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Li F, Liu L. Comparison of kainate-induced seizures, cognitive impairment and hippocampal damage in male and female mice. Life Sci 2019; 232:116621. [PMID: 31269415 DOI: 10.1016/j.lfs.2019.116621] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/11/2019] [Accepted: 06/29/2019] [Indexed: 12/22/2022]
Abstract
Kainate (KA) mouse model induced by intraperitoneal injection has been widely used for epilepsy and neurodegeneration studies. KA elicits sustained epileptic activity in mouse brain revealed by recurrent behavioral seizures, deteriorative neurodegeneration and various neurological deficits. However, to date, the vast majority of the studies used male mice only, and few studies on the comparison of brain injury between male and female mice in this model were reported. Epidemiological studies indicate that sex may affect the susceptibility to seizure response and neurodegeneration process. Therefore, this study focused on the effect of sex difference on KA-induced recurrent seizures and mortality, locomotor activity and cognitive impairment, and hippocampal neurodegeneration and reactive gliosis in mice. Our results showed that, compared to females, adult male mice exhibited worse performance in mortality rate, severity of epileptic seizures, and cognitive impairment indicated by novel object recognition task. Unexpectedly, post-KA male and female mice underwent similar decline and recovery of locomotor activity. KA-induced neurodegeneration in the whole hippocampus, particularly in CA1 and CA3 subregions, along with the deteriorative reactive gliosis in astrocytes and microglia, was more severe in males than that in females. These data provided the direct in vivo evidence that indicates the key role of sex difference in studies with KA mouse model, and this could be beneficial for optimizing the design of future studies.
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Affiliation(s)
- Fengling Li
- Department of Pharmacy, Linyi Tumor Hospital, Linyi, Shandong 276001, China
| | - Lei Liu
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
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2
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Robson JP, Wagner B, Glitzner E, Heppner FL, Steinkellner T, Khan D, Petritsch C, Pollak DD, Sitte HH, Sibilia M. Impaired neural stem cell expansion and hypersensitivity to epileptic seizures in mice lacking the EGFR in the brain. FEBS J 2018; 285:3175-3196. [PMID: 30028091 PMCID: PMC6174950 DOI: 10.1111/febs.14603] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/18/2018] [Accepted: 07/17/2018] [Indexed: 12/20/2022]
Abstract
Mice lacking the epidermal growth factor receptor (EGFR) develop an early postnatal degeneration of the frontal cortex and olfactory bulbs and show increased cortical astrocyte apoptosis. The poor health and early lethality of EGFR−/− mice prevented the analysis of mechanisms responsible for the neurodegeneration and function of the EGFR in the adult brain. Here, we show that postnatal EGFR‐deficient neural stem cells are impaired in their self‐renewal potential and lack clonal expansion capacity in vitro. Mice lacking the EGFR in the brain (EGFRΔbrain) show low penetrance of cortical degeneration compared to EGFR−/− mice despite genetic recombination of the conditional allele. Adult EGFRΔ mice establish a proper blood–brain barrier and perform reactive astrogliosis in response to mechanical and infectious brain injury, but are more sensitive to Kainic acid‐induced epileptic seizures. EGFR‐deficient cortical astrocytes, but not midbrain astrocytes, have reduced expression of glutamate transporters Glt1 and Glast, and show reduced glutamate uptake in vitro, illustrating an excitotoxic mechanism to explain the hypersensitivity to Kainic acid and region‐specific neurodegeneration observed in EGFR‐deficient brains.
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Affiliation(s)
- Jonathan P Robson
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Austria
| | - Bettina Wagner
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Austria
| | - Elisabeth Glitzner
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Austria
| | - Frank L Heppner
- Department of Neuropathology, Cluster of Excellence, NeuroCure, Charité - Universitätsmedizin Berlin, Germany
| | - Thomas Steinkellner
- Centre for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Austria
| | - Deeba Khan
- Centre for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Austria
| | - Claudia Petritsch
- Department of Neurological Surgery, UCSF Broad Institute of Regeneration Medicine, University of California San Francisco, CA, USA
| | - Daniela D Pollak
- Centre for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Austria
| | - Harald H Sitte
- Centre for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Austria
| | - Maria Sibilia
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Austria
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Li F, Liu L. SIRT5 Deficiency Enhances Susceptibility to Kainate-Induced Seizures and Exacerbates Hippocampal Neurodegeneration not through Mitochondrial Antioxidant Enzyme SOD2. Front Cell Neurosci 2016; 10:171. [PMID: 27445698 PMCID: PMC4922023 DOI: 10.3389/fncel.2016.00171] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022] Open
Abstract
Epilepsy is a common and serious neurological disorder characterized by occurrence of recurrent spontaneous seizures, and emerging evidences support the association of mitochondrial dysfunction with epilepsy. Sirtuin 5 (SIRT5), localized in mitochondrial matrix, has been considered as an important functional modulator of mitochondria that contributes to ageing and neurological diseases. Our data shows that SIRT5 deficiency strikingly increased mortality rate and severity of response to epileptic seizures, dramatically exacerbated hippocampal neuronal loss and degeneration in mice exposed to Kainate (KA), and triggered more severe reactive astrogliosis. We found that the expression of mitochondrial SIRT5 of injured hippocampus was relatively up-regulated, indicating its potential contribution to the comparably increased survival of these cells and its possible neuroprotective role. Unexpectedly, SIRT5 seems not to apparently alter the decline of antioxidant enzymes superoxide dismutase 2 (SOD2) and glutathione peroxidase (GPx) in hippocampus caused by KA exposure in our paradigm, which indicates the protective role of SIRT5 on seizures and cellular degeneration might through different regulatory mechanism that would be explored in the future. In the present study, we provided strong evidences for the first time to demonstrate the association between SIRT5 and epilepsy, which offers a new understanding of the roles of SIRT5 in mitochondrial functional regulation. The neuroprotection of SIRT5 in KA-induced epileptic seizure and neurodegeneration will improve our current knowledge of the nature of SIRT5 in central nervous system (CNS) and neurological diseases.
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Affiliation(s)
- Fengling Li
- Department of Pharmacy, Linyi Tumor Hospital Linyi, Shandong, China
| | - Lei Liu
- Department of Anesthesiology, University of FloridaGainesville, FL, USA; Center for Translational Research in Neurodegenerative Disease, University of FloridaGainesville, FL, USA
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Chan CB, Chen Y, Liu X, Papale L, Escayg A, Mei L, Ye K. Essential role of PIKE GTPases in neuronal protection against excitotoxic insults. Adv Biol Regul 2013; 52:66-76. [PMID: 21925531 DOI: 10.1016/j.advenzreg.2011.09.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 09/06/2011] [Indexed: 11/19/2022]
Affiliation(s)
- Chi Bun Chan
- Department of Pathology and Laboratory Medicine, USA
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5
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Krajewska M, You Z, Rong J, Kress C, Huang X, Yang J, Kyoda T, Leyva R, Banares S, Hu Y, Sze CH, Whalen MJ, Salmena L, Hakem R, Head BP, Reed JC, Krajewski S. Neuronal deletion of caspase 8 protects against brain injury in mouse models of controlled cortical impact and kainic acid-induced excitotoxicity. PLoS One 2011; 6:e24341. [PMID: 21957448 PMCID: PMC3174961 DOI: 10.1371/journal.pone.0024341] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 08/09/2011] [Indexed: 11/25/2022] Open
Abstract
Background Acute brain injury is an important health problem. Given the critical position of caspase 8 at the crossroads of cell death pathways, we generated a new viable mouse line (Ncasp8−/−), in which the gene encoding caspase 8 was selectively deleted in neurons by cre-lox system. Methodology/Principal Findings Caspase 8 deletion reduced rates of neuronal cell death in primary neuronal cultures and in whole brain organotypic coronal slice cultures prepared from 4 and 8 month old mice and cultivated up to 14 days in vitro. Treatments of cultures with recombinant murine TNFα (100 ng/ml) or TRAIL (250 ng/mL) plus cyclohexamide significantly protected neurons against cell death induced by these apoptosis-inducing ligands. A protective role of caspase 8 deletion in vivo was also demonstrated using a controlled cortical impact (CCI) model of traumatic brain injury (TBI) and seizure-induced brain injury caused by kainic acid (KA). Morphometric analyses were performed using digital imaging in conjunction with image analysis algorithms. By employing virtual images of hundreds of brain sections, we were able to perform quantitative morphometry of histological and immunohistochemical staining data in an unbiased manner. In the TBI model, homozygous deletion of caspase 8 resulted in reduced lesion volumes, improved post-injury motor performance, superior learning and memory retention, decreased apoptosis, diminished proteolytic processing of caspases and caspase substrates, and less neuronal degeneration, compared to wild type, homozygous cre, and caspase 8-floxed control mice. In the KA model, Ncasp8−/− mice demonstrated superior survival, reduced seizure severity, less apoptosis, and reduced caspase 3 processing. Uninjured aged knockout mice showed improved learning and memory, implicating a possible role for caspase 8 in cognitive decline with aging. Conclusions Neuron-specific deletion of caspase 8 reduces brain damage and improves post-traumatic functional outcomes, suggesting an important role for this caspase in pathophysiology of acute brain trauma.
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Affiliation(s)
- Maryla Krajewska
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Zerong You
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Juan Rong
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Christina Kress
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Xianshu Huang
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Jinsheng Yang
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Tiffany Kyoda
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Ricardo Leyva
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Steven Banares
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Yue Hu
- Department of Anesthesiology, University of California San Diego, La Jolla, California, United States of America
- VA San Diego Healthcare System, San Diego, California, United States of America
| | - Chia-Hung Sze
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Michael J. Whalen
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Leonardo Salmena
- Department of Medical Biophysics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Razqallah Hakem
- Department of Medical Biophysics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Brian P. Head
- Department of Anesthesiology, University of California San Diego, La Jolla, California, United States of America
| | - John C. Reed
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (SK); (JCR)
| | - Stan Krajewski
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (SK); (JCR)
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Valnegri P, Khelfaoui M, Dorseuil O, Bassani S, Lagneaux C, Gianfelice A, Benfante R, Chelly J, Billuart P, Sala C, Passafaro M. A circadian clock in hippocampus is regulated by interaction between oligophrenin-1 and Rev-erbα. Nat Neurosci 2011; 14:1293-301. [DOI: 10.1038/nn.2911] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 07/21/2011] [Indexed: 11/09/2022]
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Metabotropic actions of kainate receptors in the control of glutamate release in the hippocampus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 717:39-48. [PMID: 21713665 DOI: 10.1007/978-1-4419-9557-5_4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Kainate-type glutamate receptors (KARs) structurally present the credentials of the other ionotropic glutamate receptor (iGluR) family members (NMDA and AMPA receptors), but functionally often purport examples of a metabotropic mode of operation. In the present chapter, we describe these metabotropic roles of KARs in the modulation of glutamate release in the hippocampus at CA3 Schaffer Collateral (SC)-CA1 Pyramidal Cell (PC) synapses and dentate gyrus granule cell Mossy Fiber (MF)-CA3 PC synapses. As autoreceptors on SC terminals, KARs inhibit the release of glutamate at SC-CA1 PC synapses through a mechanism dependent on a pertussis toxin-sensitive G(i/o) protein thought to couple via its Gβγ subunit to a decrease in Ca(2+) channel function. At MF-CA3 PC synapses, autoreceptors on MF terminals respond diametrically depending on the agonist concentration. At low KA concentrations (< 100 nM), a G-protein-independent process invokes the activation of proteins kinase A (PKA) to effect a facilitation of glutamate release. This facilitation possibly involves the Ca(2+)-dependent (rather than GPCR-dependent) activation of adenylate cyclase (AC). At high KA concentrations (<100 nM), a mechanism involving a pertussis toxin-sensitive G(i/o) protein is invoked to inhibit AC activity and thereby suppress PKA activity. Taken together with the heterosynaptic regulation of GABA release by KARs working with a metabotropic modus operandi, there is therefore compelling evidence that these ionotropic glutamate receptors are involved in a noncanonical modulation of glutamate release that does not rely on their typical ionotropic activity.
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Chihara K, Saito A, Murakami T, Hino SI, Aoki Y, Sekiya H, Aikawa Y, Wanaka A, Imaizumi K. Increased vulnerability of hippocampal pyramidal neurons to the toxicity of kainic acid in OASIS-deficient mice. J Neurochem 2009; 110:956-65. [PMID: 19549009 DOI: 10.1111/j.1471-4159.2009.06188.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The endoplasmic reticulum (ER) stress response is a defense system for dealing with the accumulation of unfolded proteins in the ER lumen. Old astrocyte specifically induced substance (OASIS) is known to be expressed in astrocytes and involved in the ER stress response; however the function of OASIS in the injured brain has remained unclear. In this study, we examined the roles of OASIS in neuronal degeneration in the hippocampi of mice intraperitoneally injected with kainic acid (KA). OASIS mRNA was strongly induced in response to KA injection, with a similar time course to the induction of ER molecular chaperone immunoglobulin heavy chain binding protein mRNA. In situ hybridization showed that KA injection causes induction of immunoglobulin heavy chain binding protein mRNA in glial fibrillary acidic protein-positive astrocytes as well as in pyramidal neurons, although up-regulation of OASIS mRNA was only detected in glial fibrillary acidic protein-positive astrocytes. Primary cultured astrocytes, but not the neurons of OASIS-/- mice, revealed reduced vulnerability to ER stress. Furthermore, pyramidal neurons in the hippocampi of OASIS-/- mice were more susceptible to the toxicity induced by KA than those of wild-type mice. Taken together, these data suggest that OASIS expressed in astrocytes plays important roles in protection against the neuronal damage induced by KA.
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Affiliation(s)
- Kazuyasu Chihara
- Division of Molecular and Cellular Biology, Department of Anatomy, Faculty of Medicine, University of Miyazaki, Kihara, Kiyotake, Miyazaki, Japan
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9
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Tucholski J, Roth KA, Johnson GVW. Tissue transglutaminase overexpression in the brain potentiates calcium-induced hippocampal damage. J Neurochem 2006; 97:582-94. [PMID: 16539654 DOI: 10.1111/j.1471-4159.2006.03780.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tissue transglutaminase (tTG) post-translationally modifies proteins in a calcium-dependent manner by incorporation of polyamines, deamination or crosslinking. Moreover, tTG can also bind and hydrolyze GTP. tTG is the major transglutaminase in the mammalian nervous system, localizing predominantly in neurons. Although tTG has been clearly demonstrated to be elevated in neurodegenerative diseases and in response to acute CNS injury, its role in these pathogenic processes remains unclear. Transgenic mice that overexpress human tTG (htTG) primarily in CNS neurons were generated to explore the role of tTG in the nervous system and its contribution to neuropathological processes. tTG transgenic mice were phenotypically normal and were born with the expected Mendelian frequency. However, when challenged systemically with kainic acid, tTG transgenic mice, in comparison to wild-type (WT) mice, developed more extensive hippocampal neuronal damage. This was evidenced by a decreased number of healthy neurons, and increased terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) labeling as an indicator of neuronal cell death in the kainic acid-treated transgenic mice. Moreover, the duration and severity of seizures developed by htTG transgenics in response to kainic acid administration were significantly more pronounced than those observed in WT mice. These data indicate for the first time that tTG may play an active role in excitatory amino acid-induced neuronal cell death, which has been postulated to be an important component of acute CNS injury and chronic CNS neurodegenerative conditions.
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Affiliation(s)
- Janusz Tucholski
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, 35294, USA
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10
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Jung YS, Lee BK, Park HS, Shim JK, Kim SU, Lee SH, Baik EJ, Moon CH. Activation of protein kinase C-delta attenuates kainate-induced cell death of cortical neurons. Neuroreport 2005; 16:741-4. [PMID: 15858417 DOI: 10.1097/00001756-200505120-00017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the role of individual protein kinase C (PKC) isoforms during kainate toxicity in cortical neurons. Treatment with 50 microM kainate induced isoform-specific activation of PKC-delta according to the translocation from the soluble to the particulate fraction, while it caused remarkable decreases in PKC alpha, beta, epsilon and zeta in both fractions. Kainate-induced neuronal death was significantly increased by pharmacological inhibition of PKC-delta with rottlerin, suggesting a protective role of PKC-delta against kainate toxicity. A PKC activator phorbol 12-myristate 13-acetate remarkably attenuated the kainate-induced neuronal death. Although phorbol 12-myristate 13-acetate activates PKC-epsilon and PKC-delta, the protective effect of phorbol 12-myristate 13-acetate was almost completely abolished by rottlerin, but not by epsilonV1-2. These results suggest that activation of PKC-delta attenuates the kainate-induced cell death of cortical neurons.
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Affiliation(s)
- Yi-Sook Jung
- Department of Physiology, School of Medicine, Ajou University, Suwon, Kyungkido 442-749, Korea.
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11
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Wu Y, Zhang D, Lou D, Fan Y, Aronow B, Xu M, Zhang J. c-fos regulates neuropeptide Y expression in mouse dentate gyrus. Neurosci Lett 2004; 363:6-10. [PMID: 15157984 DOI: 10.1016/j.neulet.2004.02.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 02/04/2004] [Accepted: 02/11/2004] [Indexed: 11/21/2022]
Abstract
Excitotoxicity by which excitatory amino acid induces neuronal cell death may underlie mechanisms of neurodegenerative diseases. We previously found that c-fos is critically involved in neuronal excitability and survival. Mice that carry hippocampal mutations of c-fos exhibited hyper-excitability, hyper-excitotoxicity and higher mortality in kainic acid (KA)-induced seizures compared to wild-type mice. To further understand the neuroprotective signal transduction pathways regulated by c-fos in the hippocampal formation, we identified 172 genes that are either regulated by KA or are differentially expressed in wild-type and hippocampal-specific c-fos mutant mice using cDNA microarrays. One gene encodes the neuropeptide Y (NPY). We confirmed that c-fos regulates the expression of NPY by using immunohistochemistry. We found that c-fos is critical in up-regulation of NPY expression in the granule cell layer of dentate gyrus in response to KA administration. As NPY is an important endogenous anti-epileptic agent, our result is consistent with a hypothesis that the neuroprotective function of c-fos is mediated in part by regulation of NPY expression.
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Affiliation(s)
- Yongfei Wu
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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12
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Kim AH, Yano H, Cho H, Meyer D, Monks B, Margolis B, Birnbaum MJ, Chao MV. Akt1 regulates a JNK scaffold during excitotoxic apoptosis. Neuron 2002; 35:697-709. [PMID: 12194869 DOI: 10.1016/s0896-6273(02)00821-8] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cell survival is determined by a balance among signaling cascades, including those that recruit the Akt and JNK pathways. Here we describe a novel interaction between Akt1 and JNK interacting protein 1 (JIP1), a JNK pathway scaffold. Direct association between Akt1 and JIP1 was observed in primary neurons. Neuronal exposure to an excitotoxic stimulus decreased the Akt1-JIP1 interaction and concomitantly increased association between JIP1 and JNK. Akt1 interaction with JIP1 inhibited JIP1-mediated potentiation of JNK activity by decreasing JIP1 binding to specific JNK pathway kinases. Consistent with this view, neurons from Akt1-deficient mice exhibited higher susceptibility to kainate than wild-type littermates. Overexpression of Akt1 mutants that bind JIP1 reduced excitotoxic apoptosis. These results suggest that Akt1 binding to JIP1 acts as a regulatory gate preventing JNK activation, which is released under conditions of excitotoxic injury.
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Affiliation(s)
- Albert H Kim
- Molecular Neurobiology Program, Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
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13
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Zhang J, Zhang D, McQuade JS, Behbehani M, Tsien JZ, Xu M. c-fos regulates neuronal excitability and survival. Nat Genet 2002; 30:416-20. [PMID: 11925568 DOI: 10.1038/ng859] [Citation(s) in RCA: 230] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Excitotoxicity is a process in which glutamate or other excitatory amino acids induce neuronal cell death. Accumulating evidence suggests that excitotoxicity may contribute to human neuronal cell loss caused by acute insults and chronic degeneration in the central nervous system. The immediate early gene (IEG) c-fos encodes a transcription factor. The c-Fos proteins form heterodimers with Jun family proteins, and the resulting AP-1 complexes regulate transcription by binding to the AP-1 sequence found in many cellular genes. Emerging evidence suggests that c-fos is essential in regulating neuronal cell survival versus death. Although c-fos is induced by neuronal activity, including kainic acid-induced seizures, whether and how c-fos is involved in excitotoxicity is still unknown. To address this issue, we generated a mouse in which c-fos expression is largely eliminated in the hippocampus. We found that these mutant mice have more severe kainic acid-induced seizures, increased neuronal excitability and neuronal cell death, compared with control mice. Moreover, c-Fos regulates the expression of the kainic acid receptor GluR6 and brain-derived neurotrophic factor (BDNF), both in vivo and in vitro. Our results suggest that c-fos is a genetic regulator for cellular mechanisms mediating neuronal excitability and survival.
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Affiliation(s)
- Jianhua Zhang
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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14
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Zhang J, Lee H, Agarwala A, Wen Lou D, Xu M. Dna fragmentation factor 45 mutant mice exhibit resistance to kainic acid-induced neuronal cell death. Biochem Biophys Res Commun 2001; 285:1143-9. [PMID: 11478773 DOI: 10.1006/bbrc.2001.5313] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Excitotoxicity is a process where glutamate or other excitatory amino acids induce neuronal cell death. Emerging evidence suggests that apoptosis plays a key part in excitotoxic neurodegeneration. The DNA fragmentation factor 45 (DFF45 or ICAD) is a subunit of a heterodimeric DNase complex crucial for DNA fragmentation during apoptosis. Using a DFF45 mutant mouse model, we previously found that DFF45 deficient cells are more resistant to apoptosis than normal control cells. To investigate whether the lack of DFF45 may attenuate neuronal cell death induced by excitotoxicity, we compared kainic acid-induced seizure behavior and neuronal cell death in DFF45 mutant and wild-type control mice. We found that the mutant mice exhibit similar kainic acid-induced seizure severity compared to control mice. However, DFF45 mutant mice are more resistant than control mice to kainic acid-induced CA3 neuronal cell death. Interestingly, residual DNA degradation can be detected in the hippocampus of DFF45 mutant mice that exhibit KA-induced lesions. Our results suggest that a lack of DFF45 can lead to neuronal resistance to excessive activity-induced toxicity.
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Affiliation(s)
- J Zhang
- Department of Cell Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0521, USA
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15
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Schauwecker PE. Seizure-induced neuronal death is associated with induction of c-Jun N-terminal kinase and is dependent on genetic background. Brain Res 2000; 884:116-28. [PMID: 11082493 DOI: 10.1016/s0006-8993(00)02888-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous studies have shown that expression of c-Jun protein, as well as the c-Jun amino-terminal kinase (JNK) group of mitogen-activated protein kinases, may play a critical role in the pathogenesis of glutamate neurotoxicity. In order to define the molecular cascade that leads to c-Jun activation following excitotoxic injury and delineate whether induction of protein synthesis is related to cell death signaling cascades or those changes associated with increased seizure activity, we examined the expression of JNK-1, as well as its substrate, c-Jun and N-terminal phosphorylated c-Jun following kainic acid (KA) administration in two strains of mice. In the present study, we assessed the immunohistochemical expression of these proteins at time points between 2 h and 7 days, in excitotoxic cell death-resistant (C57BL/6) and -susceptible (FVB/N) mouse strains that were systemically injected with saline or kainic acid. No strain-related differences in the immunohistochemical expression of any of the proteins were observed in intact control mice. However, following KA administration, the magnitude and period of induction of JNK-1 protein was associated with impending cell death, while increased phosphorylation of c-Jun protein was associated with resistance to cell death. In contrast, expression of c-Jun protein does not appear to be a reliable indicator of impending cell death, as it was expressed in resistant and vulnerable subfields in mice susceptible to kainate injury. These results provide the first evidence that JNK-1 expression may be involved in producing the neuronal cell death response following excitotoxin-induced injury.
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Affiliation(s)
- P E Schauwecker
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, BMT 401, 1333 San Pablo Street, Los Angeles, CA 90033, USA.
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Liu H, Cao Y, Basbaum AI, Mazarati AM, Sankar R, Wasterlain CG. Resistance to excitotoxin-induced seizures and neuronal death in mice lacking the preprotachykinin A gene. Proc Natl Acad Sci U S A 1999; 96:12096-101. [PMID: 10518582 PMCID: PMC18418 DOI: 10.1073/pnas.96.21.12096] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epileptic seizures are associated with increases in hippocampal excitability, but the mechanisms that render the hippocampus hyperexcitable chronically (in epilepsy) or acutely (in status epilepticus) are poorly understood. Recent evidence suggests that substance P (SP), a peptide that has been implicated in cardiovascular function, inflammatory responses, and nociception, also contributes to hippocampal excitability and status epilepticus, in part by enhancing glutamate release. Here we report that mice with disruption of the preprotachykinin A gene, which encodes SP and neurokinin A, are resistant to kainate excitoxicity. The mice show a reduction in the duration and severity of seizures induced by kainate or pentylenetetrazole, and both necrosis and apoptosis of hippocampal neurons are prevented. Although kainate induced the expression of bax and caspase 3 in the hippocampus of wild-type mice, these critical intracellular mediators of cell death pathways were not altered by kainate injection in the mutant mice. These results indicate that the reduction of seizure activity and the neuroprotection observed in preprotachykinin A null mice are caused by the extinction of a SP/neurokinin A-mediated signaling pathway that is activated by seizures. They suggest that these neurokinins are critical to the control of hippocampal excitability, hippocampal seizures, and hippocampal vulnerability.
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Affiliation(s)
- H Liu
- Epilepsy Research Laboratory, Veterans Administration Medical Center, Sepulveda, CA 91343, USA.
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Behrens A, Sibilia M, Wagner EF. Amino-terminal phosphorylation of c-Jun regulates stress-induced apoptosis and cellular proliferation. Nat Genet 1999; 21:326-9. [PMID: 10080190 DOI: 10.1038/6854] [Citation(s) in RCA: 547] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
c-Jun is a major component of the heterodimeric transcription factor AP-1 and is essential for embryonic development, as fetuses lacking Jun die at mid-gestation with impaired hepatogenesis and primary Jun-/- fibroblasts have a severe proliferation defect and undergo premature senescence in vitro. c-Jun and AP-1 activities are regulated by c-Jun N-terminal phosphorylation (JNP) at serines 63 and 73 through Jun N-terminal kinases(JNKs). JNP is thought to be required for the anti-apoptotic function of c-Jun during hepatogenesis, as mice lacking the JNK kinase SEK1 exhibit liver defects similar to those seen in Jun-/- fetuses. To investigate the physiological relevance of JNP, we replaced endogenous Jun by a mutant Jun allele with serines 63 and 73 mutated to alanines (Jun(tm1wag); hereafter referred to as JunAA). Here we show that primary JunAA fibroblasts have proliferation- and stress-induced apoptotic defects, accompanied by reduced AP-1 activity. JunAA mice are viable and fertile, smaller than controls and resistant to epileptic seizures and neuronal apoptosis induced by the excitatory amino acid kainate. Primary mutant neurons are also protected from apoptosis and exhibit unaltered JNK activity. Our results provide evidence that JNP is dispensable for mouse development, and identify c-Jun as the essential substrate of JNK signalling during kainate-induced neuronal apoptosis.
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Affiliation(s)
- A Behrens
- Research Institute of Molecular Pathology, Vienna, Austria
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Yang DD, Kuan CY, Whitmarsh AJ, Rincón M, Zheng TS, Davis RJ, Rakic P, Flavell RA. Absence of excitotoxicity-induced apoptosis in the hippocampus of mice lacking the Jnk3 gene. Nature 1997; 389:865-70. [PMID: 9349820 DOI: 10.1038/39899] [Citation(s) in RCA: 981] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Excitatory amino acids induce both acute membrane depolarization and latent cellular toxicity, which often leads to apoptosis in many neurological disorders. Recent studies indicate that glutamate toxicity may involve the c-Jun amino-terminal kinase (JNK) group of mitogen-activated protein (MAP) kinases. One member of the JNK family, Jnk3, may be required for stress-induced neuronal apoptosis, as it is selectively expressed in the nervous system. Here we report that disruption of the gene encoding Jnk3 in mice caused the mice to be resistant to the excitotoxic glutamate-receptor agonist kainic acid: they showed a reduction in seizure activity and hippocampal neuron apoptosis was prevented. Although application of kainic acid imposed the same level of noxious stress, the phosphorylation of c-Jun and the transcriptional activity of the AP-1 transcription factor complex were markedly reduced in the mutant mice. These data indicate that the observed neuroprotection is due to the extinction of a Jnk3-mediated signalling pathway, which is an important component in the pathogenesis of glutamate neurotoxicity.
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Affiliation(s)
- D D Yang
- Section of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Poli A, Contestabile A, Migani P, Rossi L, Rondelli C, Virgili M, Bissoli R, Barnabei O. Kainic acid differentially affects the synaptosomal release of endogenous and exogenous amino acidic neurotransmitters. J Neurochem 1985; 45:1677-86. [PMID: 2865332 DOI: 10.1111/j.1471-4159.1985.tb10522.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Presynaptic actions of kainic acid have been tested on uptake and release mechanisms in synaptosome-enriched preparations from rat hippocampus and goldfish brain. Kainic acid increased in a Ca2+-dependent way the basal release of endogenous glutamate and aspartate from both synaptosomal preparations, with the maximum effect (40-80%) being reached at the highest concentration tested (1 mM). In addition, kainic acid potentiated, in an additive or synergic way, the release of excitatory amino acids stimulated by high K+ concentrations. Kainic acid at 1 mM showed a completely opposite effect on the release of exogenously accumulated D-[3H]aspartate. The drug, in fact, caused a marked inhibition of both the basal and the high K+-stimulated release. Kainic acid at 0.1 mM had no clear-cut effect, whereas at 0.01 mM it caused a small stimulation of the basal release. The present results suggest that kainic acid differentially affects two neurotransmitter pools that are not readily miscible in the synaptic terminals. The release from an endogenous, possibly vesiculate, pool of excitatory amino acids is stimulated, whereas the release from an exogenously accumulated, possibly cytoplasmic and carrier-mediated, pool is inhibited or slightly stimulated, depending on the external concentration of kainic acid. Kainic acid, in addition, strongly inhibits the high-affinity uptake of L-glutamate and D-aspartate in synaptic terminals. All these effects appear specific for excitatory amino acids, making it likely that they are mediated through specific recognition sites present on the membranes of glutamatergic and aspartatergic terminals. The relevance of the present findings to the mechanism of excitotoxicity of kainic acid is discussed.
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