inflammatory, analgesic and antioxidant activities of the methanolic extract of Cyathula prostrata (Linn) Blume. MATERIALS AND METHODS The anti-inflammatory (phorbol 12-myristate 13-acetate (PMA)-induced reactive oxygen species (ROS), lipopolysaccharide (LPS) induced nitric oxide production in U937 macrophages, LPS-induced COX-2 expression, carrageenan-induced rat paw oedema, arachidonic acid-induced ear oedema and xylene-induced ear oedema), analgesic (acetic acid-induced writhing and hot plate tests) and antioxidant activities (DPPH [1,1-diphenyl-2-picrylhydrazyl] and lipid peroxidation assays) activities of the plant extract were investigated. RESULTS The methanolic extract of Cyathula prostrata did not show inhibitory activity in the in vitro PMA-induced reactive oxygen species, LPS-induced nitric oxide production and LPS-induced COX-2 expression assays. In the in vivo anti-inflammatory assays, the extract (50, 100 and 200mg/kg) showed a significant (P<0.05) dose-dependent inhibition in the carrageenan, arachidonic acid and xylene-induced tests. Cyathula prostrata produced a significant (P<0.05, 0.001) dose-dependent inhibition in the acetic acid and hot plate analgesic tests respectively. The plant extract did not exhibit any antioxidant activity in the DPPH and lipid peroxidation assays. CONCLUSION The results suggest that the methanolic extract of Cyathula prostrata possesses anti-inflammatory and analgesic activities and this authenticates the use of the plant in the traditional treatment of ailments associated with inflammation and pain.
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Affiliation(s)
- Bolanle Ibrahim
- Department of Pharmacognosy, Faculty of Pharmacy, University of Lagos, College of Medicine Campus, Idi-Araba, Lagos, Nigeria
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Rao JS, Kellom M, Kim HW, Rapoport SI, Reese EA. Neuroinflammation and synaptic loss. Neurochem Res 2012; 37:903-10. [PMID: 22311128 PMCID: PMC3478877 DOI: 10.1007/s11064-012-0708-2] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 01/08/2012] [Accepted: 01/11/2012] [Indexed: 01/14/2023]
Abstract
Neuroinflammation plays a critical role in the progression of many neurodegenerative, neuropsychiatric and viral diseases. In neuroinflammation, activated microglia and astrocytes release cytokines and chemokines as well as nitric oxide, which in turn activate many signal transduction pathways. The cytokines, interleukin-1 beta and tumor necrosis factor alpha, regulate transcription of a number of genes within the brain, which can lead to the formation of pro-inflammatory products of the arachidonic acid cascade. Formation of pro-inflammatory agents and associated cytotoxic products during neuroinflammation can be detrimental to neurons by altering synaptic proteins. Neuroinflammation as well as excitotoxic insults reduce synaptic markers such as synaptophysin and drebrin. Neurodegenerative, neuropsychiatric illnesses and viral infections are accompanied by loss of both pre- and post-synaptic proteins. These synaptic changes may contribute to the progressive cognitive decline and behavioral changes associated with these illnesses.
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Affiliation(s)
- Jagadeesh S Rao
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bldg. 9, Rm. 1S126 MSC 0947, Bethesda, MD 20892-0947, USA.
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Al-Shorbagy MY, El Sayeh BM, Abdallah DM. Diverse effects of variant doses of dexamethasone in lithium–pilocarpine induced seizures in rats. Can J Physiol Pharmacol 2012; 90:13-21. [DOI: 10.1139/y11-096] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Corticosteroids are used in the management of several epileptic aliments; however, their effectiveness in combating seizures remains controversial, with pro- and anti-convulsive effects ascribed. The current study aimed to address the modulatory effect of dexamethasone (DEX) utilizing 3 dose levels (5, 10, and 20 mg/kg body mass of male Wistar rat) in the rat lithium–pilocarpine (Li-PIL) epilepsy model. Li-PIL induced seizures that were associated with neuronal cell loss in the CA3 region, and increased prostaglandin (PG)E2, tumor necrosis factor (TNF)-α, interleukin (IL)-10, nitric oxide, and neutrophil infiltration in the hippocampus. However, Li-PIL compromised the oxidant–antioxidant balance of the hippocampus. Effective anticonvulsant activity was only observed with10 mg DEX/kg body mass, which reduced seizure production and incidence, as well as neuronal cell loss in the CA3 region. At this anticonvulsant dose, enhancements in the antioxidant system and IL-10, as well as suppression of altered inflammatory markers were observed. Conversely, doubling the dose showed a tendency to shorten seizure latency, and neither affected seizure incidence nor CA3 neuronal cell loss. These effects were associated with an increase in levels of PGE2 and TNF-α. The present study found a lack of protection at 5 mg DEX/kg body mass, an anticonvulsant effect at 10 mg/kg, and a loss of protection at 20 mg/kg in the Li-PIL epilepsy model, which indicates that there is an optimal dose of DEX for preventing the induction of seizures.
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Affiliation(s)
- Muhammad Y. Al-Shorbagy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El-Aini Str, 11562 Cairo, Egypt
| | - Bahia M. El Sayeh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El-Aini Str, 11562 Cairo, Egypt
| | - Dalaal M. Abdallah
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El-Aini Str, 11562 Cairo, Egypt
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Neri M, Cantatore S, Pomara C, Riezzo I, Bello S, Turillazzi E, Fineschi V. Immunohistochemical expression of proinflammatory cytokines IL-1β, IL-6, TNF-α and involvement of COX-2, quantitatively confirmed by Western blot analysis, in Wernicke's encephalopathy. Pathol Res Pract 2011; 207:652-8. [PMID: 21930349 DOI: 10.1016/j.prp.2011.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Revised: 05/16/2011] [Accepted: 07/27/2011] [Indexed: 11/27/2022]
Abstract
Selective cerebral vulnerability is a major consequence of Wernicke's encephalopathy (WE), in which focal areas of the brain exhibit symmetrical profound neuronal loss and accompanying gliosis, occurring most frequently in diencephalic regions such as the thalamus and the mammillary bodies. Many processes have been proposed to explain the selective cerebral vulnerability and the focal neuronal cell death in Wernicke's encephalopathy. There are several mechanisms which are common to the pathophysiology of encephalopathies caused by thiamine deficiency (TD). Recently, emphasis is being placed on deficit in mitochondrial oxidative metabolism, oxidative/nitrosative stress, and the release of proinflammatory cytokines such as IL-1β, IL-6, and tumor necrosis factor-α (TNF-α). Cyclooxygenase-2 (COX-2) plays major roles in regulating brain damage and inflammation. Here we present two fatal cases of non-alcohol associated WE. The immunohistochemical study revealed increased proinflammatory cytokine immunoreactivity in the neurons of the mammillary bodies and medial thalamus, and in the periaqueductal regions, compared with basal constitutive levels of expression in the frontal cortex. Positive (WE cases) and negative (immediate trauma deaths) case-controls were used to confirm the results. TD induced IL-1β proteins weakly, while moderate increase was observed for TNF-α and IL-6. Immunofluorescence analysis by confocal microscopy confirmed the staining results for immunoreactivity in WE brains. Further, the induction of proinflammatory cytokine protein expression levels was quantified by Western blot analysis.
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Affiliation(s)
- Margherita Neri
- Department of Forensic Pathology, University of Foggia, Ospedale Colonnello D'Avanzo, Italy
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Hou CC, Lin H, Chang CP, Huang WT, Lin MT. Oxidative stress and pyrogenic fever pathogenesis. Eur J Pharmacol 2011; 667:6-12. [DOI: 10.1016/j.ejphar.2011.05.075] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/16/2011] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
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Neuroprotective effect of cyclooxygenase inhibitors in ICV-STZ induced sporadic Alzheimer's disease in rats. J Mol Neurosci 2011; 46:223-35. [PMID: 21701788 DOI: 10.1007/s12031-011-9583-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 06/13/2011] [Indexed: 12/15/2022]
Abstract
Sporadic Alzheimer's disease is an age-related neurological and psychiatric disorder characterized by impaired energy metabolism. Oxidative stress and neuroinflammation have been implicated in pathophysiology of sporadic type of dementia. The central streptozotocin administration induces behavioral and biochemical alterations resembling those in sporadic type of Alzheimer's patients. The present study was designed to investigate the effects of chronic pretreatment with cyclooxygenase-1 or cyclooxygenase-2 or cyclooxygenase-3 selective inhibitors on cognitive dysfunction and oxidative stress markers in intracerebroventricular streptozotocin-treated rats. Chronic treatment with valeryl salicylate (5 and 10 mg/kg, i.p.) and etoricoxib (5 and 10 mg/kg, i.p.) on a daily basis for a period of 21 days, beginning 1 h prior to first intracerebroventricular streptozotocin injection, significantly improved streptozotocin-induced cognitive impairment. However, phenacetin (20 and 40 mg/kg, i.p.) failed to restore the cognitive performances of streptozotocin-treated rats. Besides, improving cognitive dysfunction, chronic administration of highly selective cyclooxygenase-1 and/or cyclooxygenase-2 inhibitors (valeryl salicylate and etoricoxib, respectively), but not cyclooxygenase-3 inhibitor (phenacetin), significantly reduced elevated malondialdehyde, nitrite levels, and restored reduced glutathione and superoxide dismutase levels. Furthermore, cyclooxygenase-1 and/or cyclooxygenase-2 inhibitors significantly increased the survival of pyramidal neurons. In summary, we demonstrate for the first time that both cyclooxygenase-1 and cyclooxygenase-2 isoforms, but not cyclooxygenase-3, are involved in the progression of neuronal damage in intracerebroventricular streptozotocin-treated rats.
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Abstract
Mood stabilizers that are approved for treating bipolar disorder (BD), when given chronically to rats, decrease expression of markers of the brain arachidonic metabolic cascade, and reduce excitotoxicity and neuroinflammation-induced upregulation of these markers. These observations, plus evidence for neuroinflammation and excitotoxicity in BD, suggest that arachidonic acid (AA) cascade markers are upregulated in the BD brain. To test this hypothesis, these markers were measured in postmortem frontal cortex from 10 BD patients and 10 age-matched controls. Mean protein and mRNA levels of AA-selective cytosolic phospholipase A(2) (cPLA(2)) IVA, secretory sPLA(2) IIA, cyclooxygenase (COX)-2 and membrane prostaglandin E synthase (mPGES) were significantly elevated in the BD cortex. Levels of COX-1 and cytosolic PGES (cPGES) were significantly reduced relative to controls, whereas Ca(2+)-independent iPLA(2)VIA, 5-, 12-, and 15-lipoxygenase, thromboxane synthase and cytochrome p450 epoxygenase protein and mRNA levels were not significantly different. These results confirm that the brain AA cascade is disturbed in BD, and that certain enzymes associated with AA release from membrane phospholipid and with its downstream metabolism are upregulated. As mood stabilizers downregulate many of these brain enzymes in animal models, their clinical efficacy may depend on suppressing a pathologically upregulated cascade in BD. An upregulated cascade should be considered as a target for drug development and for neuroimaging in BD.
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Kalonia H, Kumar A. Suppressing inflammatory cascade by cyclo-oxygenase inhibitors attenuates quinolinic acid induced Huntington's disease-like alterations in rats. Life Sci 2011; 88:784-91. [DOI: 10.1016/j.lfs.2011.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 01/22/2011] [Accepted: 02/16/2011] [Indexed: 12/20/2022]
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Farrell SMJ, Groeger G, Bhatt L, Finnegan S, O’Brien CJ, Cotter TG. bFGF-mediated redox activation of the PI3K/Akt pathway in retinal photoreceptor cells. Eur J Neurosci 2011; 33:632-41. [DOI: 10.1111/j.1460-9568.2010.07559.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Abstract
Stroke is the major cause of disability in the Western world and is the third greatest cause of death, but there are no widely effective treatments to prevent the devastating effects of stroke. Extensive and growing evidence implicates inflammatory and immune processes in the occurrence of stroke and particularly in the subsequent injury. Several inflammatory mediators have been identified in the pathogenesis of stroke including specific cytokines, adhesion molecules, matrix metalloproteinases, and eicosanoids. An early clinical trial suggests that inhibiting interleukin-1 may be of benefit in the treatment of acute stroke.
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Guzmán CB, Graham KA, Grace LA, Moore AH. Sex-dependent effect of cyclooxygenase-2 inhibition on mouse spatial memory. Behav Brain Res 2009; 199:355-9. [PMID: 19162088 DOI: 10.1016/j.bbr.2009.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 11/24/2008] [Accepted: 01/04/2009] [Indexed: 11/30/2022]
Abstract
Cyclooxygenase (COX)-2 is constitutively expressed in neurons of the hippocampus and neocortex. Therefore, non-steroidal anti-inflammatory drugs (NSAIDs) targeting inflammation-induced COX-2 in the periphery and the central nervous system may also affect cognitive function mediated by basal COX-2 activity. We report that systemic administration of the selective COX-2 inhibitor NS-398 6h prior to behavioral assessment does not influence spatial acquisition or retention in male C57BL/6J mice. However, we observed impaired spatial retention in female mice treated with NS-398, suggesting a sex-dependent role of COX-2 in spatial memory of mice.
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Affiliation(s)
- Cristina B Guzmán
- Department of Biology, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053, United States
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22
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Basselin M, Chang L, Chen M, Bell JM, Rapoport SI. Chronic administration of valproic acid reduces brain NMDA signaling via arachidonic acid in unanesthetized rats. Neurochem Res 2008; 33:2229-40. [PMID: 18461450 PMCID: PMC2564799 DOI: 10.1007/s11064-008-9700-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 04/03/2008] [Indexed: 01/12/2023]
Abstract
Evidence that brain glutamatergic activity is pathologically elevated in bipolar disorder suggests that mood stabilizers are therapeutic in the disease in part by downregulating glutamatergic activity. Such activity can involve the second messenger, arachidonic acid (AA, 20:4n - 6). We tested this hypothesis with regard to valproic acid (VPA), when stimulating glutamatergic N-methyl-D: -aspartate (NMDA) receptors in rat brain and measuring AA and related responses. An acute subconvulsant dose of NMDA (25 mg/kg i.p.) or saline was administered to unanesthetized rats that had been treated i.p. daily with VPA (200 mg/kg) or vehicle for 30 days. Quantitative autoradiography following intravenous [1-(14)C]AA infusion was used to image regional brain AA incorporation coefficients k*, markers of AA signaling. In chronic vehicle-pretreated rats, NMDA compared with saline significantly increased k* in 41 of 82 examined brain regions, many of which have high NMDA receptor densities, and also increased brain concentrations of the AA metabolites, prostaglandin E(2) (PGE(2)) and thromboxane B(2) (TXB(2)). VPA pretreatment reduced baseline concentrations of PGE(2) and TXB(2), and blocked the NMDA induced increases in k* and in eicosanoid concentrations. These results, taken with evidence that carbamazepine and lithium also block k* responses to NMDA in rat brain, suggest that mood stabilizers act in bipolar disorder in part by downregulating glutamatergic signaling involving AA.
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Affiliation(s)
- Mireille Basselin
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bldg 9, Room 1S126, MSC 0947, 9 Memorial Drive, Bethesda, MD, 20892, USA.
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23
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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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Windelborn JA, Lipton P. Lysosomal release of cathepsins causes ischemic damage in the rat hippocampal slice and depends on NMDA-mediated calcium influx, arachidonic acid metabolism, and free radical production. J Neurochem 2008; 106:56-69. [PMID: 18363826 DOI: 10.1111/j.1471-4159.2008.05349.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NMDA-mediated calcium entry and reactive oxygen species (ROS) production are well-recognized perpetrators of ischemic neuronal damage. The current studies show that these events lead to the release of the protein hydrolase, cathepsin B, from lysosomes 2 h following 5-min oxygen-glucose deprivation in the rat hippocampal slice. This release reflects a lysosomal membrane permeabilization (LMP) and was measured as the appearance of diffuse immunolabeled cathepsin B in the cytosol of CA1 pyramidal neurons. Necrotic neuronal damage begins after the release of cathepsins and is prevented by inhibitors of either cathepsin B or D indicating that the release of cathepsins is an important mediator of severe damage. There was an increase in superoxide levels, measured by dihydroethidium fluorescence, at the same time as LMP and reducing ROS levels with antioxidants, Trolox or N-tert-butyl-alpha-phenyl nitrone, blocked LMP. Both LMP and ROS production were blocked by an NMDA channel blocker (MK-801) and by inhibitors of mitogen-activated protein kinase kinase (U0126), calcium-dependent/independent phospholipases A2 (methyl arachidonyl fluorophosphonate) but not calcium-independent phospholipases A2 (bromoenol lactone) and cyclooxygenase-2 (NS398). A cell-permeant specific inhibitor of calpain (PD150606) prevented LMP, but not ROS production. It is concluded that LMP results in part from calcium-initiated and extracellular signal-regulated kinase-initiated arachidonic acid metabolism, which produces free radicals; it also requires the action of calpain.
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Affiliation(s)
- James A Windelborn
- Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin 53706, USA
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Bhatia HS, Candelario-Jalil E, de Oliveira ACP, Olajide OA, Martínez-Sánchez G, Fiebich BL. Mangiferin inhibits cyclooxygenase-2 expression and prostaglandin E2 production in activated rat microglial cells. Arch Biochem Biophys 2008; 477:253-8. [PMID: 18621015 DOI: 10.1016/j.abb.2008.06.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/13/2008] [Accepted: 06/25/2008] [Indexed: 11/26/2022]
Abstract
Mangiferin, a naturally occurring glucosylxanthone, has potent antioxidant and anti-inflammatory properties, as demonstrated in several reports. However, very limited information is available on the effects of this natural polyphenol on microglial activation. Thus, the aim of this study was to examine whether mangiferin is able to reduce prostaglandin E(2) (PGE(2)) and 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) production by lipopolysaccharide (LPS)-activated primary rat microglia. Microglial cells were stimulated with 10ng/ml of LPS in the presence or absence of different concentrations of mangiferin (1-50 microM). After 24h incubation, culture media were collected to measure the production of PGE(2) and 8-iso-PGF(2alpha) using enzyme immunoassays. Protein levels of cyclooxygenase (COX)-1 and COX-2 were studied by immunoblotting after 24h of incubation with LPS. Mangiferin potently reduced LPS-induced PGE(2) synthesis and the formation of 8-iso-PGF(2alpha). Interestingly, mangiferin dose-dependently reduced LPS-induced COX-2 protein synthesis without modifying COX-2 transcription. This was due to a decrease in COX-2 transcript stability. However, mangiferin did not modify LPS-mediated phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), a key factor involved in enhancing COX-2 mRNA stability and COX-2 translation in primary microglia. Mangiferin had no effects on LPS-induced expression of inducible nitric oxide synthase (iNOS) or TNF-alpha production. Taken together, results from the present study indicate that mangiferin is able to limit microglial activation, in terms of attenuation of PGE(2) production, free radical formation and reduction in COX-2 synthesis induced by LPS. These data suggest that modulation of microglial activation might contribute to the mechanism of cerebral protection by mangiferin.
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Affiliation(s)
- Harsharan S Bhatia
- Neurochemistry Research Group, Department of Psychiatry, University of Freiburg Medical School, Hauptstrasse 5, D-79104 Freiburg, Germany
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Gu B, Desjardins P, Butterworth RF. Selective increase of neuronal cyclooxygenase-2 (COX-2) expression in vulnerable brain regions of rats with experimental Wernicke's encephalopathy: effect of nimesulide. Metab Brain Dis 2008; 23:175-87. [PMID: 18481165 DOI: 10.1007/s11011-008-9089-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 02/18/2008] [Indexed: 10/22/2022]
Abstract
Thiamine deficiency (TD) in both humans and experimental animals results in severe mitochondrial dysfunction and leads to selective neuronal cell death in diencephalic and cerebellar structures. We have investigated cyclooxygenase-2 (COX-2) expression in vulnerable (medial thalamus, inferior colliculus) and spared (frontal cortex) regions of rats with thiamine deficiency. Expression of COX-2 mRNA was selectively increased (twofold, p < 0.001) in vulnerable regions at symptomatic stages of encephalopathy (14 days) of TD compared to pair-fed controls or presymptomatic (days 12) rats. Induction of COX-2 expression was accompanied by a significant increase (two- to threefold, p < 0.001) in prostanglandin E2 (PGE2) synthesis in vulnerable regions at symptomatic stages of TD. COX-2 immunolabeling revealed a neuronal localization and COX-2 immunoreactive neurons were significantly increased at symptomatic stages of encephalopathy. Administration of nimesulide, a highly specific COX-2 inhibitor, significantly reduced PGE-2 levels in vulnerable regions but, rather than being neuroprotective, precipitated encephalopathy and exacerbated neuronal cell death due to TD. These findings suggest that newly synthesized prostanoids exert a neuroprotective role in TD.
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Affiliation(s)
- Baoying Gu
- Neuroscience Research Unit, CHUM/Campus Saint-Luc, 1058 St-Denis Street, Montreal, Quebec, Canada, H2X 3J4
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27
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García-Bueno B, Madrigal JLM, Pérez-Nievas BG, Leza JC. Stress mediators regulate brain prostaglandin synthesis and peroxisome proliferator-activated receptor-gamma activation after stress in rats. Endocrinology 2008; 149:1969-78. [PMID: 18079203 DOI: 10.1210/en.2007-0482] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Stress exposure leads to oxidative/nitrosative and neuroinflammatory changes that have been shown to be regulated by antiinflammatory pathways in the brain. In particular, acute restraint stress is followed by cyclooxygenase (COX)-2 up-regulation and subsequent proinflammatory prostaglandin (PG) E2 release in rat brain cortex. Concomitantly, the synthesis of the antiinflammatory prostaglandin 15d-PGJ(2) and the activation of its nuclear target the peroxisome proliferator-activated receptor (PPAR)-gamma are also produced. This study aimed to determine the possible role of the main stress mediators: catecholamines, glucocorticoids, and excitatory amino acids (glutamate) in the above-mentioned stress-related effects. By using specific pharmacological tools, our results show that the main mediators of the stress response are implicated in the regulation of prostaglandin synthesis and PPARgamma activation in rat brain cortex described after acute restraint stress exposure. Pharmacological inhibition (predominantly through beta-adrenergic receptor) of the stress-released catecholamines in the central nervous system regulates 15d-PGJ(2) and PGE(2) synthesis, by reducing COX-2 overexpression, and reduces PPARgamma activation. Stress-produced glucocorticoids carry out their effects on prostaglandin synthesis through their interaction with mineralocorticoid and glucocorticoid receptors to a very similar degree. However, in the case of PPARgamma regulation, only the actions through the glucocorticoid receptor seem to be relevant. Finally, the selective blockade of the N-methyl-d-aspartate type of glutamate receptor after stress also negatively regulates 15d-PGJ(2) and PGE(2) production by COX-2 down-regulation and decrease in PPARgamma transcriptional activity and expression. In conclusion, we show here that the main stress mediators, catecholamines, GCs, and glutamate, concomitantly regulate the activation of proinflammatory and antiinflammatory pathways in a possible coregulatory mechanism of the inflammatory process induced in rat brain cortex by acute restraint stress exposure.
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Affiliation(s)
- Borja García-Bueno
- Department of Pharmacology, Faculty of Medicine and Pharmacology and Toxicology Institute, Consejo Superior de Investigaciones Centificas-UCM, Complutense University, 28040 Madrid, Spain
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Piscopo P, Bernardo A, Calamandrei G, Venerosi A, Valanzano A, Bianchi D, Confaloni A, Minghetti L. Altered expression of cyclooxygenase-2, presenilins and oxygen radical scavenging enzymes in a rat model of global perinatal asphyxia. Exp Neurol 2008; 209:192-8. [DOI: 10.1016/j.expneurol.2007.09.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 07/30/2007] [Accepted: 09/17/2007] [Indexed: 11/15/2022]
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Soodi M, Sharifzadeh M, Naghdi N, Ostad N, Abdollahi M, Roghani A. Systemic and developmental exposure to lead causes spatial memory deficits and a reduction in COX-2 immunoreactivity in the hippocampus of male rats. J Neurosci Res 2007; 85:3183-92. [PMID: 17639600 DOI: 10.1002/jnr.21423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Chronic lead exposure during development is known to produce learning deficits. In the present study, we investigated the effects of developmental exposure to lead on spatial memory, as shown in the Morris water maze, and on expression of inducible cyclooxygenase-2 protein in the hippocampi of male rats. Rats were separated into four groups according to which concentration of lead acetate at which developmental stage they were exposed. One group was exposed maternally to lead acetate at a concentration of 250 parts per million (ppm), one group was exposed continuously to 250 ppm lead, one group was exposed maternally to 750 ppm lead, and one group was exposed continuously to 750 ppm lead. Increases were observed in both average escape latency and traveled distance of the rats in the maternally and continuously 750 ppm lead-exposed groups, indicating significant impairment of spatial memory. Quantitative immunostaining analysis by optical density measurement of brain sections from rats in all lead-exposed groups revealed a significant reduction (P < 0.001) in the intensity of cyclooxygenase-2 immunoreactivity in the Ammon's horn region 1 (CA1) and the dentate gyrus areas of the hippocampus. This reduction was concentration-dependent, with the maximum reduction observed in rats exposed to 750 ppm lead. Taken together, these findings suggest that exposure to lead causes spatial memory deficits in male rats and a significant reduction in cyclooxygenase-2 immunoreactivity in the CA1 and dentate gyrus areas.
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Affiliation(s)
- Maliheh Soodi
- Department of Toxicology and Pharmacology, School of Pharmacy, Pharmaceutical Sciences and Medicinal Plants Research Centers, Tehran University of Medical Sciences, Tehran, Iran
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Basselin M, Villacreses NE, Chen M, Bell JM, Rapoport SI. Chronic carbamazepine administration reduces N-methyl-D-aspartate receptor-initiated signaling via arachidonic acid in rat brain. Biol Psychiatry 2007; 62:934-43. [PMID: 17628508 PMCID: PMC2131715 DOI: 10.1016/j.biopsych.2007.04.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 04/11/2007] [Accepted: 04/11/2007] [Indexed: 01/16/2023]
Abstract
BACKGROUND Lithium and carbamazepine (CBZ) are used to treat mania in bipolar disorder. When given chronically to rats, both agents reduce arachidonic acid (AA) turnover in brain phospholipids and downstream AA metabolism. Lithium in rats also attenuates brain N-methyl-D-aspartic acid receptor (NMDAR) signaling via AA. We hypothesized that, like chronic lithium, chronic CBZ administration to rats would reduce NMDAR-mediated signaling via AA. METHODS We used our fatty acid method with quantitative autoradiography to image the regional brain incorporation coefficient k* of AA, a marker of AA signaling, in unanesthetized rats that had been given 25 mg/kg/day I.P. CBZ or vehicle for 30 days, then injected with NMDA (25 mg/kg I.P.) or saline. We also measured brain concentrations of two AA metabolites, prostaglandin E(2) (PGE(2)) and thromboxane B(2) (TXB(2)). RESULTS In chronic vehicle-treated rats, NMDA compared with saline increased k* significantly in 69 of 82 brain regions examined, but did not change k* significantly in any region in CBZ-treated rats. In vehicle- but not CBZ-treated rats, NMDA also increased brain concentrations of PGE(2) and TXB(2). CONCLUSIONS Chronic CBZ administration to rats blocks increments in the AA signal k*, and in PGE(2) and TXB(2) concentrations that are produced by NMDA in vehicle-treated rats. The clinical action of antimanic drugs might involve inhibition of brain NMDAR-mediated signaling involving AA and its metabolites.
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Affiliation(s)
- Mireille Basselin
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Candelario-Jalil E, de Oliveira ACP, Gräf S, Bhatia HS, Hüll M, Muñoz E, Fiebich BL. Resveratrol potently reduces prostaglandin E2 production and free radical formation in lipopolysaccharide-activated primary rat microglia. J Neuroinflammation 2007; 4:25. [PMID: 17927823 PMCID: PMC2100038 DOI: 10.1186/1742-2094-4-25] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 10/10/2007] [Indexed: 01/22/2023] Open
Abstract
Background Neuroinflammatory responses are triggered by diverse ethiologies and can provide either beneficial or harmful results. Microglial cells are the major cell type involved in neuroinflammation, releasing several mediators, which contribute to the neuronal demise in several diseases including cerebral ischemia and neurodegenerative disorders. Attenuation of microglial activation has been shown to confer protection against different types of brain injury. Recent evidence suggests that resveratrol has anti-inflammatory and potent antioxidant properties. It has been also shown that resveratrol is a potent inhibitor of cyclooxygenase (COX)-1 activity. Previous findings have demonstrated that this compound is able to reduce neuronal injury in different models, both in vitro and in vivo. The aim of this study was to examine whether resveratrol is able to reduce prostaglandin E2 (PGE2) and 8-iso-prostaglandin F2α (8-iso-PGF2α) production by lipopolysaccharide (LPS)-activated primary rat microglia. Methods Primary microglial cell cultures were prepared from cerebral cortices of neonatal rats. Microglial cells were stimulated with 10 ng/ml of LPS in the presence or absence of different concentrations of resveratrol (1–50 μM). After 24 h incubation, culture media were collected to measure the production of PGE2 and 8-iso-PGF2α using enzyme immunoassays. Protein levels of COX-1, COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) were studied by Western blotting after 24 h of incubation with LPS. Expression of mPGES-1 at the mRNA level was investigated using reverse transcription-polymerase chain reaction (RT-PCR) analysis. Results Our results indicate that resveratrol potently reduced LPS-induced PGE2 synthesis and the formation of 8-iso-PGF2α, a measure of free radical production. Interestingly, resveratrol dose-dependently reduced the expression (mRNA and protein) of mPGES-1, which is a key enzyme responsible for the synthesis of PGE2 by activated microglia, whereas resveratrol did not affect the expression of COX-2. Resveratrol is therefore the first known inhibitor which specifically prevents mPGES-1 expression without affecting COX-2 levels. Another important observation of the present study is that other COX-1 selective inhibitors (SC-560 and Valeroyl Salicylate) potently reduced PGE2 and 8-iso-PGF2α production by LPS-activated microglia. Conclusion These findings suggest that the naturally occurring polyphenol resveratrol is able to reduce microglial activation, an effect that might help to explain its neuroprotective effects in several in vivo models of brain injury.
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Affiliation(s)
- Eduardo Candelario-Jalil
- Neurochemistry Research Group, Department of Psychiatry, University of Freiburg Medical School, Hauptstrasse 5, D-79104 Freiburg, Germany.
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Ueda Y, Doi T, Nagatomo K, Nakajima A. In vivo activation of N-methyl-D-aspartate receptors generates free radicals and reduces antioxidant ability in the rat hippocampus: experimental protocol of in vivo ESR spectroscopy and microdialysis for redox status evaluation. Brain Res 2007; 1178:20-7. [PMID: 17920572 DOI: 10.1016/j.brainres.2007.08.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 11/29/2022]
Abstract
The pathological mechanisms of various CNS diseases are closely related to glutamate neuronal excitotoxicity following NMDA receptor activation. To verify this relationship, in vivo microdialysis in the hippocampus of rats was applied to ESR spectroscopy during NMDA perfusion. Microdialysis co-perfusion of 0.1 mM NMDA dissolved in 150 mM POBN for 60 min revealed six-line carbon-centered radical ESR spectra. The hfc values were aN=15.7 G and aHbeta=2.5 G, corresponding to the values produced from the generation of lipid radicals. The antioxidant activity during the freely moving state was examined utilizing the principle that systemically applied nitroxide radicals are reduced and lose their paramagnetism by antioxidant activity in the brain. ESR analysis of sequential changes in the signal amplitude of nitroxide radicals in both the NMDA group and the control group revealed an exponential decay. The half-life of the nitroxide radical was significantly longer in the NMDA group than in the control group. The homeostasis of a steady redox balance was destroyed by acute NMDA infusion, which resulted in the generation of lipid radicals and the reduction of antioxidant ability in the hippocampus. The redox imbalance induced by the activation of NMDA-R was recovered by the inhibition of PLA2 and NOS. These results indicated that NMDA-R activation caused the shift to oxidized condition of the redox state, which subsequently leads to neuron death in the hippocampus in the model of glutamate-associated neuronal disease.
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Affiliation(s)
- Yuto Ueda
- Section of Psychiatry, Department of Clinical Neuroscience, Faculty of Medicine, University of Miyazaki 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
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Wright G, Jalan R. Ammonia and inflammation in the pathogenesis of hepatic encephalopathy: Pandora's box? Hepatology 2007; 46:291-4. [PMID: 17661413 DOI: 10.1002/hep.21843] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kumar P, Padi SSV, Naidu PS, Kumar A. Cyclooxygenase inhibition attenuates 3-nitropropionic acid-induced neurotoxicity in rats: possible antioxidant mechanisms. Fundam Clin Pharmacol 2007; 21:297-306. [PMID: 17521299 DOI: 10.1111/j.1472-8206.2007.00485.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Systemic administration of 3-nitropropionic acid (3-NP), a complex II inhibitor of the electron transport chain, causes motor and cognitive deficits that are associated with excitotoxicity and excessive free radical generation. Recently, cyclooxygenase (COX) inhibitors have been implicated as a neuroprotectant in the treatment of various neurological disorders. The present study was designed to investigate the effects of COX inhibitors in 3-NP-induced cognitive impairment and oxidative stress in rats. Intraperitoneal administration of 3-NP (20 mg/kg for 4 days) showed motor abnormalities and cognitive impairment in rats. Chronic treatment with naproxen (10 and 20 mg/kg) and valdecoxib (5 and 10 mg/kg) once daily for a period of 8 days beginning 4 days prior to 3-NP administration significantly improved 3-NP-induced motor and cognitive impairment in rats. Biochemical analysis revealed that systemic 3-NP administration significantly increased lipid peroxidation and nitrite levels, depleted reduced glutathione levels and reduced succinate dehydrogenase (SDH) activity in the brains of rats, whereas administration of naproxen, a nonselective COX inhibitor (10 and 20 mg/kg p.o.) and valdecoxib, a selective COX-2 inhibitor (5 and 10 mg/kg p.o.) significantly attenuated 3-NP-induced oxidative stress. Cyclooxygenase inhibitors also significantly restored the decreased SDH activity. The results of the present study clearly indicate that naproxen and valdecoxib showed protection against 3-NP-induced motor and cognitive impairment by decreasing oxidative stress.
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Affiliation(s)
- P Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Punjab University, Chandigarh 160014, India
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Basselin M, Villacreses NE, Lee HJ, Bell JM, Rapoport SI. Chronic lithium administration attenuates up-regulated brain arachidonic acid metabolism in a rat model of neuroinflammation. J Neurochem 2007; 102:761-72. [PMID: 17488274 DOI: 10.1111/j.1471-4159.2007.04593.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neuroinflammation, caused by a 6-day intracerebroventricular infusion of lipopolysaccharide (LPS) in rats, is associated with the up-regulation of brain arachidonic acid (AA) metabolism markers. Because chronic LiCl down-regulates markers of brain AA metabolism, we hypothesized that it would attenuate increments of these markers in LPS-infused rats. Incorporation coefficients k* of AA from plasma into brain, and other brain AA metabolic markers, were measured in rats that had been fed a LiCl or control diet for 6 weeks, and subjected in the last 6 days on the diet to intracerebroventricular infusion of artificial CSF or of LPS. In rats on the control diet, LPS compared with CSF infusion increased k* significantly in 28 regions, whereas the LiCl diet prevented k* increments in 18 of these regions. LiCl in CSF infused rats increased k* in 14 regions, largely belonging to auditory and visual systems. Brain cytoplasmic phospholipase A(2) activity, and prostaglandin E(2) and thromboxane B(2) concentrations, were increased significantly by LPS infusion in rats fed the control but not the LiCl diet. Chronic LiCl administration attenuates LPS-induced up-regulation of a number of brain AA metabolism markers. To the extent that this up-regulation has neuropathological consequences, lithium might be considered for treating human brain diseases accompanied by neuroinflammation.
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Affiliation(s)
- Mireille Basselin
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda 20892-0947, Maryland, USA.
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Ahmad AS, Zhuang H, Echeverria V, Doré S. Stimulation of prostaglandin EP2 receptors prevents NMDA-induced excitotoxicity. J Neurotrauma 2007; 23:1895-903. [PMID: 17184197 DOI: 10.1089/neu.2006.23.1895] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Prostaglandin E(2) (PGE(2)) plays an important role in inflammation and neurologic disorders. The neuromodulatory effects of PGE(2) are mediated through regulation of four G-protein-coupled receptors known as EP1, EP2, EP3, and EP4. The goal of the current study was to determine whether EP2 receptor activation protects neurons from acute NMDA-mediated excitotoxicity. To examine the effects of EP2 activation, mice were given an injection of the EP2 receptor-selective agonist butaprost (K (i) = 110 nM for EP2 receptor; K (i) > 10,000 for other prostaglandin receptors) in the cerebral ventricle and then an injection of NMDA in the right striatum. After 48 h, a significant reduction in NMDA-induced lesion volume was observed in groups pretreated with butaprost (1-300 nmol/L), with maximal protection at 100 nmol/L (p < 0.001). To determine if EP2-activated protection was specific to neurons, mouse neuronal cultures were treated with butaprost, and cell viability was analyzed after 24 h of NMDA excitotoxicity. The results showed that butaprost significantly increased neuron survival in a dose-dependent fashion. Furthermore, treatment of primary neurons with butaprost significantly increased cAMP levels (p < 0.001). Together, these data reveal that EP2 receptor stimulation mediates neuroprotection against NMDA excitotoxicity both in vivo and in vitro and that butaprost can limit acute brain damage. Development and testing of specific PGE(2) receptor mimetics could lead to a decrease in side effects associated with anti-inflammatory drugs and could help to fight acute and/or chronic neurologic disorders.
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Affiliation(s)
- Abdullah Shafique Ahmad
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Brady KM, Texel SJ, Kishimoto K, Koehler RC, Sapirstein A. Cytosolic phospholipase A alpha modulates NMDA neurotoxicity in mouse hippocampal cultures. Eur J Neurosci 2007; 24:3381-6. [PMID: 17229087 DOI: 10.1111/j.1460-9568.2006.05237.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The arachidonic acid-specific cytosolic phospholipase A(2) alpha (cPLA(2)alpha) has been implicated in the generation of neurological injuries. cPLA(2)alpha-dependent neurological injury has been postulated to be mediated through inflammatory and eicosanoid pathways. We determined if cPLA(2)alpha amplifies the injury of a non-inflammatory, excitotoxic stimulus by modifying a well-described toxicity assay to measure the toxicity of N-methyl-d-aspartate (NMDA) in the CA1 region of organotypic, mouse hippocampal cultures. Hippocampal cultures from wild-type and cPLA(2)alpha knockout mice were exposed to 5, 7.5 or 10 microm NMDA for 1 h. Toxicity was measured 23 h later. Cultures derived from cPLA(2)alpha(-/-) mice and cultures treated with the selective inhibitor AACOCF(3) were significantly protected from NMDA toxicity, as compared with wild-type cultures. To determine if cPLA(2)alpha-dependent toxicity is cyclooxygenase (COX)-2 dependent, COX-2 and PGE(2) levels were measured 7 and 25 h after NMDA treatment. NMDA treatment failed to induce COX-2 protein or increase PGE(2) in the culture media in either genotype at either time. In contrast, phorbol 12-myristate 13-acetate and ionophore treatment caused robust induction of COX-2 and PGE(2) in both genotypes. We conclude that cPLA(2)alpha may have a hitherto unrecognized direct effect on excitatory neurotoxicity, suggesting that cPLA(2)alpha inhibition is a therapeutic candidate for treatment of the early, excitotoxic injury observed in stroke.
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Affiliation(s)
- Ken M Brady
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Candelario-Jalil E, González-Falcón A, García-Cabrera M, León OS, Fiebich BL. Post-ischaemic treatment with the cyclooxygenase-2 inhibitor nimesulide reduces blood-brain barrier disruption and leukocyte infiltration following transient focal cerebral ischaemia in rats. J Neurochem 2007; 100:1108-20. [PMID: 17176264 DOI: 10.1111/j.1471-4159.2006.04280.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several studies suggest that cyclooxygenase (COX)-2 plays a pivotal role in the progression of ischaemic brain damage. In the present study, we investigated the effects of selective inhibition of COX-2 with nimesulide (12 mg/kg) and selective inhibition of COX-1 with valeryl salicylate (VAS, 12-120 mg/kg) on prostaglandin E(2) (PGE(2)) levels, myeloperoxidase (MPO) activity, Evans blue (EB) extravasation and infarct volume in a standardized model of transient focal cerebral ischaemia in the rat. Post-ischaemic treatment with nimesulide markedly reduced the increase in PGE(2) levels in the ischaemic cerebral cortex 24 h after stroke and diminished infarct size by 48% with respect to vehicle-treated animals after 3 days of reperfusion. Furthermore, nimesulide significantly attenuated the blood-brain barrier (BBB) damage and leukocyte infiltration (as measured by EB leakage and MPO activity, respectively) seen at 48 h after the initial ischaemic episode. These studies provide the first experimental evidence that COX-2 inhibition with nimesulide is able to limit BBB disruption and leukocyte infiltration following transient focal cerebral ischaemia. Neuroprotection afforded by nimesulide is observed even when the treatment is delayed until 6 h after the onset of ischaemia, confirming a wide therapeutic window of COX-2 inhibitors in experimental stroke. On the contrary, selective inhibition of COX-1 with VAS had no significant effect on the evaluated parameters. These data suggest that COX-2 activity, but not COX-1 activity, contributes to the progression of focal ischaemic brain injury, and that the beneficial effects observed with non-selective COX inhibitors are probably associated to COX-2 rather than to COX-1 inhibition.
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Affiliation(s)
- Eduardo Candelario-Jalil
- Neurochemistry Research Group, Department of Psychiatry, University of Freiburg Medical School, Freiburg, Germany.
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Abstract
There is now considerable evidence from both experimental and clinical studies that immune and inflammatory processes can contribute to the onset of stroke and the neurologic and psychologic outcomes. Several specific therapeutic targets have been identified that may significantly improve the devastating impact of stroke.
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Affiliation(s)
- Robert Skinner
- Faculty of Life Sciences, Michael Smith Building (C2210), University of Manchester, Acker Street, Manchester M13 9PT, UK.
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40
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Esposito G, Giovacchini G, Der M, Liow JS, Bhattacharjee AK, Ma K, Herscovitch P, Channing M, Eckelman WC, Hallett M, Carson RE, Rapoport SI. Imaging signal transduction via arachidonic acid in the human brain during visual stimulation, by means of positron emission tomography. Neuroimage 2006; 34:1342-51. [PMID: 17196833 PMCID: PMC2040045 DOI: 10.1016/j.neuroimage.2006.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 10/20/2006] [Accepted: 11/01/2006] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Arachidonic acid (AA, 20:4n-6), an important second messenger, is released from membrane phospholipid following receptor mediated activation of phospholipase A(2) (PLA(2)). This signaling process can be imaged in brain as a regional brain AA incorporation coefficient K*. HYPOTHESIS K* will be increased in brain visual areas of subjects submitted to visual stimulation. SUBJECTS AND METHODS Regional values of K* were measured with positron emission tomography (PET), following the intravenous injection of [1-(11)C]AA, in 16 healthy volunteers subjected to visual stimulation at flash frequencies 2.9 Hz (8 subjects) or 7.8 Hz (8 subjects), compared with the dark (0 Hz) condition. Regional cerebral blood flow (rCBF) was measured with intravenous [(15)O]water under comparable conditions. RESULTS During flash stimulation at 2.9 Hz or 7.8 Hz vs. 0 Hz, K* was increased significantly by 2.3-8.9% in Brodmann areas 17, 18 and 19, and in additional frontal, parietal and temporal cortical regions. rCBF was increased significantly by 3.1-22%, often in comparable regions. Increments at 7.8 Hz often exceeded those at 2.9 Hz for both K* and rCBF. Decrements in both parameters also were produced, particularly in frontal brain regions. CONCLUSIONS AA plays a role in signaling processes provoked by visual stimulation, since visual stimulation at flash frequencies of 2.9 and 7.8 Hz compared to 0 Hz modifies both K* for AA and rCBF in visual and related areas of the human brain. The two-stimulus condition paradigm of this study might be used with PET to image effects of other functional activations and of drugs on brain signaling via AA.
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Affiliation(s)
- Giuseppe Esposito
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Giampiero Giovacchini
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Department of Radiology, University of Pisa, Pisa, Italy
| | - Margaret Der
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - Jeih-San Liow
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Abesh K. Bhattacharjee
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Kaizong Ma
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Peter Herscovitch
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - Michael Channing
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
| | - William C. Eckelman
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Molecular Tracer, LLC, Snow Point Drive, Bethesda MD
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disease and Stroke; National Institutes of Health, Bethesda, MD
| | - Richard E. Carson
- PET Department, Warren Magnusson Clinical Center, National Institutes of Health, Bethesda, MD
- Department of Diagnostic Radiology and Biomedical Engineering, Yale University, New Haven, CT
| | - Stanley I. Rapoport
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD
- *Corresponding Author: Brain Physiology and Metabolism Section, Bldg. 9, Rm. 1S128, National Institute on Aging, National Institutes of Health, 9 Memorial Drive, Bethesda, MD 20892, Tel: 301 496 1765, Fax: 301 402 0074, E-mail:
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Kumar A, Seghal N, Padi SV, Naidu PS. Differential effects of cyclooxygenase inhibitors on intracerebroventricular colchicine-induced dysfunction and oxidative stress in rats. Eur J Pharmacol 2006; 551:58-66. [PMID: 17027965 DOI: 10.1016/j.ejphar.2006.08.076] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 08/16/2006] [Accepted: 08/21/2006] [Indexed: 11/20/2022]
Abstract
Alzheimer's disease is a progressive neurological and psychiatric disorder. Oxidative stress and neuroinflammation have been implicated in pathophysiology of Alzheimer's disease. Inflammatory cells, such as astrocytes and microglia, are activated in areas of the brain affected by amyloid plaques and inflammatory mediators including cytokines, chemokines, prostaglandins, oxygen free radicals and reactive nitrogen species may have a crucial role in Alzheimer's disease pathogenesis. Central administration of colchicine, a microtubule-disrupting agent, causes loss of cholinergic neurons and cognitive dysfunction that is associated with excessive free radical generation. The present study was aimed to evaluate the effects of cyclooxygenase inhibitors against colchicine-induced cognitive dysfunction and oxidative stress in rats. Following intracerebroventricular (i.c.v.) administration of colchicine (15 microg/5 microl), rats exhibited poor retention of memory in Morris water maze and elevated plus maze task paradigms and oxidative stress in rats. Chronic treatment with naproxen (per se; 20 and 40 mg/kg, p.o.) or valdecoxib (per se; 5 and 10 mg/kg, p.o.) daily respectively for a period of 25 days beginning 4 days prior to colchicine injection significantly improved colchicine-induced cognitive impairment. Intracerebroventricular colchicine injection resulted in free radical generation characterized by alterations in oxidative stress markers with a significant increase in malondialdehyde and nitrite levels and depletion of reduced glutathione levels in the brains of rats. It also caused a decrease in acetylcholinesterase activity. Besides, improving cognitive dysfunction, chronic administration of cyclooxygenase inhibitors (naproxen and valdecoxib) significantly reduced elevated malondialdehyde, nitrite levels and restored reduced glutathione levels and acetylcholinesterase activity. The results of the present study indicated that naproxen (per se; 20 and 40 mg/kg, p.o.) or valdecoxib (per se; 5 and 10 mg/kg, p.o.) treatment has a neuroprotective role against colchicine-induced cognitive impairment and associated oxidative stress. The present findings further support the potential use of cyclooxygenase inhibitors in treatment of neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Anil Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh-160014, India.
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Bishnoi M, Patil CS, Kumar A, Kulkarni SK. Co-Administration of Acetyl-11-Keto-β-Boswellic Acid, a Specific 5-Lipoxygenase Inhibitor, Potentiates the Protective Effect of COX-2 Inhibitors in Kainic Acid-Induced Neurotoxicity in Mice. Pharmacology 2006; 79:34-41. [PMID: 17139192 DOI: 10.1159/000097627] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Accepted: 09/20/2006] [Indexed: 11/19/2022]
Abstract
Cyclooxygenase (COX) and lipoxygenase (LOX) are responsible for the metabolism of arachidonic acid into inflammatory metabolites, prostaglandins and leukotrienes, respectively. The upregulation of these enzymes in the central nervous system has been demonstrated to be responsible for the increased neuronal vulnerability to degeneration. Kainic acid, a glutamate receptor agonist and responsible for neuronal excitotoxicity and oxidative damage via different mechanisms, is capable of stimulating mRNA of both COX-2 and 5-LOX in the brain. The present study was designed to study the effects of COX inhibitors (indomethacin, nimesulide, rofecoxib) and a 5-LOX inhibitor (acetyl-11-keto-beta-boswellic acid; AKBA) and the combination of these inhibitors (dual inhibition) on kainic acid induced excitotoxicity and oxidative and nitrosative damage in mice. The results from the present study indicated that AKBA, indomethacin, and nimesulide per se did not produce any change in the behavioural parameters after kainic acid administration; however, rofecoxib per seproduced a significant increase in the latency of clonic (seizure-like) movement and a decrease in mortality rate as compared with kainic acid treated animals. In combination studies AKBA, rofecoxib, and nimesulide produced a more pronounced effect than either of these drugs alone. Further, the effect of AKBA combined with rofecoxib was significantly more marked when compared with AKBA combined with nimesulide. Besides this, identical results were found for the effect of these agents and their combination against oxidative damage induced by kainic acid. These findings indicate the potential role of COX-2 inhibitors and also their combination with the 5-LOX inhibitor in kainic acid induced excitotoxicity and oxidative damage by virtue of their antioxidant effect and suggest the need for the development of dual inhibitors for the treatment of neuronal excitotoxicity.
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Affiliation(s)
- Mahendra Bishnoi
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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Kumar A, Naidu PS, Seghal N, Padi SSV. Neuroprotective Effects of Resveratrol against Intracerebroventricular Colchicine-Induced Cognitive Impairment and Oxidative Stress in Rats. Pharmacology 2006; 79:17-26. [PMID: 17135773 DOI: 10.1159/000097511] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Accepted: 09/13/2006] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease is a complex and multifactorial neurodegenerative disease. Central administration of colchicine, a microtubule-disrupting agent, causes loss of cholinergic neurons and cognitive dysfunction that is associated with excessive free radical generation. The present study was aimed at evaluating the effects of trans-resveratrol in the prevention of colchicine-induced cognitive impairment and oxidative stress in rats. Intracerebroventricular administration of colchicine (15 microg/5 microl) induced impaired cognitive functions in both the Morris water maze task and the elevated plus-maze task. Chronic treatment with resveratrol (10 and 20 mg/kg, p.o.) for a period of 25 days, beginning 4 days prior to colchicine injection, significantly improved the colchicine-induced cognitive impairment. Intracerebroventricular colchicine injection resulted in free radical generation characterized by alterations in oxidative stress markers with a significant increase in malondialdehyde (MDA) and nitrite levels and depletion of reduced glutathione (GSH) activity in the rat brains. It also showed a significant decrease in acetylcholinesterase activity. Besides improving cognitive dysfunction, chronic administration of resveratrol significantly reduced the elevated MDA and nitrite levels and restored the depleted GSH and acetylcholinesterase activity. Results of the present study indicated that trans-resveratrol has a neuroprotective role against colchicine-induced cognitive impairment and associated oxidative stress.
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Affiliation(s)
- A Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India.
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Im JY, Kim D, Paik SG, Han PL. Cyclooxygenase-2-dependent neuronal death proceeds via superoxide anion generation. Free Radic Biol Med 2006; 41:960-72. [PMID: 16934679 DOI: 10.1016/j.freeradbiomed.2006.06.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 05/03/2006] [Accepted: 06/02/2006] [Indexed: 11/20/2022]
Abstract
Cyclooxygenase-2 (COX-2) expression is induced in the neurons of the pathologic brain and elevated COX-2 expressions can lead to neuronal death. Here, we report that COX-2 induction in cortical neurons induced by LPS pretreatment for more than 12 h increased the neurotoxic effects of low doses of Fe2+ by more than 2.5-fold. Moreover, the neurotoxicity induced by 30 muM Fe2+ in LPS-pretreated cells exceeded that induced by 100 microM Fe2+ in LPS-untreated cells. LPS pretreatment also similarly aggravated the neurotoxic effects of low doses of H2O2, Zn2+, and sodium nitroprusside. This LPS-induced Fe2+ -toxicity enhancement was blocked by trolox, vitamin C, the SOD mimetic MnTBAP, and by the COX-2-specific inhibitor NS398, but not by inhibitors of xanthine oxidase, NADPH oxidase, NOS, and monoamine oxidase. Cortical neurons with enhanced COX-2 expression showed superoxide generation, GSH depletion, and lipid peroxidation in response to low doses of Fe2+, and all of these changes were repressed by MnTBAP or NS398. Consistent with this pharmacological data, cortical neurons prepared from COX-2 knockout mice showed marked reductions in LPS-induced Fe2+ -toxicity enhancement and superoxide generation. These results suggest that COX-2 functions as a cellular factor which induces superoxide-mediated cell death in primary cortical neurons.
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Affiliation(s)
- Joo-Young Im
- Division of Nano Science and Department of Life Sciences, Ewha Womans University, 11-1, Daehyun-Dong, Seodaemoon-Gu, Seoul, Republic of Korea
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Phillis JW, Horrocks LA, Farooqui AA. Cyclooxygenases, lipoxygenases, and epoxygenases in CNS: Their role and involvement in neurological disorders. ACTA ACUST UNITED AC 2006; 52:201-43. [PMID: 16647138 DOI: 10.1016/j.brainresrev.2006.02.002] [Citation(s) in RCA: 266] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 02/23/2006] [Accepted: 02/24/2006] [Indexed: 01/01/2023]
Abstract
Three enzyme systems, cyclooxygenases that generate prostaglandins, lipoxygenases that form hydroxy derivatives and leukotrienes, and epoxygenases that give rise to epoxyeicosatrienoic products, metabolize arachidonic acid after its release from neural membrane phospholipids by the action of phospholipase A(2). Lysophospholipids, the other products of phospholipase A(2) reactions, are either reacylated or metabolized to platelet-activating factor. Under normal conditions, these metabolites play important roles in synaptic function, cerebral blood flow regulation, apoptosis, angiogenesis, and gene expression. Increased activities of cyclooxygenases, lipoxygenases, and epoxygenases under pathological situations such as ischemia, epilepsy, Alzheimer's disease, Parkinson disease, amyotrophic lateral sclerosis, and Creutzfeldt-Jakob disease produce neuroinflammation involving vasodilation and vasoconstriction, platelet aggregation, leukocyte chemotaxis and release of cytokines, and oxidative stress. These are closely associated with the neural cell injury which occurs in these neurological conditions. The metabolic products of docosahexaenoic acid, through these enzymes, generate a new class of lipid mediators, namely docosatrienes and resolvins. These metabolites antagonize the effect of metabolites derived from arachidonic acid. Recent studies provide insight into how these arachidonic acid metabolites interact with each other and other bioactive mediators such as platelet-activating factor, endocannabinoids, and docosatrienes under normal and pathological conditions. Here, we review present knowledge of the functions of cyclooxygenases, lipoxygenases, and epoxygenases in brain and their association with neurodegenerative diseases.
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Affiliation(s)
- John W Phillis
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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Zhao Y, Patzer A, Herdegen T, Gohlke P, Culman J. Activation of cerebral peroxisome proliferator-activated receptors gamma promotes neuroprotection by attenuation of neuronal cyclooxygenase-2 overexpression after focal cerebral ischemia in rats. FASEB J 2006; 20:1162-75. [PMID: 16770015 DOI: 10.1096/fj.05-5007com] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Up-regulation of cyclooxygenase (COX)-2 exacerbates neuronal injury after cerebral ischemia and contributes to neuronal cell death. The present study clarifies the function of cerebral peroxisome-proliferator-activated receptor(s) gamma (PPARgamma) in the expression of COX-2 in neurons of the rat brain after middle cerebral artery occlusion (MCAO) with reperfusion by immunohistochemistry, Western blot, and immunofluorescence staining. In peri-infarct cortical areas the PPARgamma was located in both microglia and neurons, whereas COX-2 was almost exclusively expressed in neurons. PPARgamma immunolabeling reached the peak 12 h after MCAO, whereas the number of COX-2 immunostained cells gradually rose and reached its peak at 48 h. Intracerebroventricular infusion of pioglitazone, an agonist of the PPARgamma, over a 5-day period before and 2 days after MCAO, reduced the infarct size, the expression of tumor necrosis factor alpha (TNF-alpha), COX-2, and the number of cells positively stained for COX-1 and COX-2 in the peri-infarct cortical regions. COX-2 induction was also attenuated in the ipsilateral but not in the contralateral hippocampus. In primary cortical neurons expressing the PPARgamma, pioglitazone suppressed COX-2 expression in response to oxidative stress. This protective effect was reversed after cotreatment with GW 9662, a selective antagonist of the PPARgamma, clearly demonstrating a PPARgamma-dependent mechanism. Our data provide evidence that activation of neuronal PPARgamma considerably contributes to neuroprotection by prevention of COX-2 up-regulation in vitro and in peri-infarct brain areas.
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Affiliation(s)
- Yi Zhao
- Institute of Pharmacology, University Hospital of Schleswig-Holstein, Campus Kiel Hospitalstrasse 4 24105 Kiel, Germany
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47
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Ajmone-Cat MA, Iosif RE, Ekdahl CT, Kokaia Z, Minghetti L, Lindvall O. Prostaglandin E2 and BDNF levels in rat hippocampus are negatively correlated with status epilepticus severity: No impact on survival of seizure-generated neurons. Neurobiol Dis 2006; 23:23-35. [PMID: 16531049 DOI: 10.1016/j.nbd.2006.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Revised: 01/24/2006] [Accepted: 01/27/2006] [Indexed: 10/24/2022] Open
Abstract
Partial and generalized status epilepticus (pSE and gSE) trigger the same level of progenitor cell proliferation in adult dentate gyrus, but survival of new neurons is poor after gSE. Here, we show markedly elevated levels of prostaglandin E2 (PGE2) and brain-derived neurotrophic factor (BDNF) in rat hippocampal formation at 7 days following pSE but not gSE. Administration of the cyclooxygenase (COX) inhibitor flurbiprofen for 1 week, starting at day 8 post-SE, abated PGE2 and decreased BDNF levels, but did not affect survival of new neurons 4 weeks later. Thus, high PGE2 and BDNF levels induced by pSE are probably not of major importance for survival of new neurons during the first days after formation. We propose that they modulate other aspects of synaptic and cellular plasticity, and thereby may influence epileptogenesis.
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Affiliation(s)
- Maria Antonietta Ajmone-Cat
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
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Candelario-Jalil E, Akundi RS, Bhatia HS, Lieb K, Appel K, Muñoz E, Hüll M, Fiebich BL. Ascorbic acid enhances the inhibitory effect of aspirin on neuronal cyclooxygenase-2-mediated prostaglandin E2 production. J Neuroimmunol 2006; 174:39-51. [PMID: 16529823 DOI: 10.1016/j.jneuroim.2006.01.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 12/22/2005] [Accepted: 01/09/2006] [Indexed: 12/31/2022]
Abstract
Inhibition of neuronal cyclooxygenase-2 (COX-2) and hence prostaglandin E2 (PGE2) synthesis by non-steroidal anti-inflammatory drugs has been suggested to protect neuronal cells in a variety of pathophysiological situations including Alzheimer's disease and ischemic stroke. Ascorbic acid (vitamin C) has also been shown to protect cerebral tissue in a variety of experimental conditions, which has been attributed to its antioxidant capacity. In the present study, we show that ascorbic acid dose-dependently inhibited interleukin-1beta (IL-1beta)-mediated PGE2 synthesis in the human neuronal cell line, SK-N-SH. Furthermore, in combination with aspirin, ascorbic acid augmented the inhibitory effect of aspirin on PGE2 synthesis. However, ascorbic acid had no synergistic effect along with other COX inhibitors (SC-58125 and indomethacin). The inhibition of IL-1beta-mediated PGE2 synthesis by ascorbic acid was not due to the inhibition of the expression of COX-2 or microsomal prostaglandin E synthase (mPGES-1). Rather, ascorbic acid dose-dependently (0.1-100 microM) produced a significant reduction in IL-1beta-mediated production of 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha), a reliable indicator of free radical formation, suggesting that the effects of ascorbic acid on COX-2-mediated PGE2 biosynthesis may be the result of the maintenance of the neuronal redox status since COX activity is known to be enhanced by oxidative stress. Our results provide in vitro evidence that the neuroprotective effects of ascorbic acid may depend, at least in part, on its ability to reduce neuronal COX-2 activity and PGE2 synthesis, owing to its antioxidant properties. Further, these experiments suggest that a combination of aspirin with ascorbic acid constitutes a novel approach to render COX-2 more sensitive to inhibition by aspirin, allowing an anti-inflammatory therapy with lower doses of aspirin, thereby avoiding the side effects of the usually high dose aspirin treatment.
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Affiliation(s)
- Eduardo Candelario-Jalil
- Neurochemistry Research Group, Department of Psychiatry, University of Freiburg Medical School, Hauptstrasse 5, D-79104 Freiburg, Germany
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Seifert G, Schilling K, Steinhäuser C. Astrocyte dysfunction in neurological disorders: a molecular perspective. Nat Rev Neurosci 2006; 7:194-206. [PMID: 16495941 DOI: 10.1038/nrn1870] [Citation(s) in RCA: 565] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent work on glial cell physiology has revealed that glial cells, and astrocytes in particular, are much more actively involved in brain information processing than previously thought. This finding has stimulated the view that the active brain should no longer be regarded solely as a network of neuronal contacts, but instead as a circuit of integrated, interactive neurons and glial cells. Consequently, glial cells could also have as yet unexpected roles in the diseased brain. An improved understanding of astrocyte biology and heterogeneity and the involvement of these cells in pathogenesis offers the potential for developing novel strategies to treat neurological disorders.
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Affiliation(s)
- Gerald Seifert
- Department of Experimental Neurobiology, Clinic of Neurosurgery, University of Bonn, Germany
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Cassano P, Hidalgo A, Burgos V, Adris S, Argibay P. Hippocampal upregulation of the cyclooxygenase-2 gene following neonatal clomipramine treatment (a model of depression). THE PHARMACOGENOMICS JOURNAL 2006; 6:381-7. [PMID: 16568149 DOI: 10.1038/sj.tpj.6500385] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although a putative role has been attributed to inflammation in the pathogenesis of depressive disorders, the relationship of prostaglandins, known mediators of inflammation, and depression has not been elucidated. Clomipramine is an antidepressive drug with a pro-depressive paradoxical effect in adult rats when administrated neonatally. Using this effect as a model of depression, we investigated the differential expression of the cyclooxygenase (COX-2) gene in rat brains. Rats injected neonatally with clomipramine showed depressive-like symptoms in adulthood, as well as decreased levels of the brain-derived neurotrophic factor (BDNF) and a quantitative differential expression of the COX-2 gene (Real Time PCR) and protein (immunohistochemistry) in the hippocampus. As evidenced, the relationship between a key enzyme in the prostaglandin synthesis and biological and behavioral depression-like changes opens an interesting line of investigation regarding the molecular bases of depression and its potential treatment through immunomodulatory drugs.
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Affiliation(s)
- P Cassano
- Unit of Brain Research, Instituto de Ciencias Básicas y Medicina Experimental del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
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