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Baudry M, Bi X. Revisiting the calpain hypothesis of learning and memory 40 years later. Front Mol Neurosci 2024; 17:1337850. [PMID: 38361744 PMCID: PMC10867166 DOI: 10.3389/fnmol.2024.1337850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024] Open
Abstract
In 1984, Gary Lynch and Michel Baudry published in Science a novel biochemical hypothesis for learning and memory, in which they postulated that the calcium-dependent protease, calpain, played a critical role in regulating synaptic properties and the distribution of glutamate receptors, thereby participating in memory formation in hippocampus. Over the following 40 years, much work has been done to refine this hypothesis and to provide convincing arguments supporting what was viewed at the time as a simplistic view of synaptic biochemistry. We have now demonstrated that the two major calpain isoforms in the brain, calpain-1 and calpain-2, execute opposite functions in both synaptic plasticity/learning and memory and in neuroprotection/neurodegeneration. Thus, calpain-1 activation is required for triggering long-term potentiation (LTP) of synaptic transmission and learning of episodic memory, while calpain-2 activation limits the magnitude of LTP and the extent of learning. On the other hand, calpain-1 is neuroprotective while calpain-2 is neurodegenerative, and its prolonged activation following various types of brain insults leads to neurodegeneration. The signaling pathways responsible for these functions have been identified and involve local protein synthesis, cytoskeletal regulation, and regulation of glutamate receptors. Human families with mutations in calpain-1 have been reported to have impairment in motor and cognitive functions. Selective calpain-2 inhibitors have been synthesized and clinical studies to test their potential use to treat disorders associated with acute neuronal damage, such as traumatic brain injury, are being planned. This review will illustrate the long and difficult journey to validate a bold hypothesis.
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Affiliation(s)
- Michel Baudry
- Western University of Health Sciences, Pomona, CA, United States
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2
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Aquatic Freshwater Vertebrate Models of Epilepsy Pathology: Past Discoveries and Future Directions for Therapeutic Discovery. Int J Mol Sci 2022; 23:ijms23158608. [PMID: 35955745 PMCID: PMC9368815 DOI: 10.3390/ijms23158608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 12/04/2022] Open
Abstract
Epilepsy is an international public health concern that greatly affects patients’ health and lifestyle. About 30% of patients do not respond to available therapies, making new research models important for further drug discovery. Aquatic vertebrates present a promising avenue for improved seizure drug screening and discovery. Zebrafish (Danio rerio) and African clawed frogs (Xenopus laevis and tropicalis) are increasing in popularity for seizure research due to their cost-effective housing and rearing, similar genome to humans, ease of genetic manipulation, and simplicity of drug dosing. These organisms have demonstrated utility in a variety of seizure-induction models including chemical and genetic methods. Past studies with these methods have produced promising data and generated questions for further applications of these models to promote discovery of drug-resistant seizure pathology and lead to effective treatments for these patients.
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Marcoli M, Cervetto C, Amato S, Fiorucci C, Maura G, Mariottini P, Cervelli M. Transgenic Mouse Overexpressing Spermine Oxidase in Cerebrocortical Neurons: Astrocyte Dysfunction and Susceptibility to Epileptic Seizures. Biomolecules 2022; 12:204. [PMID: 35204705 PMCID: PMC8961639 DOI: 10.3390/biom12020204] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
Polyamines are organic polycations ubiquitously present in living cells. Polyamines are involved in many cellular processes, and their content in mammalian cells is tightly controlled. Among their function, these molecules modulate the activity of several ion channels. Spermine oxidase, specifically oxidized spermine, is a neuromodulator of several types of ion channel and ionotropic glutamate receptors, and its deregulated activity has been linked to several brain pathologies, including epilepsy. The Dach-SMOX mouse line was generated using a Cre/loxP-based recombination approach to study the complex and critical functions carried out by spermine oxidase and spermine in the mammalian brain. This mouse genetic model overexpresses spermine oxidase in the neocortex and is a chronic model of excitotoxic/oxidative injury and neuron vulnerability to oxidative stress and excitotoxic, since its phenotype revealed to be more susceptible to different acute oxidative insults. In this review, the molecular mechanisms underlined the Dach-SMOX phenotype, linked to reactive astrocytosis, neuron loss, chronic oxidative and excitotoxic stress, and susceptibility to seizures have been discussed in detail. The Dach-SMOX mouse model overexpressing SMOX may help in shedding lights on the susceptibility to epileptic seizures, possibly helping to understand the mechanisms underlying epileptogenesis in vulnerable individuals and contributing to provide new molecular mechanism targets to search for novel antiepileptic drugs.
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Affiliation(s)
- Manuela Marcoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), Lucio Lazzarino 1, 56122 Pisa, Italy
| | - Chiara Cervetto
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research (Centro 3R), Lucio Lazzarino 1, 56122 Pisa, Italy
| | - Sarah Amato
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
| | - Cristian Fiorucci
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
| | - Guido Maura
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genoa, Italy; (S.A.); (G.M.)
| | - Paolo Mariottini
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
| | - Manuela Cervelli
- Department of Science, University of Rome “Roma Tre”, Viale Marconi 446, 00146 Rome, Italy; (C.F.); (P.M.)
- Neurodevelopment, Neurogenetics and Molecular Neurobiology Unit, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy
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4
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Cervelli M, Bellavia G, D'Amelio M, Cavallucci V, Moreno S, Berger J, Nardacci R, Marcoli M, Maura G, Piacentini M, Amendola R, Cecconi F, Mariottini P. A New Transgenic Mouse Model for Studying the Neurotoxicity of Spermine Oxidase Dosage in the Response to Excitotoxic Injury. PLoS One 2013; 8:e64810. [PMID: 23840306 PMCID: PMC3686797 DOI: 10.1371/journal.pone.0064810] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/18/2013] [Indexed: 11/18/2022] Open
Abstract
Spermine oxidase is a FAD-containing enzyme involved in polyamines catabolism, selectively oxidizing spermine to produce H2O2, spermidine, and 3-aminopropanal. Spermine oxidase is highly expressed in the mouse brain and plays a key role in regulating the levels of spermine, which is involved in protein synthesis, cell division and cell growth. Spermine is normally released by neurons at synaptic sites where it exerts a neuromodulatory function, by specifically interacting with different types of ion channels, and with ionotropic glutamate receptors. In order to get an insight into the neurobiological roles of spermine oxidase and spermine, we have deregulated spermine oxidase gene expression producing and characterizing the transgenic mouse model JoSMOrec, conditionally overexpressing the enzyme in the neocortex. We have investigated the effects of spermine oxidase overexpression in the mouse neocortex by transcript accumulation, immunohistochemical analysis, enzymatic assays and polyamine content in young and aged animals. Transgenic JoSMOrec mice showed in the neocortex a higher H2O2 production in respect to Wild-Type controls, indicating an increase of oxidative stress due to SMO overexpression. Moreover, the response of transgenic mice to excitotoxic brain injury, induced by kainic acid injection, was evaluated by analysing the behavioural phenotype, the immunodistribution of neural cell populations, and the ultrastructural features of neocortical neurons. Spermine oxidase overexpression and the consequently altered polyamine levels in the neocortex affects the cytoarchitecture in the adult and aging brain, as well as after neurotoxic insult. It resulted that the transgenic JoSMOrec mouse line is more sensitive to KA than Wild-Type mice, indicating an important role of spermine oxidase during excitotoxicity. These results provide novel evidences of the complex and critical functions carried out by spermine oxidase and spermine in the mammalian brain.
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Affiliation(s)
| | | | - Marcello D'Amelio
- Laboratory of Molecular Neuroembryology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
| | - Virve Cavallucci
- Laboratory of Molecular Neuroembryology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
| | - Sandra Moreno
- Dipartimento di Biologia, Università “Roma Tre,” Rome, Italy
| | - Joachim Berger
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Australia
| | - Roberta Nardacci
- Istituto Nazionale per le Malattie Infettive, IRCCS “L. Spallanzani,” Rome, Italy
| | - Manuela Marcoli
- Dipartimento di Farmacia, Sez. Farmacologia e Tossicologia, Centro di Eccellenza per la Ricerca Biomedica CEBR, Università di Genova, Genoa, Italy
| | - Guido Maura
- Dipartimento di Farmacia, Sez. Farmacologia e Tossicologia, Centro di Eccellenza per la Ricerca Biomedica CEBR, Università di Genova, Genoa, Italy
| | - Mauro Piacentini
- Istituto Nazionale per le Malattie Infettive, IRCCS “L. Spallanzani,” Rome, Italy
| | - Roberto Amendola
- Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile (ENEA), Il Centro Ricerche Casaccia, Sezione Tossicologia e Scienze Biomediche (BAS-BIOTECMED), Rome, Italy
| | - Francesco Cecconi
- Laboratory of Molecular Neuroembryology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
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5
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Bell MR, Belarde JA, Johnson HF, Aizenman CD. A neuroprotective role for polyamines in a Xenopus tadpole model of epilepsy. Nat Neurosci 2011; 14:505-12. [PMID: 21378970 DOI: 10.1038/nn.2777] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 01/24/2011] [Indexed: 11/09/2022]
Abstract
Polyamines are endogenous molecules involved in cell damage following neurological insults, although it is unclear whether polyamines reduce or exacerbate this damage. We used a developmental seizure model in which we exposed Xenopus laevis tadpoles to pentylenetetrazole (PTZ), a known convulsant. We found that, after an initial PTZ exposure, seizure onset times were delayed in response to a second PTZ exposure 4 h later. This protective effect was a result of activity-dependent increases in synthesis of putrescine, the simplest polyamine. Unlike more complex polyamines that directly modulate ion channels, putrescine exerted its effect by altering the balance of excitation to inhibition. Tectal neuron recordings, 4 h after the initial seizure, revealed an elevated frequency of GABAergic spontaneous inhibitory postsynaptic currents. Our data suggest that this effect is mediated by an atypical pathway that converts putrescine into GABA, which then activates presynaptic GABA(B) receptors. Our data suggest that polyamines have a previously unknown neuroprotective role in the developing brain.
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Affiliation(s)
- Mark R Bell
- Department of Neuroscience, Brown University, Providence, Rhode Island, USA
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6
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Jänne J, Alhonen L, Keinänen TA, Pietilä M, Uimari A, Pirinen E, Hyvönen MT, Järvinen A. Animal disease models generated by genetic engineering of polyamine metabolism. J Cell Mol Med 2006; 9:865-82. [PMID: 16364196 PMCID: PMC6740286 DOI: 10.1111/j.1582-4934.2005.tb00385.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The polyamines putrescine, spermidine and spermine are natural components of all living cells. Although their exact cellular functions are still largely unknown, a constant supply of these compounds is required for mammalian cell proliferation to occur. Studies with animals displaying genetically altered polyamine metabolism have shown that polyamines are intimately involved in the development of diverse tumors, putrescine apparently has specific role in skin physiology and neuroprotection and the higher polyamines spermidine and spermine are required for the maintenance of pancreatic integrity and liver regeneration. In the absence of ongoing polyamine biosynthesis, murine embryogenesis does not proceed beyond the blastocyst stage. The last years have also witnessed the appearance of the first reports linking genetically altered polyamine metabolism to human diseases.
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Affiliation(s)
- Juhani Jänne
- Department of Biotechnology and Molecular Medicine, AI Virtanen Institute for Molecular Sciences, University of Kuopio, Finland.
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7
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Jänne J, Alhonen L, Pietilä M, Keinänen TA, Uimari A, Hyvönen MT, Pirinen E, Järvinen A. Genetic Manipulation of Polyamine Catabolism in Rodents. ACTA ACUST UNITED AC 2006; 139:155-60. [PMID: 16452302 DOI: 10.1093/jb/mvj035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Activation of polyamine catabolism through the overexpression of spermidine/spermine N1-acetyltransferase (SSAT) in transgenic rodents does not only lead to distorted tissue polyamine homeostasis, manifested as striking accumulation of putrescine, appearance N1-acetylspermidine and reduction of tissue spermidine and/or spermine pools, but likewise creates striking phenotypic changes. The latter include loss of hair, lipoatrophy and female infertility. Forced expression of SSAT modulates skin, prostate and intestinal carcinogenesis, induces acute pancreatitis and blocks early liver regeneration. Although many of these features are directly attributable to altered tissue polyamine pools, some of them are more likely related to the greatly accelerated flux of the polyamines caused by activated catabolism and compensatorily enhanced biosynthesis.
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Affiliation(s)
- Juhani Jänne
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio, Finland.
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8
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Abstract
The mechanisms underlying the decreased vulnerability of the immature brain to seizure-induced neuronal death remain unknown. We asked whether oxidative stress plays a role in the resistance of immature animals to seizure-induced brain damage. Mitochondrial aconitase inactivation and 8-hydroxy-2-deoxyguanosine (8-OHdG) were used as indices of steady-state mitochondrial superoxide (O(2)(-)) production and oxidative DNA damage, respectively. Kainate-induced seizures resulted in increased mitochondrial aconitase inactivation and 8-OHdG formation in adult (postnatal day 30 or more), but not in immature rats (postnatal days 12 and 21). Kainate administration did not induce manganese superoxide dismutase (MnSOD) or CuZnSOD in immature or adult rats. This developmental increase in mitochondrial O(2)(-) production and oxidative DNA damage following kainate seizures suggests that mitochondrial oxidative stress may be a key factor that renders the developing brain resistant to seizure-induced brain damage.
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Affiliation(s)
- M Patel
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Box C238, Denver, CO 80262, USA.
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9
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Pellegrini-Giampietro DE. An activity-dependent spermine-mediated mechanism that modulates glutamate transmission. Trends Neurosci 2003; 26:9-11. [PMID: 12495855 DOI: 10.1016/s0166-2236(02)00004-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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10
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Bhaskar K, Pavankumar Shetty A, Shareef MM, Ramamohan Y, Taranath Shetty K. Dinitrophenol derivatization of proteolytic products and its application in the assay of protease(s) activity. J Neurosci Methods 2002; 120:155-61. [PMID: 12385765 DOI: 10.1016/s0165-0270(02)00196-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A spectrophotometric method based on dinitrophenol (DNP) derivatization of proteolytic products was developed for monitoring the increase in NH(2)-groups as a function of protease activity. DNP derivatization of amino acids and proteolytic products was carried out at an alkaline pH of 8.8, in presence of 2,4-dinitrofluorobenzene (DNFB), followed by the stabilization of products by adjusting the pH to approximately 2.5. Using casein as substrate, under the defined assay conditions for proteases, trichloroacetic acid soluble proteolytic products were derivatized with DNFB reagent. Though alkaline pH favored the DNP derivatization of primary amino compounds, the products formed were found to be unstable. However, upon adjusting the pH to 2.5+/-0.1, DNP derivatives of amino acids and proteolytic products were found to be stable with identical lambda(max) of 395 nm. The utility of the method was evaluated by assaying the proteolytic activities of trypsin and calcium activated neutral protease (CANP). Proteolytic activity was quantified by employing the molar extinction coefficient of DNP derivatives of an equimolar concentration of glutamate and glycine. By employing this method, CANP activity in different regions of rat brain was determined. The proposed method to monitor the increase in NH(2)-end groups as a function of proteolytic activity could be employed to assay the activity of proteases.
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Affiliation(s)
- Kiran Bhaskar
- Department of Neurochemistry, National Institute of Mental Health and Neurosciences, Bangalore 560 029, India
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11
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Aizenman CD, Muñoz-Elías G, Cline HT. Visually driven modulation of glutamatergic synaptic transmission is mediated by the regulation of intracellular polyamines. Neuron 2002; 34:623-34. [PMID: 12062045 DOI: 10.1016/s0896-6273(02)00674-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Ca2+-permeable AMPARs are inwardly rectifying due to block by intracellular polyamines. Neuronal activity regulates polyamine synthesis, yet whether this affects Ca2+-AMPAR-mediated synaptic transmission is unknown. We test whether 4 hr of increased visual stimulation regulates glutamatergic retino-tectal synapses in Xenopus tadpoles. Tectal neurons containing Ca2+-AMPARs form a gradient along the rostro-caudal developmental axis. These neurons had inwardly rectifying AMPAR-mediated EPSCs. Four hours of visual stimulation or addition of intracellular spermine increased rectification in immature neurons. Polyamine synthesis inhibitors blocked the effect of visual stimulation, suggesting that visual activity regulates AMPARs via the polyamine synthesis pathway. This modulation resulted in changes in the integrative properties of tectal neurons. Regulation of polyamine synthesis by physiological stimuli is a novel form of modulation of synaptic transmission important for understanding the short-term effects of enhanced sensory experience during development.
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Affiliation(s)
- Carlos D Aizenman
- Cold Spring Harbor Laboratory, Beckman Building, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA
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12
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Liu W, Liu R, Schreiber SS, Baudry M. Role of polyamine metabolism in kainic acid excitotoxicity in organotypic hippocampal slice cultures. J Neurochem 2001; 79:976-84. [PMID: 11739609 DOI: 10.1046/j.1471-4159.2001.00650.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polyamines are ubiquitous cations that are essential for cell growth, regeneration and differentiation. Increases in polyamine metabolism have been implicated in several neuropathological conditions, including excitotoxicity. However, the precise role of polyamines in neuronal degeneration is still unclear. To investigate mechanisms by which polyamines could contribute to excitotoxic neuronal death, the present study examined the role of the polyamine interconversion pathway in kainic acid (KA) neurotoxicity using organotypic hippocampal slice cultures. Treatment of cultures with N1,N(2)-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72527), an irreversible inhibitor of polyamine oxidase, resulted in a partial but significant neuronal protection, especially in CA1 region. In addition, this pre-treatment also attenuated KA-induced increase in levels of lipid peroxidation, cytosolic cytochrome C release and glial cell activation. Furthermore, pre-treatment with a combination of cyclosporin A (an inhibitor of the mitochondrial permeability transition pore) and MDL 72527 resulted in an additive and almost total neuronal protection against KA toxicity, while the combination of MDL 72527 and EUK-134 (a synthetic catalase/superoxide dismutase mimetic) did not provide additive protection. These data strongly suggest that the polyamine interconversion pathway partially contributes to KA-induced neurodegeneration via the production of reactive oxygen species.
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Affiliation(s)
- W Liu
- Neuroscience Program, School of Medicine, University of Southern California, Los Angeles, California 90089-2520, USA
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13
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Najbauer J, Schuman EM, Mamelak AN. The aspirin metabolite sodium salicylate causes focal cerebral hemorrhage and cell death in rats with kainic acid-induced seizures. Neuroscience 2000; 99:107-17. [PMID: 10924956 DOI: 10.1016/s0306-4522(00)00158-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Aspirin (acetylsalicylic acid), and its main metabolite sodium salicylate, have been shown to protect neurons from excitotoxic cell death in vitro. The objective of our study was to investigate the possible neuroprotective effects of sodium salicylate in vivo in rats with kainic acid-induced seizures, a model for temporal lobe epilepsy in human patients. Male Sprague-Dawley rats received intraperitoneal injections of kainic acid either alone, or with sodium salicylate given before and for 40h after kainic acid injections. The control group received either phosphate-buffered saline or sodium salicylate without co-administration of kainic acid. Animals developed status epilepticus, which was aborted 1.5-2h later with diazepam. On day 3 following kainic acid-induced seizures, animals received bromodeoxyuridine to measure cellular proliferation, and were killed under anesthesia 24h later. Brains were removed, sectioned, and analysed for gross histological changes, evidence of hemorrhage, DNA fragmentation, cellular proliferation, and microglial immunohistochemistry. We report that sodium salicylate did not protect neurons from seizure-induced cell death, and to the contrary, it caused focal hemorrhage and cell death in the hippocampal formation and the entorhinal/piriform cortex of rats with kainic acid-induced seizures. Hemorrhage was never observed in animals that received vehicle, kainic acid or sodium salicylate only, which indicated that sodium salicylate exerted its effect only in animals with seizures, and was confined to select regions of the brain that undergo seizure activity. Large numbers of cells displaying DNA fragmentation were detected in the hippocampal formation, entorhinal/piriform cortex and the dorsomedial thalamic nucleus of rats that received kainic acid or kainic acid in combination with sodium salicylate. Bromodeoxyuridine immunohistochemistry revealed large numbers of proliferating cells in and around the areas with most severe neural injury induced by kainic acid or kainic acid co-administered with sodium salicylate. These same brain regions displayed intense staining with a microglia-specific marker, an indication of microglial activation in response to brain damage. In all cases, the degree of cell death, cell proliferation and microglia staining was more severe in animals that received the combination of kainic acid and sodium salicylate when compared to animals that received kainic acid alone. We hypothesize that our findings are attributable to sodium salicylate-induced blockade of cellular mechanisms that protect cells from calcium-mediated injury. These initial observations may have important clinical implications for patients with epilepsy who take aspirin while affected by these conditions, and should promote further investigation of this relationship.
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Affiliation(s)
- J Najbauer
- Division of Biology 216-76 and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
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14
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Abstract
PSD-95 is a major postsynaptic density protein that is degraded as a result of synaptic activity. We used four different methods to test the hypothesis that calpain is involved in PSD-95 turnover. Treatment of synaptic membranes with purified calpain resulted in a decrease in immunoreactivity of the native 95 kDa protein and the appearance of two smaller molecular weight species, migrating at 50 and 36 kDa, respectively. Calcium treatment of frozen-thawed brain sections produced an identical digestion pattern, an effect blocked by calpain inhibitors. N-methyl-D-aspartate treatment of organotypic hippocampal cultures produced truncation of PSD-95 and accumulation of the 36 kDa species. Finally, calpain-generated degradation products of PSD95 were prominent in neonatal hippocampus, and disappeared with postnatal development. Our data suggest that PSD-95 is a substrate for calpain, and that calpain-mediated truncation contributes to PSD-95 turnover.
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Affiliation(s)
- X Lu
- HNB 124, Neuroscience Program, USC, Los Angeles, CA 90089-2520, USA
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15
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Hayashi Y, Morizumi Y, Hattori Y, Tanaka J. Pentylenetetrazol-induced kindling stimulates the polyamine interconversion pathway in rat brain. Brain Res 1999; 828:184-8. [PMID: 10320741 DOI: 10.1016/s0006-8993(99)01362-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The levels of polyamines, N-acetylpolyamines, and GABA in the cerebral cortex and brainstem of rat brain after completion of pentylenetetrazol (PTZ)-induced kindling were investigated. Pretreatment with the polyamine oxidase inhibitor MDL72527 caused an accumulation of N1-acetylspermidine and N1-acetylspermine in normal rats. After a kindling seizure, the levels of N-acetylpolyamines were elevated, particularly in the cerebral cortex, indicating activation of polyamine interconversion. The levels of putrescine and GABA were lower in kindled rats pretreated with MDL72527. In addition, pretreatment with MDL72527 enhanced the seizure susceptibility to PTZ in normal rats. These results suggest that the polyamine interconversion pathway is involved in brain excitability, probably through the regulation of putrescine and GABA levels.
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Affiliation(s)
- Y Hayashi
- Department of Education for Handicapped Children, Naruto University of Education, Naruto, Tokushima 772-8502, Japan.
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16
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Banay-Schwartz M, DeGuzman T, Faludi G, Lajtha A, Palkovits M. Alteration of protease levels in different brain areas of suicide victims. Neurochem Res 1998; 23:953-9. [PMID: 9690737 DOI: 10.1023/a:1021028304481] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Numerous recent studies found that proteases play a major role in brain function. In addition to their role in protein turnover, they have modulatory functions and an important role in apoptosis, pathological changes, and other mechanisms. To explore possible differences in brain protein metabolism of suicide victims, we examined the activity of two proteases, cathepsin D and calpain (I and II combined), in eleven discrete areas of postmortem brain tissue of 21 victims of suicide and of 31 age- and sex-matched control subjects without a history of psychiatric or neurological disease. The levels of functionally important amino acids in five of these areas were also measured. Cathepsin D activity was found to be lower in two of eleven regions of brains of suicide victims, the parahippocampal cortex and the medial hypothalamus, by 26% and 27%, respectively. Calpain activity was lower in two different areas tested, 29% in the medulla oblongata and 26% in the lateral prefrontal cortex, and was 18% higher in the midbrain. There were no significant differences in the other areas (globus pallidus, hippocampus, amygdala, caudate nucleus, ventral tegmental area, and nucleus accumbens). Protease distribution was regionally heterogeneous--the levels in the globus pallidus were low, and in the hippocampus high, with about a two-fold difference. The length of the postmortem period for obtaining tissue, the storage time of the frozen tissue, and the age of the subject had no apparent influence on the results obtained. Although there was a tendency toward higher levels of aspartate and glycine in brain areas from suicide victims, the difference was not significant. The variations among individual brains were greater in amino acid levels than in protease levels. The findings indicate the possible role of protein metabolism in depressive or suicidal behavior.
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Affiliation(s)
- M Banay-Schwartz
- The Nathan S. Kline Inst. for Psychiatric Research, Orangeburg, NY 10962, USA.
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17
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Bi X, Chen J, Baudry M. Developmental changes in calpain activity, GluR1 receptors and in the effect of kainic acid treatment in rat brain. Neuroscience 1997; 81:1123-35. [PMID: 9330373 DOI: 10.1016/s0306-4522(97)00218-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The cellular distribution of calpain activation and glutamate receptor 1 (GluR1) subunits of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and their alterations following kainic acid-induced seizure were evaluated during postnatal development using antibodies specific for spectrin breakdown product and the C-terminus of GluR1 subunits. In the first postnatal week, most brain regions exhibited high levels of calpain activity that progressively decreased during the following weeks. The highest levels of spectrin breakdown product immunoreactivity were observed in the somata and proximal dendrites of hippocampal pyramidal cells, non-pyramidal neurons in stratum oriens, and cortical neurons. In general, during the first two postnatal weeks, kainic acid treatment induced a decrease in spectrin breakdown product immunoreactivity in neuronal cell bodies and an increase in dendritic fields. Obvious elevation in spectrin breakdown product immunoreactivity in selective non-pyramidal cells in stratum oriens started at postnatal day 14, and was further evidenced by postnatal day 21. Likewise, massive calpain activation in subpopulations of neurons in some thalamic nuclei, amygdala, and pyriform cortex was observed after the third postnatal week. GluR1 subunits were highly expressed throughout the forebrain in the first postnatal week, further increased during the second postnatal week, decreased thereafter, and reached adult levels after postnatal day 21. In cortex, intense GluR1 immunostaining was found in the somata and proximal processes of pyramidal and non-pyramidal neurons, with the non-pyramidal neurons in layers IV through VI exhibiting the densest immunolabelling. In the first two postnatal weeks, the somata of hippocampal pyramidal neurons exhibited intense GluR1 immunostaining that became more dendritic in the subsequent developmental period. While hilar cells exhibited a similar developmental pattern as CA regions, the molecular layer of dentate gyrus exhibited weak immunoreactivity from postnatal day 7 to postnatal day 14. The early increase in GluR1 immunoreactivity in hippocampal pyramidal layer following kainic acid treatment occurred throughout the developmental period, while the later decrease in CA regions, amygdala, and pyriform cortex was observed only in postnatal day 21 animals. The combined immunocytochemical studies of spectrin breakdown product localization and GluR1 expression indicate that calpain activation might play an important role in synaptic formation, developmental regulation of synaptic plasticity, and neuronal vulnerability to excitotoxicity during postnatal development. Moreover, calpain-mediated modulation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors might underlie these processes.
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Affiliation(s)
- X Bi
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520, USA
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18
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Tocco G, Bi X, Vician L, Lim IK, Herschman H, Baudry M. Two synaptotagmin genes, Syt1 and Syt4, are differentially regulated in adult brain and during postnatal development following kainic acid-induced seizures. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1996; 40:229-39. [PMID: 8872307 DOI: 10.1016/0169-328x(96)00055-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The synaptotagmins together with other vesicle proteins are thought to be essential for the docking and/or fusion of synaptic vesicles with the plasma membrane that occurs following depolarization and calcium influx in presynatic terminals. Syt4, the fourth identified member of the synaptotagmin family, is inducible in PC12 cells by depolarization and secretagogues, and in limbic regions of the adult rat brain by kainic acid-induced seizures. In the present study, we examined the time course of the seizure-induced changes in the expression of Syt4 and Syt1, both in adult animals and during the postnatal period. Syt4 was transiently induced in several structures of the adult rat brain following seizure activity with peak inductions between 4 and 8 h and overal return to control values by 30 h. No induction was observed following seizure activity in 7-day-old animals. The brain regions most sensitive to increased induction were, in decreasing order of sensitivity, hippocampal pyramidal cells dentate granule cells and piriform cortex pyramidal cells. The brain areas showing the greatest Syt4 stimulation in adults were also the areas in which Syt4 was induced by seizures earlier in development. In contrast, Syt1 mRNA was depressed in adult brains following seizure activity, particularly in the dentate granule cells. Our results suggest that the differential regulation of different synaptotagmin genes following excessive neuronal activity might participate in rapid adaptation of subsequent transmitter release.
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Affiliation(s)
- G Tocco
- Neuroscience Program, University of Southern California, Los Angeles, 90089-2520, USA
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19
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Bi X, Chang V, Siman R, Tocco G, Baudry M. Regional distribution and time-course of calpain activation following kainate-induced seizure activity in adult rat brain. Brain Res 1996; 726:98-108. [PMID: 8836550 DOI: 10.1016/0006-8993(95)01360-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Systemic injection of kainic acid (KA) in adult rat elicits a pattern of neuronal pathology which exhibits several features of human temporal lobe epilepsy. KA-induced seizure activity is accompanied by the activation of the calcium-dependent protease calpain in limbic structures. In the present study, we evaluated the spatio-temporal activation of calpain after the onset of seizure activity by immunohistochemistry using an antibody for the spectrin breakdown product (sbdp) generated by calpain-mediated spectrin proteolysis. In addition, we compared the changes in sbdp immunoreactivity with those in immunoreactivity to subunits of the Glu/AMPA receptors (GluR1 and GluR2/3). One hour after seizure onset, sbdp accumulation was observed in selected interneurons in stratum oriens and in the hilus of the dentate gyrus. By 4 h, sbdp immunoreactivity was prominent in dendritic fields of the hippocampus as well as in neurons in thalamus and piriform cortex. By 8 h, sbdp immunoreactivity had disappeared from interneurons but was localized in pyramidal cell bodies in hippocampus. Intense labeling of cell bodies and dendritic fields persisted until 5 days following KA treatment. Changes in GluR subunit immunoreactivity were mirror images of those seen for sbdp. In general, increased sbdp immunoreactivity in dendritic fields was associated with decreased GluR1 immunoreactivity. However, increased sbdp immunoreactivity in neuronal perikarya was also associated with increased GluR immunoreactivity. These results indicate that calpain activation following seizure onset exhibits a specific spatio-temporal pattern, with activation in restricted interneurons preceding widespread activation in pyramidal neurons. Calpain activation also precedes neuronal pathology and could thus represent an initial trigger for neuronal pathology. Finally, the results suggest that calpain activation produces rapid alterations in GluR subunit properties which could be involved in the hyperexcitability observed following seizure activity.
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Affiliation(s)
- X Bi
- Neuroscience Program, USC, Los Angeles 90089-2520, USA. xiaoning@hbpmb. usc.edu
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20
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Standley S, Tocco G, Tourigny MF, Massicotte G, Thompson RF, Baudry M. Developmental changes in alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor properties and expression in the rat hippocampal formation. Neuroscience 1995; 67:881-92. [PMID: 7545799 DOI: 10.1016/0306-4522(95)00075-t] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The developmental changes in alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor properties in rat hippocampus were evaluated with quantitative autoradiography of ligand binding and in situ hybridization performed in adjacent sections with antisense oligonucleotides for AMPA receptor subunits (GluR1-3, flip and flop splice variants). Specific 3H-AMPA binding in different hippocampal subfields increased between postnatal day 7 and 15 and was higher in CA3 during the postnatal period when compared to adult levels. This effect was mostly due to high levels of high affinity binding sites in cell body layers during the developmental period. By contrast, autoradiograms of 3H-AMPA binding predominantly to the low affinity binding sites indicated an absence of these sites in cell body layers and the overall levels of binding exhibited little overshoot compared to adult levels during the developmental period. The changes in binding of the antagonist of the AMPA receptor, 6-nitro-7-cyanoquinoxaline-2,3-dione were markedly different from those for the high affinity AMPA binding sites but quite similar to those for the low affinity sites. The binding was extremely low at postnatal day 7 and increased rapidly between postnatal day 7 and 15 and slowly between postnatal day 15 and adult. Low levels of binding were observed in the cell body layer at every postnatal age. The changes in expression of messenger RNAs for the different subunits of the AMPA receptors were well correlated with the modifications in high affinity AMPA binding sites measured in the cell body layers also exhibiting an increased expression of the receptors at the transcriptional level during the developmental period as compared to adult levels. The relative expression of the GluR2 subunits decreased during the postnatal period and the time course for this reduction paralleled that for the increased vulnerability of hippocampal pyramidal neurons to a variety of insults. The results indicate that both the messenger RNAs for the subunits and the AMPA receptors exhibit increased levels of expression during the postnatal period compared to adult levels. They also suggest that nascent receptors might bind AMPA with high affinity before their insertion in membranes into functional receptors that have low affinity for agonists and high affinity for antagonists. The changes in subunit composition of the receptors during the postnatal period may have important implications for mechanisms of plasticity as well as of neuropathology.
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Affiliation(s)
- S Standley
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520, USA
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21
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Hayashi Y, Baudry M. Effect of kainate-induced seizure activity on the polyamine interconversion pathway in juvenile rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1995; 87:96-9. [PMID: 7554238 DOI: 10.1016/0165-3806(95)00053-g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The activity of the polyamine interconversion pathway was investigated in the hippocampus and piriform cortex after systemic KA administration in juvenile rats. Pretreatment of 7-day-old rats with the polyamine oxidase inhibitor, MDL 72527, induced a similar accumulation of N-acetylspermidine and N-acetylspermine in control and kainate-treated animals. The results indicate that KA-induced seizure activity has no effect on the polyamine interconversion pathway in developing rat brain.
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Affiliation(s)
- Y Hayashi
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520, USA
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22
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Abstract
Several indices of free radical generation were determined in limbic structures after kainate (KA)-induced seizure activity in adult and postnatal day (PND) 12 and 17 rats. Superoxide dismutase, catalase, and glutathione peroxidase activities were measured in piriform cortex and hippocampal subfields at 8, 16, 48 h, and 5 days after KA injection in adults and pups, and also at 3 weeks postinjection in adults. KA-induced seizure activity had no significant effect on enzyme activities in PND 12 and 17 rats. In adults, superoxide dismutase and catalase activities were significantly increased at 5 days after KA administration, and returned to preinjection levels by 3 weeks. Glutathione peroxidase activity was also increased significantly at 5 days postinjection, but remained elevated at 3 weeks. Lipid peroxidation, as indicated by malondialdehyde (MDA) concentration, exhibited an early significant increase at 8 and 16 h, followed at 48 h and 5 days by a significant decrease. At 3 weeks postinjection, MDA levels were still significantly decreased in CA3 and dentate gyrus. KA administration in PND 12 and 17 rats had no significant effect on MDA content. KA-induced seizure activity in adults also resulted in a large and sustained increase in protein oxidation in piriform cortex and hippocampus. The early increase in MDA and protein oxidation in adult rats strongly suggests the involvement of oxygen free radicals in the initial phases of KA-induced pathology, whereas the changes in scavenging enzyme activities and MDA content at 5 days and 3 weeks post KA injection possibly reflect glial proliferation subsequent to neuronal death.
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Affiliation(s)
- A J Bruce
- Program in Neuroscience, University of Southern California, Los Angeles 90089-2520, USA
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23
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Bruce AJ, Sakhi S, Schreiber SS, Baudry M. Development of kainic acid and N-methyl-D-aspartic acid toxicity in organotypic hippocampal cultures. Exp Neurol 1995; 132:209-19. [PMID: 7540554 DOI: 10.1016/0014-4886(95)90026-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The excitotoxic effects of N-methyl-D-aspartic acid (NMDA) and kainic acid (KA) were studied in organotypic hippocampal slices maintained in vitro for various periods of time. Cultures aged to equivalent Postnatal Day (EPD) 10-12, 15-17, and 23-26 were exposed to 50 microM KA or 50 microM NMDA and were analyzed at 0, 3, 6, 9, 12, 24, 48 h, or 5 days after the initiation of the excitotoxin exposure. Neuronal injury was determined by: (1) propidium iodide (PI) uptake; (2) lactate dehydrogenase (LDH) release; (3) morphological damage in hematoxylin and eosin (H/E) stained sections; (4) loss of Nissl stain. Changes in PI uptake and LDH release after KA or NMDA treatment indicated that there was a developmental shift towards increasing sensitivity to KA toxicity during in vitro development, whereas cultures of all ages were equally sensitive to NMDA toxicity. The profile of damage in H/E-stained sections after treatment with KA or NMDA indicated a transient phase of damaged morphology at 12 and 24 h that was not evident after 5 days. To determine whether the disappearance of morphological manifestations of neuronal damage 5 days after treatment was due to recovery of morphology or to neuronal death, neuronal loss in Nissl-stained sections was also quantified. KA treatment did not cause significant neuronal loss in any hippocampal region in EPD 10-12 cultures, indicating that the neurons were able to successfully recover from the damage demonstrated in H/E sections at 12 and 24 h in these cultures. KA treatment in mature cultures (EPD 23-26) and NMDA treatment in all cultures produced a marked loss of identifiable Nissl-stained neurons at 5 days, indicating neuronal death and disintegration. The results provide further support for the similarities between the organotypic hippocampal culture model and in vivo excitotoxic models and also confirm that excitotoxic neuronal injury can be reversible under some conditions.
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Affiliation(s)
- A J Bruce
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520, USA
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24
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Baudry M, Najm I. Kainate-induced seizure activity stimulates the polyamine interconversion pathway in rat brain. Neurosci Lett 1994; 171:151-4. [PMID: 8084478 DOI: 10.1016/0304-3940(94)90627-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Systemic injection of kainic acid in adult rat is accompanied by a large increase in the accumulation of acetylated derivatives of spermidine and spermine in the hippocampus and piriform cortex of animals pretreated with the polyamine oxidase inhibitor, MDL 72527. Furthermore, the activity of the enzyme spermine/spermidine acetyltransferase is increased at 8 and 16 h after kainate injection in piriform cortex and hippocampus. These results indicate that the polyamine interconversion pathway is rapidly activated in limbic areas following kainate-induced seizure activity, and suggest that this pathway might participate in the resulting neuronal damage.
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Affiliation(s)
- M Baudry
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520
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25
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Najm I, Schreiber SS, Baudry M. Transcriptional activation of ornithine decarboxylase in adult and neonatal hippocampal slices. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1993; 74:193-7. [PMID: 8403382 DOI: 10.1016/0165-3806(93)90004-t] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Ornithine decarboxylase (ODC) is the rate-limiting enzyme in polyamine synthesis and is regulated by both transcription-dependent and transcription-independent mechanisms. We compared the effects of asparagine, an amino acid previously shown to increase ODC activity in adult hippocampal slices, on ODC mRNA and activity in adult and neonatal hippocampal slices. In addition, we evaluated the effects of asparagine on ODC activity following seizure activity elicited by systemic administration of kainic acid (KA) in both adult and neonatal rats. Asparagine produced an increase in ODC gene expression and activity in both adult and neonatal hippocampal slices. The increase in ODC activity elicited by asparagine in hippocampal slices was the same in control animals as in animals sacrificed 16 h after KA-induced seizure activity. The asparagine-elicited increase in ODC activity in neonatal and adult hippocampal slices was blocked by the RNA synthesis inhibitor, actinomycin D. Finally, polyamines produced an inhibition of ODC activity in neonatal hippocampal slices. The results indicate that the regulation of the expression and activity of ODC is similar in neonatal and adult hippocampus.
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Affiliation(s)
- I Najm
- Neuroscience Program, University of Southern California, Los Angeles 90089-2520
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