701
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Sica REP, Nicola AFD, González Deniselle MC, Rodriguez G, Monachelli GMG, Peralta LM, Bettini M. Sporadic amyotrophic lateral sclerosis: new hypothesis regarding its etiology and pathogenesis suggests that astrocytes might be the primary target hosting a still unknown external agent. ARQUIVOS DE NEURO-PSIQUIATRIA 2012; 69:699-706. [PMID: 21877044 DOI: 10.1590/s0004-282x2011000500023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 04/05/2011] [Indexed: 12/11/2022]
Abstract
This article briefly describes the already known clinical features and pathogenic mechanisms underlying sporadic amyotrophic lateral sclerosis, namely excitoxicity, oxidative stress, protein damage, inflammation, genetic abnormalities and neuronal death. Thereafter, it puts forward the hypothesis that astrocytes may be the cells which serve as targets for the harmful action of a still unknown environmental agent, while neuronal death may be a secondary event following the initial insult to glial cells. The article also suggests that an emergent virus or a misfolded infectious protein might be potential candidates to accomplish this task.
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Affiliation(s)
- Roberto E P Sica
- Institute of Cardiological Investigations, Neurological Unit, School of Medicine, Buenos Aires University, Pueyrredon 1061 / piso 10, dpto. B 1118, Buenos Aires - Argentina.
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702
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Dong XX, Wang YR, Qin S, Liang ZQ, Liu BH, Qin ZH, Wang Y. p53 mediates autophagy activation and mitochondria dysfunction in kainic acid-induced excitotoxicity in primary striatal neurons. Neuroscience 2012; 207:52-64. [PMID: 22330834 DOI: 10.1016/j.neuroscience.2012.01.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 01/03/2012] [Accepted: 01/11/2012] [Indexed: 12/24/2022]
Abstract
The present study sought to investigate if p53 mediates autophagy activation and mitochondria dysfunction in primary striatal neurons in kainic acid (KA)-induced excitotoxicity. The excitotoxic model of primary striatal neurons was established with KA. The levels of p53, microtubule-associated protein 1 light chain 3 (LC3), Beclin1, and p62 were examined by Western blot and immunostaining. Autophagy activation was also determined with electron microscope. To evaluate the contribution of p53 to autophagy activation and mitochondria dysfunction in KA-induced excitotoxicity, the protein levels of LC3, Beclin1, and p62, the mitochondrial transmembrane potential and the mitochondrial Reactive oxygen species (ROS) after pretreatment with the p53 inhibitor pifithrin-alpha (PFT-α) and the autophagy inhibitor 3-methyladenine (3-MA) were analyzed. Excitotoxic neuronal injury was induced after KA treatment as demonstrated by increases in lactate dehydrogenase (LDH) leakage and was significantly inhibited by PFT-α. Western blot and immunostaining showed that the induction of p53 protein occurred in the cytosol and the nucleus. Increases in autophagic proteins LC3 and Beclin1 were observed, whereas the protein levels of p62 decreased after KA treatment. Electron microscope analysis showed increased autophagosomes in the cytoplasm. The changes in LC3, Beclin1, and p62 levels were blocked by PFT-α, PFT-μ, 3-MA, and E64d but not Z-DEVD-FMK. JC-1 staining showed the depolarization of mitochondrial membrane potential after excitotoxic insult. Mito-tracker and RedoxSensor Red CC-1 staining showed an increased production of mitochondrial ROS after excitotoxic insult. These effects were significantly suppressed after pretreatment with PFT-α and 3-MA. This study suggests that p53 mediates KA-induced autophagy activation and mitochondrial dysfunction in striatal neurons.
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Affiliation(s)
- X X Dong
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases (SZS0703), Soochow University, School of Pharmaceutical Science, Wen Jing Road, Suzhou 215123, China
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703
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Chan CB, Ye K. Phosphoinositide 3-kinase enhancer (PIKE) in the brain: is it simply a phosphoinositide 3-kinase/Akt enhancer? Rev Neurosci 2012; 23:153-61. [PMID: 22499674 DOI: 10.1515/revneuro-2011-0066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Accepted: 12/12/2011] [Indexed: 02/06/2023]
Abstract
Since its discovery in 2000, phosphoinositide 3-kinase enhancer (PIKE) has been recognized as a class of GTPase that controls the enzymatic activities of phosphoinositide 3-kinase (PI3K) and Akt in the central nervous system (CNS). However, recent studies suggest that PIKEs are not only enhancers to PI3K/Akt but also modulators to other kinases including insulin receptor tyrosine kinase and focal adhesion kinases. Moreover, they regulate transcription factors such as signal transducer and activator of transcription and nuclear factor κB. Indeed, PIKE proteins participate in multiple cellular processes including control of cell survival, brain development, memory formation, gene transcription, and metabolism. In this review, we have summarized the functions of PIKE proteins in CNS and discussed their potential implications in various neurological disorders.
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Affiliation(s)
- Chi Bun Chan
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA.
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704
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Borre Y, Bosman E, Lemstra S, Westphal KG, Olivier B, Oosting RS. Memantine partly rescues behavioral and cognitive deficits in an animal model of neurodegeneration. Neuropharmacology 2012; 62:2010-7. [PMID: 22248638 DOI: 10.1016/j.neuropharm.2011.12.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 12/05/2011] [Accepted: 12/26/2011] [Indexed: 12/21/2022]
Abstract
Memantine, a non-competitive NMDA receptor antagonist, is used for the treatment of Alzheimer's disease (AD) and off-label as an anti-depressant. Here we investigated possible anti-depressant, cognitive enhancing and neuroprotective effects of memantine in the olfactory bulbectomized (OBX) rat. OBX is used as a screening model for antidepressants and shows cognitive disturbances. In Experiment I, memantine treatment started 14 days after OBX surgery (this setup is similar to what we use for screening of potential antidepressants) and 2 days before surgery in experiment II. In both experiments, memantine (20 mg/kg, p.o) was administered once daily for 28 days. Animals were tested in the open field (locomotor activity), passive avoidance (fear learning and memory), and holeboard (spatial acquisition and memory) before and after the bulbectomy. Memantine, when administered before surgery, prevented OBX-induced hyperactivity and partly fear memory loss. These behavioral effects were present for at least 3 weeks after cessation of treatment. Memantine, however did not improve spatial memory. When administered 2 weeks after OBX surgery, memantine was ineffective in normalizing open field hyperactivity and improving cognitive deficits. Interestingly, after the animals were retrained in passive avoidance, memantine- treated OBX rats (both in experiment I and II) showed improved fear learning and memory. Our findings suggest that memantine has both neuroprotective and cognitive enhancing effects without antidepressant-like properties in the OBX rat. Based on our results, we propose that memantine may be more beneficial to AD patients when administered early in the disease process.
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Affiliation(s)
- Yuliya Borre
- Department of Pharmacology, Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.
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705
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Roberto E. Sporadic Amyotrophic Lateral Sclerosis: Brief Pathogenic Review and a New Causal Hypothesis. Biocybern Biomed Eng 2012. [DOI: 10.1016/s0208-5216(12)70046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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706
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Effects of chronic guanosine treatment on hippocampal damage and cognitive impairment of rats submitted to chronic cerebral hypoperfusion. Neurol Sci 2011; 33:985-97. [PMID: 22167652 DOI: 10.1007/s10072-011-0872-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 11/23/2011] [Indexed: 01/22/2023]
Abstract
Chronic cerebral hypoperfusion contributes to a cognitive decline related to brain disorders. Its experimental model in rats is a permanent bilateral common carotid artery occlusion (2VO). Overstimulation of the glutamatergic system excitotoxicity due to brain energetic disturbance in 2VO animals seems to play a pivotal role as a mechanism of cerebral damage. The nucleoside guanosine (GUO) exerts extracellular effects including antagonism of glutamatergic activity. Accordingly, our group demonstrated several neuroprotective effects of GUO against glutamatergic excitotoxicity. Therefore, in this study, we evaluated a chronic GUO treatment effects in rats submitted to 2VO. We evaluated the animals performance in the Morris water maze and hippocampal damage by neurons and astrocytes immunohistochemistry. In addition, we investigated the cerebrospinal fluid (CSF) brain derived neurotrophic factor (BDNF) and serum S100B levels. Additionally, the purine CSF and plasma levels were determined. GUO treatment did not prevent the cognitive impairment promoted by 2VO. However, none of the 2VO animals treated with GUO showed differences in the hippocampal regions compared to control, while 20% of 2VO rats not treated with GUO presented loss of pyramidal neurons and increased glial labeling cells in CA1 hippocampal region. In addition, we did not observe differences in CSF BDNF nor serum S100B levels among the groups. Of note, both the 2VO surgery and GUO treatment changed the purine CSF and plasma profile. In conclusion, GUO treatment did not prevent the cognitive impairment observed in 2VO animals, but our data suggest that GUO could be neuroprotective against hippocampal damage induced by 2VO.
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707
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Jafari P, Braissant O, Bonafé L, Ballhausen D. The unsolved puzzle of neuropathogenesis in glutaric aciduria type I. Mol Genet Metab 2011; 104:425-37. [PMID: 21944461 DOI: 10.1016/j.ymgme.2011.08.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/23/2011] [Accepted: 08/23/2011] [Indexed: 12/22/2022]
Abstract
Glutaric aciduria type I (GA-I) is a cerebral organic aciduria caused by deficiency of glutaryl-Co-A dehydrogenase (GCDH). GCDH deficiency leads to accumulation of glutaric acid (GA) and 3-hydroxyglutaric acid (3-OHGA), two metabolites that are believed to be neurotoxic, in brain and body fluids. The disorder usually becomes clinically manifest during a catabolic state (e.g. intercurrent illness) with an acute encephalopathic crisis that results in striatal necrosis and in a permanent dystonic-dyskinetic movement disorder. The results of numerous in vitro and in vivo studies have pointed to three main mechanisms involved in the metabolite-mediated neuronal damage: excitotoxicity, impairment of energy metabolism and oxidative stress. There is evidence that during a metabolic crisis GA and its metabolites are produced endogenously in the CNS and accumulate because of limiting transport mechanisms across the blood-brain barrier. Despite extensive experimental work, the relative contribution of the proposed pathogenic mechanisms remains unclear and specific therapeutic approaches have yet to be developed. Here, we review the experimental evidence and try to delineate possible pathogenetic models and approaches for future studies.
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Affiliation(s)
- Paris Jafari
- Inborn Errors of Metabolism, Molecular Pediatrics, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1011 Lausanne, Switzerland
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708
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Bodai L, Marsh JL. A novel target for Huntington's disease: ERK at the crossroads of signaling. Bioessays 2011; 34:142-8. [DOI: 10.1002/bies.201100116] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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709
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Golechha M, Bhatia J, Ojha S, Arya DS. Hydroalcoholic extract of Emblica officinalis protects against kainic acid-induced status epilepticus in rats: evidence for an antioxidant, anti-inflammatory, and neuroprotective intervention. PHARMACEUTICAL BIOLOGY 2011; 49:1128-1136. [PMID: 21749189 DOI: 10.3109/13880209.2011.571264] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
CONTEXT Emblica officinalis (Euphorbiaceae), commonly known as amla, is traditionally used for central nervous system (CNS) disorders. OBJECTIVE In the present study, the effect of standardized hydroalcoholic extract of E. officinalis fruit (HAEEO), an Indian medicinal plant with potent antioxidant activity, was studied against kainic acid (KA)-induced seizures, cognitive deficits and on markers of oxidative stress. MATERIALS AND METHODS Rats were administered KA (10 mg/kg, i.p.) and observed for behavioral changes, incidence, and latency of convulsions over 4 h. The rats were thereafter sacrificed for estimation of oxidative stress parameters: thiobarbituric acid-reactive substances (TBARS) and glutathione (GSH). The proinflammatory cytokine tumor necrosis factor alpha (TNF-α) was also determined in the rat brain. RESULTS Pretreatment with HAEEO (500 and 700 mg/kg, i.p.) significantly (P < 0.001) increased the latency of seizures as compared with the vehicle-treated KA group. HAEEO significantly prevented the increase in TBARS levels and ameliorated the fall in GSH. Furthermore, HAEEO dose-dependently attenuated the KA-induced increase in the TNF-α level in the brain. HAEEO also significantly improved the cognitive deficit induced by KA, as evidenced by increased latency in passive avoidance task. DISCUSSION AND CONCLUSION HAEEO at the dose of 700 mg/kg, i.p., was most effective in suppressing KA-induced seizures, cognitive decline, and oxidative stress in the brain. These neuroprotective effects may be due to the antioxidant and anti-inflammatory effects of HAEEO.
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Affiliation(s)
- Mahaveer Golechha
- Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India
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710
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Annweiler C, Fantino B, Parot-Schinkel E, Thiery S, Gautier J, Beauchet O. Alzheimer's disease--input of vitamin D with mEmantine assay (AD-IDEA trial): study protocol for a randomized controlled trial. Trials 2011; 12:230. [PMID: 22014101 PMCID: PMC3212921 DOI: 10.1186/1745-6215-12-230] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 10/20/2011] [Indexed: 12/15/2022] Open
Abstract
Background Current treatments for Alzheimer's disease and related disorders (ADRD) are symptomatic and can only temporarily slow down ADRD. Future possibilities of care rely on multi-target drugs therapies that address simultaneously several pathophysiological processes leading to neurodegeneration. We hypothesized that the combination of memantine with vitamin D could be neuroprotective in ADRD, thereby limiting neuronal loss and cognitive decline. The aim of this trial is to compare the effect after 24 weeks of the oral intake of vitamin D3 (cholecalciferol) with the effect of a placebo on the change of cognitive performance in patients suffering from moderate ADRD and receiving memantine. Methods The AD-IDEA Trial is a unicentre, double-blind, randomized, placebo-controlled, intent-to-treat, superiority trial. Patients aged 60 years and older presenting with moderate ADRD (i.e., Mini-Mental State Examination [MMSE] score between 10-20), hypovitaminosis D (i.e., serum 25-hydroxyvitamin D [25OHD] < 30 ng/mL), normocalcemia (i.e., serum calcium < 2.65 mmol/L) and receiving no antidementia treatment at time of inclusion are being recruited. All participants receive memantine 20 mg once daily -titrated in 5 mg increments over 4 weeks- and each one is randomized to one of the two treatment options: either cholecalciferol (one 100,000 IU drinking vial every 4 weeks) or placebo (administered at the same pace). One hundred and twenty participants are being recruited and treatment continues for 24 weeks. Primary outcome measure is change in cognitive performance using Alzheimer's Disease Assessment Scale-cognition score. Secondary outcomes are changes in other cognitive scores (MMSE, Frontal Assessment Battery, Trail Making Test parts A and B), change in functional performance (Activities of Daily Living scale, and 4-item Instrumental Activities of Daily Living scale), posture and gait (Timed Up & Go, Five Time Sit-to-Stand, spatio-temporal analysis of walking), as well as the between-groups comparison of compliance to treatment and tolerance. These outcomes are assessed at baseline, 12 and 24 weeks, together with the serum concentrations of 25OHD, calcium and parathyroid hormone. Discussion The combination of memantine plus vitamin D may represent a new multi-target therapeutic class for the treatment of ADRD. The AD-IDEA Trial seeks to provide evidence on its efficacy in limiting cognitive and functional declines in ADRD. Trial Registration ClinicalTrials.gov number, NCT01409694
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711
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Glutamate excitotoxicity is involved in the induction of paralysis in mice after infection by a human coronavirus with a single point mutation in its spike protein. J Virol 2011; 85:12464-73. [PMID: 21957311 DOI: 10.1128/jvi.05576-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Human coronaviruses (HCoV) are recognized respiratory pathogens, and some strains, including HCoV-OC43, can infect human neuronal and glial cells of the central nervous system (CNS) and activate neuroinflammatory mechanisms. Moreover, HCoV-OC43 is neuroinvasive, neurotropic, and neurovirulent in susceptible mice, where it induces chronic encephalitis. Herein, we show that a single point mutation in the viral spike (S) glycoprotein (Y241H), acquired during viral persistence in human neural cells, led to a hind-limb paralytic disease in infected mice. Inhibition of glutamate excitotoxicity using a 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propranoic acid (AMPA) receptor antagonist (GYKI-52466) improved clinical scores related to the paralysis and motor disabilities in S mutant virus-infected mice, as well as protected the CNS from neuronal dysfunctions, as illustrated by restoration of the phosphorylation state of neurofilaments. Expression of the glial glutamate transporter GLT-1, responsible for glutamate homeostasis, was downregulated following infection, and GYKI-52466 also significantly restored its steady-state expression level. Finally, GYKI-52466 treatment of S mutant virus-infected mice led to reduced microglial activation, which may lead to improvement in the regulation of CNS glutamate homeostasis. Taken together, our results strongly suggest an involvement of excitotoxicity in the paralysis-associated neuropathology induced by an HCoV-OC43 mutant which harbors a single point mutation in its spike protein that is acquired upon persistent virus infection.
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712
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2-(Cyclohexylamino)-1-(4-cyclopentylpiperazin-1-yl)-2-methylpropan-1-one, a novel compound with neuroprotective and neurotrophic effects in vitro. Neurochem Int 2011; 59:821-9. [PMID: 21854820 DOI: 10.1016/j.neuint.2011.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/27/2011] [Accepted: 08/01/2011] [Indexed: 11/23/2022]
Abstract
Focusing on development of novel drug candidates for the treatment of neurodegenerative diseases, we developed and synthesized a new compound, 2-(cyclohexylamino)-1-(4-cyclopentylpiperazin-1-yl)-2-methylpropan-1-one (amido-piperizine 1). The compound demonstrated robust neuroprotective properties after both glutamate excitotoxicity and peroxide induced oxidative stress in primary cortical cultures. Furthermore, amido-piperizine 1 was found to significantly induce neurite outgrowth in vitro which could suggest central reparative and regenerative potential of the compound. With these potential beneficial effects in CNS, the ability of the amido-piperizine 1 to penetrate the blood-brain barrier was tested using MDR1-MDCK cells. Amido-piperizine 1 was found not to be a P-gp substrate and to have a high blood-brain barrier penetration potential, indicating excellent availability to the CNS. Moreover, amido-piperizine 1 had a fast metabolic clearance rate in vitro, suggesting that parenteral in vivo administration seems preferable. As an attempt to elucidate a possible mechanism of action, we found that amido-piperizine 1 bound in nano-molar range to the sigma-1 receptor, which could explain the observed neuroprotective and neurotrophic properties, and with a 100-fold lower affinity to the sigma-2 receptor. These results propose that amido-piperizine 1 may hold promise as a drug candidate for the treatment of stroke/traumatic brain injury or other neurodegenerative diseases.
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713
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Chang G, Guo Y, Jia Y, Duan W, Li B, Yu J, Li C. Protective effect of combination of sulforaphane and riluzole on glutamate-mediated excitotoxicity. Biol Pharm Bull 2011; 33:1477-83. [PMID: 20823560 DOI: 10.1248/bpb.33.1477] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Threohydroxyaspartate (THA) causes glutamate excitotoxicity in motor neurons in organotypic culture of rat spinal cord. Some drugs, including sulforaphane (SF) and riluzole, can protect motor neuron against excitotoxicity. It has been demonstrated that SF is a potent inducer of Phase II enzymes, while riluzole is a classic anti-glutamate agent. The objective of the current study is to investigate whether the combination of SF and riluzole is superior to either one used alone. In our study, the combination of SF with riluzole not only stimulates the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), reduced nicotinamide adenine dinucleotide phosphate (NADPH): quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1), but also reduces the extracellular accumulation of glutamate. When used at optimal doses, SF (10 microM) and riluzole (5 microM), either alone or in combination, all exert significant and similar neuroprotection, as measured by the number of motor neuron, medium malondialdehyde (MDA) level and lactate dehydrogenase (LDH) level. When used at low doses, the combination is better than each agent used alone. In conclusion, these results suggest the potential utility of combination use of SF and riluzole for protection of motor neuron against excitotoxicity.
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Affiliation(s)
- Geng Chang
- Department of Neurology, The Second Hospital of Hebei Medical University, Hebei, China
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714
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Flores ÉM, Cappelari SE, Pereira P, Picada JN. Effects of memantine, a non-competitive N-methyl-D-aspartate receptor antagonist, on genomic stability. Basic Clin Pharmacol Toxicol 2011; 109:413-7. [PMID: 21699656 DOI: 10.1111/j.1742-7843.2011.00744.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Memantine is an aminoadamantane drug useful in neurodegenerative diseases, with beneficial effects on cognitive functions. Some studies have shown that memantine protects brain cells, thereby decreasing glutamate excitotoxicity. This study evaluated the genotoxic/antigenotoxic and mutagenic effects of memantine in CF-1 mice, following standardized protocols. Memantine was administered i.p. at 7.5, 15 or 30 mg/kg for three consecutive days. Blood and brain samples were collected to assess DNA damage using the alkaline comet assay. The mutagenic effect was assessed using the bone marrow micronucleus test. In addition, possible antioxidant effects were evaluated measuring the survival of Saccharomyces cerevisiae yeast strains [wild-type (WT) and isogenic mutants lacking superoxide dismutase] to cotreatment of memantine plus hydrogen peroxide. Memantine decreased DNA oxidative damage mainly in brain tissue. This antigenotoxic effect corroborated an increase observed in the survival of S. cerevisiae WT strain against hydrogen peroxide-induced damage. Furthermore, memantine did not increase the micronucleus frequency. The overall results indicate that memantine showed no mutagenic activity, did not cause DNA damage in the blood and brain tissues and showed antigenotoxic effects in brain tissue.
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Affiliation(s)
- Édina Madeira Flores
- Laboratório de Genética Toxicológica, Programa de Pós-Graduação em Genética e Toxicologia Aplicada, ULBRA, Canoas, RS, Brazil
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715
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Cleva RM, Gass JT, Widholm JJ, Olive MF. Glutamatergic targets for enhancing extinction learning in drug addiction. Curr Neuropharmacol 2011; 8:394-408. [PMID: 21629446 PMCID: PMC3080595 DOI: 10.2174/157015910793358169] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 05/11/2010] [Accepted: 05/26/2010] [Indexed: 12/29/2022] Open
Abstract
The persistence of the motivational salience of drug-related environmental cues and contexts is one of the most problematic obstacles to successful treatment of drug addiction. Behavioral approaches to extinguishing the salience of drug-associated cues, such as cue exposure therapy, have generally produced disappointing results which have been attributed to, among other things, the context specificity of extinction and inadequate consolidation of extinction learning. Extinction of any behavior or conditioned response is a process of new and active learning, and increasing evidence suggests that glutamatergic neurotransmission, a key component of the neural plasticity that underlies normal learning and memory, is also involved in extinction learning. This review will summarize findings from both animal and human studies that suggest that pharmacological enhancement of glutamatergic neurotransmission facilitates extinction learning in the context of drug addiction. Pharmacological agents that have shown potential efficacy include NMDA partial agonists, mGluR5 receptor positive allosteric modulators, inhibitors of the GlyT1 glycine transporter, AMPA receptor potentiators, and activators of the cystine-glutamate exchanger. These classes of cognition-enhancing compounds could potentially serve as novel pharmacological adjuncts to cue exposure therapy to increase success rates in attenuating cue-induced drug craving and relapse.
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Affiliation(s)
- R M Cleva
- Center for Drug and Alcohol Programs, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, 29425, USA
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716
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Yang JL, Sykora P, Wilson DM, Mattson MP, Bohr VA. The excitatory neurotransmitter glutamate stimulates DNA repair to increase neuronal resiliency. Mech Ageing Dev 2011; 132:405-11. [PMID: 21729715 DOI: 10.1016/j.mad.2011.06.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 05/27/2011] [Accepted: 06/20/2011] [Indexed: 10/18/2022]
Abstract
Glutamate is the most abundant excitatory neurotransmitter in the vertebrate central nervous system and plays an important role in synaptic plasticity required for learning and memory. Activation of glutamate ionotropic receptors promptly triggers membrane depolarization and Ca(2+) influx, resulting in the activation of several different protein kinases and transcription factors. For example, glutamate-mediated Ca(2+) influx activates Ca(2+)/calmodulin-dependent kinase, protein kinase C, and mitogen activated protein kinases resulting in activation of transcription factors such as cyclic AMP response element binding protein (CREB). Abnormally prolonged exposure to glutamate causes neuronal injury, and such "excitotoxicity" has been implicated in many acute and chronic diseases including ischemic stroke, epilepsy, amyotrophic lateral sclerosis, Alzheimer's, Huntington's and Parkinson's diseases. Interestingly, although glutamate-induced Ca(2+) influx can cause DNA damage by a mitochondrial reactive oxygen species-mediated mechanism, the Ca(2+) simultaneously activates CREB, resulting in up-regulation of the DNA repair and redox protein apurinic/apyrimidinic endonuclease 1. Here, we review connections between physiological or aberrant glutamate receptor activation, Ca(2+)-mediated signaling, oxidative DNA damage and repair efficiency, and neuronal vulnerability. We conclude that glutamate signaling involves an adaptive cellular stress response pathway that enhances DNA repair capability, thereby protecting neurons against injury and disease.
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Affiliation(s)
- Jenq-Lin Yang
- Laboratory of Molecular Gerontology, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
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717
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Li CY, Shi HB, Song NY, Yin SK. Bilirubin enhances neuronal excitability by increasing glutamatergic transmission in the rat lateral superior olive. Toxicology 2011; 284:19-25. [PMID: 21440030 DOI: 10.1016/j.tox.2011.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 11/26/2022]
Abstract
Hyperbilirubinemia is one of the most common clinical phenomena observed in human newborns. To achieve effective therapeutic treatment, numerous studies have been done to determine the molecular mechanisms of bilirubin-induced neuronal excitotoxicity. However, there is no conclusive evidence for the involvement of glutamatergic synaptic transmission in bilirubin-induced neuronal hyperexcitation and excitotoxicity. In the present study, using gramicidin-perforated patch-clamp techniques, spontaneous excitatory postsynaptic currents (sEPSCs) were recorded from lateral superior olive (LSO) neurons isolated from postnatal 11-14-day-old (P11-14) rats. The application of 3 μM bilirubin increased the frequency, but not the amplitude, of sEPSCs. The action of bilirubin was tetrodotoxin (TTX)-insensitive, as bilirubin also increased the frequency, but not the amplitude, of mEPSCs. The amplitudes of GABA-activated (I(GABA)) and glutamate-activated (I(glu)) currents were not affected by bilirubin. Under current-clamp conditions, no spontaneous action potentials were observed in control solution. However, the application of 3 μM bilirubin for 4-6 min evoked a considerable rate of action-potential firing. The evoked firing was partially occluded by D,L-2-amino-5-phosphonovaleric acid (APV), an NMDA receptor antagonist, but completely inhibited by a combination of APV and 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX), an AMPA receptor antagonist. These results indicate that bilirubin facilitates presynaptic glutamate release, enhances glutamatergic synaptic transmission by activating postsynaptic AMPA and NMDA receptors, and leads to neuronal hyperexcitation. This study provides a better understanding of the mechanism of bilirubin-induced excitotoxicity and determines for the first time that both AMPA and NMDA receptors are likely involved in the excitotoxicity produced by bilirubin.
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Affiliation(s)
- Chun-Yan Li
- Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiaotong University, 600 Yishan Road, Shanghai 200233, China
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718
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Licofelone attenuates quinolinic acid induced Huntington like symptoms: possible behavioral, biochemical and cellular alterations. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:607-15. [PMID: 21237233 DOI: 10.1016/j.pnpbp.2011.01.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 12/08/2010] [Accepted: 01/05/2011] [Indexed: 11/22/2022]
Abstract
Cyclo-oxygenase and lipoxygenase enzymes are involved in arachidonic acid metabolism. Emerging evidence indicates that cyclo-oxygenase and lipoxygenase inhibitors prevent neurodegenerative processes and related complications. Therefore, the present study has been designed to explore the neuroprotective potential of licofelone (dual COX-2/5-LOX inhibitor) against quinolinic acid induced Huntington like symptom in rats. Intrastriatal administration of quinolinic acid significantly caused reduction in body weight and motor function (locomotor activity, rotarod performance and beam walk test), oxidative defense (as evidenced by increased lipid peroxidation, nitrite concentration and decreased endogenous antioxidant enzymes), alteration in mitochondrial enzyme complex (I, II and IV) activities, raised TNF-α level and striatal lesion volume as compared to sham treated animals. Licofelone (2.5, 5 and 10 mg/kg) treatment significantly improved body weight, locomotor activity, rotarod performance, balance beam walk performance, oxidative defense, mitochondrial enzyme complex activities and attenuated TNF-α level and striatal lesion as compared to control (quinolinic acid). The present study highlights that licofelone attenuates behavioral, biochemical and cellular alterations against quinolinic acid induced neurotoxicity and this could be an important therapeutic avenue to ameliorate the Huntington like symptoms.
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719
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Varella PPV, Santiago JFC, Carrete Jr. H, Higa EMS, Yacubian EMT, Centeno RS, Caboclo LOSF, Castro Neto EFD, Canzian M, Amado D, Cavalheiro EA, Naffah- Mazzacoratti MDG. Relationship between fluid-attenuated inversion-recovery (FLAIR) signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis. ARQUIVOS DE NEURO-PSIQUIATRIA 2011; 69:91-9. [DOI: 10.1590/s0004-282x2011000100018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 08/02/2010] [Indexed: 11/22/2022]
Abstract
We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS) and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO) levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10) were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE) -MTS group (p<0.001), suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05) demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.
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720
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Baptista FI, Gaspar JM, Cristóvão A, Santos PF, Köfalvi A, Ambrósio AF. Diabetes induces early transient changes in the content of vesicular transporters and no major effects in neurotransmitter release in hippocampus and retina. Brain Res 2011; 1383:257-69. [PMID: 21281613 DOI: 10.1016/j.brainres.2011.01.071] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 01/20/2011] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
Abstract
Diabetes induces changes in neurotransmitter release in central nervous system, which depend on the type of neurotransmitter and region studied. In this study, we evaluated the effect of diabetes (two and eight weeks duration) on basal and evoked release of [(14)C]glutamate and [(3)H]GABA in hippocampal and retinal synaptosomes. We also analyzed the effect of diabetes on the protein content of vesicular glutamate and GABA transporters, VGluT-1, VGluT-2 and VGAT, and on the α(1A) subunit of P/Q type calcium channels, which are abundant in nerve terminals. The protein content of vesicular glutamate and GABA transporters, and of the α(1A) subunit, was differently affected by diabetes in hippocampal and retinal synaptosomes. The changes were more pronounced in the retina than in hippocampus. VGluT-1 and VGluT-2 content was not affected in hippocampus. Moreover, changes occurred early, at two weeks of diabetes, but after eight weeks almost no changes were detected, with the exception of VGAT in the retina. Regarding neurotransmitter release, no major changes were detected. After two weeks of diabetes, neurotransmitter release was similar to controls. After eight weeks of diabetes, the basal release of glutamate slightly increased in hippocampus and the evoked GABA release decreased in retina. In conclusion, diabetes induces early transient changes in the content of glutamate and/or GABA vesicular transporters, and on calcium channels subunit, in retinal or hippocampal synaptosomes, but only minor changes in the release of glutamate or GABA. These results point to the importance of diabetes-induced changes in neural tissues at the presynaptic level, which may underlie alterations in synaptic transmission, particularly if they become permanent during the later stages of the disease.
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Affiliation(s)
- Filipa I Baptista
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, 3004-548 Coimbra, Portugal
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721
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Palmer AM. Neuroprotective therapeutics for Alzheimer's disease: progress and prospects. Trends Pharmacol Sci 2011; 32:141-7. [PMID: 21256602 DOI: 10.1016/j.tips.2010.12.007] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 12/17/2010] [Accepted: 12/20/2010] [Indexed: 12/31/2022]
Abstract
The number of people with Alzheimer's disease (AD) has never been greater and is set to increase substantially in the decades ahead as the proportion of the population aged 65 years or more rises sharply. There is therefore an urgent need for safe and effective pharmacotherapy to help combat the corresponding and substantial increase in disease burden. Increased understanding of disease aetiology and pathophysiology, particularly in relation to the loss of vulnerable neurons and the formation of plaques and tangles, has increased hope for medications that can slow (or perhaps even halt) the course of the disease. In this article I review the neurobiological basis of AD, current progress towards neuroprotective therapeutics, and prospects for the future.
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Affiliation(s)
- Alan M Palmer
- MS Therapeutics Ltd, Beechey House, 87 Church Street, Crowthorne, Berkshire RG45 7AW, UK.
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722
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Joyner PM, Cichewicz RH. Bringing natural products into the fold – exploring the therapeutic lead potential of secondary metabolites for the treatment of protein-misfolding-related neurodegenerative diseases. Nat Prod Rep 2011; 28:26-47. [DOI: 10.1039/c0np00017e] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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723
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Giust D, Albasanz JL, Martín M, Marega R, Delforge A, Bonifazi D. [60]Fullerene-based monolayers as neuroprotective biocompatible hybrid materials. Chem Commun (Camb) 2011; 47:10617-9. [DOI: 10.1039/c1cc13971a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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724
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Golechha M, Chaudhry U, Bhatia J, Saluja D, Arya DS. Naringin Protects against Kainic Acid-Induced Status Epilepticus in Rats: Evidence for an Antioxidant, Anti-inflammatory and Neuroprotective Intervention. Biol Pharm Bull 2011; 34:360-5. [DOI: 10.1248/bpb.34.360] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Uma Chaudhry
- Department of Biomedical Sciences, University of Delhi
| | - Jagriti Bhatia
- Department of Pharmacology, All India Institute of Medical Sciences
| | - Daman Saluja
- Department of Biomedical Sciences, University of Delhi
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725
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Takeda A. Insight into glutamate excitotoxicity from synaptic zinc homeostasis. Int J Alzheimers Dis 2010; 2011:491597. [PMID: 21234391 PMCID: PMC3017909 DOI: 10.4061/2011/491597] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 11/05/2010] [Indexed: 02/06/2023] Open
Abstract
Zinc is released from glutamatergic (zincergic) neuron terminals in the hippocampus, followed by the increase in Zn(2+) concentration in the intracellular (cytosol) compartment, as well as that in the extracellular compartment. The increase in Zn(2+) concentration in the intracellular compartment during synaptic excitation is mainly due to Zn(2+) influx through calcium-permeable channels and serves as Zn(2+) signaling as well as the case in the extracellular compartment. Synaptic Zn(2+) homeostasis is important for glutamate signaling and altered under numerous pathological processes such as Alzheimer's disease. Synaptic Zn(2+) homeostasis might be altered in old age, and this alteration might be involved in the pathogenesis and progression of Alzheimer's disease; Zinc may play as a key-mediating factor in the pathophysiology of Alzheimer's disease. This paper summarizes the role of Zn(2+) signaling in glutamate excitotoxicity, which is involved in Alzheimer's disease, to understand the significance of synaptic Zn(2+) homeostasis in the pathophysiology of Alzheimer's disease.
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Affiliation(s)
- Atsushi Takeda
- Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Global COE, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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726
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Ribeiro FM, Pires RGW, Ferguson SSG. Huntington's disease and Group I metabotropic glutamate receptors. Mol Neurobiol 2010; 43:1-11. [PMID: 21153060 DOI: 10.1007/s12035-010-8153-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/15/2010] [Indexed: 12/21/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by involuntary body movement, cognitive impairment and psychiatric disturbance. A polyglutamine expansion in the amino-terminal region of the huntingtin (htt) protein is the genetic cause of HD. Htt protein interacts with a wide variety of proteins, and htt mutation causes cell signaling alterations in various neurotransmitter systems, including dopaminergic, glutamatergic, and cannabinoid systems, as well as trophic factor systems. This review will overview recent findings concerning htt-promoted alterations in cell signaling that involve different neurotransmitters and trophic factor systems, especially involving mGluR1/5, as glutamate plays a crucial role in neuronal cell death. The neuronal cell death that takes place in the striatum and cortex of HD patients is the most important factor underlying HD progression. Metabotropic glutamate receptors (mGluR1 and mGluR5) have a very controversial role in neuronal cell death and it is not clear whether mGluR1/5 activation either protects or exacerbates neuronal death. Thus, understanding how mutant htt protein affects glutamatergic receptor signaling will be essential to further establish a role for glutamate receptors in HD and develop therapeutic strategies to treat HD.
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Affiliation(s)
- Fabiola M Ribeiro
- Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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727
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Nitric oxide and neuronal death. Nitric Oxide 2010; 23:153-65. [DOI: 10.1016/j.niox.2010.06.001] [Citation(s) in RCA: 280] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 06/04/2010] [Accepted: 06/07/2010] [Indexed: 12/14/2022]
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728
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Swamy M, Yusof WRW, Sirajudeen KNS, Mustapha Z, Govindasamy C. Decreased glutamine synthetase, increased citrulline–nitric oxide cycle activities, and oxidative stress in different regions of brain in epilepsy rat model. J Physiol Biochem 2010; 67:105-13. [DOI: 10.1007/s13105-010-0054-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 10/04/2010] [Indexed: 11/30/2022]
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729
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Baranzini SE, Srinivasan R, Khankhanian P, Okuda DT, Nelson SJ, Matthews PM, Hauser SL, Oksenberg JR, Pelletier D. Genetic variation influences glutamate concentrations in brains of patients with multiple sclerosis. ACTA ACUST UNITED AC 2010; 133:2603-11. [PMID: 20802204 DOI: 10.1093/brain/awq192] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glutamate is the main excitatory neurotransmitter in the mammalian brain. Appropriate transmission of nerve impulses through glutamatergic synapses is required throughout the brain and forms the basis of many processes including learning and memory. However, abnormally high levels of extracellular brain glutamate can lead to neuroaxonal cell death. We have previously reported elevated glutamate levels in the brains of patients suffering from multiple sclerosis. Here two complementary analyses to assess the extent of genomic control over glutamate levels were used. First, a genome-wide association analysis in 382 patients with multiple sclerosis using brain glutamate concentration as a quantitative trait was conducted. In a second approach, a protein interaction network was used to find associated genes within the same pathway. The top associated marker was rs794185 (P < 6.44 x 10(-7)), a non-coding single nucleotide polymorphism within the gene sulphatase modifying factor 1. Our pathway approach identified a module composed of 70 genes with high relevance to glutamate biology. Individuals carrying a higher number of associated alleles from genes in this module showed the highest levels of glutamate. These individuals also showed greater decreases in N-acetylaspartate and in brain volume over 1 year of follow-up. Patients were then stratified by the amount of annual brain volume loss and the same approach was performed in the 'high' (n = 250) and 'low' (n = 132) neurodegeneration groups. The association with rs794185 was highly significant in the group with high neurodegeneration. Further, results from the network-based pathway analysis remained largely unchanged even after stratification. Results from these analyses indicated that variance in the activity of neurochemical pathways implicated in neurodegeneration is explained, at least in part, by the inheritance of common genetic polymorphisms. Spectroscopy-based imaging provides a novel quantitative endophenotype for genetic association studies directed towards identifying new factors that contribute to the heterogeneity of clinical expression of multiple sclerosis.
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Affiliation(s)
- Sergio E Baranzini
- Department of Neurology, School of Medicine, University of California-San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143-0435, USA.
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730
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Moidunny S, Dias RB, Wesseling E, Sekino Y, Boddeke HWGM, Sebastião AM, Biber K. Interleukin-6-type cytokines in neuroprotection and neuromodulation: oncostatin M, but not leukemia inhibitory factor, requires neuronal adenosine A1 receptor function. J Neurochem 2010; 114:1667-77. [DOI: 10.1111/j.1471-4159.2010.06881.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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731
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Miller BR, Bezprozvanny I. Corticostriatal circuit dysfunction in Huntington's disease: intersection of glutamate, dopamine and calcium. FUTURE NEUROLOGY 2010; 5:735-756. [PMID: 21977007 DOI: 10.2217/fnl.10.41] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Huntington's disease (HD) is a noncurable and progressive autosomal-dominant neurodegenerative disorder that results from a polyglutamine expansion in the amino-terminal region of the huntingtin protein. The generation of rodent HD models has revealed that cellular dysfunction, rather than cell death alone, occurs early in the disease progression, appearing even before overt symptom onset. Much evidence has now established that dysfunction of the corticostriatal circuit is key to HD symptomology. In this article, we summarize the most current findings that implicate glutamate, dopamine and calcium signaling in this system and discuss how they work in concert to disrupt corticostriatal function. In addition, we highlight therapeutic strategies related to altered corticostriatal signaling in HD.
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Affiliation(s)
- Benjamin Ray Miller
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
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732
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Ponce J, Brea D, Carrascal M, Guirao V, Degregorio-Rocasolano N, Sobrino T, Castillo J, Dávalos A, Gasull T. The effect of simvastatin on the proteome of detergent-resistant membrane domains: decreases of specific proteins previously related to cytoskeleton regulation, calcium homeostasis and cell fate. Proteomics 2010; 10:1954-65. [PMID: 20217863 DOI: 10.1002/pmic.200900055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cell death induced by over-activation of glutamate receptors occurs in different neuropathologies. Cholesterol depletors protect from neurotoxic over-activation of glutamate receptors, and we have recently reported that this neuroprotection is associated with a reduction of the N-methyl-D-aspartate subtype of glutamate receptors in detergent-resistant membrane domains (DRM). In the present study we used comparative proteomics to further identify which proteins, besides the N-methyl-D-aspartate receptor, change its percentage of association to DRM after treatment of neurons with simvastatin. We detected 338 spots in neuronal DRM subjected to 2-DE; eleven of these spots changed its intensity after treatment with simvastatin. All 11 differential spots showed reduced intensity in simvastatin-treated samples and were identified as adipocyte plasma membrane associated protein, enolase, calretinin, coronin 1a, f-actin capping protein alpha1, f-actin capping protein alpha2, heat shock cognate protein 71, malate dehydrogenase, n-myc downregulated gene 1, prohibitin 2, Rab GDP dissociation inhibitor, translationally controlled tumor protein and voltage dependent anion selective channel protein 1. The proteins tested colocalized with the lipid raft marker caveolin-1. Interestingly, the proteins we have identified in the present study had been previously reported to play a role in cell fate and, thus, they might represent novel targets for neuroprotection.
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Affiliation(s)
- Jovita Ponce
- Cellular and Molecular Neurobiology Research Group and Grup de Recerca en Neurociencies del IGTP, Department of Neurosciences, Fundació Institut d'Investigació en Ciències de la Salut Germans Trias I Pujol-Universitat Autónoma de Barcelona, Badalona, Spain
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733
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Zheng YL, Amin ND, Hu YF, Rudrabhatla P, Shukla V, Kanungo J, Kesavapany S, Grant P, Albers W, Pant HC. A 24-residue peptide (p5), derived from p35, the Cdk5 neuronal activator, specifically inhibits Cdk5-p25 hyperactivity and tau hyperphosphorylation. J Biol Chem 2010; 285:34202-12. [PMID: 20720012 DOI: 10.1074/jbc.m110.134643] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The activity of Cdk5-p35 is tightly regulated in the developing and mature nervous system. Stress-induced cleavage of the activator p35 to p25 and a p10 N-terminal domain induces deregulated Cdk5 hyperactivity and perikaryal aggregations of hyperphosphorylated Tau and neurofilaments, pathogenic hallmarks in neurodegenerative diseases, such as Alzheimer disease and amyotrophic lateral sclerosis, respectively. Previously, we identified a 125-residue truncated fragment of p35 called CIP that effectively and specifically inhibited Cdk5-p25 activity and Tau hyperphosphorylation induced by Aβ peptides in vitro, in HEK293 cells, and in neuronal cells. Although these results offer a possible therapeutic approach to those neurodegenerative diseases assumed to derive from Cdk5-p25 hyperactivity and/or Aβ induced pathology, CIP is too large for successful therapeutic regimens. To identify a smaller, more effective peptide, in this study we prepared a 24-residue peptide, p5, spanning CIP residues Lys(245)-Ala(277). p5 more effectively inhibited Cdk5-p25 activity than did CIP in vitro. In neuron cells, p5 inhibited deregulated Cdk5-p25 activity but had no effect on the activity of endogenous Cdk5-p35 or on any related endogenous cyclin-dependent kinases in HEK293 cells. Specificity of p5 inhibition in cortical neurons may depend on the p10 domain in p35, which is absent in p25. Furthermore, we have demonstrated that p5 reduced Aβ(1-42)-induced Tau hyperphosphorylation and apoptosis in cortical neurons. These results suggest that p5 peptide may be a unique and useful candidate for therapeutic studies of certain neurodegenerative diseases.
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Affiliation(s)
- Ya-Li Zheng
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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734
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Kalonia H, Kumar P, Kumar A. Comparative neuroprotective profile of statins in quinolinic acid induced neurotoxicity in rats. Behav Brain Res 2010; 216:220-8. [PMID: 20696189 DOI: 10.1016/j.bbr.2010.07.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 07/28/2010] [Accepted: 07/31/2010] [Indexed: 01/09/2023]
Abstract
A possible neuroprotective role has been recently suggested for 3H3MGCoA reductase inhibitors (statins). Here, we sought to determine neuroprotective effect of statins in quinolinic acid induced neurotoxicity in rats. Rats were surgically administered quinolinic acid and treated with Atorvastatin (10, 20 mg/kg), simvastatin (15, 30 mg/kg) and fluvastatin (5, 10 mg/kg) once daily up to 3 weeks. Atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) treatment significantly attenuated the quinolinic acid induced behavioral (locomotor activity, rotarod performance and beam walk test), biochemical (lipid peroxidation, nitrite concentration, SOD and catalase), mitochondrial enzyme complex alterations in rats suggesting their free radical scavenging potential. Additionally, atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) significantly decrease the TNF-α level and striatal lesion volume in quinolinic acid treated animals indicating their anti-inflammatory effects. In comparing the protective effect of different statins, atorvastatin is effective at both the doses while simvastatin and fluvastatins at respective lower doses were not able to produce the protective effect in quinolinic acid treated animals. These modulations can account, at least partly, for the beneficial effect of statins in our rodent model of striatal degeneration. Our findings show that statins could be explored as possible neuroprotective agents for neurodegenerative disorders such as HD.
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Affiliation(s)
- Harikesh Kalonia
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study, Panjab University, Chandigarh 160014, India
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735
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Swamy M, Salleh MJM, Sirajudeen KNS, Yusof WRW, Chandran G. Nitric oxide (no), citrulline - no cycle enzymes, glutamine synthetase and oxidative stress in anoxia (hypobaric hypoxia) and reperfusion in rat brain. Int J Med Sci 2010; 7:147-54. [PMID: 20567615 PMCID: PMC2880843 DOI: 10.7150/ijms.7.147] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 05/26/2010] [Indexed: 12/31/2022] Open
Abstract
Nitric oxide is postulated to be involved in the pathophysiology of neurological disorders due to hypoxia/ anoxia in brain due to increased release of glutamate and activation of N-methyl-D-aspartate receptors. Reactive oxygen species have been implicated in pathophysiology of many neurological disorders and in brain function. To understand their role in anoxia (hypobaric hypoxia) and reperfusion (reoxygenation), the nitric oxide synthase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase and arginase activities along with the concentration of nitrate /nitrite, thiobarbituric acid reactive substances and total antioxidant status were estimated in cerebral cortex, cerebellum and brain stem of rats subjected to anoxia and reperfusion. The results of this study clearly demonstrated the increased production of nitric oxide by increased activity of nitric oxide synthase. The increased activities of argininosuccinate synthetase and argininosuccinate lyase suggest the increased and effective recycling of citrulline to arginine in anoxia, making nitric oxide production more effective and contributing to its toxic effects. The decreased activity of glutamine synthetase may favor the prolonged availability of glutamic acid causing excitotoxicity leading to neuronal damage in anoxia. The increased formation of thiobarbituric acid reactive substances and decreased total antioxidant status indicate the presence of oxidative stress in anoxia and reperfusion. The increased arginase and sustained decrease of GS activity in reperfusion group likely to be protective.
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Affiliation(s)
- M Swamy
- Department of Chemical Pathology, School of Medical Sciences, Health campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
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736
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Wu GM, Hou XY. Oligomerized Abeta25-35 induces increased tyrosine phosphorylation of NMDA receptor subunit 2A in rat hippocampal CA1 subfield. Brain Res 2010; 1343:186-93. [PMID: 20441772 DOI: 10.1016/j.brainres.2010.04.055] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 04/20/2010] [Accepted: 04/20/2010] [Indexed: 11/24/2022]
Abstract
Amyloid-beta peptide (Abeta) plays a causal role in the pathogenesis of Alzheimer's disease (AD). To elucidate the mechanisms underlying the over-activation of NMDA receptors in AD, we investigated the alteration of NR2A tyrosine phosphorylation after intracerebroventricular infusion of Abeta25-35 oligomers. Abeta25-35 treatment resulted in the elevated tyrosine phosphorylation of NR2A in rat hippocampal CA1 subfield and facilitated the interactions of NR2A or PSD-95 with Src kinases. PP2, a specific inhibitor of Src family protein tyrosine kinases (SrcPTKs), not only attenuated the Abeta25-35-induced increases in the tyrosine phosphorylation of NR2A and in the associations among Src, NR2A, and PSD-95, but also protected against neuronal loss in the CA1 region. Preapplication of a noncompetitive NMDA receptor antagonist amantadine, an NR2A-selective NMDA receptor antagonist NVP-AAM077, or an NR2B-selective NMDA receptor antagonist Ro25-6981 inhibited the increased tyrosine phosphorylation of NR2A and prevented the associations among Src, NR2A, and PSD-95, but Ro25-6981 had less contribution. These results suggest that the activation of NMDA receptors after Abeta treatment promotes the formation of NR2A-PSD-95-Src complex and thus increases the tyrosine phosphorylation of NR2A by Src kinases, which up-regulates the function of NMDA receptors. Such positive feedback mediates the Abeta-induced over-activation of NMDA receptors and is involved in neuronal impairment.
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Affiliation(s)
- Gui-Mei Wu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 84 West Huaihai Road, Jiangsu 221002, China
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737
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Bottum K, Poon E, Haley B, Karmarkar S, Tischkau SA. Suprachiasmatic nucleus neurons display endogenous resistance to excitotoxicity. Exp Biol Med (Maywood) 2010; 235:237-46. [PMID: 20404040 DOI: 10.1258/ebm.2009.009244] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A comprehensive understanding of neuroprotective pathways is essential to progress in the battle against numerous neurodegenerative conditions. The hypothalamic suprachiasmatic nucleus (SCN) is endogenously resistant to glutamate (Glu) excitotoxicity in vivo. This study was designed to determine whether immortalized SCN neurons (SCN2.2 cells) retain this characteristic. We first established that SCN2.2 cells retained the ability to respond to Glu. SCN2.2 cells expressed N-methyl-d-aspartate (NMDA) receptor subtypes NR1 and NR2A/2B, suggesting the presence of functional receptors. mRNA for the NMDA receptor subunits NR2A and NR2B were higher in the SCN2.2 than in the control hypothalamic neurons (GT1-7). Specific NMDA receptor antagonists (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate and d-(-)-2-amino-5-phosphonovaleric acid blocked Glu-induced activation of gene expression. SCN2.2 cells were resistant to Glu excitotoxicity compared with GT1-7 neurons as assessed with a mitochondrial function assay, cell death by trypan blue exclusion and apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labeling. SCN2.2 resistance to Glu excitoxicity was retained in the presence of the broad spectrum Glu transport inhibitor, l-trans-pyrrolidine-2,4 dicarboxylate, excluding glial Glu uptake as a major neuroprotective mechanism. Collectively, these observations demonstrate endogenous neuroprotection in SCN2.2 cells; this cell line is resistant to excitotoxicity under conditions that are toxic to other immortalized cell lines. Thus, the SCN2.2 cell line may provide insights into the molecular mechanisms that confer endogenous neuroprotection in the SCN.
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Affiliation(s)
- Kathleen Bottum
- Department of Medicine, Division of Internal Medicine and Psychiatry, Southern Illinois School of Medicine, Springfield, IL 62794-9636, USA
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738
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Castillo CA, León DA, Ballesteros-Yáñez I, Albasanz JL, Martín M. Glutamate differently modulates excitatory and inhibitory adenosine receptors in neuronal and glial cells. Neurochem Int 2010; 57:33-42. [PMID: 20399823 DOI: 10.1016/j.neuint.2010.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 03/31/2010] [Accepted: 04/03/2010] [Indexed: 12/20/2022]
Abstract
Adenosine is a neuromodulator which acts through adenosine receptors regulating functions such as inhibition of glutamate release. Adenosine A(1) and A(2A) receptor activations most often regulate opposing actions. Primary rat cortical neurons and rat C6 cells, an astrocytic derived cell line, were exposed to 100muM l-glutamate, and cell viability and transduction pathways mediated by both A(1) and A(2A) receptors were analyzed. Glutamate-induced excitotoxic damage was found only in cortical neurons, with C6 cells preserved. In C6 cells, adenosine A(1) and A(2A) receptors were increased and decreased, respectively. Consequently, A(1)-mediated adenylyl cyclase inhibition and A(2A)-mediated adenylyl cyclase stimulation were, respectively, increased and decreased after glutamate exposure. In cortical neurons, glutamate treatment increased both A(1) and A(2A) receptors. Moreover, adenylyl cyclase responsiveness to A(1) or A(2A) receptor agonists was heightened in these cells, in which pharmacological activation of AC induced cell death. Finally, activation of A(1) receptor or blockade of A(2A) receptor during glutamate treatment partially prevented the glutamate-induced cell death detected in cultured cortical neurons. Results show that adenosine receptors are regulated by glutamate, and that this regulation is dependent on the cell type, suggesting that adenosine receptors might be promising targets in the therapy against excitotoxic cell death.
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Affiliation(s)
- Carlos Alberto Castillo
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencias Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha (UCLM), Avenida Camilo José Cela, 10, 13071 Ciudad Real, Spain
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739
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Hampl R, Bicíková M. Neuroimmunomodulatory steroids in Alzheimer dementia. J Steroid Biochem Mol Biol 2010; 119:97-104. [PMID: 20153425 DOI: 10.1016/j.jsbmb.2010.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 02/03/2010] [Accepted: 02/04/2010] [Indexed: 01/09/2023]
Abstract
Though pathobiochemical and neurochemical changes and accompanied morphological alterations in Alzheimer dementia are well known, the triggering mechanisms, if any, remain obscure. Important factors influencing the development and progression of Alzheimer disease include hormonal steroids and their metabolites, some of which may serve as therapeutic agents. This review focusses on major biochemical alterations in the brain of Alzheimer patients with respect to the involvement of steroids. It includes their role in impairment of fuel supply and in brain glycoregulation, with especial emphasis on glucocorticoids and their counter-regulatory steroids as dehydroepiandrosterone and its metabolites. Further, the role of steroids in beta-amyloid pathology is reviewed including alterations in tau-protein(s) phosphorylation. The (auto)immune theory of Alzheimer dementia is briefly outlined, pointing to the possible involvement of steroids in brain ageing, immunosenescence and neuronal apoptosis. Some effects of steroids are briefly mentioned on the formation and removal of reactive oxygen species and their effect on calcium flux and cytotoxicity. The recent biochemical research of Alzheimer disease focusses on molecular signalling at which steroids also take part. New findings may be anticipated when the mosaic describing the molecular mechanisms behind these events becomes more complete.
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740
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Wang X, Michaelis EK. Selective neuronal vulnerability to oxidative stress in the brain. Front Aging Neurosci 2010; 2:12. [PMID: 20552050 PMCID: PMC2874397 DOI: 10.3389/fnagi.2010.00012] [Citation(s) in RCA: 411] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 03/11/2010] [Indexed: 12/21/2022] Open
Abstract
Oxidative stress (OS), caused by the imbalance between the generation and detoxification of reactive oxygen and nitrogen species (ROS/RNS), plays an important role in brain aging, neurodegenerative diseases, and other related adverse conditions, such as ischemia. While ROS/RNS serve as signaling molecules at physiological levels, an excessive amount of these molecules leads to oxidative modification and, therefore, dysfunction of proteins, nucleic acids, and lipids. The response of neurons to this pervasive stress, however, is not uniform in the brain. While many brain neurons can cope with a rise in OS, there are select populations of neurons in the brain that are vulnerable. Because of their selective vulnerability, these neurons are usually the first to exhibit functional decline and cell death during normal aging, or in age-associated neurodegenerative diseases, such as Alzheimer's disease. Understanding the molecular and cellular mechanisms of selective neuronal vulnerability (SNV) to OS is important in the development of future intervention approaches to protect such vulnerable neurons from the stresses of the aging process and the pathological states that lead to neurodegeneration. In this review, the currently known molecular and cellular factors that contribute to SNV to OS are summarized. Included among the major underlying factors are high intrinsic OS, high demand for ROS/RNS-based signaling, low ATP production, mitochondrial dysfunction, and high inflammatory response in vulnerable neurons. The contribution to the selective vulnerability of neurons to OS by other intrinsic or extrinsic factors, such as deficient DNA damage repair, low calcium-buffering capacity, and glutamate excitotoxicity, are also discussed.
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Affiliation(s)
- Xinkun Wang
- Higuchi Biosciences Center, The University of Kansas Lawrence, KS, USA
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741
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Glutamate differently modulates metabotropic glutamate receptors in neuronal and glial cells. Neurochem Res 2010; 35:1050-63. [PMID: 20309728 DOI: 10.1007/s11064-010-0154-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2010] [Indexed: 12/17/2022]
Abstract
Glutamate is an excitatory neurotransmitter implicated in learning and memory processes, but at high concentrations it acts as an excitotoxin causing degeneration and neuronal death. The aim of this work was to determine the excitotoxic effect of glutamate and the regulation of metabotropic glutamate receptors (mGluR) during excitotoxicity in neurons and C6 glioma cells. Results show that glutamate causes excitotoxic damage only in cortical neurons. Loss of cell viability in neurons was glutamate concentration- and time-dependent. Total mGluR levels were significantly reduced in these cells when exposed to glutamate. However, in C6 cells, which have been used as a model of glial cells, these receptors were regulated in a biphasic manner, decreased after 6 h, and increased after 24/48 h of treatment. Results show a cell dependent mGluR regulation by glutamate exposure which could mediate the vulnerability or not to glutamate mediated excitotoxicity.
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742
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Chronic pretreatment with acetyl-L-carnitine and ±DL-α-lipoic acid protects against acute glutamate-induced neurotoxicity in rat brain by altering mitochondrial function. Neurotox Res 2010; 19:319-29. [PMID: 20217290 DOI: 10.1007/s12640-010-9165-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/23/2009] [Accepted: 02/20/2010] [Indexed: 01/05/2023]
Abstract
Cellular oxidative stress and energy failure were shown to be involved in Glutamate (L-Glu) neurotoxicity, whereas, acetyl-L-carnitine (ALCAR) and ±DL-α-lipoic acid (LA) are known to be key players in the mitochondrial energy production. To evaluate the effects of the above antioxidants, adult rats were pretreated with ALCAR (100 mg/kg i.p for 21 days) and both ALCAR and LA (100 mg/kg i.p + 50 mg/kg i.p for 21 days), before stereotactically administering L-Glu bolus (1 μmole/1 μl) in the cerebral cortex. Results showed that acute L-Glu increased ROS (P < 0.001), LPO (P < 0.001), Ca(2+) (P < 0.001), TNF-α (P < 0.001), IFN-γ (P < 0.001), NO (P < 0.001) levels and mRNA expression of Caspase-3, Casapase-9, iNOS, and nNOS genes with respect to saline-injected control group. Key antioxidant parameters such as SOD, CAT, GSH, GR along with mitochondrial transmembrane potential (Ψ∆m) were decreased (P < 0.05), while ALCAR pretreatment prevented these effects by significantly inhibiting ROS (P < 0.001), LPO (P < 0.001), Ca(2+) (P < 0.05), TNF-α (P < 0.05), IFN-γ (P < 0.001), NO (P < 0.01) levels and expression of the above genes. This chronic pretreatment of ALCAR also increased SOD, CAT, GSH, GR, and Ψ∆m (P < 0.0.01, P < 0.0.01, P < 0.05, P < 0.05, and P < 0.001, respectively) with respect to L: -Glu group. The addition of LA to ALCAR resulted in further increases in CAT (P < 0.05), GSH (P < 0.01), GR (P < 0.05), Ψ∆m (P < 0.05) and additional decreases in ROS (P < 0.001), LPO (P < 0.05), Ca(2+) (P < 0.05), TNF-α (P < 0.05) and mRNA expression of iNOS and nNOS genes with respect to ALCAR group. Hence, this "one-two punch" of ALCAR + LA may help in ameliorating the deleterious cellular events that occur after L-Glu.
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743
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744
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Costa C, Tozzi A, Luchetti E, Siliquini S, Belcastro V, Tantucci M, Picconi B, Ientile R, Calabresi P, Pisani F. Electrophysiological actions of zonisamide on striatal neurons: Selective neuroprotection against complex I mitochondrial dysfunction. Exp Neurol 2010; 221:217-24. [DOI: 10.1016/j.expneurol.2009.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 11/02/2009] [Accepted: 11/03/2009] [Indexed: 12/21/2022]
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745
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Antoniou X, Sclip A, Ploia C, Colombo A, Moroy G, Borsello T. JNK contributes to Hif-1alpha regulation in hypoxic neurons. Molecules 2009; 15:114-27. [PMID: 20110876 PMCID: PMC6256924 DOI: 10.3390/molecules15010114] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/18/2009] [Accepted: 12/28/2009] [Indexed: 12/16/2022] Open
Abstract
Hypoxia is an established factor of neurodegeneration. Nowadays, attention is directed at understanding how alterations in the expression of stress-related signaling proteins contribute to age dependent neuronal vulnerability to injury. The purpose of this study was to investigate how Hif-1alpha, a major neuroprotective factor, and JNK signaling, a key pathway in neurodegeneration, relate to hypoxic injury in young (6DIV) and adult (12DIV) neurons. We could show that in young neurons as compared to mature ones, the protective factor Hif-1alpha is more induced while the stress protein phospho-JNK displays lower basal levels. Indeed, changes in the expression levels of these proteins correlated with increased vulnerability of adult neurons to hypoxic injury. Furthermore, we describe for the first time that treatment with the D-JNKI1, a JNK-inhibiting peptide, rescues adult hypoxic neurons from death and contributes to Hif-1alpha upregulation, probably via a direct interaction with the Hif-1alpha protein.
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Affiliation(s)
- Xanthi Antoniou
- Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20157 Milano, Italy; E-Mails: (X.A.); (A.S.); (C.P.); (A.C.)
| | - Alessandra Sclip
- Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20157 Milano, Italy; E-Mails: (X.A.); (A.S.); (C.P.); (A.C.)
| | - Cristina Ploia
- Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20157 Milano, Italy; E-Mails: (X.A.); (A.S.); (C.P.); (A.C.)
| | - Alessio Colombo
- Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20157 Milano, Italy; E-Mails: (X.A.); (A.S.); (C.P.); (A.C.)
| | - Gautier Moroy
- Xigen SA, Rue des Terreaux 17, CH-1015 Lausanne, Switzerland; E-Mail: (G.M.)
| | - Tiziana Borsello
- Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20157 Milano, Italy; E-Mails: (X.A.); (A.S.); (C.P.); (A.C.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +39-02 39014469
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746
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Hardeland R. Neuroprotection by radical avoidance: search for suitable agents. Molecules 2009; 14:5054-102. [PMID: 20032877 PMCID: PMC6255388 DOI: 10.3390/molecules14125054] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 11/30/2009] [Accepted: 12/04/2009] [Indexed: 02/07/2023] Open
Abstract
Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. L-theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals.
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Affiliation(s)
- Rüdiger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Berliner str. 28, D-37073 Göttingen, Germany.
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747
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Anzini M, Chelini A, Mancini A, Cappelli A, Frosini M, Ricci L, Valoti M, Magistretti J, Castelli L, Giordani A, Makovec F, Vomero S. Synthesis and Biological Evaluation of Amidine, Guanidine, and Thiourea Derivatives of 2-Amino(6-trifluoromethoxy)benzothiazole as Neuroprotective Agents Potentially Useful in Brain Diseases. J Med Chem 2009; 53:734-44. [DOI: 10.1021/jm901375r] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maurizio Anzini
- Dipartimento Farmaco Chimico Tecnologico and European Research Centre for Drug Discovery and Development, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Alessia Chelini
- Dipartimento Farmaco Chimico Tecnologico and European Research Centre for Drug Discovery and Development, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Alessandra Mancini
- Dipartimento Farmaco Chimico Tecnologico and European Research Centre for Drug Discovery and Development, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Andrea Cappelli
- Dipartimento Farmaco Chimico Tecnologico and European Research Centre for Drug Discovery and Development, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Maria Frosini
- Dipartimento di Neuroscienze, Sezione di Farmacologia, Fisiologia e Tossicologia, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Lorenzo Ricci
- Dipartimento di Neuroscienze, Sezione di Farmacologia, Fisiologia e Tossicologia, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Massimo Valoti
- Dipartimento di Neuroscienze, Sezione di Farmacologia, Fisiologia e Tossicologia, Università di Siena, Via A. Moro, 53100 Siena, Italy
| | - Jacopo Magistretti
- Dipartimento di Fisiologia, Sezione di Fisiologia Generale, Università di Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Loretta Castelli
- Dipartimento di Fisiologia, Sezione di Fisiologia Generale, Università di Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | | | - Salvatore Vomero
- Dipartimento Farmaco Chimico Tecnologico and European Research Centre for Drug Discovery and Development, Università di Siena, Via A. Moro, 53100 Siena, Italy
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748
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ElMlili N, Boix J, Ahabrach H, Rodrigo R, Errami M, Felipo V. Chronic hyperammonemia induces tonic activation of NMDA receptors in cerebellum. J Neurochem 2009; 112:1005-14. [PMID: 20002515 DOI: 10.1111/j.1471-4159.2009.06520.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reduced function of the glutamate--nitric oxide (NO)--cGMP pathway is responsible for some cognitive alterations in rats with hyperammonemia and hepatic encephalopathy. Hyperammonemia impairs the pathway in cerebellum by increasing neuronal nitric oxide synthase (nNOS) phosphorylation in Ser847 by calcium-calmodulin-dependent protein kinase II (CaMKII), reducing nNOS activity, and by reducing nNOS amount in synaptic membranes, which reduces its activation following NMDA receptors activation. The reason for increased CaMKII activity in hyperammonemia remains unknown. We hypothesized that it would be as a result of increased tonic activation of NMDA receptors. The aims of this work were to assess: (i) whether tonic NMDA activation receptors is increased in cerebellum in chronic hyperammonemia in vivo; and (ii) whether this tonic activation is responsible for increased CaMKII activity and reduced activity of nNOS and of the glutamate--NO--cGMP pathway. Blocking NMDA receptors with MK-801 increases cGMP and NO metabolites in cerebellum in vivo and in slices from hyperammonemic rats. This is because of reduced phosphorylation and activity of CaMKII, leading to normalization of nNOS phosphorylation and activity. MK-801 also increases nNOS in synaptic membranes and reduces it in cytosol. This indicates that hyperammonemia increases tonic activation of NMDA receptors leading to reduced activity of nNOS and of the glutamate--NO--cGMP pathway.
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Affiliation(s)
- Nisrin ElMlili
- Laboratory of Neurobiology, Centro de Investigacion Principe Felipe, Valencia, Spain
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749
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Shibata N, Yamamoto T, Hiroi A, Omi Y, Kato Y, Kobayashi M. Activation of STAT3 and inhibitory effects of pioglitazone on STAT3 activity in a mouse model of SOD1-mutated amyotrophic lateral sclerosis. Neuropathology 2009; 30:353-60. [DOI: 10.1111/j.1440-1789.2009.01078.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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750
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Duman RS. Neuronal damage and protection in the pathophysiology and treatment of psychiatric illness: stress and depression. DIALOGUES IN CLINICAL NEUROSCIENCE 2009. [PMID: 19877493 PMCID: PMC3181922 DOI: 10.31887/dcns.2009.11.3/rsduman] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The discovery that stress and depression, as well as other psychiatric illnesses, are characterized by structural alterations, and that these changes result from atrophy and loss of neurons and glia in specific limbic regions and circuits, has contributed to a fundamental change in our understanding of these illnesses. These structural changes are accompanied by dysregulation of neuroprotective and neurotrophic signaling mechanisms that are required for the maturation, growth, and survival of neurons and glia. Conversely, behavioral and therapeutic interventions can reverse these structural alterations by stimulating neuroprotective and neurotrophic pathways and by blocking the damaging, excitotoxic, and inflammatory effects of stress. Lifetime exposure to cellular and environmental stressors and interactions with genetic factors contribute to individual susceptibility or resilience. This exciting area of research holds promise and potential for further elucidating the pathophysiology of psychiatric illness and for development of novel therapeutic interventions.
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Affiliation(s)
- Ronald S Duman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06508, USA.
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