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Rai SN, Dilnashin H, Birla H, Singh SS, Zahra W, Rathore AS, Singh BK, Singh SP. The Role of PI3K/Akt and ERK in Neurodegenerative Disorders. Neurotox Res 2019; 35:775-795. [PMID: 30707354 DOI: 10.1007/s12640-019-0003-y] [Citation(s) in RCA: 247] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/05/2019] [Accepted: 01/15/2019] [Indexed: 12/27/2022]
Abstract
Disruption of Akt and Erk-mediated signal transduction significantly contributes in the pathogenesis of various neurodegenerative diseases (NDs), such as Parkinson's disease, Alzheimer's diseases, Huntington's disease, and many others. These regulatory proteins serve as the regulator of cell survival, motility, transcription, metabolism, and progression of the cell cycle. Therefore, targeting Akt and Erk pathway has been proposed as a reasonable approach to suppress ND progression. This review has emphasized on involvement of Akt/Erk cascade in the neurodegeneration. Akt has been reported to regulate neuronal toxicity through its various substrates like FOXos, GSK3β, and caspase-9 etc. Akt is also involved with PI3K in signaling pathway to mediate neuronal survival. ERK is another kinase which also regulates proliferation, differentiation, and survival of the neural cell. There has also been much progress in developing a therapeutic molecule targeting Akt and Erk signaling. Therefore, improved understanding of the molecular mechanism behind the regulatory aspect of Akt and Erk networks can make strong impact on exploration of the neurodegenerative disease pathogenesis.
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Key Words
- 6-OHDA, 6-hydroxydopamine
- BDNF, brain-derived neurotrophic factor
- HD, Huntington disease
- MAPK, mitogen-activated protein-extracellular kinase
- MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- NDs, neurodegenerative disorders
- Nrf2, nuclear factor erythroid 2 p45-related factor 2
- PD, Parkinson’s disease
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Affiliation(s)
- Sachchida Nand Rai
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Hagera Dilnashin
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Hareram Birla
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Saumitra Sen Singh
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Walia Zahra
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Aaina Singh Rathore
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Brijesh Kumar Singh
- Department of Pathology and Cell Biology, Columbia University Medical Centre, Columbia University, New York, NY, 10032, USA
| | - Surya Pratap Singh
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
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Sun C, Fukushi Y, Wang Y, Yamamoto S. Astrocytes Protect Neurons in the Hippocampal CA3 Against Ischemia by Suppressing the Intracellular Ca 2+ Overload. Front Cell Neurosci 2018; 12:280. [PMID: 30197589 PMCID: PMC6118169 DOI: 10.3389/fncel.2018.00280] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/09/2018] [Indexed: 01/22/2023] Open
Abstract
In the hippocampus, delayed neuronal death is normally seen in neurons of the CA1 region but not in those of the CA3 region. Astrocytes have been reported to play multiple supporting or pathological roles in neuronal functioning. While evidence indicates that astrocytes could exert neuroprotective effects following ischemia, the possible underlying mechanisms remain unclear. We aimed to investigate the roles of astrocytes in the process of delayed neuronal death following transient forebrain ischemia. L-α-aminoadipic acid (L-α-AAA), an astrocyte-selective gliotoxin, was injected into the hippocampal CA3 region of rats through a cranial window to selectively damage astrocytes. Immunofluorescence staining of glial fibrillary acidic protein (GFAP) was used to evaluate the effect of L-α-AAA on astrocyte numbers. Three days after the L-α-AAA injection, transient forebrain ischemia was induced by a modification of the four-vessel occlusion procedure. Seven days after transient forebrain ischemia, hematoxylin-eosin staining was performed to reveal the morphology of hippocampal pyramidal neurons. In rats with ischemia and reperfusion, regional cerebral blood flow (rCBF) and change in intracellular Ca2+ concentration ([Ca2+]i) were separately measured in CA1 and CA3 regions. L-α-AAA injection significantly decreased the number of astrocytes in CA3, but did not affect the pattern of rCBF changes upon ischemia/reperfusion. Seven days after transient forebrain ischemia, in rats receiving L-α-AAA, delayed neuronal death comparable with that in CA1 was observed in the CA3 region. In addition, the pattern of increase in [Ca2+]i due to transient forebrain ischemia was completely changed in the hippocampal CA3. The loss of astrocytes induced a persistent increase in [Ca2+]i in the CA3 region following transient ischemia, similar to what is observed in the CA1 region. Our study indicates that astrocytes in the hippocampal CA3 region exert neuroprotective effects following transient forebrain ischemia and act by suppressing the intracellular Ca2+ overload. Furthermore, our study will most likely provide a new therapeutic strategy for brain ischemic diseases, targeted to astrocytes.
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Affiliation(s)
- Chuanqi Sun
- Department of Innovative Medical Photonics, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yasuko Fukushi
- Department of Innovative Medical Photonics, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yong Wang
- Department of Neurosurgery, First Affiliated Hospital of China Medical University, Shenyang, China
| | - Seiji Yamamoto
- Department of Innovative Medical Photonics, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Jo M, Chung AY, Yachie N, Seo M, Jeon H, Nam Y, Seo Y, Kim E, Zhong Q, Vidal M, Park HC, Roth FP, Suk K. Yeast genetic interaction screen of human genes associated with amyotrophic lateral sclerosis: identification of MAP2K5 kinase as a potential drug target. Genome Res 2017; 27:1487-1500. [PMID: 28596290 PMCID: PMC5580709 DOI: 10.1101/gr.211649.116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 06/06/2017] [Indexed: 12/13/2022]
Abstract
To understand disease mechanisms, a large-scale analysis of human–yeast genetic interactions was performed. Of 1305 human disease genes assayed, 20 genes exhibited strong toxicity in yeast. Human–yeast genetic interactions were identified by en masse transformation of the human disease genes into a pool of 4653 homozygous diploid yeast deletion mutants with unique barcode sequences, followed by multiplexed barcode sequencing to identify yeast toxicity modifiers. Subsequent network analyses focusing on amyotrophic lateral sclerosis (ALS)-associated genes, such as optineurin (OPTN) and angiogenin (ANG), showed that the human orthologs of the yeast toxicity modifiers of these ALS genes are enriched for several biological processes, such as cell death, lipid metabolism, and molecular transport. When yeast genetic interaction partners held in common between human OPTN and ANG were validated in mammalian cells and zebrafish, MAP2K5 kinase emerged as a potential drug target for ALS therapy. The toxicity modifiers identified in this study may deepen our understanding of the pathogenic mechanisms of ALS and other devastating diseases.
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Affiliation(s)
- Myungjin Jo
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
| | - Ah Young Chung
- Department of Biomedical Sciences, Korea University Ansan Hospital, Ansan-si, Gyeonggi-do, 425-707, Korea
| | - Nozomu Yachie
- Donnelly Centre and Departments of Molecular Genetics and Computer Science, University of Toronto and Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
| | - Minchul Seo
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
| | - Hyejin Jeon
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
| | - Youngpyo Nam
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
| | - Yeojin Seo
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
| | - Eunmi Kim
- Department of Biomedical Sciences, Korea University Ansan Hospital, Ansan-si, Gyeonggi-do, 425-707, Korea
| | - Quan Zhong
- Department of Biological Sciences, Wright State University, Dayton, Ohio 45435, USA
| | - Marc Vidal
- Department of Biological Sciences, Wright State University, Dayton, Ohio 45435, USA
| | - Hae Chul Park
- Department of Biomedical Sciences, Korea University Ansan Hospital, Ansan-si, Gyeonggi-do, 425-707, Korea
| | - Frederick P Roth
- Donnelly Centre and Departments of Molecular Genetics and Computer Science, University of Toronto and Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario M5G 1X5, Canada.,Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science and Engineering Institute, and Department of Biomedical Sciences, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu, 41944, Korea
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Gu N, Ge K, Hao C, Ji Y, Li H, Guo Y. Neuregulin1β Effects on Brain Tissue via ERK5-Dependent MAPK Pathway in a Rat Model of Cerebral Ischemia-Reperfusion Injury. J Mol Neurosci 2017; 61:607-616. [PMID: 28265860 DOI: 10.1007/s12031-017-0902-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/16/2017] [Indexed: 11/29/2022]
Abstract
Neuregulin1β (NRG1β), a member of the excitomotor of tyrosine kinase receptor (erbB) family, was recently shown to play a neuroprotective role in cerebral ischemia-reperfusion injury. The present study analyzed the effects and its possible signaling pathway of NRG1β on brain tissues after cerebral ischemia-reperfusion injury. A focal cerebral ischemic model was established by inserting a monofilament thread to achieve middle cerebral artery occlusion, followed by an NRG1β injection via the internal carotid artery. NRG1β injection resulted in significantly improved neurobehavioral activity according to the modified neurological severity score test. Tetrazolium chloridestaining revealed a smaller cerebral infarction volume; hematoxylin-eosin staining and transmission electron microscopy showed significantly alleviated neurodegeneration in the middle cerebral artery occlusion rats. Moreover, expression of phosphorylated MEK5, phosphorylated ERK5, and phosphorylated MEK2C increased after NRG1β treatment, and the neuroprotective effect of NRG1β was attenuated by an injection of the MEK5 inhibitor, BIX02189. Results from the present study demonstrate that NRG1β provides neuroprotection following cerebral ischemia-reperfusion injury via the ERK5-dependent MAPK pathway.
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Affiliation(s)
- Ning Gu
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China.,Institute of Integrated Medicine, Qingdao University Medical College, Qingdao, Shandong, China
| | - Keli Ge
- Institute of Integrated Medicine, Qingdao University Medical College, Qingdao, Shandong, China
| | - Cui Hao
- Institute of Cerebrovascular Diseases, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Yaqing Ji
- Institute of Integrated Medicine, Qingdao University Medical College, Qingdao, Shandong, China
| | - Hongyun Li
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China.
| | - Yunliang Guo
- Institute of Cerebrovascular Diseases, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China.
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Demyanenko SV, Panchenko SN, Uzdensky AB. Expression of neuronal and signaling proteins in penumbra around a photothrombotic infarction core in rat cerebral cortex. BIOCHEMISTRY (MOSCOW) 2016; 80:790-9. [PMID: 26531025 DOI: 10.1134/s0006297915060152] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Photodynamic impact on animal cerebral cortex using water-soluble Bengal Rose as a photosensitizer, which does not cross the blood-brain barrier and remains in blood vessels, induces platelet aggregation, vessel occlusion, and brain tissue infarction. This reproduces ischemic stroke. Irreversible cell damage within the infarction core propagates to adjacent tissue and forms a transition zone - the penumbra. Tissue necrosis in the infarction core is too fast (minutes) to be prevented, but much slower penumbral injury (hours) can be limited. We studied the changes in morphology and protein expression profile in penumbra 1 h after local photothrombotic infarction induced by laser irradiation of the cerebral cortex after Bengal Rose administration. Morphological study using standard hematoxylin/eosin staining showed a 3-mm infarct core surrounded by 1.5-2.0 mm penumbra. Morphological changes in the penumbra were lesser and decreased towards its periphery. Antibody microarrays against 224 neuronal and signaling proteins were used for proteomic study. The observed upregulation of penumbra proteins involved in maintaining neurite integrity and guidance (NAV3, MAP1, CRMP2, PMP22); intercellular interactions (N-cadherin); synaptic transmission (glutamate decarboxylase, tryptophan hydroxylase, Munc-18-1, Munc-18-3, and synphilin-1); mitochondria quality control and mitophagy (PINK1 and Parkin); ubiquitin-mediated proteolysis and tissue clearance (UCHL1, PINK1, Parkin, synphilin-1); and signaling proteins (PKBα and ERK5) could be associated with tissue recovery. Downregulation of PKC, PKCβ1/2, and TDP-43 could also reduce tissue injury. These changes in expression of some neuronal proteins were directed mainly to protection and tissue recovery in the penumbra. Some upregulated proteins might serve as markers of protection processes in a penumbra.
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Affiliation(s)
- S V Demyanenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, 344090, Russia.
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Zhang X, Zhang Q, Tu J, Zhu Y, Yang F, Liu B, Brann D, Wang R. Prosurvival NMDA 2A receptor signaling mediates postconditioning neuroprotection in the hippocampus. Hippocampus 2014; 25:286-96. [PMID: 25271147 DOI: 10.1002/hipo.22372] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2014] [Indexed: 11/11/2022]
Abstract
Ischemic postconditioning (Post C), which involves administration of a brief ischemia after the initial ischemic event, has been demonstrated to be strongly neuroprotective against global cerebral ischemia (GCI) and to improve cognitive outcome. To enhance understanding of the underlying mechanisms, the current study examined the role of NMDA receptors in mediating the beneficial effects of Post C (3 min ischemia) administered 2 days after GCI in adult male rats. The results revealed that Post C was strongly neuroprotective against GCI, and that this effect was blocked by administration of the NMDA receptor antagonist MK-801. Further work revealed that the NR2A-type NMDA receptors mediate the Post C beneficial effects as administration of a NR2A-preferring antagonist (NVP-A) blocked Post C neuroprotection and cognitive enhancement, while administration of a NR2B-preferring antagonist (Ro25) was without effect. Post C significantly up-regulated NR2A levels and phosphorylation of NR2A in the hippocampal CA1 region after Post C. Post C also increased Ca(2+) influx and activation/phosphorylation of CamKIIα at Thr(286), effects that were NR2A mediated as they were blocked by NVP-A. Phosphorylation of ERK and CREB was also increased by Post C, as were two downstream CREB-dependent prosurvival factors, brain derived neurotropic factor (BDNF) and Bcl2, effects that were blocked by the NR2A antagonist, NVP-A. Taken as a whole, the current study provides evidence that NR2A-activation and downstream prosurvival signaling is a critical mediator of Post C-induced neuroprotection and cognitive enhancement following GCI.
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Affiliation(s)
- Xi Zhang
- Neurobiology Institute of Medical Research Center, Hebei United University, Tangshan, Hebei, 063000, China
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Yang K, Cao F, Sheikh AM, Malik M, Wen G, Wei H, Ted Brown W, Li X. Up-regulation of Ras/Raf/ERK1/2 signaling impairs cultured neuronal cell migration, neurogenesis, synapse formation, and dendritic spine development. Brain Struct Funct 2012; 218:669-82. [PMID: 22555958 DOI: 10.1007/s00429-012-0420-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/18/2012] [Indexed: 11/26/2022]
Abstract
The Ras/Raf/ERK1/2 signaling pathway controls many cellular responses such as cell proliferation, migration, differentiation, and death. In the nervous system, emerging evidence also points to a death-promoting role for ERK1/2 in both in vitro and in vivo models of neuronal death. Recent studies have suggested that abnormal apoptosis in the central nervous system may be involved in the pathogenesis of autism. Two studies reported that both a microdeletion and microduplication on chromosome 16, which includes the MAPK3 gene that encodes ERK1, are associated with autism. In addition, our recent work showed that Ras/Raf/ERK1/2 signaling activities were significantly up-regulated in the frontal cortex of autistic individuals and in the BTBR murine model of autism. To further investigate how Ras/Raf/ERK1/2 up-regulation may lead to the development of autism, we developed a cellular model of Raf/ERK up-regulation by over-expressing c-Raf in cultured cortical neurons (CNs) and cerebellar granule cells (CGCs). We found that Raf/ERK up-regulation stimulates the migration of both CNs and CGCs, and impairs the formation of excitatory synapses in CNs. In addition, we found that Raf/ERK up-regulation inhibits the development of mature dendritic spines in CNs. Investigating the possible mechanisms through which Raf/ERK up-regulation affects excitatory synapse formation and dendritic spine development, we discovered that Raf/ERK up-regulation suppresses the development and maturation of CNs. Together, these results suggest that the up-regulation of the Raf/ERK signaling pathway may contribute to the pathogenesis of autism through both its impairment of cortical neuron development and causing neural circuit imbalances.
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Affiliation(s)
- Kun Yang
- Department of Neurochemistry, NY State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, NY, 10314, USA
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8
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Stroke Preconditioning to Identify Endogenous Protective or Regenerative Mechanisms. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Yang K, Sheikh AM, Malik M, Wen G, Zou H, Brown WT, Li X. Upregulation of Ras/Raf/ERK1/2 signaling and ERK5 in the brain of autistic subjects. GENES BRAIN AND BEHAVIOR 2011; 10:834-43. [PMID: 21848643 DOI: 10.1111/j.1601-183x.2011.00723.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. A number of studies have shown that the Ras/Raf/ERK1/2 (extracellular signal-regulated kinase) signaling pathway plays important roles in the genesis of neural progenitors, learning and memory. Ras/Raf/ERK1/2 and ERK5 have also been shown to have death-promoting apoptotic roles in neural cells. Recent studies have shown a possible association between neural cell death and autism. In addition, two recent studies reported that a deletion of a locus on chromosome 16, which included the mitogen-activated protein kinase 3 (MAPK3) gene that encodes ERK1, is associated with autism. Most recently, our laboratory detected that Ras/Raf/ERK1/2 signaling activities were significantly enhanced in the brain of BTBR mice that model autism, as they exhibit many autism-like behaviors. We thus hypothesized that Ras/Raf/ERK1/2 signaling and ERK5 could be abnormally regulated in the brain of autistic subjects. In this study, we show that the expression of Ras protein was significantly elevated in the frontal cortex of autistic subjects. C-Raf phosphorylation was increased in the frontal cortex, while both C-Raf and A-Raf activities were enhanced in the cerebellum of autistic subjects. We also detected that both the protein expression and activities of ERK1/2 were significantly upregulated in the frontal cortex of autistic subjects, but not in the cerebellum. Furthermore, we showed that ERK5 protein expression is upregulated in both frontal cortex and cerebellum of autistic subjects. These results suggest that the upregulation of Ras/Raf/ERK1/2 signaling and ERK5 activities mainly found in the frontal cortex of autistic subjects may be critically involved in the pathogenesis of autism.
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Affiliation(s)
- K Yang
- Department of Neurochemistry, NY State Institute for Basic Research in Developmental Disabilities, New York, NY 10314, USA
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Otani N, Nawashiro H, Nagatani K, Takeuchi S, Kobayashi H, Shima K. Mitogen-Activated Protein Kinase Pathways Following Traumatic Brain Injury. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/nm.2011.23028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Gene expression profile in rat hippocampus with and without memory deficit. Neurobiol Learn Mem 2010; 94:42-56. [PMID: 20359541 DOI: 10.1016/j.nlm.2010.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/08/2010] [Accepted: 03/25/2010] [Indexed: 01/22/2023]
Abstract
The cholinergic neuronal system, through its projections to the hippocampus, plays an important role in learning and memory. The aim of the study was to identify genes and networks in rat hippocampus with and without memory deficit. Genome-scale screening was used to analyze gene expression changes in rats submitted or not to intraparenchymal injection of 192 IgG-saporin and trained in spatial/object novelty tasks. Results showed learning processes were associated with significant expression of genes that could be grouped into several clusters of similar expression profiles and that are involved in biological functions, namely lipid metabolism, signal transduction, protein metabolism and modification, and transcription regulation. Memory loss following hippocampal cholinergic deafferentation was associated with significant expression of genes that did not show similar cluster organization. Only one cluster of genes could be identified; it included genes that would be involved in tissue remodeling. More important, most of the genes significantly altered in lesioned rats were down-regulated.
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Neuroprotection of ethanol against ischemia/reperfusion-induced brain injury through decreasing c-Jun N-terminal kinase 3 (JNK3) activation by enhancing GABA release. Neuroscience 2010; 167:1125-37. [PMID: 20219637 DOI: 10.1016/j.neuroscience.2010.02.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 01/30/2010] [Accepted: 02/09/2010] [Indexed: 01/05/2023]
Abstract
Our latest study indicated that ethanol could attenuate cerebral ischemia/reperfusion-induced brain injury through activating Ionotropic glutamate receptors Kainate Family (Gluk1)-kainate (KA) receptors and gamma-aminobutyric acid (GABA) receptors. However, the possible mechanism of the neuroprotective effects of ethanol remains unclear. In this study we report that ethanol shows neuroprotective effects against ischemic brain injury through enhancing GABA release and then decreasing c-Jun N-terminal kinase 3 (JNK3) activation. Electrophysiologic recording indicated that ethanol enhances GABA release from presynaptic neurons and the released GABA subsequently inhibits the KA receptor-mediated whole-cell currents. Moreover, our data show that ethanol can inhibit the increased assembly of the Gluk2-PSD-95-MLK3 (postsynaptic density protein-95, PSD-95 and mixed-lineage kinase 3, MLK3) module induced by cerebral ischemia and the activation of the MLK3-MKK4/7-JNK (mitogen-activated protein kinase kinase 4/7, MKK4/7) cascade. Pretreatment of the GABA(A) receptor antagonist bicuculline and antagonist of VGCC (a broad-spectrum blocker of the voltage-gated calcium channel [VGCC]) Chromic (CdCl(2)) can demolish the neuroprotective effects of ethanol. The results suggest that during ischemia-reperfusion, ethanol may activate presynaptic Gluk1-KA and facilitate Ca(2+)-dependent GABA release. The released GABA activates postsynaptic GABA(A) receptors, which suppress the ischemic depolarization and decrease the association of signaling module Gluk2-PSD-95-MLK3 induced by the activation of postsynaptic Gluk2-KA receptors. There is a raised possibility that ethanol inhibiting the JNK3 apoptotic pathway (MLK3/MKK4/7/JNK3/c-Jun/Fas-L) performs a neuroprotective function against ischemic brain injury.
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Abstract
Extracellular signal-regulated kinase (ERK) is a versatile protein kinase that regulates many cellular functions. Growing evidence suggests that ERK1/2 plays a crucial role in promoting cell death in a variety of neuronal systems, including neurodegenerative diseases. It is believed that the magnitude and the duration of ERK1/2 activity determine its cellular function. In this review, we summarize recent evidence for a role of ERK1/2 in neuronal death. Furthermore, we discuss the mechanisms involved in ERK1/2 mediating neuronal death.
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Affiliation(s)
- Srinivasa Subramaniam
- Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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14
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Qi SH, Guan QH, Wang M, Zhang GY. Action of ERK5 in ischemic tolerance suggests its probable participation in the signaling mechanism. J Recept Signal Transduct Res 2009; 29:38-43. [PMID: 19519168 DOI: 10.1080/10799890802675767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Here we examined the effects of ischemia preconditioning and ketamine, an NMDA receptor antagonist, on the activation and its nucleus translocation of ERK5 in hippocampal CA1 region. Our results showed ERK5 was not activated in rat hippocampus CA1 region. But in cytosol extracts preconditioned with 3 min of sublethal ischaemia, ERK5 activation was enhanced significantly, with two peaks occurring at 3 hr and 3 days, respectively. This activation returned to base level 3 days later. The results lead us to conclude that preconditioning increased the activations of ERK5 during reperfusion after lethal ischemia through NMDA receptor. Preconditioning increased the activation and nucleus translocation of ERK5 during reperfusion after lethal ischemia through the NMDA receptor. These findings might provide some clues to understanding the mechanism underlying ischemia tolerance and to finding clinical therapies for stroke using the endogenous neuroprotection.
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Affiliation(s)
- Su-Hua Qi
- School of Life Science and Biotechnology, China Pharmaceutical University, 24 Tongjia Street, Nanjing, PR China
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15
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Cellular and molecular neurobiology of brain preconditioning. Mol Neurobiol 2009; 39:50-61. [PMID: 19153843 DOI: 10.1007/s12035-009-8051-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 01/08/2009] [Indexed: 12/11/2022]
Abstract
The tolerant brain which is a consequence of adaptation to repeated nonlethal insults is accompanied by the upregulation of protective mechanisms and the downregulation of prodegenerative pathways. During the past 20 years, evidence has accumulated to suggest that protective mechanisms include increased production of chaperones, trophic factors, and other antiapoptotic proteins. In contrast, preconditioning can cause substantial dampening of the organism's metabolic state and decreased expression of proapoptotic proteins. Recent microarray analyses have also helped to document a role of several molecular pathways in the induction of the brain refractory state. The present review highlights some of these findings and suggests that a better understanding of these mechanisms will inform treatment of a number of neuropsychiatric disorders.
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Wang RM, Zhang QG, Li J, Yang LC, Yang F, Brann DW. The ERK5-MEF2C transcription factor pathway contributes to anti-apoptotic effect of cerebral ischemia preconditioning in the hippocampal CA1 region of rats. Brain Res 2008; 1255:32-41. [PMID: 19103177 DOI: 10.1016/j.brainres.2008.12.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/25/2008] [Accepted: 12/01/2008] [Indexed: 11/18/2022]
Abstract
The purpose of the present study was to investigate the role of myocyte enhancer binding factor 2C (MEF2C), a common substrate of p38 kinase and extracellular signal-regulated kinase 5 (ERK5) in the hippocampal CA1 region following cerebral ischemia preconditioning (CIP) and without CIP. In animals that did not undergo preconditioning, MEF2C was significantly activated with an early peak at 30 min of reperfusion, which was followed by a pronounced decrease of MEF2C protein levels in the late phase of reperfusion (3-5 d). Co-immunoprecipitation studies failed to show an interaction between ERK5 and MEF2C, and ERK5-antisense oligonucleotide (ERK5-AS) had no effect on MEF2C activation, suggesting that the MEF2C activation is mediated by a kinase other than ERK5. Following preconditioning (3 min ischemia), MEF2C was strongly activated during the late stage of reperfusion (6 h-5 d). Co-immunoprecipitation studies showed that the interaction of ERK5 and MEF2C significantly increased at 3 d of reperfusion, and this increase was markedly inhibited by ERK5-AS. Inhibition of the ERK5-MEF2C pathway resulted in a significant increase in the number of TUNEL-positive apoptotic cells compared with CIP groups in the hippocampal CA1 region, and abolished the neuroprotective effect induced by CIP. Taken together, these results demonstrate that ERK5-MEF2C signaling is significantly enhanced in the hippocampus CA1 following CIP, and that ERK5-MEF2C signaling plays a critical role in the mediation of the anti-apoptotic and neuroprotective actions of ischemic preconditioning.
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Affiliation(s)
- Rui-Min Wang
- Research Center for Molecular Biology, North China Coal Medical University, Tangshan 063000, China.
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17
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Dwivedi Y, Rizavi HS, Teppen T, Sasaki N, Chen H, Zhang H, Roberts RC, Conley RR, Pandey GN. Aberrant extracellular signal-regulated kinase (ERK) 5 signaling in hippocampus of suicide subjects. Neuropsychopharmacology 2007; 32:2338-50. [PMID: 17342168 DOI: 10.1038/sj.npp.1301372] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Extracellular signal-regulated kinase 5 (ERK5), the newest member of the mitogen-activated protein (MAP) kinase family, is regulated differently than the other MAP kinases. Emerging evidence suggest the role of ERK5 signaling in promoting cell proliferation, differentiation, neuronal survival, and neuroprotection. The present study investigates whether suicide brain is associated with alterations in components of the ERK5 signaling cascade. In the prefrontal cortex (PFC) and hippocampus of suicide subjects (n=28) and nonpsychiatric control subjects (n=21), we examined the catalytic activities and protein levels of ERK5 and upstream MAP kinase kinase MEK5 in various subcellular fractions; mRNA levels of ERK5 in total RNA; and DNA-binding activity of myocyte enhancer factor (MEF)2C, a substrate of ERK5. In the hippocampus of suicide subjects, we observed that catalytic activity of ERK5 was decreased in cytosolic and nuclear fractions, whereas catalytic activity of MEK5 was decreased in the total fraction. Further, decreased mRNA and protein levels of ERK5, but no change in protein level of MEK5 were noted. A decrease in MEF2C-DNA-binding activity in the nuclear fraction was also observed. No significant alterations were noted in the PFC of suicide subjects. The observed changes were not related to a specific psychiatric diagnosis. Our findings of reduced activation and/or expression of ERK5 and MEK5, and reduced MEF2C-DNA-binding activity demonstrate abnormalities in ERK5 signaling in hippocampus of suicide subjects and suggest possible involvement of this aberrant signaling in pathogenic mechanisms of suicide.
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Affiliation(s)
- Yogesh Dwivedi
- Department of Psychiatry, Psychiatric Institute, University of Illinois at Chicago, Chicago, IL 60612, USA.
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18
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Di Loreto S, Zimmitti V, Sebastiani P, Cervelli C, Falone S, Amicarelli F. Methylglyoxal causes strong weakening of detoxifying capacity and apoptotic cell death in rat hippocampal neurons. Int J Biochem Cell Biol 2007; 40:245-57. [PMID: 17869161 DOI: 10.1016/j.biocel.2007.07.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 07/24/2007] [Accepted: 07/25/2007] [Indexed: 01/10/2023]
Abstract
The hippocampus is known to play a crucial role in learning and memory. Recent data from literature show that cognitive problems, common to aged or diabetic patients, may be related to accumulation of toxic alpha-oxoaldehydes such as methylglyoxal. Thus, it is possible that methylglyoxal could be, at least in part, responsible for the impairment of cognitive functions, and the knowledge of the mechanisms through which this compound elicits neuronal toxicity could be useful for the development of possible therapeutic strategies. We previously reported a high susceptibility of hippocampal neurons to methylglyoxal, through an oxidation-dependent mechanism. In the present study, we extend our investigation on the molecular mechanisms which underlie methylglyoxal toxicity, focusing on possible effects on expression and activity of glyoxalases, its main detoxifying enzymes, and glutathione peroxidase, as well as on the levels of reduced glutathione. We also investigate methylglyoxal-induced modulation of brain derived neurotrophic factor and proinflammatory cytokines. Our results show that methylglyoxal causes a dramatic depletion of reduced glutathione and a significant inhibition of both glyoxalase and glutathione peroxidase activities. Furthermore, methylglyoxal treatment seems to affect the expression of inflammatory cytokines and survival factors. In conclusion, our findings suggest that methylglyoxal-induced neurotoxicity occurs through the impairment of detoxification pathway and depletion of reduced glutathione. This, in turn, triggers widespread apoptotic cell death, occurring through the convergence of both mitochondrial and Fas-receptor pathways.
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Affiliation(s)
- Silvia Di Loreto
- Institute for Organ Transplantation and Immunocytology (ITOI), CNR, P. le Collemaggio, 67100 L'Aquila, Italy.
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19
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Jover-Mengual T, Zukin RS, Etgen AM. MAPK signaling is critical to estradiol protection of CA1 neurons in global ischemia. Endocrinology 2007; 148:1131-43. [PMID: 17138646 PMCID: PMC2528200 DOI: 10.1210/en.2006-1137] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The importance of hormone therapy in affording protection against the sequelae of global ischemia in postmenopausal women remains controversial. Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which estrogens intervene in global ischemia-induced apoptotic cell death are unclear. Here we show that estradiol acts via the classical estrogen receptors, the IGF-I receptor, and the ERK/MAPK signaling cascade to protect CA1 neurons in ovariectomized female rats and gerbils. We demonstrate that global ischemia promotes early dephosphorylation and inactivation of ERK1 and the transcription factor cAMP-response element binding protein (CREB), subsequent down-regulation of the antiapoptotic protein Bcl-2, a known gene target of estradiol and CREB, and activation of caspase-3. Estradiol treatment increases basal phosphorylation of both ERK1 and ERK2 in hippocampal CA1 and prevents ischemia-induced dephosphorylation and inactivation of ERK1 and CREB, down-regulation of Bcl-2 and activation of the caspase death cascade. Whereas ERK/MAPK signaling is critical to CREB activation and neuronal survival, the impact of estradiol on Bcl-2 levels is ERK independent. These findings support a model whereby estradiol acts via the classical estrogen receptors and IGF-I receptors, which converge on activation of ERK/MAPK signaling and CREB to promote neuronal survival in the face of global ischemia.
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Affiliation(s)
- Teresa Jover-Mengual
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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20
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Di Benedetto B, Hitz C, Hölter SM, Kühn R, Vogt Weisenhorn DM, Wurst W. Differential mRNA distribution of components of the ERK/MAPK signalling cascade in the adult mouse brain. J Comp Neurol 2007; 500:542-56. [PMID: 17120291 DOI: 10.1002/cne.21186] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mitogen-activated protein kinases (MAPKs), also called extracellular signal-regulated kinases (ERKs), are a group of serine/threonine terminal protein kinases activated downstream of a pleiotrophy of transmembrane receptors. Main intracellular components of the MAPK signalling pathway are the RAF, MEK, and ERK proteins, which work in a cascade of activator and effector proteins. They regulate many fundamental cellular functions, including cell proliferation, cell survival, and cell differentiation by transducing extracellular signals to cytoplasmic and nuclear effectors. To reveal more details about possible activation cascades in this pathway, the present study gives a complete description of the differential expression of Braf, Mek1, Mek2, Mek5, Erk1, Erk2, Erk3, and Erk5 in the adult murine brain by way of in situ hybridization analysis. In this study, we found that each gene is widely expressed in the whole brain, except for Mek2, but each displays a very distinct expression pattern, leading to distinct interactions of the MAPK components within different regions. Most notably we found that 1) Braf and Erk3 are coexpressed in the hippocampus proper, confirming a possible functional interaction; 2) in most forebrain areas, Mek5 and Erk5 are coexpressed; and 3) in the neurogenic regions of the brain, namely, the olfactory bulb and the dentate gyrus, Braf is absent, indicating that other activator proteins have to take over its function. Despite these differences, our results show widespread coexpression of the pathway components, thereby confirming the hypothesis of redundant functions among several MEK and ERK proteins in some regions of the brain.
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Affiliation(s)
- Barbara Di Benedetto
- GSF National Research Center for Environment and Health, Institute of Developmental Genetics, 85764 Neuherberg, Germany
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21
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Wang RM, Yang F, Zhang YX. Preconditioning-induced activation of ERK5 is dependent on moderate Ca2+ influx via NMDA receptors and contributes to ischemic tolerance in the hippocampal CA1 region of rats. Life Sci 2006; 79:1839-46. [PMID: 16859717 DOI: 10.1016/j.lfs.2006.06.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 05/23/2006] [Accepted: 06/13/2006] [Indexed: 11/15/2022]
Abstract
Accumulating evidence implicates activation (phosphorylation) of mitogen-activated protein kinases (MAPK) during nonlethal ischemic preconditioning in the protection of hippocampal CA1 neuron against subsequent ischemic events. In this paper, we undertook to identify the role of extracellular signal regulated kinase (ERK) 5 in cerebral ischemic preconditioning (CIP). Three minutes of ischemia was induced as preconditioning stimulus. Three days later, 6 min of ischemia was induced. The levels of ERK5 protein expression and its activation were detected with or without the CIP in hippocampal CA1 and the dentate gyrus (DG) regions. Our results showed that ERK5 was activated selectively in hippocampal CA1 region with, but not without, the ischemic preconditioning. Notably, during the later phase of reperfusion, the rise in ERK5 activation was strong and persistent with a peak occurring at the third day. The activation peak was effectively prevented and ERK5 protein expression was significantly decreased by intracerebroventricular infusion of ERK5 antisense oligonucleotide (every 24 h for 3 days before the preconditioning), but not by sense oligonucleotide or vehicle. Subsequently, the CA1 neuronal loss was largely elevated. Moreover, both MK801 (10 microM), an antagonist of NMDA receptor, and EGTA (100 mM, but neither 50 nor 150 mM), an extracellular Ca2+ chelator, not only effectively inhibited the ERK5 activation but also markedly abolished CIP-induced survival of the CA1 neurons. These results suggested that activation of the ERK5 pathway by CIP was at least partly dependent on moderate Ca2+ influx via NMDA receptor, which might contribute to ischemic tolerance in hippocampal CA1 region of rats.
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Affiliation(s)
- Rui-Min Wang
- Research Center for Molecular Biology, North China Coal Medical College, Tangshan, Hebei, PR China.
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22
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Liu XM, Pei DS, Guan QH, Sun YF, Wang XT, Zhang QX, Zhang GY. Neuroprotection of Tat-GluR6-9c against neuronal death induced by kainate in rat hippocampus via nuclear and non-nuclear pathways. J Biol Chem 2006; 281:17432-17445. [PMID: 16624817 DOI: 10.1074/jbc.m513490200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies have suggested that glutamate receptor 6 (GluR6) subunit- and JNK-deficient mice can resist kainate-induced epileptic seizure and neuronal toxicity (Yang, D. D., Kuan, C.-Y., Whitmarsh, A. J., Rinoćn, M., Zheng, T. S., Davis, R. J., Rakic, P., and Flavell, R. A. (1997) Nature 389, 865-870; Mulle, C., Seiler, A., Perez-Otano, I., Dickinson-Anson, H., Castillo, P. E., Bureau, I., Maron, C., Gage, F. H., Mann, J. R., Bettler, B., and Heinemmann, S. F. (1998) Nature 392, 601-605). In this study, we show that kainate can enhance the assembly of the GluR6-PSD95-MLK3 module and facilitate the phosphorylation of JNK in rat hippocampal CA1 and CA3/dentate gyrus (DG) subfields. More important, a peptide containing the Tat protein transduction sequence (Tat-GluR6-9c) perturbed the assembly of the GluR6-PSD95-MLK3 signaling module and suppressed the activation of MLK3, MKK7, and JNK. As a result, the inhibition of JNK activation by Tat-GluR6-9c diminished the phosphorylation of the transcription factor c-Jun and down-regulated Fas ligand expression in hippocampal CA1 and CA3/DG regions. The inhibition of JNK activation by Tat-Glur6-9c attenuated Bax translocation, the release of cytochrome c, and the activation of caspase-3 in CA1 and CA3/DG subfields. Furthermore, kainate-induced neuronal loss in hippocampal CA1 and CA3 subregions was prevented by intracerebroventricular injection of Tat-Glur6 - 9c. Taken together, our findings strongly suggest that the GluR6-PSD95-MLK3 signaling module mediates activation of the nuclear and non-nuclear pathways of JNK, which is involved in brain injury induced by kainate. Tat-GluR6-9c, the peptide we constructed, gives new insight into seizure therapy.
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Affiliation(s)
- Xiao-Mei Liu
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Dong-Sheng Pei
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Qiu-Hua Guan
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Ya-Feng Sun
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Xiao-Tian Wang
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Qing-Xiu Zhang
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China
| | - Guang-Yi Zhang
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China.
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23
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Pei DS, Wang XT, Liu Y, Sun YF, Guan QH, Wang W, Yan JZ, Zong YY, Xu TL, Zhang GY. Neuroprotection against ischaemic brain injury by a GluR6-9c peptide containing the TAT protein transduction sequence. Brain 2006; 129:465-79. [PMID: 16330502 DOI: 10.1093/brain/awh700] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
It is well documented that N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors play a pivotal role in ischaemic brain injury. Recent studies have shown that kainate (KA) receptors are involved in neuronal cell death induced by seizure, which is mediated by the GluR6*PSD-95*MLK3 signalling module and subsequent c-Jun N-terminal kinase (JNK) activation. Here we investigate whether GluR6 mediated JNK activation is correlated with ischaemic brain injury. Our results show that cerebral ischaemia followed by reperfusion can enhance the assembly of the GluR6*PSD-95*MLK3 signalling module and JNK activation. As a result, activated JNK can not only phosphorylate the transcription factor c-Jun and up-regulate Fas L expression but can also phosphorylate 14-3-3 and promote Bax translocation to mitochondria, increase the release of cytochrome c and increase caspase-3 activation. These results indicate that GluR6 mediated JNK activation induced by ischaemia/reperfusion ultimately results in neuronal cell death via nuclear and non-nuclear pathways. Furthermore, the peptides we constructed, Tat-GluR6-9c, show a protective role against neuronal death induced by cerebral ischaemia/reperfusion through inhibiting the GluR6 mediated signal pathway. In summary, our results indicate that the KA receptor subunit GluR6 mediated JNK activation is involved in ischaemic brain injury and provides a new approach for stroke therapy.
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Affiliation(s)
- Dong-Sheng Pei
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, China
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24
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Subramaniam S, Unsicker K. Extracellular signal-regulated kinase as an inducer of non-apoptotic neuronal death. Neuroscience 2006; 138:1055-65. [PMID: 16442236 DOI: 10.1016/j.neuroscience.2005.12.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 11/23/2005] [Accepted: 12/01/2005] [Indexed: 11/17/2022]
Abstract
Extracellular signal-regulated kinase (ERK) is a versatile protein kinase, which has been implicated in signaling numerous biological functions ranging from embryonic development to memory formation. Recent reports, including ours, indicate that ERK plays a central role in promoting neuronal degeneration in various neuronal systems including neurodegenerative diseases. Mechanisms involved in ERK-induced neuronal degeneration are beginning to emerge. In this review, we summarize evidence suggesting ERK to be a predominant inducer of a non-apoptotic mode of neuronal death. Further, we discuss the mechanisms and the putative molecular inter-players associated with ERK-mediated neuronal death.
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Affiliation(s)
- S Subramaniam
- Neuroanatomy and Interdisciplinary Center for Neurosciences, University of Heidelberg, Im Neuenheimer Feld 307, D-69120, Heidelberg, Germany.
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25
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Zhang QG, Wang RM, Yin XH, Pan J, Xu TL, Zhang GY. Knock-down of POSH expression is neuroprotective through down-regulating activation of the MLK3-MKK4-JNK pathway following cerebral ischaemia in the rat hippocampal CA1 subfield. J Neurochem 2005; 95:784-95. [PMID: 16248889 DOI: 10.1111/j.1471-4159.2005.03435.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We investigated the expression and subcellular localization of the multidomain protein POSH (plenty of SH3s) by immunohistochemistry and western blot analysis, as well as its role in the selective activation of mixed-lineage kinases (MLKs) 3, MAP kinase kinase (MKK) 4, c-Jun N-terminal kinases (JNKs) and the c-Jun signalling cascade in the rat hippocampal CA1 region following cerebral ischaemia. Our results indicated that the cytosol immunoreactivity of POSH was strong in the CA1-CA3 pyramidal cell but weak in the DG granule cell of the rat hippocampus both in sham control and after reperfusion. Co-immunoprecipitation experiments showed that the interactions of MLK3, MKK4 and phospho-JNKs with POSH were persistently enhanced during the early (30 min) and the later reperfusion period (from 1 to 3 days) compared with sham controls. Consistently, MLK3-MKK4-JNK activation was rapidly increased with peaks both at 30 min and 3 days of reperfusion. Intracerebroventricular infusion of POSH antisense oligodeoxynucleotides (AS-ODNs) not only significantly reduced the protein level of POSH, markedly decreased its interactions with MLK3, MKK4 and phospho-JNKs, but also attenuated the activation of the JNK signalling pathway. In addition, infusion of POSH AS-ODNs significantly increased the neuronal density in the CA1 region at 5 days of reperfusion. Our results suggest that POSH might serve as a scaffold mediating JNK signalling activation in the hippocampal CA1 region following cerebral ischaemia, and POSH AS-ODNs exerts its protective effects on ischaemic injury through a mechanism of inhibition of the MLK3-MKK4-JNK signalling pathway, involving c-Jun and caspase 3 activation.
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Affiliation(s)
- Quan-Guang Zhang
- Department of Neurobiology and Biophysics, University of Science and Technology of China, Hefei, Anhui, China
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