151
|
Regional Susceptibility to Domoic Acid in Primary Astrocyte Cells Cultured from the Brain Stem and Hippocampus. Mar Drugs 2008. [DOI: 10.3390/md6010025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
|
152
|
Gill SS, Hou Y, Ghane T, Pulido OM. Regional susceptibility to domoic acid in primary astrocyte cells cultured from the brain stem and hippocampus. Mar Drugs 2008; 6:25-38. [PMID: 18648670 PMCID: PMC2474954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/23/2008] [Accepted: 02/09/2008] [Indexed: 11/26/2022] Open
Abstract
Domoic acid is a marine biotoxin associated with harmful algal blooms and is the causative agent of amnesic shellfish poisoning in marine animals and humans. It is also an excitatory amino acid analog to glutamate and kainic acid which acts through glutamate receptors eliciting a very rapid and potent neurotoxic response. The hippocampus, among other brain regions, has been identified as a specific target site having high sensitivity to DOM toxicity. Histopathology evidence indicates that in addition to neurons, the astrocytes were also injured. Electron microscopy data reported in this study further supports the light microscopy findings. Furthermore, the effect of DOM was confirmed by culturing primary astrocytes from the hippocampus and the brain stem and subsequently exposing them to domoic acid. The RNA was extracted and used for biomarker analysis. The biomarker analysis was done for the early response genes including c-fos, c-jun, c-myc, Hsp-72; specific marker for the astrocytes- GFAP and the glutamate receptors including GluR 2, NMDAR 1, NMDAR 2A and B. Although, the astrocyte-GFAP and c-fos were not affected, c-jun and GluR 2 were down-regulated. The microarray analysis revealed that the chemokines / cytokines, tyrosine kinases (Trk), and apoptotic genes were altered. The chemokines that were up-regulated included - IL1-alpha, IL-Beta, IL-6, the small inducible cytokine, interferon protein 10P-10, CXC chemokine LIX, and IGF binding proteins. The Bax, Bcl-2, Trk A and Trk B were all down-regulated. Interestingly, only the hippocampal astrocytes were affected. Our findings suggest that astrocytes may present a possible target for pharmacological interventions for the prevention and treatment of amnesic shellfish poisoning and for other brain pathologies involving excitotoxicity.
Collapse
Affiliation(s)
- Santokh S. Gill
- Toxicology Research Division, Food Directorate, Health Products and Foods Branch, Banting Research Center, P.L. 2202D2, Tunney’s Pasture, Ottawa, ON, Canada, K1A 0L22 E-mail:
(S. G.). E-mail:
(Y. H.). E-mail:
(O. P.)
| | - Yangxun Hou
- Toxicology Research Division, Food Directorate, Health Products and Foods Branch, Banting Research Center, P.L. 2202D2, Tunney’s Pasture, Ottawa, ON, Canada, K1A 0L22 E-mail:
(S. G.). E-mail:
(Y. H.). E-mail:
(O. P.)
| | - Talat Ghane
- Department of Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Enghelab Avenue, Tehran, Iran 14174, P.O. Box: 14155/6451
| | - Olga M. Pulido
- Toxicology Research Division, Food Directorate, Health Products and Foods Branch, Banting Research Center, P.L. 2202D2, Tunney’s Pasture, Ottawa, ON, Canada, K1A 0L22 E-mail:
(S. G.). E-mail:
(Y. H.). E-mail:
(O. P.)
| |
Collapse
|
153
|
Chen MK, Guilarte TR. Translocator protein 18 kDa (TSPO): molecular sensor of brain injury and repair. Pharmacol Ther 2008; 118:1-17. [PMID: 18374421 DOI: 10.1016/j.pharmthera.2007.12.004] [Citation(s) in RCA: 401] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 12/21/2007] [Indexed: 11/25/2022]
Abstract
For over 15 years, the peripheral benzodiazepine receptor (PBR), recently named translocator protein 18 kDa (TSPO) has been studied as a biomarker of reactive gliosis and inflammation associated with a variety of neuropathological conditions. Early studies documented that in the brain parenchyma, TSPO is exclusively localized in glial cells. Under normal physiological conditions, TSPO levels are low in the brain neuropil but they markedly increase at sites of brain injury and inflammation making it uniquely suited for assessing active gliosis. This research has generated significant efforts from multiple research groups throughout the world to apply TSPO as a marker of "active" brain pathology using in vivo imaging modalities such as Positron Emission Tomography (PET) in experimental animals and humans. Further, in the last few years, there has been an increased interest in understanding the molecular and cellular function(s) of TSPO in glial cells. The latest evidence suggests that TSPO may not only serve as a biomarker of active brain disease but also the use of TSPO-specific ligands may have therapeutic implications in brain injury and repair. This review presents an overview of the history and function of TSPO focusing on studies related to its use as a sensor of active brain disease in experimental animals and in human studies.
Collapse
Affiliation(s)
- Ming-Kai Chen
- Neurotoxicology & Molecular Imaging Laboratory, Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
154
|
Simões P, Silva A, Pereira F, Marques E, Grade S, Milhazes N, Borges F, Ribeiro C, Macedo T. Methamphetamine induces alterations on hippocampal NMDA and AMPA receptor subunit levels and impairs spatial working memory. Neuroscience 2007; 150:433-41. [DOI: 10.1016/j.neuroscience.2007.09.044] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/28/2007] [Accepted: 09/11/2007] [Indexed: 11/27/2022]
|
155
|
Zou W, Kim BO, Zhou BY, Liu Y, Messing A, He JJ. Protection against human immunodeficiency virus type 1 Tat neurotoxicity by Ginkgo biloba extract EGb 761 involving glial fibrillary acidic protein. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1923-35. [PMID: 18055541 DOI: 10.2353/ajpath.2007.070333] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human immunodeficiency virus (HIV)-1 Tat protein is an important pathogenic factor in HIV-associated neuropathogenesis. Despite recent progress, the molecular mechanisms underlying Tat neurotoxicity are still not completely understood. However, few therapeutics have been developed to specifically target HIV infection in the brain. Recent development of an inducible brain-specific Tat transgenic mouse model has made it possible to define the mechanisms of Tat neurotoxicity and evaluate anti-neuroAIDS therapeutic candidates in the context of a whole organism. Herein, we demonstrate that administration of EGb 761, a standardized formulation of Ginkgo biloba extract, markedly protected Tat transgenic mice from Tat-induced developmental retardation, inflammation, death, astrocytosis, and neuron loss. EGb 761 directly down-regulated glial fibrillary acidic protein (GFAP) expression at both protein and mRNA levels. This down-regulation was, at least in part, attributable to direct effects of EGb 761 on the interactions of the AP1 and NF-kappaB transcription factors with the GFAP promoter. Most strikingly, Tat-induced neuropathological phenotypes including macrophage/microglia activation, central nervous system infiltration of T lymphocytes, and oxidative stress were significantly alleviated in GFAP-null/Tat transgenic mice. Taken together, these results provide the first evidence to support the potential for clinical use of EGb 761 to treat HIV-associated neurological diseases. Moreover, these findings suggest for the first time that GFAP activation is directly involved in Tat neurotoxicity, supporting the notion that astrocyte activation or astrocytosis may directly contribute to HIV-associated neurological disorders.
Collapse
Affiliation(s)
- Wei Zou
- Department of Microbiology and Immunology, Indiana University School of Medicine, R2 302, 950 W. Walnut St., Indianapolis, IN 46202, USA
| | | | | | | | | | | |
Collapse
|
156
|
Abstract
BACKGROUND HIV can reside in the brain for many years. While astrocytes are known to tolerate long-term HIV infection, the potential of other neural cell types to harbour HIV is unclear. OBJECTIVE To investigate whether HIV can persist in neural progenitor cell populations. DESIGN A multipotent human neural stem cell line (HNSC.100) was used to compare HIV infection in neural progenitor and astrocyte cell populations. METHODS Expression of cellular genes/proteins was analysed by real-time reverse transcriptase PCR, Western blot, immunocytochemistry and flow cytometry. Morphological properties of cells were measured by quantitative fluorescent image analysis. Virus release by cells exposed to HIV-1IIIB was monitored by enzyme-linked immunosorbent assay for Gag. Proviral copy numbers were determined by real-time PCR and early HIV transcripts by reverse transcriptase PCR. Rev activity was determined with a fluorescent-based reporter assay. RESULTS Progenitor populations differed from astrocyte populations by showing much lower glial fibrillary acidic protein (GFAP) production, higher cell-surface expression of the CXCR4 chemokine receptor, higher Rev activity and distinct cell morphologies. HIV-exposed progenitor cultures released moderate amounts of virus for over 2 months and continued to display cell-associated HIV markers (proviral DNA, early HIV transcripts) during the entire observation period (115 days). Differentiation of HIV-infected progenitor cells to astrocytes was associated with transient activation of virus production. Long-term HIV infection of progenitor populations led to upregulation of GFAP and changes in cell morphology. CONCLUSION These studies suggest that neural progenitor populations can contribute to the reservoir for HIV in the brain and undergo changes as a consequence of HIV persistence.
Collapse
|
157
|
El-Fawal HAN, O'Callaghan JP. Autoantibodies to neurotypic and gliotypic proteins as biomarkers of neurotoxicity: assessment of trimethyltin (TMT). Neurotoxicology 2007; 29:109-15. [PMID: 18001836 DOI: 10.1016/j.neuro.2007.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 08/30/2007] [Accepted: 09/23/2007] [Indexed: 12/24/2022]
Abstract
Developing accessible biomarkers of neurotoxic effects which are readily applicable to human populations poses a challenge for neurotoxicology. In the past, the neurotoxic organometal trimethyltin (TMT) has been used as a denervation tool to validate the enhanced expression of GFAP as a biomarker of astrogliosis and neurotoxicity resulting from chemical exposures. In the present study, TMT was used to assess the detection of serum autoantibodies as biomarkers of neurotoxicity. Previous studies in both human and animals have demonstrated the presence of serum autoantibodies to neurotypic [e.g., neurofilament triplet (NF)] and gliotypic proteins [myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP)] as a peripheral marker of neurodegeneration that may be applicable to humans and experimental studies. Male Long-Evans rats (45 days of age) were administered either TMT (8 mg/kg; s) or an equal volume of sterile 0.9% saline. At 1, 2, and 3 weeks post-administration, serum was collected, and rats were sacrificed for the collection of brains. Serum autoantibodies (both IgM and IgG isotypes) to NF68, NF160, NF200, MBP, and GFAP were assayed using an ELISA. Saline only rats did not have detectable levels of autoantibodies. Only sera from TMT-exposed rats had detectable titers of autoantibodies to NFs with IgG predominating starting week 2. Anti-NF68 titers were highest compared to NF160, or NF200. Autoantibodies to MBP and GFAP also were detected; however, there was no significant increase in their titers until week 3. Hippocampal GFAP, detected at these time points, was significantly (p<0.05) higher than in control brains, indicating the induction of astrogliosis as confirmed by immunostaining of brain sections. The detection of anti-NFs, as indicative of neuronal insult, was consistent with loss of hippocampal neurons in CA3 and CA1. Our results suggest that the detection of autoantibodies to neurotypic and gliotypic proteins may be used as peripheral biomarkers to reveal evidence of nervous system neurotoxicity.
Collapse
Affiliation(s)
- Hassan A N El-Fawal
- Neurotoxicology Laboratory, Division of Health Professions and Natural Sciences, Mercy College, 555 Broadway, Dobbs Ferry, NY 10522, USA.
| | | |
Collapse
|
158
|
Monnet-Tschudi F, Zurich MG, Honegger P. Neurotoxicant-induced inflammatory response in three-dimensional brain cell cultures. Hum Exp Toxicol 2007; 26:339-46. [PMID: 17615115 DOI: 10.1177/0960327107074589] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Brain inflammatory response is triggered by the activation of microglial cells and astrocytes in response to various types of CNS injury, including neurotoxic insults. Its outcome is determined by cellular interactions, inflammatory mediators, as well as trophic and/or cytotoxic signals, and depends on many additional factors such as the intensity and duration of the insult, the extent of both the primary neuronal damage and glial reactivity and the developmental stage of the brain. Depending on particular circumstances, the brain inflammatory response can promote neuroprotection, regeneration or neurodegeneration. Glial reactivity, regarded as the central phenomenon of brain inflammation, has also been used as an early marker of neurotoxicity. To study the mechanisms underlying the glial reactivity, serum-free aggregating brain cell cultures were used as an in vitro model to test the effects of conventional neurotoxicants such as organophosphate pesticides, heavy metals, excitotoxins and mycotoxins. This approach was found to be relevant and justified by the complex cell-cell interactions involved in the brain inflammatory response, the variability of the glial reactions and the multitude of mediators involved. All these variables need to be considered for the elucidation of the specific cellular and molecular reactions and their consequences caused by a given chemical insult.
Collapse
Affiliation(s)
- F Monnet-Tschudi
- Department of Physiology, University of Lausanne, Lausanne, Switzerland.
| | | | | |
Collapse
|
159
|
Esposito G, Scuderi C, Savani C, Steardo L, De Filippis D, Cottone P, Iuvone T, Cuomo V, Steardo L. Cannabidiol in vivo blunts beta-amyloid induced neuroinflammation by suppressing IL-1beta and iNOS expression. Br J Pharmacol 2007; 151:1272-9. [PMID: 17592514 PMCID: PMC2189818 DOI: 10.1038/sj.bjp.0707337] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Pharmacological inhibition of beta-amyloid (Abeta) induced reactive gliosis may represent a novel rationale to develop drugs able to blunt neuronal damage and slow the course of Alzheimer's disease (AD). Cannabidiol (CBD), the main non-psychotropic natural cannabinoid, exerts in vitro a combination of neuroprotective effects in different models of Abeta neurotoxicity. The present study, performed in a mouse model of AD-related neuroinflammation, was aimed at confirming in vivo the previously reported antiinflammatory properties of CBD. EXPERIMENTAL APPROACH Mice were inoculated with human Abeta (1-42) peptide into the right dorsal hippocampus, and treated daily with vehicle or CBD (2.5 or 10 mg kg(-1), i.p.) for 7 days. mRNA for glial fibrillary acidic protein (GFAP) was assessed by in situ hybridization. Protein expression of GFAP, inducible nitric oxide synthase (iNOS) and IL-1beta was determined by immunofluorescence analysis. In addition, ELISA assay of IL-1beta level and the measurement of NO were performed in dissected and homogenized ipsilateral hippocampi, derived from vehicle and Abeta inoculated mice, in the absence or presence of CBD. KEY RESULTS In contrast to vehicle, CBD dose-dependently and significantly inhibited GFAP mRNA and protein expression in Abeta injected animals. Moreover, under the same experimental conditions, CBD impaired iNOS and IL-1beta protein expression, and the related NO and IL-1beta release. CONCLUSION AND IMPLICATIONS The results of the present study confirm in vivo anti-inflammatory actions of CBD, emphasizing the importance of this compound as a novel promising pharmacological tool capable of attenuating Abeta evoked neuroinflammatory responses.
Collapse
Affiliation(s)
- G Esposito
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
| | - C Scuderi
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
| | - C Savani
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
| | - L Steardo
- Department of Psychiatry, Medical School, Second University of Naples Naples, Italy
| | - D De Filippis
- Department of Experimental Pharmacology, University of Naples Federico II Naples, Italy
| | - P Cottone
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
| | - T Iuvone
- Department of Experimental Pharmacology, University of Naples Federico II Naples, Italy
| | - V Cuomo
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
| | - L Steardo
- Department of Human Physiology and Pharmacology ‘V Erspamer', University of Rome ‘La Sapienza' Rome, Italy
- Author for correspondence:
| |
Collapse
|
160
|
Brillaud E, Piotrowski A, de Seze R. Effect of an acute 900MHz GSM exposure on glia in the rat brain: a time-dependent study. Toxicology 2007; 238:23-33. [PMID: 17624651 DOI: 10.1016/j.tox.2007.05.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 05/10/2007] [Accepted: 05/14/2007] [Indexed: 11/25/2022]
Abstract
Because of the increasing use of mobile phones, the possible risks of radio frequency electromagnetic fields adverse effects on the human brain has to be evaluated. In this work we measured GFAP expression, to evaluate glial evolution 2, 3, 6 and 10 days after a single GSM exposure (15min, brain averaged SAR=6W/kg, 900MHz signal) in the rat brain. A statistically significant increase of GFAP stained surface area was observed 2 days after exposure in the frontal cortex and the caudate putamen. A smaller statistically significant increase was noted 3 days after exposure in the same areas and in the cerebellum cortex. Our results confirm the Mausset-Bonnefont et al. study [Mausset-Bonnefont, A.L., Hirbec, H., Bonnefont, X., Privat, A., Vignon, J., de Seze, R., 2004. Acute exposure to GSM 900MHz electromagnetic fields induces glial reactivity and biochemical modifications in the rat brain. Neurobiol. Dis. 17, 445-454], showing the existence of glial reactivity after a 15min GSM acute exposure at a brain averaged SAR of 6W/kg. We conclude to a temporary effect, probably due to a hypertrophy of glial cells, with a temporal and a spatial modulation of the effect. Whether this effect could be harmful remains to be studied.
Collapse
Affiliation(s)
- Elsa Brillaud
- INERIS, Unité de Toxicologie Expérimentale, Parc Technologique ALATA, BP no. 2, 60550 Verneuil-en-Halatte, France.
| | | | | |
Collapse
|
161
|
Tramontina F, Leite MC, Cereser K, de Souza DF, Tramontina AC, Nardin P, Andreazza AC, Gottfried C, Kapczinski F, Gonçalves CA. Immunoassay for glial fibrillary acidic protein: antigen recognition is affected by its phosphorylation state. J Neurosci Methods 2007; 162:282-6. [PMID: 17303248 DOI: 10.1016/j.jneumeth.2007.01.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 12/20/2006] [Accepted: 01/04/2007] [Indexed: 11/29/2022]
Abstract
Glial fibrillary acid protein (GFAP) is used commonly as a marker of astrogliosis and astrocyte activation in several situations involving brain injury. Its content may be measured by immunocytochemistry, immunoblotting or enzyme-linked immunosorbent assay (ELISA), usually employing commercial antibodies. Two major post-translational modifications in GFAP (phosphorylation and proteolysis) may alter the interpretation of results or for immunoassay standardization. This study using a non-sandwich ELISA aimed to investigate the putative changes in the immunorecognition due to the phosphorylated state of the antigen by a routinely used polyclonal anti-GFAP antibody from DAKO. Results involving in vitro phosphorylation of purified GFAP or biological samples (brain tissue, cell culture and cerebrospinal fluid) mediated by protein kinase dependent on cAMP indicate that GFAP phosphorylation improves the recognition by the used antibody. These results provide support to the understanding of fast changes in the GFAP-immunoreactivity and suggest that caution is necessary in the interpretation of results using this antibody, as well as indicate that the effect of post-translational modifications must be considered during the standardization of immunoassays with other antibodies.
Collapse
Affiliation(s)
- Francine Tramontina
- Department of Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil
| | | | | | | | | | | | | | | | | | | |
Collapse
|
162
|
Baumann MH, Wang X, Rothman RB. 3,4-Methylenedioxymethamphetamine (MDMA) neurotoxicity in rats: a reappraisal of past and present findings. Psychopharmacology (Berl) 2007; 189:407-24. [PMID: 16541247 PMCID: PMC1705495 DOI: 10.1007/s00213-006-0322-6] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 01/07/2006] [Indexed: 12/30/2022]
Abstract
RATIONALE 3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been interpreted as neurotoxicity. Whether such 5-HT deficits reflect neuronal damage is a matter of ongoing debate. OBJECTIVE The present paper reviews four specific issues related to the hypothesis of MDMA neurotoxicity in rats: (1) the effects of MDMA on monoamine neurons, (2) the use of "interspecies scaling" to adjust MDMA doses across species, (3) the effects of MDMA on established markers of neuronal damage, and (4) functional impairments associated with MDMA-induced 5-HT depletions. RESULTS MDMA is a substrate for monoamine transporters, and stimulated release of 5-HT, NE, and DA mediates effects of the drug. MDMA produces neurochemical, endocrine, and behavioral actions in rats and humans at equivalent doses (e.g., 1-2 mg/kg), suggesting that there is no reason to adjust doses between these species. Typical doses of MDMA causing long-term 5-HT depletions in rats (e.g., 10-20 mg/kg) do not reliably increase markers of neurotoxic damage such as cell death, silver staining, or reactive gliosis. MDMA-induced 5-HT depletions are accompanied by a number of functional consequences including reductions in evoked 5-HT release and changes in hormone secretion. Perhaps more importantly, administration of MDMA to rats induces persistent anxiety-like behaviors in the absence of measurable 5-HT deficits. CONCLUSIONS MDMA-induced 5-HT depletions are not necessarily synonymous with neurotoxic damage. However, doses of MDMA which do not cause long-term 5-HT depletions can have protracted effects on behavior, suggesting even moderate doses of the drug may pose risks.
Collapse
Affiliation(s)
- Michael H Baumann
- Clinical Psychopharmacology Section, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
| | | | | |
Collapse
|
163
|
Berman JW, Carson MJ, Chang L, Cox BM, Fox HS, Gonzalez RG, Hanson GR, Hauser KF, Ho WZ, Hong JS, Major EO, Maragos WF, Masliah E, McArthur JC, Miller DB, Nath A, O’Callaghan JP, Persidsky Y, Power C, Rogers TJ, Royal W. NeuroAIDS, Drug Abuse, and Inflammation: Building Collaborative Research Activities. J Neuroimmune Pharmacol 2006; 1:351-99. [DOI: 10.1007/s11481-006-9048-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Accepted: 09/18/2006] [Indexed: 12/25/2022]
|
164
|
Antonini JM, O'Callaghan JP, Miller DB. Development of an animal model to study the potential neurotoxic effects associated with welding fume inhalation. Neurotoxicology 2006; 27:745-51. [PMID: 16546258 DOI: 10.1016/j.neuro.2006.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 01/20/2006] [Accepted: 01/21/2006] [Indexed: 11/20/2022]
Abstract
Serious questions have been raised regarding a possible causal association between neurological effects in welders and the presence of manganese in welding fume. An experimental model is needed that could examine the potential neurotoxic effect of manganese after pulmonary exposure to welding fume. The National Institute for Occupational Safety and Health (NIOSH) has recently finished construction of a completely automated, computer controlled welding fume generation and inhalation exposure system for laboratory animals. The system is comprised of a programmable six-axis robotic welding arm and a water-cooled arc welding torch. A flexible trunk has been attached to the robotic arm of the welder and is used to collect and transport fume from the vicinity of the arc to the animal exposure chamber. Preliminary fume characterization studies have indicated that particle morphology, size, and chemical composition were comparable to welding fume generated in the workplace. Animal inhalation studies are currently underway. With the development of this novel system, an animal model has been established using controlled welding exposures to investigate the possible mechanisms by which welding fume may affect the central nervous system.
Collapse
Affiliation(s)
- James M Antonini
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA.
| | | | | |
Collapse
|
165
|
Gordh T, Chu H, Sharma HS. Spinal nerve lesion alters blood-spinal cord barrier function and activates astrocytes in the rat. Pain 2006; 124:211-21. [PMID: 16806707 DOI: 10.1016/j.pain.2006.05.020] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2005] [Revised: 05/16/2006] [Accepted: 05/22/2006] [Indexed: 01/23/2023]
Abstract
Alterations in the spinal cord microenvironment in a neuropathic pain model in rats comprising right L-4 spinal nerve lesion were examined following 1, 2, 4 and 10 weeks using albumin and glial fibrillary acidic protein (GFAP) immunoreactivity. Rats subjected to nerve lesion showed pronounced activation of GFAP indicating astrocyte activation, and exhibited marked leakage of albumin, suggesting defects of the blood-spinal cord barrier (BSCB) function in the corresponding spinal cord segment. The intensities of these changes were most prominent in the gray matter of the lesioned side compared to the contralateral cord in both the dorsal and ventral horns. The most marked changes in albumin and GFAP immunoreaction were seen after 2 weeks and persisted with mild intensities even after 10 weeks. Distortion of nerve cells, loss of neurons and general sponginess were evident in the gray matter of the spinal cord corresponding to the lesion side. These nerve cell and glial cell changes was mainly evident in the areas showing leakage of endogenous albumin in the spinal cord. These novel observations indicate that chronic nerve lesion has the capacity to induce a selective increase in local BSCB permeability that could be instrumental in nerve cell and glial cell activation. These findings may be relevant to our current understanding on the pathophysiology of neuropathic pain.
Collapse
Affiliation(s)
- Torsten Gordh
- Laboratory of Pain Research, Department of Surgical Sciences, Division of Anaesthesiology and Intensive Care Medicine, Uppsala University Hospital, SE-75185, Uppsala, Sweden
| | | | | |
Collapse
|
166
|
Quinton MS, Yamamoto BK. Causes and consequences of methamphetamine and MDMA toxicity. AAPS JOURNAL 2006; 8:E337-47. [PMID: 16796384 PMCID: PMC3231568 DOI: 10.1007/bf02854904] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Methamphetamine (METH) and its derivative 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) are 2 substituted amphetamines with very high abuse liability in the United States. These amphetamine-like stimulants have been associated with loss of multiple markers for dopaminergic and serotonergic terminals in the brain. Among other causes, oxidative stress, excitotoxicity and mitochondrial dysfunction appear to play a major role in the neurotoxicity produced by the substituted amphetamines. The present review will focus on these events and how they interact and converge to produce the monoaminergic depletions that are typically observed after METH or MDMA administration. In addition, more recently identified consequences of METH or MDMA-induced oxidative stress, excitotoxicity, and mitochondrial dysfunction are described in relation to the classical markers of METH-induced damage to dopamine terminals.
Collapse
Affiliation(s)
- Maria S. Quinton
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Room L-613, 715 Albany Street, 02118 Boston, MA
| | - Bryan K. Yamamoto
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Room L-613, 715 Albany Street, 02118 Boston, MA
| |
Collapse
|
167
|
Monnet-Tschudi F, Zurich MG, Boschat C, Corbaz A, Honegger P. Involvement of environmental mercury and lead in the etiology of neurodegenerative diseases. REVIEWS ON ENVIRONMENTAL HEALTH 2006; 21:105-17. [PMID: 16898674 DOI: 10.1515/reveh.2006.21.2.105] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The incidence of neurodegenerative disease like Parkinson's disease and Alzheimer's disease (AD) increases dramatically with age; only a small percentage is directly related to familial forms. The etiology of the most abundant, sporadic forms is complex and multifactorial, involving both genetic and environmental factors. Several environmental pollutants have been associated with neurodegenerative disorders. The present article focuses on results obtained in experimental neurotoxicology studies that indicate a potential pathogenic role of lead and mercury in the development of neurodegenerative diseases. Both heavy metals have been shown to interfere with a multitude of intracellular targets, thereby contributing to several pathogenic processes typical of neurodegenerative disorders, including mitochondrial dysfunction, oxidative stress, deregulation of protein turnover, and brain inflammation. Exposure to heavy metals early in development can precondition the brain for developing a neurodegenerative disease later in life. Alternatively, heavy metals can exert their adverse effects through acute neurotoxicity or through slow accumulation during prolonged periods of life. The pro-oxidant effects of heavy metals can exacerbate the age-related increase in oxidative stress that is related to the decline of the antioxidant defense systems. Brain inflammatory reactions also generate oxidative stress. Chronic inflammation can contribute to the formation of the senile plaques that are typical for AD. In accord with this view, nonsteroidal anti-inflammatory drugs and antioxidants suppress early pathogenic processes leading to Alzheimer's disease, thus decreasing the risk of developing the disease. The effects of lead and mercury were also tested in aggregating brain-cell cultures of fetal rat telencephalon, a three-dimensional brain-cell culture system. The continuous application for 10 to 50 days of non-cytotoxic concentrations of heavy metals resulted in their accumulation in brain cells and the occurrence of delayed toxic effects. When applied at non-toxic concentrations, methylmercury, the most common environmental form of mercury, becomes neurotoxic under pro-oxidant conditions. Furthermore, lead and mercury induce glial cell reactivity, a hallmark of brain inflammation. Both mercury and lead increase the expression of the amyloid precursor protein; mercury also stimulates the formation of insoluble beta-amyloid, which plays a crucial role in the pathogenesis of AD and causes oxidative stress and neurotoxicity in vitro. Taken together, a considerable body of evidence suggests that the heavy metals lead and mercury contribute to the etiology of neurodegenerative diseases and emphasizes the importance of taking preventive measures in this regard.
Collapse
|
168
|
Wang X, Baumann MH, Xu H, Morales M, Rothman RB. (±)-3,4-Methylenedioxymethamphetamine Administration to Rats Does Not Decrease Levels of the Serotonin Transporter Protein or Alter Its Distribution between Endosomes and the Plasma Membrane. J Pharmacol Exp Ther 2005; 314:1002-12. [PMID: 15937150 DOI: 10.1124/jpet.105.088476] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We showed that the serotonin (5-HT) neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) reduces brain tissue 5-HT, decreases expression of 5-HT transporter (SERT) protein, and increases expression of glial fibrillary acidic protein (GFAP). In contrast, doses of (+/-)-3,4-methylenedioxymethamphetamine (MDMA) that decrease brain tissue 5-HT fail to alter expression of SERT or GFAP. Using a new and highly sensitive anti-SERT antibody, we determined whether MDMA alters the subcellular distribution of SERT protein by measuring SERT expression in endosomes and plasma membranes 2 weeks after MDMA administration. Rat brain tissues (caudate, cortex, and hippocampus) were collected 3 days and 2 weeks after MDMA (7.5 mg/kg i.p., every 2 h x 3 doses) or 5,7-DHT (150 microg/rat i.c.v.) administration. Representative results from cortex are as follows. At both 3 days and 2 weeks postinjection, MDMA decreased tissue 5-HT (65%) and had no effect on GFAP expression. MDMA increased heat shock protein 32 (HSP32; a marker for microglial activation) expression (30%) at 3 days, but not 2 weeks. MDMA did not alter SERT expression at either time point and did not alter SERT levels in either endosomes or plasma membranes (2 weeks). 5,7-DHT decreased tissue 5-HT (80%), increased HSP32 expression at both time points (about 50%), and increased GFAP expression at 2 weeks (40%). 5,7-DHT decreased SERT expression (33%) at 2 weeks, but not at 3 days. These findings indicate that a dosing regimen of MDMA that depletes brain 5-HT does not alter SERT protein expression or the distribution of SERT between endosomes and the plasma membrane and does not produce detectable evidence for neurotoxicity.
Collapse
Affiliation(s)
- Xiaoying Wang
- Clinical Psychopharmacology Section, Intramural Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland, USA
| | | | | | | | | |
Collapse
|