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Galkina OV, Bakhtyukov AA, Akhmetshin MO, Prokopenko VM, Eshchenko ND. The glutathione system in the subcellular fractions of developing rat brain and liver. NEUROCHEM J+ 2017. [DOI: 10.1134/s1819712417030047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Attoff K, Kertika D, Lundqvist J, Oredsson S, Forsby A. Acrylamide affects proliferation and differentiation of the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y. Toxicol In Vitro 2016; 35:100-11. [PMID: 27241584 DOI: 10.1016/j.tiv.2016.05.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 05/08/2016] [Accepted: 05/26/2016] [Indexed: 10/21/2022]
Abstract
Acrylamide is a well-known neurotoxic compound and people get exposed to the compound by food consumption and environmental pollutants. Since acrylamide crosses the placenta barrier, the fetus is also being exposed resulting in a risk for developmental neurotoxicity. In this study, the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y were used to study proliferation and differentiation as alerting indicators for developmental neurotoxicity. For both cell lines, acrylamide reduced the number of viable cells by reducing proliferation and inducing cell death in undifferentiated cells. Acrylamide concentrations starting at 10fM attenuated the differentiation process in SH-SY5Y cells by sustaining cell proliferation and neurite outgrowth was reduced at concentrations from 10pM. Acrylamide significantly reduced the number of neurons starting at 1μM and altered the ratio between the different phenotypes in differentiating C17.2 cell cultures. Ten micromolar of acrylamide also reduced the expression of the neuronal and astrocyte biomarkers. Although the neurotoxic concentrations in the femtomolar range seem to be specific for the SH-SY5Y cell line, the fact that micromolar concentrations of acrylamide seem to attenuate the differentiation process in both cell lines raises the interest to further investigations on the possible developmental neurotoxicity of acrylamide.
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Affiliation(s)
- K Attoff
- Department of Neurochemistry, Stockholm University, Stockholm 106 91, Sweden.
| | - D Kertika
- Department of Neurochemistry, Stockholm University, Stockholm 106 91, Sweden.
| | - J Lundqvist
- Department of Neurochemistry, Stockholm University, Stockholm 106 91, Sweden.
| | - S Oredsson
- Department of Biology, Lund University, Lund 223 62, Sweden.
| | - A Forsby
- Department of Neurochemistry, Stockholm University, Stockholm 106 91, Sweden; Swedish Toxicology Science Center (Swetox), Södertälje, Sweden.
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Glutathione-Dependent Detoxification Processes in Astrocytes. Neurochem Res 2014; 40:2570-82. [PMID: 25428182 DOI: 10.1007/s11064-014-1481-1] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 11/10/2014] [Accepted: 11/15/2014] [Indexed: 01/17/2023]
Abstract
Astrocytes have a pivotal role in brain as partners of neurons in homeostatic and metabolic processes. Astrocytes also protect other types of brain cells against the toxicity of reactive oxygen species and are considered as first line of defence against the toxic potential of xenobiotics. A key component in many of the astrocytic detoxification processes is the tripeptide glutathione (GSH) which serves as electron donor in the GSH peroxidase-catalyzed reduction of peroxides. In addition, GSH is substrate in the detoxification of xenobiotics and endogenous compounds by GSH-S-transferases which generate GSH conjugates that are efficiently exported from the cells by multidrug resistance proteins. Moreover, GSH reacts with the reactive endogenous carbonyls methylglyoxal and formaldehyde to intermediates which are substrates of detoxifying enzymes. In this article we will review the current knowledge on the GSH metabolism of astrocytes with a special emphasis on GSH-dependent detoxification processes.
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Merzoug S, Toumi ML, Tahraoui A. Quercetin mitigates Adriamycin-induced anxiety- and depression-like behaviors, immune dysfunction, and brain oxidative stress in rats. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:921-33. [DOI: 10.1007/s00210-014-1008-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/10/2014] [Indexed: 12/11/2022]
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Galkina OV. The specific features of free-radical processes and the antioxidant defense in the adult brain. NEUROCHEM J+ 2013. [DOI: 10.1134/s1819712413020025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Adriamycin-related anxiety-like behavior, brain oxidative stress and myelotoxicity in male Wistar rats. Pharmacol Biochem Behav 2011; 99:639-47. [DOI: 10.1016/j.pbb.2011.06.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 06/08/2011] [Accepted: 06/10/2011] [Indexed: 11/20/2022]
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Schmidt MM, Dringen R. Fumaric acid diesters deprive cultured primary astrocytes rapidly of glutathione. Neurochem Int 2010; 57:460-7. [DOI: 10.1016/j.neuint.2010.01.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 11/24/2009] [Accepted: 01/13/2010] [Indexed: 12/18/2022]
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Schmidt MM, Rohwedder A, Dringen R. Effects of Chlorinated Acetates on the Glutathione Metabolism and on Glycolysis of Cultured Astrocytes. Neurotox Res 2010; 19:628-37. [DOI: 10.1007/s12640-010-9209-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/29/2010] [Accepted: 07/01/2010] [Indexed: 01/05/2023]
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Bokara KK, Blaylock I, Denise SB, Bettaiya R, Rajanna S, Yallapragada PR. Influence of lead acetate on glutathione and its related enzymes in different regions of rat brain. J Appl Toxicol 2010; 29:452-8. [PMID: 19263481 DOI: 10.1002/jat.1423] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This study is intended to determine the effect of lead acetate on glutathione and its associated enzymes of rat brain. Wistar male rats were treated with lead acetate (500 ppm) through drinking water for a period of 8 weeks and parallel controls were maintained. They were sacrificed at the first, fourth and eighth week to isolate whole brains, which were separated into cerebellum, hippocampus, frontal cortex and brain stem. The data indicate enhanced (P < 0.05) glutathione peroxidase (G-Px) activity at most of the intervals for cerebellum, frontal cortex and brain stem, suggesting conversion of GSH to GSSG, while the hippocampus showed decreased levels. In contrast, glutathione reductase (GR) decreased significantly (P < 0.05) in cerebellum, frontal cortex and brain stem at all intervals except the fourth week in frontal cortex and brain stem. Hippocampus exhibited a gradual and significant (P < 0.05) increase in GR activity. Glutathione-S-transferase (GSTase) activity increased with exposure time in all four brain tissues, showing protection against lead acetate toxicity. The GSH and GSSG levels correlated well with the activities of GPx, GR and GSTase in all four regions of the brain. Overall the results indicate that lead acetate affects glutathione-related enzymes differentially and these changes can be attributed to differences in tissue susceptibility.
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Shikano N, Ogura M, Sagara JI, Nakajima S, Kobayashi M, Baba T, Yamaguchi N, Iwamura Y, Kubota N, Kawai K. Stimulation of 125I-3-iodo-alpha-methyl-L-tyrosine uptake in Chinese hamster ovary (CHO-K1) cells by tyrosine esters. Nucl Med Biol 2009; 37:189-96. [PMID: 20152718 DOI: 10.1016/j.nucmedbio.2009.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 09/17/2009] [Accepted: 10/02/2009] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Transport of the amino acid analog (123)I-3-iodo-alpha-methyl-L-tyrosine, which is used in clinical SPECT imaging, occurs mainly via L-type amino acid transporter type 1 (LAT1; an amino acid exchanger). As LAT1 is highly expressed in actively proliferating tumors, we made a preliminary investigation of the effects of amino acid esters on enhancement of (125)I-3-iodo-alpha-methyl-L-tyrosine (IMT) uptake via LAT1 in Chinese hamster ovary (CHO-K1) cells. METHODS Because the sequence of the CHO-K1 LAT1 gene is not available, we confirmed LAT1 expression through IMT (18.5 kBq) uptake mechanisms using specific inhibitors. L-Gly, L-Ser, L-Leu, L-Phe, L-Met, L-Tyr, D-Tyr, L-Val and L-Lys ethyl/methyl esters were tested in combination with IMT. Time-course studies over a 3-h period were conducted, and the concentration dependence of L-Tyr ethyl and methyl esters (0.001 to 10 mM) in combination with IMT was also examined. For a proof of de-esterification of L- and D-Tyr ethyl and methyl esters in the cells (by enzymatic attack or other cause), the concentration of L- and D-Tyr was analyzed by high-performance liquid chromatography of the esters in phosphate buffer (pH 7.4) and cell homogenates at 37 degrees C or under ice-cold conditions. RESULTS Inhibition tests suggested that LAT1 is involved in IMT uptake by CHO-K1 cells. Co-administration of 1 mM of l-Tyr ethyl or methyl ester with IMT produced the greatest enhancement. The de-esterification reaction was stereo selective and temperature dependent in the homogenate. De-esterification kinetics were very fast in the homogenate and very slow in the phosphate buffer. CONCLUSIONS The L-Tyr ethyl or methyl esters were the most effective enhancers of IMT uptake into CHO-K1 cells and acted by trans-stimulation of the amino acid exchange function of LAT1. This result suggests that de-esterification in the cells may be caused by enzymatic attack. We will use IMT and L-Tyr ethyl or methyl esters to examine LAT1 function in tumor cells or tissues in vivo.
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Affiliation(s)
- Naoto Shikano
- Department of Radiological Sciences, Center for Medical Sciences and Center for Humanities and Sciences, Ibaraki Prefectural University of Health Sciences, Inashiki-gun, Ibaraki, Japan.
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Schmidt MM, Dringen R. Differential effects of iodoacetamide and iodoacetate on glycolysis and glutathione metabolism of cultured astrocytes. FRONTIERS IN NEUROENERGETICS 2009; 1:1. [PMID: 19584905 PMCID: PMC2691547 DOI: 10.3389/neuro.14.001.2009] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Accepted: 03/12/2009] [Indexed: 11/23/2022]
Abstract
Iodoacetamide (IAA) and iodoacetate (IA) have frequently been used to inhibit glycolysis, since these compounds are known for their ability to irreversibly inhibit the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). However, the consequences of a treatment with such thiol reagents on the glutathione (GSH) metabolism of brain cells have not been explored. Exposure of astroglia-rich primary cultures to IAA or IA in concentrations of up to 1 mM deprived the cells of GSH, inhibited cellular GAPDH activity, lowered cellular lactate production and caused a delayed cell death that was detectable after 90 min of incubation. However, the two thiol reagents differed substantially in their potential to deprive cellular GSH and to inhibit astrocytic glycolysis. IAA depleted the cellular GSH content more efficiently than IA as demonstrated by half-maximal effects for IAA and IA that were observed at concentrations of about 10 and 100 μM, respectively. In contrast, IA was highly efficient in inactivating GAPDH and lactate production with half-maximal effects observed already at a concentration below 100 μM, whereas IAA had to be applied in 10 times higher concentration to inhibit lactate production by 50%. These substantial differences of IAA and IA to affect GSH content and glycolysis of cultured astrocytes suggest that in order to inhibit astrocytic glycolysis without substantially compromising the cellular GSH metabolism, IA – and not IAA – should be used in low concentrations and/or for short incubation periods.
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Affiliation(s)
- Maike M Schmidt
- Center for Biomolecular Interactions Bremen, University of Bremen Bremen, Germany
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Noninvasive and quantitative assessment of the function of multidrug resistance-associated protein 1 in the living brain. J Cereb Blood Flow Metab 2009; 29:504-11. [PMID: 18985052 DOI: 10.1038/jcbfm.2008.135] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Multidrug resistance-associated protein 1 (MRP1) acts as a defense mechanism by pumping xenobiotics and endogenous metabolites out of the brain. The currently available techniques for studying brain-to-blood efflux have significant limitations related to either their invasiveness or the qualitative assessment. Here, we describe an in vivo method, which overcomes these limitations for assessing MRP1 function, using positron emission tomography (PET) and a PET probe. 6-Bromo-7-[(11)C]methylpurine was designed to readily enter the brain after intravenous administration and to be efficiently converted to its glutathione conjugate (MRP1 substrate) in situ. Dynamic PET scan provided the brain time-activity curve after injection of 6-bromo-7-[(11)C]methylpurine into mice. The efflux rate of the substrate was kinetically estimated to be 1.4 h(-1) with high precision. Moreover, knockout of Mrp1 gene caused approximately a 90% reduction of the efflux rate, compared with wild-type mice. In conclusion, our method allows noninvasive and quantitative assessment for MRP1 function in the living brain.
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Frampton JP, Shuler ML, Shain W, Hynd MR. Biomedical Technologies for in vitro Screening and Controlled Delivery of Neuroactive Compounds. Cent Nerv Syst Agents Med Chem 2008; 8:203-219. [PMID: 19079777 PMCID: PMC2600660 DOI: 10.2174/187152408785699613] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell culture models can provide information pertaining to the effective dose, toxiciology, and kinetics, for a variety of neuroactive compounds. However, many in vitro models fail to adequately predict how such compounds will perform in a living organism. At the systems level, interactions between organs can dramatically affect the properties of a compound by alteration of its biological activity or by elimination of it from the body. At the tissue level, interaction between cell types can alter the transport properties of a particular compound, or can buffer its effects on target cells by uptake, processing, or changes in chemical signaling between cells. In any given tissue, cells exist in a three-dimensional environment bounded on all sides by other cells and components of the extracellular matrix, providing kinetics that are dramatically different from the kinetics in traditional two-dimensional cell culture systems. Cell culture analogs are currently being developed to better model the complex transport and processing that occur prior to drug uptake in the CNS, and to predict blood-brain barrier permeability. These approaches utilize microfluidics, hydrogel matrices, and a variety of cell types (including lung epithelial cells, hepatocytes, adipocytes, glial cells, and neurons) to more accurately model drug transport and biological activity. Similar strategies are also being used to control both the spatial and temporal release of therapeutic compounds for targeted treatment of CNS disease.
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Affiliation(s)
- John P Frampton
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
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Erdιlyi DJ, Kámory E, Csókay B, Andrikovics H, Tordai A, Kiss C, Fιlnι-Semsei Á, Janszky I, Zalka A, Fekete G, Falus A, Kovács GT, Szalai C. Synergistic interaction of ABCB1 and ABCG2 polymorphisms predicts the prevalence of toxic encephalopathy during anticancer chemotherapy. THE PHARMACOGENOMICS JOURNAL 2007; 8:321-7. [DOI: 10.1038/sj.tpj.6500480] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Dallas S, Miller DS, Bendayan R. Multidrug Resistance-Associated Proteins: Expression and Function in the Central Nervous System. Pharmacol Rev 2006; 58:140-61. [PMID: 16714484 DOI: 10.1124/pr.58.2.3] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Drug delivery to the brain is highly restricted, since compounds must cross a series of structural and metabolic barriers to reach their final destination, often a cellular compartment such as neurons, microglia, or astrocytes. The primary barriers to the central nervous system are the blood-brain and blood-cerebrospinal fluid barriers. Through structural modifications, including the presence of tight junctions that greatly limit paracellular transport, the cells that make up these barriers restrict diffusion of many pharmaceutically active compounds. In addition, the cells that comprise the blood-brain and blood-cerebrospinal fluid barriers express multiple ATP-dependent, membrane-bound, efflux transporters, such as members of the multidrug resistance-associated protein (MRP) family, which contribute to lowered drug accumulation. A relatively new concept in brain drug distribution just beginning to be explored is the possibility that cellular components of the brain parenchyma could act as a "second" barrier to brain permeation of pharmacological agents via expression of many of the same transporters. Indeed, efflux transporters expressed in brain parenchyma may facilitate the overall export of xenobiotics from the central nervous system, essentially handing them off to the barrier tissues. We propose that these primary and secondary barriers work in tandem to limit overall accumulation and distribution of xenobiotics in the central nervous system. The present review summarizes recent knowledge in this area and emphasizes the clinical significance of MRP transporter expression in a variety of neurological disorders.
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Affiliation(s)
- Shannon Dallas
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, USA
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Willmore WG, Storey KB. Purification and properties of the glutathione S-transferases from the anoxia-tolerant turtle, Trachemys scripta elegans. FEBS J 2005; 272:3602-14. [PMID: 16008560 DOI: 10.1111/j.1742-4658.2005.04783.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glutathione S-transferases (GSTs) play critical roles in detoxification, response to oxidative stress, regeneration of S-thiolated proteins, and catalysis of reactions in nondetoxification metabolic pathways. Liver GSTs were purified from the anoxia-tolerant turtle, Trachemys scripta elegans. Purification separated a homodimeric (subunit relative molecular mass =34 kDa) and a heterodimeric (subunit relative molecular mass = 32.6 and 36.8 kDa) form of GST. The enzymes were purified 23-69-fold and 156-174-fold for homodimeric and heterodimeric GSTs, respectively. Kinetic data gathered using a variety of substrates and inhibitors suggested that both homodimeric and heterodimeric GSTs were of the alpha class although they showed significant differences in substrate affinities and responses to inhibitors. For example, homodimeric GST showed activity with known alpha class substrates, cumene hydroperoxide and p-nitrobenzylchloride, whereas heterodimeric GST showed no activity with cumene hydroperoxide. The specific activity of liver GSTs with chlorodinitrobenzene (CDNB) as the substrate was reduced by 2.6- and 8.7-fold for homodimeric and heterodimeric GSTs isolated from liver of anoxic turtles as compared with aerobic controls, suggesting an anoxia-responsive stable modification of the protein that may alter its function during natural anaerobiosis.
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Ke ZJ, Gibson GE. Selective response of various brain cell types during neurodegeneration induced by mild impairment of oxidative metabolism. Neurochem Int 2004; 45:361-9. [PMID: 15145550 DOI: 10.1016/j.neuint.2003.09.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2003] [Revised: 06/26/2003] [Accepted: 09/07/2003] [Indexed: 11/25/2022]
Abstract
Age-related neurodegenerative diseases are characterized by selective neuron loss, glial activation, inflammation and abnormalities in oxidative metabolism. Thiamine deficiency (TD) is a model of neurodegeneration induced by impairment of oxidative metabolism. TD produces a time-dependent, selective neuronal death in specific brain regions, while other cell types are either activated or unaffected. TD-induced neurodegeneration occurs first in a small, well-defined brain region, the submedial thalamic nucleus (SmTN). This discrete localization permits careful analysis of the relationship between neuronal loss and the response of other cell types. The temporal analysis of the changes in the region in combination with the use of transgenic mice permits testing of proposed mechanisms of how the interaction of neurons with other cell types produces neurodegeneration. Loss of neurons and elevation in markers of neurodegeneration are accompanied by changes in microglia including increased redox active iron, the induction of nitric oxide synthase (NOS) and hemeoxygenase-1, a marker of oxidative stress. Endothelial cells also show changes in early stages of TD including induction of intracellular adhesion molecule-1 (ICAM-1) and endothelial NOS. The number of degranulating mast cells also increases in early stages of TD. Alterations in astrocytes and neutrophils occur at later stages of TD. Studies with transgenic knockouts indicate that the endothelial cell changes are particularly important. We hypothesize that TD-induced abnormalities in oxidative metabolism promote release of neuronal inflammatory signals that activate microglia, astrocytes and endothelial cells. Although at early stages the responses of non-neuronal cells may be neuroprotective, at late phases they lead to entry of peripheral inflammatory cells into the brain and promote neurodegeneration.
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Affiliation(s)
- Zun-Ji Ke
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University at Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, USA.
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Graumann U, Reynolds R, Steck AJ, Schaeren‐Wiemers N. Molecular changes in normal appearing white matter in multiple sclerosis are characteristic of neuroprotective mechanisms against hypoxic insult. Brain Pathol 2004; 13:554-73. [PMID: 14655760 PMCID: PMC8096038 DOI: 10.1111/j.1750-3639.2003.tb00485.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Multiple sclerosis is a chronic inflammatory disease of the CNS leading to focal destruction of myelin, still the earliest changes that lead to lesion formation are not known. We have studied the gene-expression pattern of 12 samples of normal appearing white matter from 10 post-mortem MS brains. Microarray analysis revealed upregulation of genes involved in maintenance of cellular homeostasis, and in neural protective mechanisms known to be induced upon ischemic preconditioning. This is best illustrated by the upregulation of the transcription factors such as HIF-1alpha and associated PI3K/Akt signalling pathways, as well as the upregulation of their target genes such as VEGF receptor 1. In addition, a general neuroprotective reaction against oxidative stress is suggested. These molecular changes might reflect an adaptation of cells to the chronic progressive pathophysiology of MS. Alternatively, they might also indicate the activation of neural protective mechanisms allowing preservation of cellular and functional properties of the CNS. Our data introduce novel concepts of the molecular pathogenesis of MS with ischemic preconditioning as a major mechanism for neuroprotection. An increased understanding of the underlying mechanisms may lead to the development of new more specific treatment to protect resident cells and thus minimize progressive oligondendrocyte and axonal loss.
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Affiliation(s)
- Ursula Graumann
- Neurobiology, Department of Research and Neurology, University Hospital Basel, Switzerland
| | - Richard Reynolds
- Department of Neuroinflammation, Division of Neuroscience, Imperial College London, Charing Cross Campus, United Kingdom
| | - Andreas J. Steck
- Neurobiology, Department of Research and Neurology, University Hospital Basel, Switzerland
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Lafon-Cazal M, Adjali O, Galéotti N, Poncet J, Jouin P, Homburger V, Bockaert J, Marin P. Proteomic analysis of astrocytic secretion in the mouse. Comparison with the cerebrospinal fluid proteome. J Biol Chem 2003; 278:24438-48. [PMID: 12709418 DOI: 10.1074/jbc.m211980200] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Astrocytes, the most abundant cell type in the central nervous system, are intimately associated with synapses. They play a pivotal role in neuronal survival and the brain inflammatory response. Some astrocytic functions are mediated by the secretion of polypeptides. Using a proteomic approach, we have identified more than 30 proteins released by cultured astrocytes. These include proteases and protease inhibitors, carrier proteins, and antioxidant proteins. Exposing astrocytes to brefeldin A, which selectively blocks secretory vesicle assembly, suppressed the release of some of these proteins. This indicates that astrocytes secrete these proteins by a classic vesicular mechanism and others by an alternative pathway. Astrocytes isolated from different brain regions secreted a similar pattern of proteins. However, the secretion of some of them, including metalloproteinase inhibitors and apolipoprotein E, was region-specific. In addition, pro-inflammatory treatments modified the profile of astrocytic protein secretion. Finally, more than two thirds of the proteins identified in the astrocyte-conditioned medium were detectable in the mouse cerebrospinal fluid, suggesting that astrocytes contribute to the cerebrospinal fluid protein content. In conclusion, this study provides the first unbiased characterization of the major proteins released by astrocytes, which may play a crucial role in the modulation of neuronal survival and function.
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Affiliation(s)
- Mireille Lafon-Cazal
- Unité Propre CNRS 2580, 141 rue de la Cardonille, 34094 Montpellier cedex 5, France
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